JP2002037899A - Film for dyeing and method of dyeing film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester film having improved dyeability. SOLUTION: The polyester film is a copolyester having a melting point within the range of 210 deg.C and 245 deg.C, is biaxially oriented and having a high temperature peak of its loss dynamic modulus in water of 85 deg.C or lower.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyester film suitable for dyeing and a method for dyeing a film using the same. More specifically, the present invention relates to a polyester film whose dyeing efficiency has been dramatically improved as compared with a conventional polyester film by making physical properties of the film proper in water, and a dyed film using the same.

[0002]

2. Description of the Related Art Biaxially stretched polyester films are used for magnetic recording medium supports, photographic supports, packaging materials, etc., due to their properties such as strength, heat resistance, dimensional stability, transparency, and chemical resistance. Used in By dyeing this biaxially stretched polyester, it can be applied as an extremely suitable material for applications such as a light-shielding film for window application. This dyeing is carried out not as coloring the film raw material polyester but as a post-process, so that it is easy to cope with many kinds and is advantageous in cost.

[0003]

However, biaxially oriented polyester films have extremely high chemical resistance. This characteristic causes the dye to impede the adsorption and impregnation of the film in the dyeing process. Conventionally, dyeing of biaxially stretched polyester film is very inefficient, such as repeating the same dyeing process several times to obtain the desired concentration, and is disadvantageous in terms of manufacturing cost compared to other materials. there were.

As a method for facilitating the dyeing of a biaxially stretched polyester film, a method of dyeing a dye using an organic solvent solution of a dye (Japanese Patent Laid-Open No. 57-12) has been known.
No. 8280), and (2) a method of using a raw material polyester resin as a copolymer of a dye and a specific component having high affinity (JP-A-6-2282, JP-A-7-118373).
Publication), and the like. However, (1) the use of organic solvents should be avoided from the viewpoint of environmental protection, and (2) if the copolymer component is also specific to a specific dye, it can be used in various types of colors. When responding, film materials also need to be applied in various types, so efficiency is poor,
Also, less specific components are expensive and disadvantageous in terms of cost.

[0005] An object of the present invention is to solve the above problems and to provide a dyeing film whose dyeing efficiency has been dramatically improved as compared with a conventional polyester film, and a method of dyeing a film using the same.

[0006]

The dyeing film of the present invention is a biaxially stretched film made of a copolymerized polyester having a melting point of 210 to 245 ° C., and has a high-temperature-side peak temperature of loss elastic modulus in water of 85 ° C. It is characterized by the following.

In the present invention, attention was paid to the physical property behavior of the film in water, and more specifically, to the flexibility of the molecular chains in the film in water. As a result, a polyester film material having properties capable of facilitating dye impregnation was obtained.

[0008] The polyester film of the present invention is a biaxially stretched film made of a copolymerized polyester having a melting point of 210 to 245 ° C. Those having a melting point of less than 210 ° C. generally contain an excess of components that make the molecular chain flexible, so that the high-temperature side peak temperature of the loss elastic modulus in water of the film described below falls within the range specified in the present invention. And it is not preferable because the obtained film has poor heat resistance. When the melting point exceeds 245 ° C., the molecular chain is generally too rigid, so that it is still difficult to set the high temperature side peak temperature of the loss elastic modulus of the film described later in water within the range specified in the present invention. It is not preferable because there is. A more preferable range of the melting point is from 212 to 235.
° C.

Further, the polyester film of the present invention comprises:
The high temperature side peak temperature of the loss modulus of the film in water is 85 ° C. or less. Here, the high temperature side peak temperature of the loss elastic modulus is measured at a measurement frequency of 10 Hz and a dynamic displacement of ± 25 × 10 ⁻⁴ cm using a dynamic viscoelasticity measurement device having a sample holding device in a water tank. Loss modulus (E ")
Among the peaks observed in the temperature change curve of FIG.

The peak temperature of E ″ can be said to be the so-called glass transition temperature of the biaxially stretched film. By controlling the peak temperature within the range specified in the present invention, the impregnation of the dye in the dyeing process can be easily carried out. When the peak temperature of E ″ exceeds 85 ° C., it becomes difficult to impregnate the dye in the dyeing step, so that the dyeing efficiency is remarkably reduced. A more preferred range of the peak temperature of E "is from 35 to 85 ° C, particularly preferably from 40 to 80 ° C. If the temperature is less than 35 ° C, the molecular chain is too flexible, so that sufficient strength cannot be maintained in the dyeing step. It may be.

It is preferable that the polyester of the present invention contains ethylene terephthalate unit as a main component in order to maintain good molding followability, adhesion and corrosion resistance even after heat history. Here, the term "containing ethylene terephthalate unit as a main component" means that the terephthalic acid component contains at least 75% of the total dicarboxylic acid component and the ethylene glycol component at least 75% of the total diol acid component.

Preferred examples of the copolymer component of the polyester of the present invention include the following.
That is, as the dicarboxylic acid component, isophthalic acid,
Orthophthalic acid, 2,6-naphthalenedicarboxylic acid,
Aromatic dicarboxylic acid components such as 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, and 4,4′-biphenylenedicarboxylic acid; cyclohexane-1,4
Alicyclic dicarboxylic acid component such as dicarboxylic acid, aliphatic dicarboxylic acid component such as succinic acid, adipic acid, sebacic acid, and the like, and diol component such as propylene glycol, trimethylene glycol, and tetramethylene glycol. Diol component, cyclohexane-
Examples thereof include alicyclic diol components such as 1,4-dimethanol, aromatic diol components such as bisphenol A, and ether condensed diol components such as diethylene glycol, polyethylene glycol, and polytetramethylene glycol. In addition, hydroxycarboxylic acid components such as p-hydroxybenzoic acid, ω-hydroxybutyric acid, ω-hydroxyvaleric acid, and lactic acid; carbonic acid components such as those found in polycarbonate; And the like.

Among these, isophthalic acid, 2,6-naphthalenedicarboxylic acid, diethylene glycol, and the like are used to easily exhibit various properties, obtain raw materials, and easily produce a copolymerized polyester. From these viewpoints, it can be mentioned as a particularly preferred copolymer component.

[0014] These polyesters can also be used in the form of a blend of two or more.

Since the polyester film of the present invention contains particles having an average particle size of 2.5 μm or less, a suitable slip property can be obtained, so that the film is excellent in handleability and sometimes advantageous during molding. preferable. The type of particles is not particularly limited, but inorganic fine particles such as silica, alumina, titanium oxide, calcium carbonate, and kaolin, precipitated fine particles of catalyst residues, and / or organic fine particles such as silicone, crosslinked polystyrene, and crosslinked acrylic are preferable. Can also be mentioned.

In addition, various additives such as a stabilizer, an antistatic agent, a dye, a pigment, and a flame retardant may be contained in the polyester film of the present invention as long as the effects of the present invention are not impaired.

Further, the polyester film of the present invention comprises:
The plane orientation coefficient is preferably from 0.10 to 0.16. If the plane orientation coefficient is less than 0.10, it may not be possible to have sufficient strength as a biaxially stretched film, and if it exceeds 0.16, it may be that the molecular chains are excessively orientated. In particular, it indicates that the overlapping of the aromatic rings in the polyester chain is excessive, and thus may be disadvantageous from the viewpoint of dye impregnation. A more preferred range of the plane orientation coefficient is 0.10 to 0.14.

Here, the plane orientation coefficient is calculated by the following formula (1) from each direction component of the refractive index of the film measured by the Abbe method. P = where _{(n MD + n TD) /} 2-n Z ... (1), P: plane orientation coefficient, n _MD: film formation direction of the refractive index, n _TD: parallel to the film plane and n _MD and perpendicular The refractive index in the direction and the refractive index in the direction perpendicular to the _nz film surface are shown, respectively.

The production of the biaxially stretched polyester film of the present invention can be carried out by a conventionally known method. That is, the pellets of the copolymerized polyester of the present invention are dried and then melted, extruded from a die onto a cooling drum and cooled to form an unstretched film. It can be manufactured by fixing. The thickness of the film is not particularly limited, but is preferably 0.5 to 250 μm.

As long as the object of the present invention is not impaired, a primer layer may be provided on the polyester film of the present invention, or a corona discharge treatment, a plasma treatment, a flame treatment, etc. may be performed for the purpose of post-processing and other properties. Is also good. The primer layer may be applied in the process of forming, stretching, and heat setting the film.

The dyeing film of the present invention is impregnated with an aqueous solution of a dye to dye the film, whereby a dyed film can be produced with high productivity. Since the dyeing efficiency is dramatically improved as compared with the conventional biaxially stretched polyester film, it is extremely advantageous in terms of cost. In particular, the method of immersing the dyeing film of the present invention in a heated aqueous solution of the dye is suitable from the viewpoint of environmental protection and cost reduction. In the dyeing operation, both continuous processing of a web-like material and batch processing of a single wafer can be performed. Here, the aqueous solution of the dye refers to an aqueous solution of a water-soluble dye and / or an aqueous dispersion of a disperse dye.

[0022]

EXAMPLE 1 A dried, intrinsic viscosity of 0.65 (o
-Measurement in chlorophenol, the same applies hereinafter) of polyethylene (terephthalate-isophthalate) copolymer (terephthalic acid component / isophthalic acid component molar ratio = 88/12)
(Containing 0.1% by weight of spherical silica particles having an average particle size of 1.5 μm) was supplied to an extruder, and was melt-extruded on a rotary cooling drum maintained at 20 ° C. to give a thickness of 240 μm.
m of unstretched film was formed. Next, the film forming direction (hereinafter,
Stretched 3.0 times in the longitudinal direction), further stretched 3.2 times in the direction perpendicular to the film-forming direction (hereinafter referred to as the transverse direction), and 190% while giving a relaxation of 3% of the entire width while being fixed in the transverse direction. C. to obtain a biaxially stretched polyester film having a thickness of 25 μm.

The properties of the film thus obtained were evaluated by the following methods, and the results are shown in Table 1. In Table 1, TA is an abbreviation of an acid component indicating a terephthalic acid component and IA is an isophthalic acid component.

(1) Melting point A sample film of 20 mg was sampled and filled in an aluminum pan, and the sample was taken by a DSC (DuPont In).
instrument 910 DSC) and set to 20
The temperature was raised from room temperature at a rate of ° C / min. The change in calorific value was recorded using an empty aluminum pan as a control, and the temperature corresponding to the endothermic peak in the hottest part was defined as the melting point (° C.).

(2) High temperature side peak temperature of loss elastic modulus in water Dynamic viscoelasticity measuring device (ORIENTEC RHEOVI)
(BRON) A sample film was set using an apparatus installed in a water tank such that a sample gripping part was immersed in water, and measurement was performed at a measurement frequency of 10 Hz and a dynamic displacement of ± 25 × 10 ⁻⁴ cm. From the obtained data, the loss modulus (E ") was
It plotted between 150-200 degreeC, and calculated | required the temperature of the peak which appears on the highest temperature side.

(3) Plane Orientation Coefficient The refractive index of the film was measured by the Abbe method. It was calculated from the obtained refractive index in each direction component by the above-described equation (1).

(4) Dyeability The sample film was prepared by using a disperse dye for PET (Mitsui Toatsu Co., Ltd.
IKETONE FBL Blue) was immersed in a 0.5% by weight aqueous dispersion and treated at 100 ° C. for 10 minutes.
Thereafter, the sample was washed with water, and the hue of the sample was measured and evaluated according to the following criteria. ：: a value of hue is 30 or more ○: a value of hue is 15 or more and less than 30 ×: a value of hue is less than 15

(5) Heat resistance The sample film heat-treated at 180 ° C. for 10 minutes was observed,
Evaluation was made according to the following criteria. A: Flatness is not impaired. And the dimensional change is within 10%. ：: flatness is not impaired. However, the dimensional change exceeds 10%. X: The flatness is impaired. And the dimensional change exceeds 10%.

[0029]

Examples 2-3, Comparative Examples 1-2 As film materials,
A film was obtained in the same manner as in Example 1 except that a polyethylene (terephthalate-isophthalate) copolymer having an intrinsic viscosity of 0.65 (the molar ratio of terephthalic acid component / isophthalic acid component was as shown in Table 1) was used. The properties of the film thus obtained were evaluated by the above-mentioned method, and the results are shown in Table 1.

[0030]

Example 4 A film was obtained in the same manner as in Example 1 except that the film thickness before stretching was 418 μm, and the stretching ratio was 3.8 times in the vertical direction and 4.4 times in the horizontal direction. . The properties of the film thus obtained were evaluated by the method described above,
The results are shown in Table 1.

[0031]

Example 5 The film thickness before stretching was set to 36 μm.
A film was obtained in the same manner as in Example 1, except that the stretching ratio was 1.2 times in both the longitudinal and transverse directions. The properties of the film thus obtained were evaluated by the above-mentioned method, and the results are shown in Table 1.

[0032]

[Table 1]

[0033]

According to the present invention, it is possible to provide a polyester film whose dyeing efficiency is remarkably improved as compared with a conventional polyester film and which has excellent heat resistance, and a dyed film using the same. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C08L 67:02 C08L 67:02 F term (reference) 4F071 AA45 AA46 AA84 AF20Y AF53Y AG31 AH03 AH19 BA01 BB06 BB08 BC01 BC09 BC10 4F073 AA15 BA23 BA24 BB01 EA02 EA11 EA75 HA04 HA09 4F210 AA24E AG01 QC05 QC06 QG01 QG18 QW12

Claims (4)

[Claims] 1. A film made of a copolymerized polyester having a melting point of 210 to 245 ° C., which is stretched biaxially, and has a high-temperature side peak temperature of a loss elastic modulus in water of 85 ° C. or lower. Dyeing film. 2. The dyeing film according to claim 1, wherein the plane orientation coefficient is 0.10 to 0.16. 3. The high temperature side peak temperature of the loss elastic modulus in water is 35 ° C. or more.
3. The dyeing film according to any one of 2. 4. A method for dyeing a film, comprising impregnating the film for dyeing according to claim 1 with an aqueous solution of a dye to dye the film.