JPS6260419B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a blue-colored high-grade polyester film. Conventionally, in the fields of textiles and films, polyester has been tinted blue, and in films, especially for X-ray photography, the base film is colored blue to make the photographic image easier to identify. . As a film coloring method,
There are methods such as solvent coloring and surface coating, but these methods are not easy because the polyester film has a physically and chemically stable structure, and the manufacturing process becomes long, so these methods are not preferred. Therefore, it is preferable to use a stock solution coloring method in which a coloring agent is added and mixed into the polyester during synthesis or hot melt molding, and the coloring agent is uniformly dispersed and melted in the polymer. If a neat coloring method is employed, the colorant used must be able to withstand the high temperatures of the polymerization and processing steps. Polyester film is usually produced using a tenter method, and the edge loss that occurs during this process is collected and reused. Therefore, when a coloring agent with poor thermal stability is recovered and reused, the color tone changes and the product value is significantly reduced. Further, when adding a colorant during polymerization, it is necessary to select a compound that does not inhibit the polymerization of polyester or promote a decrease in the degree of polymerization during melting. Next, in order for a coloring agent to be used for coloring polyester films with a stock solution, it is necessary that the coloring agent has excellent sublimation resistance. If a colorant with sublimation properties is used, for example, if it is added during the polymerization reaction of polyester, the colorant will sublimate and distill into the recovered glycol, which will only reduce the amount of colorant in the polymer. This is undesirable because it contaminates the recovery system. Further, in the molding process, during the drying process of the polyester resin, sublimation of the colorant from the master batch resin or recovered film occurs, contaminating the drying equipment. Furthermore, since the extrusion die, cast drum, and rolls in the next extrusion film forming step and the tenter in the stretching heat treatment step are contaminated, it is desirable that the colorant has excellent sublimation resistance. Furthermore, as a characteristic required of the colorant, when coloring with a stock solution, it is first necessary that the colorant be easily dispersed or dissolved in the polyester. When colorants are dispersed in polyester,
Furthermore, it has good compatibility with polyester. In particular, when used as a base film for X-ray photography, a film with a high degree of transparency and no optical defects is required, so the dispersion of the colorant may be insufficient, resulting in turbidity or particulate foreign matter in the film. is not desirable. Even if the dispersibility is good, voids should not be formed at the interface between the finely dispersed colorant particles and the polyester during the stretching process, which would increase the turbidity of the film due to light scattering. Since an X-ray photographic film has a photosensitive region on the short wavelength side, it is desirable that the blue-tinted base film has low absorption of short wavelength light. This is because when photographic emulsion is applied to both sides of the film support, such as X-ray film, a filter desensitization effect occurs during photographing, and a photographic image with a yellow cast that is difficult to distinguish is obtained. This is to prevent defects. In addition, the stretched film is generally heat treated at a relatively high temperature, but this tends to increase the absorption of light in the short wavelength range, so it is also important to select a colorant that is less prone to this tendency. be. Among blue colorants, there are various colors ranging from reddish blue to greenish blue, and from bright blue to dark blue. A film colored blue with a reddish tinge causes increased eye fatigue for the observer, and a film colored with a strong greenish tinge or a dark blue color is not preferable because the X-ray image lacks clarity. As mentioned above, the base film used for X-ray photography is required to have a very limited and narrow range of color tones. As a result of intensive studies in view of the above points, the present inventors found that two specific colorants have excellent heat resistance, sublimation resistance, and compatibility with polyester. The present invention was completed based on the discovery that a polyester film having good color tone and transparency can be obtained. That is, the present invention relates to 1,4-bis(3-cyclohexylsulfamoyl-2,4,6-trimethylphenylamino)anthraquinone (hereinafter referred to as compound (A)).
) and the following general formula ( ) (In the above general formula ()

[Formula] and

[Formula] represents a phenyl group having one or more substituents selected from lower alkyl groups. ) 1,5-bisarylamino-4,8-
The present invention relates to a polyester film for X-ray photography containing dihydroxyanthraquinone (hereinafter abbreviated as compound (B)). The present invention will be explained in more detail below. The polyester in the present invention refers to a polyester whose main constituents are terephthalic acid as an acid component and ethylene glycol as a glycol component, but may contain other third components. The third component includes one or more acid components such as isophthalic acid, naphthalene dicarboxylic acid, β-hydroxyethoxybenzoic acid, p-hydroxybenzoic acid, adipic acid, and sebacic acid, and the glycol component includes trimethylene glycol,
One or more types of aliphatic, alicyclic, and aromatic dioxy compounds such as tetramethylene glycol, hexamethylene glycol, and 1,4-cyclohexanedimethanol, and polyalkylene glycols such as polyethylene glycol can be used. In any case, the polyester of the present invention refers to a polyester in which at least 80 mol% of the repeating structural units are ethylene terephthalate units. Such polyesters are manufactured by conventional methods. For example, the first step is to transesterify terephthalic acid dimethyl ester and ethylene glycol, or to directly esterify terephthalic acid and ethylene glycol to produce bis-β-hydroxyethyl terephthalate or its low polymer. and a second stage reaction of polycondensing these. Note that as the catalyst used in this first stage reaction, a calcium compound, a zinc compound, a manganese compound, etc. are used. Antimony compounds, cobalt compounds, germanium compounds, titanium compounds, etc. are used as polycondensation catalysts for the second stage reaction. Furthermore, phosphorus compounds are used as stabilizers, but compounds that give color to the polymer should be avoided or
It is necessary to adjust the amount before use. Compound (A), which is one of the colorants used in the present invention, is represented by the following formula. Compound (A) may contain 30% or less of the following compounds as isomers. or However, if it contains too many isomers, the thermal stability will be poor, so the isomer content is preferably 20% or less. This compound (A) can be obtained, for example, as follows. That is, 1,4-dichloroanthraquinone is reacted with 2,4,6-trimethylaniline, and the obtained 1,4-bis-2',4',6'-trimethylanilinoanthraquinone is reacted with chlorosulfonic acid. and then reacting with cyclohexylamine. Another type of coloring agent used in the present invention is compound (B)
and is expressed by the general formula (). General formula ()
During,

[Formula] and

[Formula] represents a phenyl group having one or more substituents selected from lower alkyl groups. As the lower alkyl group, for example,
Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, etc.
Examples include _C1 - _C5 alkyl groups. Phenyl groups having these substituents include p-tolyl group,
p-ethylphenyl group, 2,4-xylyl group,
2,6-xylyl group, 2,3-xylyl group, 3,
5-xylyl group, 2,5-xylyl group, p-propylphenyl group, p-butylphenyl group, 2,
Examples include 4,6-trimethylphenyl group and 2,6-diethyl-4-methylphenyl group. Specific examples of compound (B) include 1,5-bis-p-toluidino-4,8-dihydroxyanthraquinone 1,5-bis-4'-butylphenylamino-
4,8-dihydroxyanthraquinone 1,5-bis-2',4'-xylidino-4,8-
Dihydroxyanthraquinone 1,5-bis-2',6'-xylidino-4,8-
Dihydroxyanthraquinone 1,5-bis-4'-ethylphenylamino-
4,8-dihydroxyanthraquinone 1,5-bis-2',3'-xylidino-4,8-
Dihydroxyanthraquinone 1,5-bis-3',5'-xylidino-4,8-
Dihydroxyanthraquinone 1,5-bis-2',5'-xylidino-4,8-
Dihydroxyanthraquinone 1,5-bis-2',4',6'-trimethylanilino-4,8-dihydroxyanthraquinone 1,5-bis-p-anisidino-4,8-dihydroxyanthraquinone 1,5-bis-p -phenetidino-4,8-dihydroxyanthraquinone and the like. As a method for synthesizing this 1,5-bisarylamino-4,8-dihydroxyanthraquinone, for example, anthralfin is used as a raw material, and the 1,5 positions are chlorinated using sulfanyl chloride in nitrobenzene as a solvent. The desired compound can be obtained by preparing 1,5-dichloro-4,8-dihydroxyanthraquinone and reacting it with aniline having an appropriate substituent. Both compound (A) and compound (B) must be used in the present invention. The amount of compound (A) added is preferably 50 to 800 ppm, more preferably 50 to 500 ppm, based on the polyester. Compound (B) is 10-
More preferably 20 to 300 ppm is better than 500 ppm. The total amount of compound (A) and compound (B) added is 80 to 800 ppm.
is preferred. Furthermore, compound (B)/compound (A) (weight ratio)
It is preferable to use in a range of 2/98 to 50/50. If the amounts of compounds (A) and (B) added are small, the coloring effect will be insufficient due to the low concentration. Furthermore, if the amount added is too large, the concentration will be too high, preventing light from passing through, and the color tone will become blackish. Compound
If the ratio of (B)/compound (A) is less than 2/98, the resulting film will have a reddish tinge, and if the ratio is more than 50/50, the film will have a strong greenish tinge, which is undesirable. . The coloring compound used in the present invention can be added at any time when uniform dissolution and dispersion can be obtained, such as during the production of polyester or by sprinkling it on pellets before molding. Considering this point, it is better to add it in the step after polycondensation and before molding. The coloring agent can be added in the molding process by directly attaching the required amount of colorant mixture to the pellets and then molding, or by creating a high-concentration masterbatch resin in advance in this way and then adding it to the masterbatch. There are methods such as diluting the resin with other resins and uncolored resin, but any method may be used. Next, the color tone of the colored polyester film of the present invention will be explained. The method of measuring object color and its display method is based on JIS-Z8722-1971 and JIS-Z8722-1971.
Specified in Z8701-1971. This standard is
1931 International Commission on Illumination “Comitee”
This method was defined by the colorimetry committee of the ``International del Eclairage.'' With this representation, all colors can be represented by x, y, and Y as defined in the Japanese Industrial Standards mentioned above. shows the chromaticity of the polyester film colored blue according to the present invention in the chromaticity diagram specified in JIS-Z8701-1971. Point C represents standard light, and points C, A, and B The area surrounded by is a graph showing the chromaticity of a polyester film colored blue according to the present invention.When the amount of colorant added is decreased, for example, point C on the C-A line
On the other hand, when the concentration is increased, it is located on a line moving away from point C on CA. A polyester film colored solely with compound (A), that is, 1,4-bis(3-cyclohexylsulfamoyl-2,4,6-trimethylphenylamino)anthraquinone, is represented by the line C-V, and compared to the present invention. The color tone of the film is reddish blue (Reddish
blue) and is unfavorable. When compound (B) is used alone, the film is represented by a C--G line and has a greenish blue color tone. Films colored using Compound (A) and Compound (B) individually in this way are not desirable in terms of color tone, but if the two compounds, Compound (A) and Compound (B) are used in an appropriate ratio, By using these together, as is clear from the display in FIG. 1, a blue film with a well-balanced color tone, rather than a reddish or greenish blue color, can be obtained. Colors obtained by mixing two different compounds often tend to be dull in tone, but the colored film obtained by the present invention is a blue film with a bright bright tone. Moreover, when observing the image obtained on the film as an X-ray photograph using transmitted light, the observer's eyes feel less fatigued, and the photographic performance is not adversely affected, and the color tone is suitable as a base film for X-ray photography. have. Next, the characteristics of the polyester containing two types of compounds will be explained. () Melt thermal stability of polyester Figure 2 shows a polyester containing 350 ppm of compound (A) and 70 ppm of 1,5-bis-2',4'-xylidino-4,8-dihydroxyanthraquinone as compound (B). It is a graph showing a decrease in the intrinsic viscosity of polyester when melted and maintained at 290°C. The ○ mark indicates the decrease in viscosity of the polyester containing the above colorant, and the solid line indicates the decrease in viscosity of the polyester without the addition of the colorant. Further, the horizontal axis shows the melting time, and the vertical axis shows the intrinsic viscosity (η). As can be seen from FIG. 2, the colorant used in the present invention does not affect the thermal stability of polyester. () Change in color tone due to melting and heating Figure 3 shows colored polyester under a nitrogen seal.
It is a graph showing the change in color tone when heated at 290°C. The horizontal axis shows the melting time, and the vertical axis shows the absorbance at 400 nm relative to the absorbance at the maximum absorption wavelength in the visible spectrum of polyester. ○・marks are compounds
As (B), 1,5-bis-2',4'-xylidino-
4,8-dihydroxyanthraquinone 150ppm alone, △・marked is 1,5-bis-3',5'-xylidino-
It is a polyester containing 150 ppm of 4,8-dihydroxyanthraquinone alone, and the mark ◎ indicates 350 ppm of compound (A) and 1,5-bis-4'-butylphenylamino-4,8-dihydroxy as compound (B). It is a polyester containing 90ppm of anthraquinone. Also, the polyester containing 250 ppm of 1-anilino-4,5-dihydroxy-8-nitroanthraquinone, which is known as a coloring agent that exhibits a blue color, like Compounds (A) and Compounds (B), is indicated by an x mark. From the graph, compound (A) and compound (B), or a mixture of them, is 1-anilino-
It can be seen that there is less change in color tone compared to 4,5-dihydroxy-8-nitroanthraquinone. In the case of the polyester film of the present invention, a certain level of film can be obtained even when recycled products are used. () Others When polyester containing the present colorant is melt-extruded into a film, there is no deterioration in stretchability such as breakage during stretching, and the dispersion and compatibility of the colorant in the film are extremely good. Further, voids are not generated at the interface between the polymer and the colorant due to poor dispersion of the colorant under stretching stress. The stretched film is heat treated to fix its orientation and further strengthen its mechanical properties, and this heat treatment is carried out with heated air. At this time, the absorption in the short wavelength region, that is, around 440 to 400 nm, in the blue-tinted stretched film may significantly increase due to the interaction of the heated air, the colorant, and the polyester. In the case of the polyester film of the present invention, it is possible to obtain a blue-colored film with a small degree of absorption in the short wavelength range even if heat treatment is performed, and therefore, a clear image can be obtained when photographically developed. . Furthermore, even if the colorant is added to the polymerization reaction at the beginning of the polymerization reaction, the polymerization reaction rate will not be affected at all.
A polyester resin colored in vivid blue can be obtained without any decomposition or sublimation of the colorant. The biaxially stretched film colored according to the present invention is
It is useful as a base film for X-ray photography as a film with a thickness of about 50 to 300 μm, but it can also be used as a film for other agricultural purposes.
In the present invention, a small amount of inert inorganic compounds such as kaolin, talc, calcium carbonate, amorphous silica, etc. may be contained to the extent that the transparency is not impaired, and antioxidants and antistatic agents may also be contained. , a weathering agent, etc. may be contained. As described above, according to the present invention, it is possible to easily obtain a polyethylene terephthalate film colored in vivid bright blue, which has been difficult to produce in the past. The present invention will be explained in more detail by giving specific examples below. In the examples, "parts" indicate parts by weight. The measurement method used is also described below. Intrinsic viscosity: 1 g of polymer was dissolved in 100 ml of phenol/tetrachloroethane (50/50 weight ratio) and measured at 30°C. Measurement of visible spectrum of colored polyester 1 Resin: Polyester containing colorant
0.6 g was dissolved in 10 c.c. of phenol/tetrachloroethane (50/50 weight ratio) and measured using a Hitachi spectrophotometer with a cell length of 1 cm. 2 Film: A 180μ colored polyester film alone was measured. Judgment of yellowness of film Measure the visible spectrum of a 180μ blue colored film using a Hitachi spectrophotometer, and calculate the absorbance at the wavelength showing maximum absorption (630nm in the case of the film of the present invention) and the absorbance at 400nm. The yellowness of the film was determined based on the ratio, A400/A630. In general, in the absorption spectrum in the visible region, objects having absorption near 400 nm have a yellowish tinge. Therefore, it can be said that the smaller the value of A400/A630, the less yellowish the blue color is. This value is preferably 0.8 or less. Example 1 100 parts of dimethyl terephthalate, 70 parts of ethylene glycol, and 0.09 parts of calcium acetate monohydrate were charged into a reactor equipped with a stirring device and a dephlegmator, and the mixture was heated to raise the temperature and distill off methanol to produce ester light. The ester photoexchange reaction was completed by distilling off excess ethylene glycol. Next, 0.04 part of phosphoric acid and 0.03 part of antimony trioxide were added to the obtained reaction product, and while the pressure inside the system was reduced, the temperature was started to increase. Final 0.3mmHg, 280℃
After carrying out the reaction for 4 hours, a polyethylene terephthalate polymer having an intrinsic viscosity of 0.66 was obtained. 1,4-bis(3-cyclohexylsulfamoyl-2,4,
6-trimethylphenylamino)anthraquinone
0.03 part and 1,5-bis-2',4'-xylidino-
0.007 part of 4,8-dihydroxyanthraquinone was added, and an unstretched film was obtained by a conventional melt film forming method. The obtained sheet was stretched 3.5 times in the longitudinal and transverse directions at a temperature above the glass transition point.
It was made into a 180μ film. The stretching operation could be carried out smoothly without any breakage, and the colorant had good dispersion compatibility in the obtained film, and no foreign matter was generated. Next, the stretched film was heat treated at 220°C. Separately, an unstretched film with a thickness of 180 μm was manufactured. 180μ unstretched film,
The visible spectra of the stretched film (without heat treatment) and the stretched heat-treated film were measured, and x and y for chromaticity display, decomposability of the colorant, degree of yellowing, etc. were evaluated. The results are shown in the sections of Example Nos. 1-1, 1-2, and 1-3 in Table 1, respectively.
As is clear from Table 1, the film colored blue using this colorant has no effect on lowering the degree of polymerization during the melt extrusion process, and the decomposition of the colorant causes discoloration, fading, and yellowing of the film. The film was colored a vivid bright blue with almost no color. A subbing layer, gelatin and odorous silver iodide emulsion layers were provided on the heat-treated biaxially stretched film obtained in this example by a conventional method (for example, the method described in Japanese Patent Publication No. 15187/1987). Even when this film was treated with a photographic phenomenon liquid, the color of the film did not change at all from before the photosensitive layer was applied. Example 2 1,4- to 100 parts of polyethylene terephthalate
bis(3-cyclohexylsulfamoyl-2,
0.035 part of 4,6-trimethylphenylamino)anthraquinone and 0.009 part of 1,5-bis-4'-butylphenylamino-4,8-dihydroxyanthraquinone were added, and a film was formed using the melt film forming method in the same manner as in Example 1. , a 180 μm unstretched film, a stretched film (no heat treatment), and a stretched heat-treated film were obtained. The results of the visible spectrum of each film are shown in the sections of Example Nos. 2-1, 2-2, and 2-3 in Table 1, respectively. As is clear from these results, the film obtained was bright and had a good color tone with little yellowing. Example 3 100 parts of dimethyl terephthalate, 70 parts of ethylene glycol, and 0.09 parts of calcium acetate monohydrate were charged into a reactor, and the temperature was raised while methanol was distilled off to perform transesterification, which was carried out for about 4 hours after the start of the reaction. The temperature was raised to 230°C, and the transesterification reaction was substantially completed. Next, 0.04 part of phosphoric acid, 0.035 part of 1,4-bis(3-cyclohexylaminosulfamoyl-2,4,6-trimethylphenylamino)anthraquinone, and 1,5-bis-3',5'-xylidino- 0.008 part of 4,8-dihydroxyanthraquinone and 0.03 part of antimony trioxide
of the solution was added, the pressure inside the system was reduced, and the polymerization reaction was started. Finally, after reacting for 4 hours at a pressure of 0.3 mmH and a temperature of 280°C, a polyester resin was obtained. The intrinsic viscosity of the obtained colored polyester was 0.64, and the polymerizability was the same as when no colorant was added. Furthermore, the colorant did not distill out of the system together with the distilled ethylene glycol during the polymerization reaction. The color tone of the obtained colored resin was bright blue, and there was almost no discoloration or turbidity due to thermal decomposition. The obtained colored resin was subjected to melt film formation in the same manner as in Example 1 to obtain an unstretched film of 180 μm. The obtained unstretched film also had a good color tone similar to that of Example 1. Table 1 shows the measurement results of the film's visible spectrum, etc. Example 4 1,4- to 100 parts of polyethylene terephthalate
bis(3-cyclohexylsulfamoyl-2,
0.020 part of 4,6-trimethylphenylamino)anthraquinone and 0.010 part of 1,5-bis-2',5'-xylidino-4,8-dihydroxyanthraquinone
%, and by the melt film forming method in the same manner as in Example 1.
A stretched heat-treated film of 180μ was obtained. The color tone of the obtained film was similar to that of Example 1, and was a bright blue film suitable for use as a base film for X-ray photography. Table 1 shows the measurement results of the film's visible spectrum, etc.

【table】

[Table] Reference example (sublimation resistance test) 1,4-bis(3-cyclohexylsulfamoyl-2,4,6-trimethylphenylamino)
3.5 kg of master pellets containing 3000 ppm of anthraquinone in polyester and 1,5-bis-4'-butylphenylamino-4 as compound (B),
1.8 kg of master pellets containing 1500 ppm of 8-dihydroxyanthraquinone in polyester and 24.7 kg of transparent resin containing no colorant were blended and dried in dry air at 180°C for 6 hours. In the resin mixture after drying, no transfer of colorant from master chip resin to uncolored diluted chip resin (adhesion of colorant to the chip resin surface) was observed, and there was no contamination of the dryer. The dried blended resin was extruded onto a casting drum using an extruder to obtain an amorphous sheet. At this time, sublimated oligomers were deposited on the casting drum, but the deposited oligomers were not colored blue. As is clear from the above results, it can be seen that the colored compound of the present invention has extremely excellent sublimation resistance.

[Brief explanation of the drawing]

(a) FIG. 1 is a graph showing the chromaticity of the film of the present invention in the chromaticity diagram defined in JIS-Z8701-1971. Points -2, -3,, are Example Nos. 1-2, 2-3, 3 shown in Table 1, respectively.
and 4, the chromaticity of the film. (b) FIG. 2 is a graph showing the change in the degree of polymerization of polyester while it is maintained in the melt. The horizontal axis shows the melting time, and the vertical axis shows the intrinsic viscosity (η). (c) Figure 3 is a graph showing changes in color tone due to melting and heating of polyester. The horizontal axis is the melting time, and the vertical axis is the absorbance at the maximum absorption wavelength.
Shows absorbance at 400nm.

Claims (1)

[Claims] 1 1,4-bis(3-cyclohexylsulfamoyl-2,4,6-trimethylphenylamino)anthraquinone and the following general formula (In the above formula, [Formula] and [Formula] represent a phenyl group having one or more substituents selected from lower alkyl groups.) 1,5-bisarylamino-4,8-dihydroxyanthraquinone A polyester film for X-ray photography containing. 2. In the polyester film for X-ray photography according to claim 1, 1,4-bis(3-cyclohexylsulfamoyl-2,4,
A polyester film for X-ray photography containing 1,5-bisarylamino-4,8-dihydroxyanthraquinone to 6-trithymelphenylamino)anthraquinone in a weight ratio of 2/98 to 50/50.