JPH06184927A - Polyester fiber exhibiting excellent deep color and its production - Google Patents

Abstract

PURPOSE:To provide a polyester fiber exhibiting an excellent deep color and excellent in abrasion durability. CONSTITUTION:An ethylene terephthalate-based polyester containing 0.1 to 10wt.% polyoxyalkylene glycol derivative represented by the general formula described below is subjected to melt spinning under >=500 spinning draft, stretched and subsequently heat treated at >=170 deg.C. The resultant fiber is treated with an aqueous solution of an alkaline compound for weight reduction, thus producing the objective fiber exhibiting >=1.38g/cm<3> fiber surface density and containing fine pores on the surface. Z[O(AO)mX]2 [Z is one or more kinds of divalent hydroxyl group-containing compound residues selected from a 5 to 10C aliphating diol, a 3 to 15C alicyclic diol, a bisphenol and a divalent phenol. A is a 2 to 4C alkylene group. m is a positive integer. X is a univalent hydroxyl group-containing compound residue].

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester fiber having excellent bathochromism and a method for producing the same. More specifically,
The present invention relates to a polyester fiber having fine pores of a specific shape on the fiber surface, exhibiting improved color depth and sharpness when colored, and also having good friction durability, and a method for producing the same.

[0002]

Polyester is widely used as a synthetic fiber because of its many excellent properties. However, polyester fibers are natural fibers such as wool and silk,
Compared to fibrous fibers such as rayon and acetate, acrylic fibers and the like, there is a drawback in that the colorability and vividness are inferior because there is no depth of color when colored.

Heretofore, attempts have been made to improve dyes and chemically modify polyesters in order to solve this drawback.
None of them have been sufficiently effective. In addition, a method of forming a transparent thin film on the surface of polyester fiber (Japanese Patent Laid-Open No. 53-53113).
-111192) or 80 to 500 m on the surface of a woven or knitted fabric.
A method has been proposed in which plasma irradiation of A · sec / cm ² is performed to form fine irregularities on the fiber surface (Japanese Patent Publication No. 59-11709). However, even by these methods, the effect of improving the color depth is insufficient, and the transparent thin film formed on the fiber surface is easily removed by washing or the like, and its durability is insufficient, and plasma is not sufficient. In the method of applying irradiation, unevenness does not occur on the surface of the fibers of the fiber part that becomes the shadow of the irradiation surface, so the smooth fiber surface appears on the surface due to the rolling of the threads in the fiber structure that occurs during wearing, and the color unevenness occurs. There is a drawback.

On the other hand, as a method for imparting unevenness to the surface of polyester fibers, fibers made of polyoxyethylene glycol or polyester containing polyoxyethylene glycol and a sulfonic acid compound are treated with an alkaline aqueous solution to arrange them in the fiber axial direction. Method for producing hygroscopic fiber to form wrinkled fine pores on the fiber surface, or polyester fiber obtained by adding and blending fine particles of an inert inorganic substance such as zinc oxide and calcium phosphate in the polyester reaction system, an alkaline aqueous solution. There has been proposed a method for producing a hygroscopic fiber in which fine pores are formed by eluting the inorganic fine particles by treating with a hygroscopic fiber. However, the fibers obtained by these methods do not have the effect of improving the color depth, but rather have a decrease in the visual density.
That is, in these methods, when the treatment with the alkaline aqueous solution is not sufficient, no effect of improving the color depth is observed, and when the treatment with the alkaline aqueous solution is sufficient, rather than improving the color depth, Perhaps because of the irregular reflection of light from the micropores, the luminous density is reduced, and even if it is colored darkly, it appears whitish, and the strength of the resulting fiber is significantly reduced, and it easily fibrillates. , Can not stand practical use.

Fibers made of polyester mixed with inorganic fine particles such as silica having a particle diameter of 80 mμ or less are alkali-reduced to give irregularities of 0.2 to 0.7 μ to the surface of the fibers and the irregularities. 50-200m inside
A method (Japanese Patent Publication No. 59-24233) of improving the color depth by making microscopic asperities exist is proposed. However, even with this method, the effect of improving the depth of color is not sufficient, and because of the extremely complicated unevenness form, the unevenness is destroyed by the physical action from the outside such as friction, and the damaged portion is destroyed. However, it has a drawback that it is greatly discolored and has a difference in gloss as compared with other non-destroyed portions, and that it is easily fibrillated.

As another method, there has been proposed a method of improving the color by reducing the alkali of fibers made of polyester containing an organic low molecular weight compound mainly composed of an imide compound having a molecular weight of 1,000 or less. However, since such an imide compound has a good compatibility with polyester, it is finely dispersed, and since the irregularities on the fiber surface to be formed are too fine, the bathochromic property is inferior, and the irregularities are easily destroyed by a physical action from the outside such as friction. There is a drawback that.

[0007]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. Its purpose is to provide excellent bathochromism and to have a great effect on fading and gloss due to friction. (EN) It is intended to provide a polyester fiber which is small and has good fibril resistance, and a method for producing the same.

[0008]

Means for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that a polyester blended with a specific polyalkylene oxide glycol derivative is subjected to high draft spinning / drawing at 170 ° C. or higher. The present invention has been completed by finding out that fine fibers having good abrasion resistance can be formed on the fiber surface by heat setting at high temperature to form polyester fiber and then subjecting to alkali weight reduction treatment.

That is, according to the present invention: A polyester fiber containing a polyoxyalkylene glycol derivative represented by the following general formula (I) and having ethylene terephthalate as a main repeating unit, the surface of which is formed by removal marks of the polyoxyalkylene glycol derivative. A polyester fiber excellent in bathochromism, characterized by having fine pores and having a density (measured by a laser Raman microprobe analysis method) of the fiber surface of 1.380 g / cm ³ or more,

[0010]

[Chemical 3]

(In the formula, Z is at least one divalent group selected from the group consisting of aliphatic diols having 5 to 10 carbon atoms, alicyclic diols having 3 to 15 carbon atoms, bisphenols, and divalent phenols. 2. A residue of a hydroxy group-containing compound, A is an alkylene group having 2 to 4 carbon atoms, X is a residue of a monovalent hydroxy group-containing compound, and m is a positive integer. Contains 0.1 to 10% by weight of the polyoxyalkylene glycol derivative represented by the above general formula (I),
A polyester composition whose main repeating unit is ethylene terephthalate is melt-spun at a spinning draft of 500 or more, then drawn and then heat treated at a temperature of 170 ° C. or more, and the obtained polyester fiber is subjected to weight reduction treatment with an aqueous solution of an alkali compound. And a method for producing a polyester fiber having excellent bathochromism.

In the present invention, a polyester whose main repeating unit is ethylene terephthalate is a main object. Here, the "main repeating unit" means 90 mol% or more, preferably 95 mol% or more of the repeating unit, and may be a polyester obtained by copolymerizing a third component as long as it is 10 mol% or less. Copolymer components preferably used include aromatic dicarboxylic acids such as isophthalic acid, 5-sodium sulfoisophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid and methylterephthalic acid, adipic acid, sebacic acid and the like. Aliphatic dicarboxylic acids such as trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, etc. Aliphatic glycols such as 1,4-cyclohexanedimethanol, etc. , Hydroquinone, bisphenol A
And other oxycarboxylic acids such as oxybenzoic acid, oxynaphthoic acid, and β-hydroxyethoxybenzoic acid. A small amount (usually 10% by weight or less based on polyester) of polyoxyalkylene glycol may be copolymerized, and trimellitic acid may be added within a range where the polyester is substantially linear (usually 1 mol% or less). , Polycarboxylic acids such as pyromellitic acid, or glycerin, trimethylolpropane,
It does not matter even if a polyol such as pentaerythritol is copolymerized.

The polyoxyalkylene glycol derivative (hereinafter sometimes referred to as a modified PAG agent) to be blended with the above polyester is a compound containing a hydroxyl group at the terminal having a monovalent hydroxyl group, as shown by the following general formula (I). It is important that it is a residue-blocked poly (oxyalkylene) glycol derivative.

[0014]

[Chemical 4]

(In the formula, Z is at least one divalent hydroxy selected from the group consisting of aliphatic diols having 5 to 10 carbon atoms, alicyclic diols having 3 to 15 carbon atoms, bisphenols, and divalent phenols. A group-containing compound residue, A is an alkylene group having 2 to 4 carbon atoms, m is a positive integer, and X is a monovalent hydroxy group-containing compound residue.) In the general formula (I), Z is a carbon atom. The residue of a divalent hydroxyl group-containing compound selected from the group consisting of an aliphatic diol having a number of 5 to 10, an alicyclic diol having a carbon number of 3 to 15, a bisphenol, and a divalent phenol means that the above divalent A residue obtained by removing a divalent hydroxyl group from a hydroxyl group-containing compound. Specific examples of the divalent hydroxyl group-containing compound constituting this residue include the following. Carbon number 5
As the aliphatic diol of 10 to 10, pentane-1,5-
C3, such as diol and hexane-1,6-diol
As cycloaliphatic diol of ~ 15, cyclohexane-1,
As bisphenols such as 4-dimethanol, bis (4-hydroxyphenyl) methane and 2,2-bis (4
-Hydroxyphenyl) propane: [bisphenol A], bis (4-hydroxyphenyl) sulfone: [bisphenol S], 2,2-bis (4-hydroxy-)
Examples of 3,5-dibromophenyl) propane and the divalent phenol include hydroquinone, catechol and resorcin.

Of the above divalent hydroxyl group-containing compounds, bisphenols are preferable, and 2,2-bis (4-hydroxyphenyl) propane is particularly preferable.

In the general formula (I), the alkylene group represented by A is an alkylene group having 2 to 4 carbon atoms such as ethylene, propylene, butylene group; and mixed groups thereof (eg mixed group of ethylene and propylene). Is mentioned.

The alkylene group A forms an oxyalkylene group (AO) with the oxygen atom O. A plurality of oxyalkylene groups (AO) present in one molecule may be the same or different, and the addition form thereof may be a block addition type, a random addition type or a mixed type of both.

If m is too large or, conversely, too small, the effect of the present invention is difficult to obtain. Therefore, it is desirable that m is in the range of 5 to 30, especially 10 to 20.

The residue of the monovalent hydroxyl group-containing compound means the residue obtained by removing the hydroxyl group from the monovalent hydroxyl group-containing compound. Specific examples of the hydroxy-containing compound that constitutes this residue include alcohols such as methanol and ethanol, and phenols such as phenol and cresol.

The polyester fiber of the present invention must be made of polyester containing the above-mentioned modified PAG agent. In order to allow the modified PAG agent to be contained in the polyester, the polyester synthesis may be completed at an arbitrary stage until the synthesis of the polyester is completed, for example, after being added and mixed in a raw material of the polyester or a polymerization reaction mixture. Alternatively, the polyester chips and the modified PAG agent may be simply dry blended or may be melt mixed in advance in a melt extruder. Further, a modified PAG agent obtained by mixing the modified PAG agent heated and melted at a temperature equal to or higher than the melting point with the polyester chips and then cooling it to the melting point or lower is preferably used.

In the composition thus obtained, as other components, optional additives such as catalysts, antioxidants, ultraviolet stabilizers, flame retardants, optical brighteners, matting agents, and colorants are added as required. And the like, and from the viewpoint of suppressing an increase in the degree of polymerization or a decrease in the degree of polymerization during melt spinning, 2,2'-bis (2-oxazoline), 2,2'-bis (3,1- A chain extender such as benzoxazin-4-one) can also be preferably added.

On the surface of the polyethylene fiber of the present invention,
It is necessary that the fine pores formed by the above-mentioned removal traces of the polyoxyalkylene glycol derivative are present, and above all, after performing false twisting or crimping processing as necessary, or further forming a fabric. After that, it is preferable that, in addition to the modified PAG agent removal traces, fine pores formed from the elution traces of the amorphous portion of the polyester are present by, for example, treating with an aqueous solution of an alkali compound to remove the polyester. . In this case, the compounding amount of the modified PAG agent is 0.1 to 10% by weight, particularly 0.5 to 5% by weight.
If it is less than 0.1% by weight, it is difficult to form fine pores on the surface of the obtained polyester fiber even when treated with an alkaline compound aqueous solution, and the bathochromic property becomes insufficient. On the other hand, when it exceeds 10% by weight, the bathochromic property and the sharpness do not show any significant improvement anymore, and on the contrary, not only the abrasion resistance is lowered but also the melt viscosity is largely lowered to make the melt spinning difficult. .

Examples of the alkali compound preferably used include sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, sodium carbonate, potassium carbonate and the like. Of these, sodium hydroxide and potassium hydroxide are particularly preferable.

The concentration of the aqueous solution of the alkaline compound is
Depending on the type of alkaline compound, processing conditions, etc.,
Usually, the range of 0.01 to 40% by weight is preferable, and particularly, the range of 0.
The range of 1 to 30% by weight is preferable. Processing temperature is room temperature ~ 1
The temperature is preferably in the range of 00 ° C., and the treatment time is usually 1 minute to 4 hours. The amount of the alkaline compound eluted and removed by the treatment with the aqueous solution is 2 with respect to the weight of the fiber.
It should be in the range of weight% or more. By thus treating with an aqueous solution of an alkali compound, it is possible to form a large number of special elliptical fine pores composed of modified PAG agent removal marks on and near the fiber surface.

In addition to the above requirements, the polyester fiber of the present invention has a laser Raman microprobe method (AJ.
Helveger, J .; Polym. Sci. , 10 ,
317 (1972)) has a fiber surface density of 1.3.
It should be 80 g / cm ³ or more. When the density of the fiber surface is less than 1.380 g / cm ³ , crystallization is insufficient, and properties such as abrasion discoloration resistance and fibril resistance are deteriorated, which is not preferable.

The laser Raman microprobe method used here is as described in A. J. Helve
This is an application of a new method for determining the crystallinity developed for polyethylene terephthalate polyester by ger. The Raman spectrum observed at the time of laser irradiation with a positional resolution of 1 μm is carbon / oxygen with a wave number of 1730 cm ^-1. The density can be calculated by the following formula from the half-width of Raman band due to stretching vibration of double bond. D = -0.004785H + 1.45995 (where D is the density and H is the half-width of the Raman band with a wave number of about 1730 cm ^-1 ). To produce the polyester fiber of the present invention described above, It is important to increase the spinning draft of ethylene terephthalate-based polyester containing 0.1 to 10% by weight of the high-quality PAG agent as compared with usual polyester melt spinning conditions, and to raise the heat treatment temperature after stretching. That is, the polyester composition described above is melt-spun with a spinning draft of 500 or more, and 170
It is important to perform heat treatment at a temperature of not less than 0 ° C, preferably not less than 180 ° C.

As a method for increasing the spinning draft to 500 or more, there is a method of increasing the take-up speed in melt spinning or a method of increasing the hole diameter of the spinneret nozzle. However, when only one of them is used, the spinning draft is 500 or more. Since it is necessary to make the take-up speed extremely large or the nozzle hole diameter extremely large, and it is easy to break the spinning yarn directly under the nozzle, which is a practical problem, it is desirable to increase the hole diameter and the take-up speed at the same time. Specifically, it is desirable to use a spinneret with a nozzle hole diameter of 0.5 mmφ or more, and a take-up speed of 2000 m / min or more.

The melt-spun undrawn yarn, after being drawn according to the spinning conditions, has a temperature higher than the heat treatment conditions adopted in the usual production of polyester fibers for clothing, that is, 170 ° C. or higher, preferably 180 ° C. It is necessary to perform heat treatment at the above temperature. By doing this, spinning draft 5
In combination with the number of 00 or more, crystallization of polyester on the surface of the fiber proceeds, and by subsequent weight reduction treatment with an aqueous solution of an alkali compound, fine pores having excellent abrasion resistance are formed on the surface of the fiber.

The weight-reduced polyester fiber is then dyed. The dyeing conditions do not have to be special, and dyeing may be performed under the conditions usually used for dyeing polyester fibers, that is, under high pressure of 130 ° C.

[0031]

The above-mentioned polyoxyalkylene glycol derivative (modified PAG agent) blended in the polyester fiber of the present invention has a reasonably good compatibility with the polyethylene terephthalate type polyester, and the movement of the polyester molecular chain. It is presumed that the crystallinity is improved and the crystallization rate is improved. Further, when cooled, the agent partly separates and precipitates. At this time, if the spinning draft is as high as 500 or more, the detailed reason is unknown, but the proportion of the fiber surface layer portion of the agent is present. As a result, crystallization of the fiber surface portion can be enhanced by heat treatment at 170 ° C. or higher.
When the polyester fiber thus obtained is subjected to weight reduction treatment with, for example, an aqueous solution of an alkali compound, a highly crystalline polymer portion remains, and a partially amorphous polyester is effective mainly in the partially precipitated PAG agent. Can be dissolved and removed to form fine irregularities with a short length in the fiber axis direction, and a fiber surface with high crystallinity (high density) can be formed. It is estimated that chromatic polyester fibers can be obtained.

Therefore, the polyester fiber of the present invention has a very remarkable effect that it is excellent in bathochromic property and is also excellent in abrasion discoloration resistance and fibril resistance.

[0033]

EXAMPLES The present invention will be described in more detail with reference to the following examples. Parts and% in the examples represent parts by weight and parts by weight, respectively, and the amount of the modified PAG agent remaining in the fibers when the resulting polyester fibers are alkali-reduced, the depth of color of the obtained dyed cloth, and the discoloration by friction. The fiber surface density and polymer crystallization rate were measured by the following methods.

Residual amount of modified PAG agent The sample cloth was treated with chloroform to determine the amount of extraction, and the residual amount of modified PAG agent was determined from the difference with the amount of extraction obtained by the same treatment without adding the modified PAG agent. I asked.

Depth of Color (Deep Chromaticity) The depth of color (K / S) was used as a measure of the depth of color. This value is the spectral reflectance (R) of the sample cloth
It was measured with a -330 type self-recording spectrophotometer and calculated from the following Kubelka-Munk equation. The larger this value, the greater the bathochromic effect (measurement wavelength 50
0 mμ). K / S = (1-R) ² / 2R where K is the absorption coefficient and S is the scattering coefficient.

Friction resistance against discoloration Using a Gakushin type flat abrasion machine for friction fastness test, a georgette made of 100% polyethylene terephthalate was used as a friction cloth, and the test cloth was subjected to 50 g under a load of 500 g.
The surface was abraded for 0 times and the degree of occurrence of discoloration was judged by a gray scale for discoloration. When the abrasion resistance was extremely low, it was classified as grade 1, and when it was extremely high, it was classified as grade 5. Practical grade 4 or higher is desirable.

Fiber Surface Density Using a laser Raman microprobe manufactured by Jobin-Yvon, the Raman spectrum of the fiber surface (some of which is the center of the fiber cross section) was measured with a positional resolution of the order of 1 μm. The full width at half maximum of the Raman band at about 1730 cm ^-1 was calculated, and the following equation D = −0.004785H + 1.45995 (wherein D is density (g / cm ³ ), H is wave number 1730 cm ⁻¹
The half-width of the Raman band is shown below) to calculate the density.

Polymer crystallization rate Using a scanning scanning calorimeter (Model 1090 manufactured by Du Pont), the crystallization peak temperature Tci at the time of temperature increase at a temperature increase rate of 20 ° C./minute,
And crystallization peak temperature Tcd when the temperature was maintained at 300 ° C. for 3 minutes and then naturally lowered, ΔT
= The size of Tcd-Tci was used as a parameter of the crystallization rate (the larger this value, the faster the crystallization rate).

[0039]

Examples 1 to 11 and Comparative Examples 1 to 8 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, 0.063 parts of calcium acetate monohydrate (0.069 mol% based on dimethyl terephthalate) and a color-matching agent. As cobalt acetate tetrahydrate 0.009 parts (0.09 relative to dimethyl terephthalate)
(07 mol%) was charged into an ester exchange can, and the ester exchange reaction was carried out while distilling out the methanol produced by raising the temperature from 140 ° C. to 220 ° C. over 3 hours in a nitrogen gas atmosphere to the outside of the system. Then, after stirring at 220 ° C. for 20 minutes, 0.058 parts of trimethyl phosphate (0.080 mol% relative to dimethyl terephthalate) was added as a stabilizer, and at the same time, the temperature rising / discharging of excess ethylene glycol was started. 10
As a post-minute polycondensation catalyst, 0.04 part of antimony trioxide (0.027 mol% based on dimethyl terephthalate) was added. Subsequently, the polyoxyalkylene glycol derivative shown in Table 3 was added to the obtained product at the ratio shown in Table 1, and when the internal temperature reached 240 ° C., the expulsion of ethylene glycol was completed, and the reaction product Was transferred to a polymerization can. Then, the reaction was carried out at normal pressure while raising the temperature until the internal temperature reached 260 ° C., then the pressure was reduced from 760 mmHg to 1 mmHg over 1 hour, and at the same time, the internal temperature was raised to 280 ° C. over 1 hour and 30 minutes. The reaction was continued under a reduced pressure of 1 mmHg or less at a polymerization temperature of 280 ° C. until the intrinsic viscosity [IV] reached about 0.64.

This polymer was made into chips by a conventional method,
After drying, melt spinning was performed at 285 ° C. at a polymer discharge rate and a winding speed shown in Table 1 using a spinneret in which 36 circular spinning holes having the nozzle diameter shown in Table 1 were formed. Then, the obtained undrawn yarn has an elongation of 30 in the finally obtained drawn yarn.
With a draw ratio of 100%, a draw roller of 84 ° C. and a plate heater of 180 ° C. were used for drawing and heat treatment to obtain a drawn yarn of 75 denier / 36 filaments.

S twist 2500 T / m or Z twist 2
A strong twist of 500 T / m was applied, and subsequently, the strong twist yarn was steam-heated at 80 ° C. for 30 minutes to stop the twist. The ply cloth Georgette fabric was woven by alternately disposing two S and Z twists of the twist-fixing strongly twisted yarn with a warp density of 47 yarns / cm and a weft density of 32 yarns / cm.

The resulting raw material was subjected to a relaxation treatment with a rotary washer at a boiling temperature for 20 minutes to form a grain, preset by a conventional method, and then treated with a 3.5% sodium hydroxide aqueous solution at a boiling temperature, 20% weight loss
The fabric was obtained.

The cloth after the alkali treatment is Dianix Black
HG-FS (Mitsubishi Kasei Co., Ltd. product) 15% owf
After dyeing at 130 ° C for 60 minutes, sodium hydroxide 1g /
A black dyed cloth was obtained by reducing and washing with an aqueous solution containing 1 liter of hydrosulfite and 1 g / liter of hydrosulfite at 70 ° C. for 20 minutes.

Table 2 shows the depth and sharpness of the resulting treated cloth. Further, the black dyed cloth is also shown with abrasion discoloration resistance after 500 abrasions.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

Claims (2)

[Claims] 1. A polyester fiber containing a polyoxyalkylene glycol derivative represented by the following general formula (I), the main repeating unit of which is ethylene terephthalate, and the surface of the fiber is free from the polyoxyalkylene glycol derivative. There are fine pores formed by traces, and the density of the fiber surface (measured by laser Raman microprobe analysis) is 1.380 g / cm ^3.
The above is a polyester fiber having excellent bathochromic properties. [Chemical 1] (In the formula, Z is an aliphatic diol having 5 to 10 carbon atoms, an alicyclic diol having 3 to 15 carbon atoms, bisphenols, and 2
A residue of at least one divalent hydroxy group-containing compound selected from the group of divalent phenols, A is an alkylene group having 2 to 4 carbon atoms, X is a residue of a monovalent hydroxy group-containing compound, and m is a positive value. Indicates an integer. ) 2. A polyester composition containing 0.1 to 10% by weight of a polyoxyalkylene glycol derivative represented by the following general formula (I) whose main repeating unit is ethylene terephthalate is melt-spun at a spinning draft of 500 or more. A method for producing polyester fibers having excellent bathochromism, which comprises subjecting the obtained polyester fibers to a heat treatment at a temperature of 170 ° C. or higher, and subjecting the obtained polyester fibers to a weight reduction treatment with an aqueous solution of an alkali compound. [Chemical 2] (In the formula, Z is an aliphatic diol having 5 to 10 carbon atoms, an alicyclic diol having 3 to 15 carbon atoms, bisphenols, and 2
A residue of at least one divalent hydroxy group-containing compound selected from the group of divalent phenols, A is an alkylene group having 2 to 4 carbon atoms, X is a residue of a monovalent hydroxy group-containing compound, and m is a positive value. Indicates an integer. )