JPH0971640A - Polyester resin and film containing the resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyester resin excellent in transparency, optical isotropy, formability, heat resistance and solvent resistance, and suitable to an optical material, etc., by compounding a specific dihydroxy compound in a specified range of the content based on the total glycol components. SOLUTION: This resin is composed of (A) an aromatic dicarboxylic acid as a dicarboxylic acid component, and (B) a dihydroxy compound of the formula [R<1> to R<4> are each a halogen, an alkyl or an alkoxy; (m), (n), (p), (q) are each 0-4] [e.g. 9,9-bis-(4-hydroxyphenyl)-fluorene] and (C) an aliphatic glycol as glycol components. The ratio of the component B is 30-80wt.% in the total glycol components. Further, it is preferable that the component B is added to a mixture of a polyethylene terephthalate, the component A and a diacetyl compound of the component B in the range of 30-80mol% based on the total glycol components. Preferably, the obtained mixture is heated to perform acidolysis, and subsequently the resultant is subjected to polycondensation under reduced pressure to obtain the objective resin.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyester resin and a film containing the same, more specifically,
Used as substrate film for liquid crystal displays, adhesives for liquid crystal displays, UV filters, etc.
The present invention relates to a polyester resin used for windows, glasses, greenhouses, skylights, windows for ovens, filters for solar distillers, and the like, and films containing the same.

[0002]

2. Description of the Related Art Conventionally, substrates for liquid crystal displays are
A glass substrate having excellent transparency, optical isotropy, heat resistance, solvent resistance, gas barrier property and the like has been used. However, in recent years, along with the trend toward higher performance of liquid crystal displays and efficiency of production processes, weight reduction compared to conventional glass substrates,
Plastic films and plastic sheets, which can be thinned and rolled and have excellent impact resistance, are drawing attention. Heretofore, plastic films made of polymethyl methacrylate, polyethylene terephthalate, polyether sulfone, polyarylate, amorphous polyolefin, polycarbonate and the like have been proposed. However, polymethylmethacrylate has a high hygroscopic property, is liable to be deformed such as a warp when formed into a molded product, and has insufficient heat resistance. Amorphous polyolefins have unsatisfactory moldability and are expensive. Polyethylene terephthalate, polyarylate and polycarbonate have a large birefringence due to slight orientation during film molding, and their control is difficult. Therefore, the production efficiency is lowered, the image quality of the display in which the polarizing plate and the liquid crystal layer are laminated is lowered, and the production of a homogeneous product becomes difficult. Polyether sulfone also has a large birefringence with a slight orientation, is not sufficiently transparent, and has a high hygroscopicity, which causes poor dimensional stability and causes deterioration. In order to solve the above problems, the following transparent polyester resins are disclosed. JP-A-63-2604
The polyester resin disclosed in Japanese Patent Publication No. 90 and Japanese Patent Application Laid-Open No. 5-175560 is a polyester resin using an aliphatic glycol having a cyclohexane ring. But,
All of them have insufficient heat resistance and are not suitable for use as a film for liquid crystal substrates. Further, JP-A-57-19243
The polyester resins disclosed in JP-A No. 2 and JP-A-3-168211 are wholly aromatic polyester resins using bisphenol having a fluorene ring or the like as a glycol component and aromatic dicarboxylic acid, and are heat-resistant and optically isotropic. Although excellent in moldability, there is a problem that the flowability is poor due to the large melt viscosity, and therefore the moldability is poor. Furthermore, the polyester resin disclosed in JP-A-64-1723 uses an aliphatic dicarboxylic acid in addition to an aromatic dicarboxylic acid as an acid component to improve the mechanical properties of the resin. However, this polyester resin has a problem that it is easily hydrolyzed under high temperature and high humidity conditions.

[0003]

DISCLOSURE OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and its object is excellent in transparency, heat resistance, optical isotropy and moldability, and even under high temperature and high humidity. It is to provide a polyester resin that does not cause hydrolysis.

[0004]

The present invention relates to a polyester resin containing an aromatic dicarboxylic acid as a dicarboxylic acid component and a dihydroxy compound represented by the general formula (1) as a glycol component and an aliphatic glycol. , The dihydroxy compound is 30 to 30 in all glycol components
It is a polyester resin characterized by being contained in a range of 80 mol%.

[0005]

Embedded image

(In the formula, R ^{1 to} R ⁴ each independently represent a halogen atom, an alkyl group or an alkoxy group,
m, n, p and q each independently represent an integer of 0-4. )

In a preferred embodiment, the polyester resin is acid-decomposed by heating a mixture of polyethylene terephthalate, an aromatic dicarboxylic acid and a diacetyl compound of the dihydroxy compound of the general formula (1), and then under reduced pressure. Polycondensation is performed, and the diacetyl compound of the above-mentioned dihydroxy compound is mixed so as to be in the range of 30 to 80 mol% with respect to the total glycol component. In a preferred embodiment, the polyester resin is a mixture of polyethylene terephthalate, an aromatic dicarboxylic acid and the dihydroxy compound represented by the general formula (1), which is subjected to acid decomposition, followed by acylation, and then, By carrying out polycondensation under reduced pressure, the dihydroxy compound is contained in an amount of 30 to 8 with respect to all glycol components.
It is mixed so as to be in the range of 0 mol%. Further, the present invention is a film containing the above polyester resin.

Next, the present invention will be described in detail. The polyester resin of the present invention contains an aromatic dicarboxylic acid as a dicarboxylic acid component, an aliphatic glycol as a diol component, and a dihydroxy compound represented by the general formula (1).

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, and it is preferable to use terephthalic acid and isophthalic acid in combination. Further, an aliphatic dicarboxylic acid may be used as long as the properties such as heat resistance of the resulting resin composition are not significantly impaired. Examples of the aliphatic dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecadioic acid and the like. Such dicarboxylic acid components may be used alone or in combination of two or more.

The amount of the above-mentioned aliphatic dicarboxylic acid used is preferably 0 to 10 mol%, more preferably 0 to 8 mol%, and particularly preferably 0 to 5 mol% in the total dicarboxylic acid components.
It is.

In the dihydroxy compound represented by the general formula (1), the halogen atom in R ^{1 to} R ⁴ includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among them, a fluorine atom, a chlorine atom, A bromine atom is preferred. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl and te.
Examples thereof include alkyl groups having 1 to 6 carbon atoms such as rt-butyl, pentyl, isopentyl, neopentyl, and n-hexyl, and among them, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl and the like. An alkyl group having 1 to 4 carbon atoms is preferable. Examples of the alkoxy group include alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, pentoxy, isopentoxy, neopentoxy and n-hexyloxy. Of these, alkoxy groups having 1 to 4 carbon atoms such as methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, sec-butoxy and tert-butoxy are preferable. Further, m and n are preferably 0, and p and q are preferably 0-2.
Further, R ³ and R ⁴ are preferably the same.

Specific examples of such a dihydroxy compound include, for example, 9,9-bis- (4-hydroxyphenyl) -fluorene, 9,9-bis- (4-hydroxy-3-methylphenyl) -fluorene, 9,9-bis-
(4-hydroxy-3-chlorophenyl) -fluorene, 9,9-bis- (4-hydroxy-3-bromophenyl) -fluorene, 9,9-bis- (4-hydroxy-3-fluorophenyl) -fluorene, 9,9-bis- (4-hydroxy-3-methoxyphenyl) -fluorene, 9,9-bis- (4-hydroxy-3,5-dimethylphenyl) -fluorene, 9,9-bis- (4-hydroxy) -3,5-dichlorophenyl) -fluorene,
Examples include 9,9-bis- (4-hydroxy-3,5-dibromophenyl) -fluorene, and among them, 9,9
-Bis- (4-hydroxyphenyl) -fluorene is economically particularly preferred. Such dihydroxy compounds may be used alone or in combination of two or more.

The above-mentioned dihydroxy compound is used in an amount of 30 to 80 mol%, preferably 30 to 80% by mol based on the total glycol component.
It is 70 mol%, particularly preferably 40 to 60 mol%.
When the amount of dihydroxy compound used is less than 30 mol%,
Due to poor heat resistance of polyester, dimensional stability becomes poor when the polyester is placed in a high temperature during or after the production process, which causes deterioration and deterioration of film quality. On the other hand, when it exceeds 80 mol%, the melt viscosity of the obtained polyester becomes large and the moldability deteriorates.

The aliphatic glycol is preferably an aliphatic glycol having 2 to 4 carbon atoms, specifically, ethylene glycol, 1,3-propanediol, 1,2-
Propanediol, 1,4-butanediol, 1,2-
Examples thereof include butanediol and 1,3-butanediol, with ethylene glycol being particularly preferred.

The amount of the above-mentioned aliphatic glycol used is
In all glycol components, preferably 20 to 70 mol%, more preferably 30 to 70 mol%, particularly preferably 40 to 70 mol%.
60 mol%. When the amount of the aliphatic glycol used is less than 20 mol%, the melt viscosity of the obtained polyester becomes large and the moldability deteriorates. Also, hydrolysis occurs at high temperature and high humidity. On the other hand, when it exceeds 70 mol%, the heat resistance of the polyester is poor, and the dimensional stability becomes poor when the polyester is placed in a high temperature during or after the production process, which causes deterioration and deterioration of the film quality. .

The above polyester resin can be polymerized by a known polycondensation method. For example, a melt polymerization method such as an interfacial polymerization method; a solution polymerization method; a transesterification method, an acetate method, an acidolysis / acetate method, and an acidolysis / acetic anhydride method can be adopted. Particularly, the melt polymerization method, especially the acidolysis / acetic anhydride method is preferable. Each polymerization method will be described below.

(Interfacial Polymerization Method) In the interfacial polymerization method, an acid chloride of an aromatic dicarboxylic acid is generally used as an active species of an acid component, and a solution prepared by dissolving the acid chloride in an organic solvent is prepared in advance by using dihydroxy of the general formula (1). It is added to an alkaline solution in which the compound and the aliphatic glycol are dissolved at room temperature with stirring. At this time, the dihydroxy compound is added in an amount of 30 to 80 mol% with respect to the total glycol component. At this time, a phase transfer catalyst is generally added to accelerate the reaction. Examples of the phase transfer catalyst include tetraethylammonium chloride, tetraethylammonium bromide, tetrapropylammonium, tetrapropylammonium chloride, tetrapropylammonium bromide and the like. Examples of the organic solvent include chloroform, 1,2-dichloroethane, 1,1,3-trichloroethane and the like. If a halide remains in the obtained polyester, it will cause a decrease in the life and reliability of the liquid crystal display when it is used as it is for a substrate for a liquid crystal display. A residual halide removal step is required.

(Solution Polymerization Method) In the solution polymerization method, generally, an acid chloride of an aromatic dicarboxylic acid as an active species of an acid component, a dihydroxy compound of the general formula (1) and an aliphatic glycol are dissolved in an organic solvent and heated. To do. At this time, the dihydroxy compound is added in an amount of 30 to 80 mol% with respect to the total glycol component. At this time, it is general to add a dehydrochlorination catalyst to promote the reaction. Examples of the dehydrochlorination catalyst include alkali metal or alkaline earth metal hydroxides and tertiary amines. Also in this polymerization method, a step of removing the residual halide such as sufficient washing and filtration is necessary so that the halide is not left in the polyester obtained in the same manner as above.

(Melt Polymerization Method) The melt polymerization method includes transesterification method, acetate method, acidolysis / acetate method,
Acidolysis / acetic anhydride method and the like. In the transesterification method, generally, a dimethyl ester of an aromatic dicarboxylic acid as an active species of an acid component, and a mixture of a dihydroxy compound of the general formula (1) and an excess of aliphatic glycol are heated to distill off methanol, Polycondensation is carried out under reduced pressure. At this time, the dihydroxy compound is mixed in a range of 30 to 80 mol% with respect to the total glycol component. At this time, it is general to add a polymerization catalyst to accelerate the reaction. Examples of the polymerization catalyst include antimony compounds, titanium compounds, germanium compounds, manganese compounds, magnesium compounds, cobalt compounds, calcium compounds, zinc compounds, lithium compounds, sodium compounds, potassium compounds, and the like.
Among them, a combination of manganese acetate and antimony oxide-based compound, a combination of calcium acetate and antimony oxide-based compound, a combination of magnesium acetate and antimony oxide-based compound, a combination of zinc acetate and germanium-based compound, a combination of manganese acetate and germanium-based compound , Tetrabutyl titanate and the like are preferable. In addition, additives such as a coloring inhibitor, an ultraviolet absorber, a phenol-based or phosphorus-based antioxidant may be added if necessary.

In the acetate method, generally, a mixture of an aromatic dicarboxylic acid, a diacetyl compound of the dihydroxy compound of the general formula (1) and a diacetyl compound of an aliphatic glycol is heated to distill off acetic acid and then under reduced pressure. Carry out polycondensation. At this time, the diacetyl compound of the dihydroxy compound is 30 to 80 mol% with respect to the total glycol component.
Mix so that it becomes the range of.

The diacetyl compound of the dihydroxy compound of the general formula (1) and the diacetyl compound of the aliphatic glycol can be obtained by dehydration condensation of the hydroxyl group of the dihydroxy compound of the general formula (1) or the aliphatic glycol and the carboxyl group of acetic acid. can get. The purity of the diacetylated product obtained at this time is preferably 99.9% or more. When the purity is less than 99.9%, the molecular weight of the polyester obtained during the polymerization is unlikely to increase. For example, 9,
The diacetylated product of 9-bis- (4-hydroxyphenyl) -fluorene is obtained by adding 9,9-bis- (4-hydroxyphenyl) -fluorene and acetic anhydride in the presence of sulfuric acid to give 10
It is obtained by heating to 0 ° C. and reacting for about 30 minutes. Also at this time, it is desirable that the purity is 99.9% or more. In addition, it is common to add a polymerization catalyst to accelerate the above reaction. As the polymerization catalyst, known catalysts such as magnesium acetate, tetrabutyl titanate, potassium acetate and calcium acetate can be used.
In addition, additives such as a coloring inhibitor, an ultraviolet absorber, a phenol-based or phosphorus-based antioxidant may be added if necessary.

In the acidolysis / acetate method, a mixture of polyethylene terephthalate, an aromatic dicarboxylic acid, and a diacetyl compound of the dihydroxy compound of the general formula (1) is heated to effect acid decomposition to obtain a uniform solution, and the mixture is decompressed under reduced pressure. To carry out polycondensation. The diacetyl compound of the dihydroxy compound is mixed in a range of 30 to 80 mol% with respect to the total glycol component. At this time, it is general to add a polymerization catalyst to accelerate the reaction. As the polymerization catalyst, known catalysts such as magnesium acetate, tetrabutyl titanate, potassium acetate and calcium acetate can be used. In addition, additives such as a coloring inhibitor, an ultraviolet absorber, a phenol-based or phosphorus-based antioxidant may be added if necessary.

In the acidolysis / acetic anhydride method, a mixture of polyethylene terephthalate, an aromatic dicarboxylic acid and a dihydroxy compound represented by the general formula (1) is heated for acid decomposition to form a uniform solution, and acetic anhydride is added. And perform acylation. Then, after further heating to make a uniform solution,
Polycondensation is carried out under reduced pressure. The dihydroxy compound is mixed in a range of 30 to 80 mol% with respect to the total glycol component. At this time, it is general to add a polymerization catalyst to accelerate the reaction. As the polymerization catalyst, known catalysts such as nickel acetylacetonate, zinc acetylacetonate, tin oxide, tetrabutyl titanate and antimony acetate can be used.
In addition, additives such as a coloring inhibitor, an ultraviolet absorber, a phenol-based or phosphorus-based antioxidant may be added if necessary.

Of these methods, the acidolysis / acetate method and the acidolysis / acetic anhydride method are preferred.
In the transesterification method, when the reactivity of the aliphatic glycol is low, the molecular weight of the obtained polyester does not easily increase. Further, in the acetate method, when the boiling point of the aliphatic glycol is low, the composition of the obtained polyester is not the desired composition.

The polyester thus obtained is
The film is formed by a dry film forming method, a wet film forming method, or a melt film forming method. Among them, the dry film-forming method is particularly preferable because the obtained polyester has a high solubility in a general solvent having a low boiling point and a high-concentration solution can be obtained. Preferable examples of the solvent used in the dry film forming method include halogen solvents such as methylene chloride, chloroform, 1,2-dichloroethane and chlorobenzene; cyclic ether solvents such as tetrahydrofuran, dioxane and dioxolane. From the viewpoint of global environment, cyclic ether solvents are particularly preferable. The polyester resin of the present invention is
The solubility in cyclic ether solvents is particularly excellent.

[0026]

In the present invention, since the polyester resin has a fluorene skeleton, it has a small orientation and birefringence due to its molecular structure, and thus becomes a polyester resin excellent in transparency and optical isotropy. . At the same time, it has excellent heat resistance and solvent resistance originally possessed by the polyester resin, and is also excellent in moldability. Furthermore, since the above polyester resin has good solubility in a low boiling point general-purpose solvent, etc., this polyester resin can be easily and inexpensively formed into a film excellent in optical isotropy by a dry film forming method. it can.

[0027]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The intrinsic viscosity, glass transition temperature, birefringence value and total light transmittance of the polyester resin in the examples were measured by the methods described below. (1) Intrinsic viscosity In a mixed solution of 50 wt% of phenol and 50 wt% of 1,2,2,2-tetrachloroethane in 25 ml, 0.1 m of resin was added.
g was melted at 40 ° C. and then measured at 25 ° C. (2) Glass transition temperature (Tg) About 10 mg of resin was used, and the resin was heated with a differential scanning calorimeter (DSC-50 manufactured by Shimadzu Corporation) at a heating rate of 10 ° C./min for measurement. At this time, crystalline / amorphous was judged by the presence / absence of an endothermic peak due to melting of crystals. (3) Birefringence Value and Refractive Index A resin was dissolved in tetrahydrofuran at a concentration of 30 wt% and cast on a PET film having good surface smoothness. This was dried at room temperature and then completely dried under reduced pressure to obtain a film having a thickness of 60 to 150 μm. The birefringence value and the refractive index of this film were measured using an Appe refractometer (ATAGO). (4) Total light transmittance The film obtained in (3) was measured using a spectrophotometer (U-3210 manufactured by Hitachi, Ltd.). (5) Solubility The solubility of the resin in tetrahydrofuran was examined.

Example 1 47 parts by weight of polyethylene terephthalate, 16 parts by weight of isophthalic acid and 36 parts by weight of 9,9-bis- (4-hydroxyphenyl) -fluorene were used as raw materials, and these were put into a reaction vessel and stirred. Acid decomposition was performed at 240 ° C.
Then, cool to 140 ° C., add 21 parts by weight of acetic anhydride,
After further stirring for 1 hour, the pressure was gradually reduced while increasing the temperature to 300 ° C, and the degree of vacuum was 0.5 mmH while maintaining the temperature at 300 ° C.
The pressure was reduced to g or less. While maintaining this condition, the viscosity was increased and the reaction was terminated when the predetermined torque was reached. The obtained polymer was extruded into water to obtain pellets. Various properties of this pellet were measured. Table 1 shows the results. In Table 1, R represents the content of the dihydroxy compound of the general formula (1) in the polyester resin represented by the following formula. In Example 1, R was 30 mol%.

[0029]

[Equation 1]

Example 2 In Example 1, 27 parts by weight of polyethylene terephthalate, 24 parts by weight of isophthalic acid, 9,9-bis- (4-
Pellets were obtained in the same manner as in Example 1 except that 49 parts by weight of hydroxyphenyl) -fluorene and 29 parts by weight of acetic anhydride were used as raw materials. Various properties of this pellet were measured. Table 1 shows the results. R is 50
It was mol%.

Example 3 In Example 1, 14 parts by weight of polyethylene terephthalate, 28 parts by weight of isophthalic acid, 9,9-bis- (4-
Pellets were obtained in the same manner as in Example 1 except that 58 parts by weight of (hydroxyphenyl) -fluorene and 34 parts by weight of acetic anhydride were used as raw materials. Various properties of this pellet were measured. Table 1 shows the results. R is 70
It was mol%.

Comparative Example 1 Various properties of a commercially available polyethylene terephthalate film for optical film were measured. Table 1 shows the results.

Comparative Example 2 Various properties of a commercially available polycarbonate film for optical film were measured. Table 1 shows the results.

Comparative Example 3 In Example 1, 59 parts by weight of polyethylene terephthalate, 13 parts by weight of isophthalic acid, 9,9-bis- (4-
Pellets were obtained in the same manner as in Example 1 except that 28 parts by weight of hydroxyphenyl) -fluorene and 13 parts by weight of acetic anhydride were used as raw materials. Various properties of this pellet were measured. Table 1 shows the results. R is 20
It was mol%.

[0035]

[Table 1]

[0036]

As is apparent from the above description, according to the present invention, it is possible to provide a polyester resin having excellent transparency, optical isotropy, moldability, heat resistance and solvent resistance. Therefore, such a polyester resin can be suitably used for an optical material. Further, since this polyester resin has good solubility in a low boiling point general-purpose solvent or the like, it can be easily and inexpensively formed into a film.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiichiro Yokoyama 2-1-1 Katata, Otsu-shi, Shiga Toyobo Co., Ltd. Research Institute (72) Inventor Tomoharu Kurita 2-1-1 Katata, Otsu, Shiga Toyobo Co., Ltd. Research Institute (72) Inventor Tadashi Inukai 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Institute (72) Inventor Yozo Yamada 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd.

Claims (4)

[Claims] 1. A polyester resin containing an aromatic dicarboxylic acid as a dicarboxylic acid component and a dihydroxy compound represented by the general formula (1) and an aliphatic glycol as a glycol component, wherein the dihydroxy compound is a total glycol component. Medium 30-80
A polyester resin characterized by being contained in the range of mol%. Embedded image (In the formula, R ^{1 to} R ⁴ are each independently a halogen atom,
It represents an alkyl group or an alkoxy group, and m, n, p and q each independently represent an integer of 0 to 4. ) 2. A method comprising heating a mixture of polyethylene terephthalate, an aromatic dicarboxylic acid and a diacetyl compound of the dihydroxy compound of the general formula (1) for acid decomposition, and then polycondensation under reduced pressure. The polyester resin according to claim 1, wherein the diacetyl compound of the dihydroxy compound is mixed in a range of 30 to 80 mol% with respect to the total glycol component. 3. A mixture of polyethylene terephthalate, an aromatic dicarboxylic acid, and the dihydroxy compound of the general formula (1) is heated for acid decomposition, followed by acylation, and then polycondensation under reduced pressure. The polyester resin according to claim 1, wherein the dihydroxy compound is mixed in a range of 30 to 80 mol% with respect to the total glycol component. 4. A film containing the polyester resin according to claim 1.