JPH06248087A - Aromatic polyester-styrenic resin copolymer - Google Patents

Abstract

PURPOSE:To obtain the subject copolymer containing a polymer block composed of styrenic unit and a polymer block composed of a specific aromatic ester unit at a specific weight ratio and having excellent fluidity, moldability and transparency and small optical distortion. CONSTITUTION:This resin copolymer is an aromatic polyester-styrenic resin copolymer containing (A) a polymer block composed of styrenic recurring unit and (B) a polymer block composed of aromatic ester recurring unit of the formula (Z is single bond or bivalent bonding group) at an A:B weight ratio of 5:95 to 95:5 and containing <=5wt.% of the sum of cyclohexane-soluble component and 1,1,1,3,3,3-hexafluoroisopropanol-soluble component. The copolymer can be produced e.g. by an interfacial polymerization process comprising the mixing and reaction of an alkaline aqueous solution of an aromatic dihydroxy compound with a solution produced by dissolving a styrenic resin and an aromatic dicarboxylic halide in a water-incompatible organic solvent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an aromatic polyester-styrene resin copolymer. More specifically, the present invention relates to an aromatic polyester-styrene resin copolymer having a low birefringence, which is useful in the production of optical parts such as optical fibers, optical disks and lenses.

[0002]

2. Description of the Related Art Generally, aromatic polyester resins, which are excellent in transparency and suitable for materials for optical devices, have excellent heat resistance and mechanical strength, but have high melt viscosity, There is a problem that it is difficult to process. In addition, there is a problem that stress distortion occurs during thermoforming processing such as injection molding, and the obtained product is likely to cause birefringence. Therefore, when the final product is an optical disk or optical guard protective film, the birefringence causes a read error or noise, and when the final product is an optical fiber, the birefringence causes the transmission loss. There is a problem such as a cause of increasing.

As a means for solving such a problem, there has been proposed a method of blending or copolymerizing resins having positive and negative inverse birefringences (Takashi Inoue, Taku Saito, "Functional Materials"). March 1987 issue, pages 21-28).
According to this method, it is considered that a resin having no birefringence can be obtained by blending or copolymerizing an aromatic polyester-based resin and a styrene-based resin having an intrinsic birefringence in positive and negative directions.

However, the aromatic polyester resin and the styrene resin have a low compatibility by simply blending them, and a transparent molded article cannot be obtained. Therefore, in order to eliminate the drawbacks of such a blend, for example, a resin in which a styrene resin and an aromatic polyester are graft-copolymerized in a specific ratio has been proposed (JP-A-1-129,011). ). According to the proposed copolymer, it is possible to obtain the resin having a reduced intrinsic birefringence to some extent and the compatibility can be improved, but such a copolymer has a large proportion of aromatic polyester. As a result, the resin itself has poor heat fluidity, and molecular orientation occurs in injection molding at low temperatures, resulting in birefringence in the molded product, and in the extreme case, white turbidity and loss of transparency. Then, in order to eliminate these drawbacks, when the molding temperature is raised to improve the heat fluidity, the styrene resin is decomposed, and as a result, the molded product is colored, especially in the short wavelength region (600 nm or less). There is a problem that transparency is lowered.

[0005]

Therefore, the inventors of the present invention have earnestly studied to solve the above problems in an aromatic polyester-styrene resin copolymer suitable for a molding material for optical equipment. As a result, by adjusting the copolymerization ratio of the aromatic polyester and the styrene resin at a specific weight ratio, the resulting copolymer has low birefringence, excellent heat fluidity and moldability, and a shorter wavelength. The inventors have found that the copolymer is also excellent in the transparency in the range and completed the present invention.

Therefore, an object of the present invention is to provide a copolymer which is excellent in transparency, has a small optical distortion, and is excellent in fluidity and moldability, especially in a short wavelength region. is there.

[0007]

[Means for Solving the Problems] That is, the present invention provides a polymer block (A) comprising a styrene-based repeating structural unit and the following general formula:

[0008]

[Chemical 2]

Aromatic polyester-styrene resin copolymerization containing a polymer block (B) comprising an aromatic ester repeating structural unit represented by the formula (wherein Z represents a single bond or a divalent bonding group) In the copolymer, the weight ratio of the polymer blocks (A) and (B) in the copolymer is 5:95 to 95: 5, and the cyclohexane-soluble component is 1,1,1,3,3. It is an aromatic polyester-styrene resin copolymer having a total content of 3,3-hexafluoroisopropanol-soluble components of 5% by weight or less.

The polymer block (A) comprising the styrene-based repeating structural unit of the present invention comprises:
In addition to styrene, for example, alkyl-substituted styrene compounds such as o-, m-, p-methylstyrene, p-tert-butylstyrene, o-, m-, p-chlorostyrene, dichlorostyrene, monobromo. Examples thereof include halogen-substituted styrene compounds such as styrene, dibromostyrene, monofluorostyrene and difluorostyrene, α-alkyl substituted styrene compounds such as α-methylstyrene and α-ethylstyrene, and a mixture of these appropriately mixed. Of course, the styrene-based monomer is not limited to those listed here, and the styrene-based repeating structural unit contains vinyl polymerization-based monomer units such as methacrylic acid ester and acrylic acid ester. Good. When these vinyl-polymerized monomer units are included, the proportion thereof is 50 mol% or less of the number of units in all styrene-based repeating structural units, and 20 mol% or less so as not to deteriorate the optical properties of the copolymer. Is desirable.

In the polymer block (B) composed of the aromatic polyester structural unit present in the copolymer of the present invention, the bonding group Z in the general formula is a single bond composed of a covalent bond with no intervening bonding atom or atomic group. And divalent linking groups, specifically, methylene group, ethylidene group, propylidene group, isopropylidene group, butylidene group, pentylidene group, hexylidene group, heptylidene group, isobutylidene group, in addition to ether bond and sulfone bond. Examples include alkylidene groups having 1 to 7 carbon atoms such as isopentylidene group, isopentylidene group, isohexylidene group, and isoheptylidene group, and phenyl-substituted alkylidene groups such as benzylidene group, phenylethylidene group, phenylpropylidene group, and phenylisopropylidene group. be able to.
Of these, a methylene group, an isopropylidene group, and a phenylethylidene group are particularly preferable, and an isopropylidene group is particularly preferable.

The aromatic polyester-styrene resin copolymer of the present invention has a polystyrene-equivalent number average molecular weight of 1,000 or more, as measured by gel permeation chromatography (GPC), and more preferably 1. It is 2,000 or more and 500,000 or less. A copolymer having a number average molecular weight of less than 1,000 is not preferable because it has insufficient physical properties as a polymer.

The aromatic polyester-polystyrene-based copolymer of the present invention has only to have a chemical bond between the polyester segment and the polystyrene-based polymer segment, and more specifically, a block copolymer. , A graft copolymer, a combination of these copolymers, and the like. Depending on the combination of raw material compositions described below, a polymer block (A) including a styrene-based repeating structural unit and an aromatic ester repeating structural unit are included. The weight ratio (A: B) with the polymer block (B) is 5: 95-
It must be in the range 95: 5. If the ratio of the polymer block (A) exceeds 95, the mechanical properties of the copolymer will be insufficient, and if it is less than 5, transparency and moldability in the short wavelength region will be impaired, such being undesirable.

As the method for producing the copolymer of the present invention, known methods such as an interfacial polymerization method, a solution polymerization method and a radical polymerization method can be used without any limitation. For example, in the interfacial polymerization method, an aromatic dihydroxy compound is dissolved in an alkaline aqueous solution, and a mixture of a styrene resin having the reactive group at the terminal and an aromatic dicarboxylic acid halide is dissolved in an organic solvent which is incompatible with water. It is carried out by mixing an alkaline aqueous solution of these aromatic dihydroxy compounds, a styrene resin and a solution of an aromatic dicarboxylic acid halide in water and an incompatible organic solvent, and stirring the mixture. The alkali used in this interfacial polymerization method is preferably sodium hydroxide or potassium hydroxide, and the organic solvent does not react with styrene resin or aromatic dicarboxylic acid halide, and these styrene resin and aromatic dicarboxylic acid do not react. There is no particular limitation as long as it is a good solvent for both the acid halide and the aromatic polyester-styrene resin copolymer produced. As the organic solvent which is incompatible with water, for example, dichloromethane, chloroform,
Halogenated hydrocarbons such as 1,2-dichloroethane and 1,1,2,2-tetrachloroethane, aromatic halogen compounds such as chlorobenzene, o-, m-, p-dichlorobenzene, benzene, and the like. Examples thereof include aromatic hydrocarbons such as toluene and xylene, and a mixture in which these are appropriately mixed.

Further, in the interfacial polymerization method, a quaternary ammonium salt such as trimethylbenzylammonium halide, triethylbenzylammonium halide, tributylbenzylammonium halide or tetrabutylbenzylammonium halide is added to accelerate the polymerization reaction. Good. The interfacial polymerization reaction is carried out at a temperature of 2 to 50 ° C., preferably 5 to 50 ° C. under stirring for a polymerization time of about 5 minutes to 8 hours.

In this interfacial polymerization method, a block copolymer of an aromatic polyester and a styrene resin is produced. Further, the solution polymerization method comprises mixing and stirring the aromatic dihydroxyl compound and a mixture of a styrene resin polymer having the reactive group at the terminal and an aromatic dicarboxylic acid halide in an organic solvent in the presence of an alkali. Done by

As the alkali used for solution polymerization,
In addition to inorganic basic compounds such as sodium hydroxide, potassium hydroxide and calcium hydroxide, tertiary amines such as triethylamine, tributylamine and pyridine, and DB
U (1,8-diazabicyclo [5.4.0] undecene-7), DBN (1,5-diazabicyclo [4.3.
[0] Nonene-5) and other organic strongly basic compounds are preferable, and the solvent does not react with a styrene resin or an aromatic dicarboxylic acid halide and is an aromatic dihydroxyl compound,
There is no particular limitation as long as it is a good solvent for any of the styrene resin, the aromatic dicarboxylic acid halide and the aromatic polyester-styrene resin copolymer produced. Examples of such a solvent include benzene, toluene, aromatic hydrocarbon compounds such as xylene, halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, chlorobenzene, dichlorobenzene, dioxane, tetrahydrofuran, and the like. Examples thereof include dimethylformamide, dimethylsulfoxide, pyridine, and the like, or a mixture thereof.

In order to control the molecular weight, o, m,
p-cresol, o, m, p-phenylphenol, p
It is also possible to add a monofunctional phenol compound such as -tert-butylphenol. In this solution polymerization method, a block copolymer of an aromatic polyester and a styrene resin is produced.

In addition to the copolymer of the present invention, the non-copolymerized aromatic polyester and the styrene resin are contained in the resins obtained by the above-mentioned several production methods. In order to obtain the copolymer of the present invention, it is necessary to remove the non-copolymerized resin from this mixture. The method for removing the non-copolymerized resin is not particularly limited, but a method by solvent extraction can be given as an example. As will be described in more detail with reference examples below, styrene resin not copolymerized is dissolved in cyclohexane, and aromatic polyester is 1,1,1,3,3.
It dissolves in 3,3-hexafluoroisopropanol.
The copolymer of the present invention does not dissolve in any of these solvents. That is, the resin obtained by the above-mentioned production method is dissolved in cyclohexane to separate it into a soluble component and an insoluble component, and then the cyclohexane insoluble component is separated into 1,1,1,3,3,3
-The copolymer of the present invention can be separated by dissolving it in hexafluoroisopropanol and separating it into a soluble component and an insoluble component.

The copolymer of the present invention contains phosphite esters and hindered phenols in an amount of 0.01 to 2% by weight in order to prevent coloring and deterioration of transparency due to thermal decomposition. can do. Examples of the phosphite used here include triphenyl phosphite, tridecyl phosphite, tributyl phosphite, tris (2-ethylhexyl) phosphite, tricresyl phosphite, and the like. In addition, the hinterpheno
Examples of the polyols include 2,6-di-tert-butyl-4-methylphenol, Ionox-100 and 300.
[Product Name: Shell Chemical Co., Ltd.], Irganox-2
45, 1010, 1076 [Product name: Ciba-Gigi-
Co., Ltd.], Irganox-B1171 [trade name: manufactured by Ciba-Geigy Co., Ltd.], topanol-CA [trade name: manufactured by iC-eye Co., Ltd.] and the like.

The method of mixing such phosphorous acid esters and hindered phenols into the copolymer of the present invention may be a known method and is not particularly limited. For example, a dry blending method, a method of melt mixing at the time of pelletization by an extruder, a master pellet having a high content of phosphite ester etc. by the melt mixing method and a mixture of the present invention containing no phosphite ester etc. It is possible to apply a method in which pellets of only the polymer are produced, and both are dry-blended.

[0022]

EXAMPLES The present invention will be specifically described below based on Reference Examples, Examples, Test Examples and Comparative Examples. Reference Examples 1 to 3 [Synthesis Example of Styrene Resin] 4,4′-azobis-4-cyanovaleric acid (ACVA) was used as a polymerization initiator, and styrene 10 was used.
0 parts by weight were radically polymerized at 90 ° C. ACVA is 1,
It was dissolved in 4-dioxane and added continuously during the polymerization as well as at the beginning of the polymerization. The styrene-based resin shown in Table 1 was obtained by changing the concentration of ACVA added initially and the concentration of ACVA added continuously.

The molecular weight was measured using a GPC measuring device HLC-802A manufactured by Toyo Soda Co., Ltd. The average number of carboxyl groups contained in one molecule of the polymer was measured by neutralizing titration of the polymer solution with a sodium hydroxide solution using an automatic titrator GT-05 type manufactured by Mitsubishi Kasei Co., Ltd.

[0024]

[Table 1]

Reference Examples 4 to 6 [Synthesis Example of Styrene Resin Having Phenolic Hydroxyl Group at Terminal from Styrene Resin] 100 parts by weight of styrene resin having a terminal carboxyl group synthesized in Reference Examples 1 to 5 parts by weight of bisphenol A are added. Was esterified at some parts to synthesize a styrenic resin having a terminal hydroxyl group.

The number of terminal hydroxyl groups was determined by quantifying unreacted carboxyl groups in the same manner as in Reference Example 1. The number of terminal hydroxyl groups is shown in Table 2. Reference Example 7 [Synthesis example of styrene resin having terminal amino group from styrene resin] 100 parts by weight of styrene resin having a terminal carboxyl group synthesized in Reference Example 2 was added with 10 parts by weight of 4,4′-diaminodiphenyl ether. Amidation was carried out to synthesize a styrene resin having an amino group at the terminal.

The number of terminal amino groups was determined by quantifying unreacted carboxyl groups in the same manner as in Reference Examples 1 to 3. The number of terminal amino groups is shown in Table 2.

[0028]

[Table 2]

Reference Example 8 [Confirmation of solvent extractability of aromatic polyester and styrene resin] Commercially available polystyrene resin [G-1 manufactured by Nippon Steel Chemical Co., Ltd.]
0] 100 parts by weight and 100 parts by weight of a commercially available aromatic polyester resin [U-polymer “U-100” manufactured by Unitika Ltd.] were melt-kneaded at 290 ° C. to obtain pellets. Further, the pellets are crushed with a crusher to have a diameter of 0.5 to 2.0.
The mm part was separated.

Soxhlet extraction was carried out for 16 hours using 50 ml of cyclohexane for 2 g of the pellets. When the weight of the extract was measured after concentrating the extract with an evaporator, the extracted weight was 0.999 g.
In addition, the proton NMR measurement of the extract revealed that the extract contained only polystyrene. Furthermore,
Soxhlet extraction was performed for 16 hours using 50 ml of 1,1,1,3,3,3-hexafluoroisopropanol for 2 g of the same pellet. When the weight of the extract was measured, the extracted weight was 0.998 g, and it was found from the proton NMR measurement that this extract consisted of aromatic polyester only.

From this reference example 8, cyclohexane extracted only styrene resin, and 1,1,1,3,3,3
It was found that 3-hexafluoroisopropanol extracts only aromatic polyesters. Examples 1 to 4 In a round-bottomed flask equipped with a stirrer, 60 parts by weight of the styrene resin synthesized in Reference Examples 4 to 7 and 11.4 each of terephthalic acid dichloride and isophthalic acid dichloride.
1 part by weight and 150 parts by weight of dichloromethane are charged and dissolved, 0.6 parts by weight of calcium hydroxide and 0.025 parts by weight of triethylamine are added as a catalyst, and the mixture is stirred for 1 hour to form an acid chloride at the end of the styrene resin. I went.

In another round-bottomed flask equipped with a stirrer, 800 parts by weight of a 1N sodium hydroxide aqueous solution was charged, and 25.5 parts by weight of bisphenol A was dissolved therein.
1.3 parts by weight of tri-n-butylbenzylammonium chloride was added as a catalyst. The acid chloride solution prepared above was added to the obtained solution, and after the addition was completed, 2
Interfacial polymerization was carried out by stirring for a period of time.

After completion of the polymerization, the two layers were separated and the organic layer was adjusted to 1N.
It was neutralized and washed with 800 parts by weight of an acetic acid aqueous solution, and only the organic layer was extracted and dissolved in 1,250 parts by weight of chloroform. This chloroform solution was filtered using a 1 μm filter and then added into 12,500 parts by weight of methanol to precipitate a polymer. The resulting polymer precipitate was filtered off, washed with methanol and dried in a vacuum dryer.

Further, Soxhlet extraction was carried out for 16 hours using 40 parts by weight of cyclohexane with respect to 2 parts by weight of the dried polymer, and then the cyclohexane extraction residue was in turn 1,1,1,3,3,3. Soxhlet extraction was carried out for 16 hours using 50 parts by weight of 3-hexafluoroisopropanol. The raffinate of Soxhlet extraction with these two solvents was dried in a vacuum dryer to obtain a copolymer.

Examples 5 to 8 In a three-necked flask equipped with a stirrer, 100 parts by weight of the styrene resin synthesized in Reference Examples 4 to 7 and bisphenol A64 were added.
Parts by weight, 2.5 parts by weight of triethylamine as a catalyst,
55 parts by weight of calcium hydroxide and 800 of dichloroethane
Part by weight was charged and dissolved. With the calcium hydroxide suspended, 29 parts by weight each of terephthalic acid dichloride and isophthalic acid dichloride were added to dichloroethane 20.
A solution dissolved in 0 part by weight was dropped, and after completion of dropping, the solution was stirred for 5 hours to carry out solution polymerization.

After completion of the polymerization, the solution was neutralized with 630 parts by weight of a 1N aqueous acetic acid solution and washed, and then a dichloroethane solution of the polymer was isolated. It was reprecipitated from methanol as in Examples 1-3, filtered and dried. Further, Soxhlet extraction was performed in the same manner as in Examples 1 to 3 to obtain a copolymer. Comparative Example 1 A copolymer was synthesized according to the example described in JP-A-1-129,011.

That is, the aromatic polyester [U polymer "U-10" manufactured by Unitika Ltd.] was used in a 500 ml beaker.
[0 ″] 20 g was dissolved in 300 ml of tetrahydrofuran, then 65 μl of allylamine was added and stirred, and then the mixture was charged into an autoclave having an internal volume of 500 ml and reacted at 90 ° C. for 2 hours. After the completion, after cooling to room temperature, the contents were put into a reactor equipped with a stirrer, 15 g of styrene was charged, and then the inside of the reactor was replaced with nitrogen gas, and then the polymerization reaction was carried out in a water bath at 90 ° C. for 7 hours. went.

After the reaction was completed, methanol was added to the reaction solution to precipitate an aromatic polyester-styrene resin copolymer, and the resulting precipitate was collected and dried overnight at 90 ° C. A polymer was obtained. Examples 1 to 1 thus obtained
8 and the polymer of Comparative Example 1 were measured for molecular weight by GPC, and the content ratio by weight of the styrene repeating structural unit (A) and the aromatic ester repeating structural unit (B) was determined by proton NMR analysis (using Varian VXR300). It was measured at. The results are shown in Table 3.

[0039]

[Table 3]

Test Example 1 [Evaluation of Moldability] For evaluating the moldability of the copolymers obtained in Examples 1 to 8 and Comparative Example 1, a flow tester C manufactured by Shimadzu Corporation.
Using FT-500, 290 ° C., shear rate 10 ³ se
The apparent melt viscosity η _a at c ⁻¹ was measured. The results are shown in Table 4.

[0041]

[Table 4]

Test Example 2 [Evaluation of Optical Properties] The copolymers obtained in Examples 1 to 8 and Comparative Example 1 were used for injection molding. Molding is Custom Scientific Instru
ments, Inc. injection molding machine (MODEL CS-183
MMX) was used at a molding temperature of 290 ° C. and 310 ° C. and a mold temperature of 80 ° C. 10 mm x 30 m as a molded body
A test piece having a size of m × thickness 1.2 mm was obtained.

The birefringence retardation of the obtained molded body was evaluated using a high-sensitivity birefringence measuring apparatus (ADR-60XY) manufactured by Oak Manufacturing Co., Ltd. Moreover, the light transmittances of 830 nm and 530 nm were measured with a spectrophotometer (U3120) manufactured by Hitachi, Ltd. Table 5 shows the molding temperature conditions and the evaluation results of the optical properties. Test Example 3 [Evaluation of Bending Strength] Bending strength was measured using the same molded body as in Test Example 2. The measurement was carried out using Shimadzu Autograph AGS-D, 25
The test was conducted at a test temperature of 1 mm / min at a temperature of ℃. The results are shown in Table 5.

[0044]

[Table 5]

From the results of the above Examples, Comparative Examples and Test Examples, the following matters were found. From the results of Test Example 1, the copolymer of the present invention has a lower melt viscosity than the copolymer of Comparative Example and is excellent in moldability. From the results of Test Example 2, the aromatic polyester-styrene resin copolymers (Examples 1 to 8) of the present invention have a lower birefringence than the copolymer of Comparative Example 1 and have a short wavelength range. It also has excellent transparency.

From the results of Test Example 3, the copolymer of the present invention has sufficient mechanical strength as compared with the copolymer of Comparative Example.

[0047]

EFFECT OF THE INVENTION The aromatic polyester-styrene copolymer of the present invention is superior in light transmittance to conventional ones, has low birefringence, and is excellent in fluidity and moldability. It is a polymer. Therefore, the aromatic polyester-styrene-based copolymer of the present invention can be used as a good optical device material, and is added to the blend of the aromatic polyester and the styrene-based copolymer to increase the compatibility. It is also possible to use it for the purpose of enhancing the tensile strength, flexural strength and flexural modulus of the blend and improving the fluidity, light transmittance and birefringence.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takamasa Owaki 23 Uji Kozakura, Uji City, Kyoto Prefecture, Unitika Stock Company Central Research Laboratory (72) Inventor Akio Motoyama 23 Uji Kozakura, Uji City, Kyoto Prefecture, Unitika Stock Company (72) Inventor Masao Kimura 1618 Ida, Nakahara-ku, Kawasaki-shi, Kanagawa, Advanced Technology Research Laboratories, Nippon Steel Corporation (72) Inventor Hiroshi Oishi 1618, Ida, Nakahara-ku, Kawasaki-shi, Kanagawa Advanced Technology Research Laboratories, Nippon Steel Co., Ltd. (72) Inventor Shinji Inaba 1618 Ida, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Advanced Technology Research Laboratories, Nippon Steel Corporation

Claims (1)

[Claims] 1. A polymer block (A) comprising a styrene-based repeating structural unit and a compound represented by the following general formula: (Wherein Z represents a single bond or a divalent bonding group), and an aromatic polyester-styrene resin copolymer containing a polymer block (B) composed of an aromatic ester repeating structural unit. And the weight ratio of the polymer blocks (A) and (B) in the copolymer is 5: 95-.
95: 5, and cyclohexane-soluble component and 1,
Aromatic polyester-styrene resin copolymer, wherein the total of 1,1,3,3,3-hexafluoroisopropanol-soluble component is 5% by weight or less.