JPH02232256A - Preparation of polyester composition - Google Patents

Abstract

PURPOSE:To obtain in a short time the title compsn. with excellent transparency, heat resistance, mechanical strengths and melt-flow characteristics when molded by incorporating a specified metal compd. in a melt-kneaded substance of a polyalkylene terephthalate and a polycarbonate. CONSTITUTION:When a polyester compsn. comprising 20-80wt.% polyalkylene terephthalate (A) contg. ethylene terephthalate as a main constituting unit and having an intrinsic viscosity eta measured in o-chlorophenol at 25 deg.C of 0.5-1.2dl/g and 20-80wt.% polycarbonate (B) contg. bisphenol A as a diol component and having an intrinsic viscosity eta of 0.5-1.2dl/g, said compsn. having an intrinsic viscosity eta of 0.5-1.2dl/g, a glass transition temp. Tg of 80-130 deg.C and a single peak, is prepd. by melt-kneading both compd. A and B, 0.01-1,000ppm one or more compd. selected from a titanium compd. of formula I (wherein R1-R4 are each H, an alkyl, aryl, etc.), formula II (wherein w, x, y and z are 0+ or -4 and w+w+y+z=2-4; R5-R8 are each H, an alkyl, an aryl, etc.) and antimony oxide or germanium oxide are incorporated in a melt-kneaded substance of both compd. A and B.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for producing a polyester composition having excellent transparency and heat resistance. More specifically, the invention provides:
A high-molecular-weight polyester composition consisting of polyalkylene terephthalate and polycarbonate that exhibits a single peak in the glass transition temperature determined by differential scanning calorimetry (DSC) and has excellent transparency, heat resistance, and mechanical strength. The present invention relates to a method for producing polyester compositions that can be prepared in hours.

Technical Background of the Invention Conventionally, resin compositions comprising polyesters such as polyethylene terephthalate and polycarbonates have been described in many prior art documents (for example,
2-51445, JP 53-51248, JP 54-18375, JP 55-145
751, Japanese Patent Publication No. 58-500614, Japanese Patent Publication No. 36-14035, Japanese Patent Publication No. 16137-1982, Japanese Patent Publication No. 58-18391, JJ. Barl
ow at al. Author, Journal oi'
App item ad Polya+erSclence, v
ol, 23. 85-99 (I979) and tl
I If u fWang et al. Author, Mak
romolekulre Chemie RapidC
omnicatlons. Vol 7, 25
5-259 (I98B)).

These prior art documents also disclose attempts to prepare compositions with excellent transparency from polyester and polycarbonate, including JP-A-52-51445, JP-A-53-51248, and JP-A-53-51248. Kosho 58-18
No. 391 discloses that a composition with excellent transparency can only be achieved with a composition containing either polyester as a main component or polycarbonate as a main component. However, all of these prior art documents describe that when the blending ratios of polyester and polycarbonate are close to equal amounts, a resin composition with excellent transparency cannot be obtained. Furthermore, the compositions based on polyester proposed in these prior art documents have excellent transparency and chemical resistance stability, but are inferior in properties such as heat resistance and impact resistance. There is a problem in that the appearance of molded products is prone to sink marks and warpage.On the other hand, polycarbonate-based compositions have poor transparency,
Although it has excellent heat resistance, it is inferior in properties such as chemical resistance stability, stress crack resistance, and melt flowability.

Further, according to the results of additional tests conducted by the present inventors, the blending ratio (weight ratio) of polyester and polycarbonate is 80 to 20/
If a resin composition having a molecular weight of 20 to 80 is prepared, a composition having excellent melt flowability, transparency and heat resistance, and also excellent mechanical strength and chemical resistance stability cannot be obtained.

Furthermore, among the prior art documents, Ill Illul W
anget al, author, Makromol. Ch
effl. Rapid Communicat1on
, 7, 255-259 (I98B) shows that even if the resin composition contains polyester and polycarbonate in nearly equal proportions, the resin composition is transparent and has a single glass transition temperature. ing. However, all of the resin compositions obtained with this prior art have low molecular weights,
Therefore, mechanical strength such as impact resistance is poor, and it cannot be used as a molding material for food containers, medical equipment parts, etc.

Furthermore, in JP-A No. 63-142057, the blending ratio (weight ratio) of polyester and polycarbonate is 8.
It is taught that a resin composition having a molecular weight of 0/20 to 20/80 has excellent transparency and heat resistance, as well as excellent mechanical strength. However, this prior art document discloses that a long reaction time of 5 to 11 hours is required to produce a transparent resin composition, and the physical properties of the resin composition deteriorate due to thermal deterioration. There are concerns.

In view of the above-mentioned state of the art regarding molding resin compositions formed from polyester and polycarbonate, the present inventors have discovered that they have excellent transparency and heat resistance, as well as impact resistance and stress resistance. In producing a resin composition made of polyester and polycarbonate that has excellent mechanical properties such as stickiness and excellent melt flowability during molding, thermal deterioration is caused by melt-kneading polyester and polycarbonate at high temperatures for a long time. As a result of studies aimed at suppressing this, it was found that one or two selected from a specific titanium compound, a specific tin compound, antimony oxide, or germanium oxide was added to a polyester composition consisting of a specific polyalkylene terephthalate and a specific polycarbonate. The present invention was completed based on the discovery that by adding more than one type of compound, it is possible to shorten the melt-kneading time and produce a polyester composition with less thermal deterioration.

Purpose of the Invention The present invention aims to solve the problems in the prior art as described above, and has excellent transparency and heat resistance, as well as mechanical strength such as impact resistance and stress crack resistance. The object of the present invention is to provide a method for producing a polyester composition comprising polyester and polycarbonate 1, which has excellent melt flowability during molding.

Summary of the Invention The method for producing a polyester composition according to the present invention comprises (A)
Polyalkylene terephthalate whose main constituent unit is ethylene telophthalate and whose intrinsic viscosity [η] determined by M1 at 25°C in 0-chlorophenol is in the range of 0.5 to 1.2 dΩ/g: 20 to 80 ffiffi% (B) Bisphenol A is used as a diol component, and the intrinsic viscosity [η] measured at 25°C in 0-chlorophenol is 0.
．． 5 to 1.2 dJ)/g of polycarbonate = 20 to 80% by weight, and the intrinsic viscosity [η] of the composition measured in 0-chlorophenol at 25° C. is 0.5 to 80% by weight. A polyester composition having a glass transition temperature [Tg] of 1.2 dfl/g, a glass transition temperature [Tg] of 80 to 130°C, and a single peak was mixed with the polyalkylene terephthalate (A) and polycarbonate (B). In manufacturing by melt-kneading, a titanium compound represented by the following general formula (I), TI(O
R ) (OR2) (OR3) (OR4) ・
...(I) ■ (However, R , R , R3 and R4 are hydrogen l
2 atoms, an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkylaryl group, or a substituted derivative thereof, and R1 and R2 or R3 and R4 may form a ring. Also, R , R SR
and R4 may be the same or different. ) A tin compound represented by the following general formula (■), S n (
OOCR s ) v ( OOCR e ) x(
OOCR7)y(00CR8)2
・・・・・・(II) (However, “+ X +
V + Z is an integer from 0 to 4, and w + x +
y + z is 2 or 4. Also, R5, R6, R
7 and R8 are a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkylaryl group, or a substituted derivative thereof, and R and R6 or R7 and R8 may form a ring. . Also, R
, R, R7 and R8 may be the same or different. ) One or more compounds selected from antimony oxide or germanium oxide from 0.01 to 10
Polyalkylene terephthalate in an amount of 0 ppm 1.
and polycarbonate.

According to the method for producing a polyester composition according to the present invention as described above, a polyester composition can be produced from polyalkylene terephthalate and polycarbonate in a short time, and thermal deterioration of the composition can be suppressed. ,
Therefore, a polyester resin composition can be obtained that has excellent transparency and heat resistance, and also has excellent mechanical strength such as impact resistance and stress crack resistance, as well as excellent melt flowability during molding.

DETAILED DESCRIPTION OF THE INVENTION The polyester composition according to the present invention will be specifically described below.

The polyester composition of the present invention is formed from polyalkylene terephthalate (A) and polycarbonate 1.(B).

First, the polyalkylene terephthalate used in the present invention (
A) will be explained.

The polyalkylene terephthalate (A) used in the present invention is preferably a polyalkylene terephthalate whose main constitutional unit is an ethylene terephthalate component unit. Such component units are formed from ethylene glycol and terephthalic acid. In the present invention, the content of the ethylene terephthalate component units forming the polyalkylene terephthalate is usually 50 mol% or more, preferably 70 mol% or more.

The polyalkylene terephthalate used in the present invention may contain other component units than the ethylene terephthalate component units in an amount of less than 50 mol%, preferably less than 30 mol%.

Here, the aromatic dicarboxylic acid component units other than terephthalic acid that form other component units constituting the polyalkylene terephthalate include, for example, those derived from isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, etc. Component units can be mentioned. Examples of diol component units other than ethylene glycol include propylene glycol, 1,4-butylene glycol, neobentyl glycol, cyclohexanediol, cyclohexanedimethanol, 1.4-bis(β
-hydroxyethoxy)benzene, L,3-bis(β-
hydroxyethoxy)benzene, 2,2-bis(4-β
-hydroxyethoxyphenyl)broban and bis(
Mention may be made of component units derived from diols having 3 to 20 carbon atoms, such as 4-β-hydroxyethoxyphenyl) sulfone.

Furthermore, in addition to the preκ-aromatic dicarboxylic acid component units and the diol component units, the polyanolekylene terephthalate may contain component units derived from other polyfunctional compounds as necessary. .

Examples of polyfunctional compounds forming component units derived from such polyfunctional compounds include aromatic polyesters such as trimellitic acid, trimesic acid, and 3.35.5-tetracarboxydiphenyl. Basic acids; aliphatic polybasic acids such as butanetetracarboxylic acid; aromatic polyols such as phlorogrunne and 1,2,4.5-tetrahydroxybenzene; glycerin, 1-limethylolethane, trimethylolbroban and bentaerythritol Examples include aliphatic polyols such as 1 oxybocarboxylic acids such as tartaric acid and malic acid.

The content of each component in polyalkylene terephthalate is usually such that the content of terephthalic acid component units is 50
~100 mol%, preferably 70 to 100 mol%, and the content of aromatic dicarboxylic acid component units other than terephthalic acid component units is usually 0 to 50 mol%, preferably 0 to 30 mol%. The content of ethylene glycol component units is usually in the range of 50 to 100 mol%, preferably 70 to 100 mol%, and the content of diol component units other than ethylene glycol component units is
It is usually in the range of 0 to 50 mol%, preferably 0 to 30 mol%, and the content of polyfunctional compound component units is
It is usually in the range of 0 to 2 mol%, preferably 0 to 1 mol%.

Further, the intrinsic viscosity [η] (value measured in 0-chlorophenol solution at 25°C) of such polyalkylene terephthalate is usually 0.5 to 1.2 dfl/g, preferably 0.5 to 1.2 dfl/g. 15 dΩ/g1, more preferably in the range of 0.5 to 1.1 dll/sr. Also upper S
The melting point of polyanolekylene terephthalate like myself is
Usually 210-265°C, preferably 220-260°C
The glass transition temperature [Tg
] is usually 50 to 80°C, preferably 55 to 78°C
The temperature is more preferably in the range of 60 to 75°C.

The above polyalkylene terephthalate used in the present invention can be produced by a conventional method.

Next, polycarbonate used in the present invention will be explained.

The polycarbonate (B) used in the present invention is preferably a polycarbonate having bisphenol A [2,2-bis(4-hydroxyphenyl)broban] as a main constituent unit, and in this case, in the present invention, ,2,
A polycarbonate having a content of 2-bis(4-hydroxyphenyl)broban component units of 50 to 100 mol% is used, and polycarbonate having a content of 70 to 100 mol% is particularly preferably used.

In the present invention, the 2.2-
In addition to the bis(4-hydroxyphenyl)propane component unit, other aromatic diol component units include 2,2-bis(4-hydroxy-3.5-dimedylphenyl)broban, bis(4-hydroxyphenyl)propane, and bis(4-hydroxyphenyl)propane. -hydroxyphenyl)methane, 1.1-bis(4-hydroxyphenyl)ethane, 2.2-bis(4-hydroxyphenyl)butane, 2
．． 2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3,5
-diethyl phenyl) broban, 2,2-bis(4-hydroxy-3,5-dibrobylphenyl) broban, 1
3l-Bis(4-hydroxyphenyl)cyclohexane, bis(4-hydroxyphenyl)ketone, bis(4-
Examples include component units derived from diol components such as hydroxyphenyl)ether, bis(4-hydroxyphenyl)thioether, bis(4-hydroxyphenyl)sulfone, and 4,4°-dihydroxybiphenyl.

Moreover, the polycarbonate may contain a small amount of aliphatic diol component units in addition to the aromatic diol component units. Specifically, the aliphatic diol component includes ethylene glycol, 1,3-brobanediol, 1
．． 4-butanediol, neobentyl glycol, cyclohexanediol, cyclohexanedimethanol, 1
, 4-bis(β-hydroxyethoxy)benzene, 1.
3-bis(β-hydroxyethoxy)benzene, 2.2
Examples include component units derived from diol components having 3 to 20 carbon atoms, such as -bis(4-β-hydroxyethoxyphenyl)propane and bis(4-β-hydroxyethoxyphenyl)sulfone.

Further, in addition to the aromatic diol component units and aliphatic diol component units, the polycarbonate may contain a small amount of polyfunctional compound component units as required. Specifically, the polyfunctional compound component unit includes aromatic polyols such as phloroglucin and 1,2,4,5-tetrahydroxybenzene, aliphatic polyols such as glycerin, trimethylolethane, trimethylolbroban, and pentaerythritol. polyols, trimellitic acid,
Aromatic polybasic acids such as trimesic acid, 3,3″,5.5′-tetracarboxydiphenyl, aliphatic polybasic acids such as butanetetracarboxylic acid, oxybolycarboxylic acids such as tartaric acid, malic acid, etc. Examples include component units derived from.

The content ratio of the component units constituting the polycarbonate is, for example, when using 2,2-bis(4-hydroxyphenyl)broban. 2.2-bis(4-hydroxyphenyl)propane component units are usually in the range of 50 to 100 mol%, preferably 70 to 100 mol%,
．． Aromatic diol component units other than 2-bis(4-hydroxyphenyl)butroban component units are usually 0 to 5
0 mol%, preferably in the range of 0 to 30 mol%, and the aliphatic diol component units and polyfunctional compound component units are usually in the range of θ to 2 mol%, preferably << is in the range of 0 to 1 mol%. It is.

There are no particular restrictions on the method for producing the polycarbonate, but
A method for producing polycarbonate by interfacial polymerization of a diol component and phosgene, or a diol component and
A method of producing polycarbonate by transesterification with a carbonic acid diester can be used.

As the catalyst used when producing the above-mentioned polycarbonate by the transesterification method, catalysts commonly used in transesterification reactions, such as antimony compounds, titanium compounds, germanium compounds, and tin compounds, can be used.

Intrinsic viscosity [η] of polycarbonate used in the present invention
(value measured at 25°C in 0-chlorophenol) is usually 0.5 to 1.2 dfI/r, preferably 0.5
~1.15 dg/g, more preferably 0.5~1.
It is in the range of 1 dg/g. In addition, the glass transition temperature [Tg] determined by DSC of such polycarbonate
is usually 120 to 160°C, preferably 140 to 15
It is in the range of 0°C.

The polyester composition according to the invention contains the polyalkylene terephthalate (A) in an amount of 20 to 80% by weight, preferably 20 to 70% by weight, particularly preferably 20 to 60% by weight, and the polycarbonate (B) 20 to 80% by weight, preferably 30 to 80% by weight, particularly preferably 40 to 80% by weight [However, (A)
The total amount of component (B) is 100% by weight. When the blending ratio of the polyalkylene terephthalate (A) becomes more than 80% by weight and the blending ratio of the polycarbonate (B) becomes less than 20% by weight, the Tg of the polyester composition approaches the value of the polyalkylene terephthalate, and the heat resistance decreases. The mechanical strength such as impact resistance also decreases. Moreover, when the blending ratio of the polyalkylene terephthalate (A) is less than 20% by weight and the blending ratio of the polycarbonate (A) is higher than 80% by weight, the melt flowability of the polyester composition decreases, and the chemical resistance of the polyester composition decreases. Stability, stress crack resistance, etc. will decrease.

The intrinsic viscosity [η] of the polyester composition according to the present invention measured in 0-chlorophenol at 25°C is 0.5 to 1.
, 26N/g, preferably 0.5-i. 15dg/g,
More preferably 0.5 to i. It is in the range of 1 dg/g. When the intrinsic viscosity [η] of the polyester introduction product is less than 0.56 l)/g, the mechanical strength such as impact resistance of the polyester composition decreases, and stress cracking resistance etc. decrease. It became like this,
On the other hand, if it is larger than 1.2 dJ7/f, the melt fluidity of the polyester composition will decrease, and therefore the moldability will decrease.

Further, the glass transition temperature [Tg] determined by DSC of the polyester composition of the present invention is 80 to 130°C, preferably 80 to 125°C, more preferably 90 to 120°C.
℃ range and has a single peak. When the glass transition temperature [Tg] of the polyester composition is lower than 80°C, there is no significant difference from the Tg of polyalkylene terephthalate, and therefore the heat resistance of the polyester composition decreases, while when it is higher than 130°C, the glass transition temperature [Tg] is lower than 80°C. There is no significant difference from carbonate, and therefore the chemical stability, stress crack resistance, etc. of the polyester composition decrease.

Furthermore, even if the glass transition temperature [Tg] measured by DSC of the polyester composition is within the above range, if it has two or more peaks, the transparency of the polyester composition may be reduced. Become.

Furthermore, 2 formed from the polyester composition of the present invention
The haze (IIa.ze) of a thick molded plate is usually 25%.
or less, preferably 20% or less, particularly preferably 15%
It is in the following range.

Next, a method for manufacturing such a polyester composition will be explained.

It is preferable that the polyalkylene terephthalate (A) and the polycarbonate (B) be dried in an atmosphere such as dry air, dry nitrogen, or under reduced pressure before use. Such polyalkylene terephthalate (A) and polycarbonate (B) are mixed in the above-mentioned composition ratio 2, and first, for example, a single screw extruder, a two-screw extruder, a Brabender cross-linking machine, etc., or a cross-extruder equivalent to these are used. 240-320℃, preferably 25
The mixture is kneaded while melting in a temperature range of 0 to 310°C, more preferably 260-300°C.

Next, if the obtained molten mixture is in a state where it has absorbed moisture due to contact with water or being placed in the atmosphere, dry air,
After drying at 80 to 100°C for 15 hours or more in an atmosphere such as dry nitrogen or reduced pressure, the dried molten mixture is dried with a specific titanium compound or a specific titanium compound as described below. Together with at least one compound selected from a tin compound, antimony oxide, and germanium oxide, the mixture is charged into a stirring device preferably equipped with a pressure reduction device, heated and melted, and stirred and kneaded. At this time, it is preferable to carry out heating and melting and mixing under reduced pressure.

The titanium compound used in the present invention is a tetravalent titanium compound represented by the above formula (I).

In the above formula (I), R SR SR3 and R
4 is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkylaryl group, or a substituted derivative thereof, and R and R2 or R3 and R4 may form a ring, Also R , R SR3 and R4
may be the same or different. Therefore, examples of ligands that coordinate to titanium include hydroxy group, methoxy group, ethoxy group, n-broboxy group,
Iso-broboxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, propenyloxy group, butenyloxy group, cyclopentyloxy group, cyclohexyloxy group, phenoxy group, methylphenoxy group, Methoxyphenoxy group, 4-(4°-hydroxyphenyloxy) phenoxy group, 4°-hydroxybiphenyl-4-oxy group, penzyloxy group, 1,2-ethanedioxy group, 1
．． 3-brobanedioxy group, 1,2-brobanedioxy group, ■,4-butanedioxy group, 2,2"-dimethyl-
1.3-brobanedioxy group, ■,2-cyclohexanedioxy group, 1.2-cyclohexanedimethoxy group, m
-xylylenedioxy group etc. are exemplified.

The tin compound used in the present invention is a compound with a carboxylic acid represented by the above formula (II). The above formula (II)
In, the substituents R SR6, R-t and R8 are
Each is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkylaryl group, or a substituted derivative thereof, and R and R or R
7 and R8 may form a ring, R , 'R , R7 and R8
may be the same or different. Therefore, the above-mentioned ligands specifically include formic acid, acetic acid, propionic acid, n-monobutyric acid, Isomonocarboxylic acid, n-monovaleric acid, cyclohexanecarboxylic acid, 4-methyl-cyclohexanecarboxylic acid, Benzoic acid, 0-}ruic acid, ffl-toluic acid, p-toluic acid, anisic acid, I-naphthalenecarboxylic acid, 2-naphthalenecarboxylic acid, phenylacetic acid, oxalic acid, malonic acid, succinic acid, maleic acid, 1 .2-Cyclohexanedicarboxylic acid, phthalic acid, 2,8-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, etc.

Specific examples of antimony oxide used in the present invention include antimony trioxide and antimony tetroxide.

Further, specific examples of germanium oxide used in the present invention include germanium monoxide and germanium dioxide.

Among the above compounds, titanium tetraethoxide,
Titanium tetrabroboxide, titanium tetrabroboxide, titanium tetrabutoxide, tin formate, tin acetate,
Mention may be made of tin oxalate, tin malonate, tin succinate, tin maleate, antimony trioxide and germanium dioxide. More preferably, titanium tetraisobutoxide, titanium tetrabutoxide, tin acetate (H), tin oxalate (U), antimony trioxide, and germanium dioxide are preferably used.

The above compounds are contained in an amount of 0.01 to 1000 ppm, preferably 0.01 to 1000 ppm, preferably 0.
．． 05-500ppm, more preferably 0.1-2
It is added in an amount of 0 0 ppm. By heating and melting polyester compositions in the presence of compounds such as those described above, polyester compositions with improved molecular weight can be produced in shorter operating times than the prior art indicates. At this time, if the amount of the above compound added is less than 0.01 ppm, it will be difficult to prepare the polyester composition in a short time, and the polyester composition will undergo thermal deterioration. On the other hand, if the amount of the above compound added is 1
If it exceeds 0 0 0 ppm, the polyester composition will not become transparent and its molecular weight will rapidly increase, making it difficult to produce a polyester composition with excellent transparency and heat resistance.

The temperature at which the polyester composition is heated and melted and kneaded is in the range of 240 to 320°C, preferably 250 to 310°C, and more preferably 260 to 300°C.

In addition, although cross-talk at this time can be carried out under an inert gas atmosphere such as nitrogen, if it is carried out under reduced pressure, the molecular weight of the composition will increase due to the progress of the polycondensation reaction, resulting in poor impact resistance. This method is preferable because a polyester composition having excellent mechanical strength and stress crack resistance, etc., can be obtained, and a polyester composition having excellent transparency can also be obtained.

When melt-kneading under reduced pressure, the degree of reduced pressure is 0.1 to 300.
m+sHg, preferably in the range of 1 to 200 mIIHg, and the kneading time at this time is 0, 5 to 4 hours,
Preferably, the time is in the range of 1 to 3 hours, and if the degree of polymerization increases and the viscosity of the system increases with the passage of time, melt-kneading may be performed while gradually increasing the kneading temperature within the above-mentioned range. is the most appropriate.

The polyester composition thus obtained is extracted in the form of a strand from the reaction tank under pressure and recovered by a conventional method such as cutting.

In addition to the polyalkylene terephthalate (A.) and the bisphenol A polycarbonate (B), conventionally known nucleating agents, inorganic fillers, lubricants, slip agents, and anti-blocking agents may be added to the polyester composition according to the present invention. Appropriate amounts of various additives such as bulking agents, stabilizers, antistatic agents, antifogging agents, and pigments can also be blended.

EXAMPLES Hereinafter, the polyester composition according to the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Note that the intrinsic viscosity [η] of the polyester composition was determined at 25° C. in 0-chlorophenol. Further, the glass transition temperature of the polyester composition was determined by measuring the temperature increase rate and temperature decrease rate at 10° C./min using a differential scanning calorimeter.

In addition, the thermal properties and mechanical strength of the polyester composition are determined according to JIS K 8719 and JIS K 8911.
Measurements were made according to standard measurement methods.

Furthermore, the transparency of the polyester composition is determined by NDI! manufactured by Nippon Denshoku Industries ■. It was measured using a -200 type haze meter.

In addition, the contents of the compositions in the examples are expressed in parts by weight unless otherwise specified.

Example 1 Polyethylene terephthalate ([η] - 0.80 dN /
g) 50 parts of polycarbonate ([η] = 0.72 r
A pellet of the mixed composition was prepared by mixing 50 parts of Hl/g) in the form of a pellet, kneading at 250 to 270°C using a single screw extruder, and chipping. Next, the pellet of this mixed composition was filled into a reaction tank equipped with a stirring device and a vacuum device for condensing the fraction distilled off by operating under reduced pressure, and 0.6 ppm of titanium tetraisobutylene oxide was added. was added and heated to 290° C. under a nitrogen atmosphere to melt the mixed composition. After melting, the inside of the system is vacuumed from atmospheric pressure to full vacuum (I~2) while stirring the composition.
msHg), and stirring was performed for 95 minutes while maintaining a full vacuum state. As the stirring time progressed, the transparency of the contents improved, and the viscosity also gradually improved. After the heat treatment was completed, the system was returned to atmospheric pressure with nitrogen, and while pressurizing with nitrogen, the treated composition was extracted in the form of a strand, cut into particles with a cutter, and collected.

The obtained polyester composition is transparent, and its intrinsic viscosity [η] is 0. 64 dβ/g, and the glass transition temperature [Tg] was a single peak and was 109°C.

Further, this granular polyester composition was press-molded at about 270°C to prepare a test piece, and its physical properties were evaluated. The heat distortion temperature of the obtained test piece was 97°C, and the bending strength was 980°C.
kg/cd, and the bending modulus is 2 4 4 0 0
kg/cd, Izod impact strength (notched, 2
3℃) is 7. 1 kg-c+n/cm, and the haze (Ilaze) was 2.4%.

Comparative Example 1 The same procedure as in Example 1 was carried out except that the titanium compound was not added, and a polyester composition could be obtained by melting and stirring for 360 minutes under full vacuum.

The intrinsic viscosity [η] of the obtained polyester composition was 0.5
7 dN/g, and the glass transition temperature [Tg] was 106°C. That is, by not adding a titanium compound, long-time stirring was required.

Examples 2 to 5 In Example 1, the amounts of polyethylene terephthalate and polycarbonate used, the additives corresponding to titanium tetraisobutoxide, the amounts added, and the reaction times are shown in Table 1.
A transparent polyester composition was produced in the same manner as in Example 1 except as shown in Example 1. The intrinsic viscosity [η] and glass transition temperature [Tg] of the obtained polyester composition were as shown in Table 1, respectively.

Examples 6 to 10 Transparent polyester compositions were produced in the same manner as in Example 1, except that the amounts of polyethylene terephthalate and polycarbonate used were changed as shown in Table 2. Intrinsic viscosity [η] of the obtained polyester composition
The glass transition temperature [Tg], heat distortion temperature, mechanical strength, and haze measured using a press-molded test piece prepared in the same manner as in Example 1 were as shown in Table 2.

Claims (1)

[Claims] (A) ethylene terephthalate as the main constituent unit, o-
Intrinsic viscosity [η] measured in chlorophenol at 25°C
Intrinsic viscosity [η] measured at 25°C in o-chlorophenol with polyalkylene terephthalate in the range of 0.5 to 1.2 dl/g: 20 to 80% by weight and (B) bisphenol A as the diol component. is 0
．． 5 to 1.2 dfl/g of polycarbonate: 20 to 80% by weight, and the intrinsic viscosity [η] of the composition measured in o-chlorophenol at 25° C. is 0.5 to 1. A polyester composition having a glass transition temperature [Tg] of 2 dl/g, a glass transition temperature [Tg] of 80 to 130°C, and a single peak is melted by melting the polyalkylene terephthalate (A) and polycarbonate (B). When producing by kneading, a titanium compound Ti(O
R_1)(OR_2)(OR_3)(OR_4)……(
I) (However, R_1, R_2, R_3 and R_4
is a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkylaryl group, or a substituted derivative thereof, and R_1 and R_2 or R_
3 and R_4 may form a ring. Also, R_1
, R_2, R_3 and R_4 may be the same or different. ) A tin compound Sn(OOCR_5)_w(OOCR_6)_x(OO
CR_7)_y(OOCR_8)_z...(II) (However, w, x, y, z are integers from 0 to 4, and w+
x+y+z is 2 or 4. Also, R_5, R_6
, R_7 and R_8 are a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, an alkylaryl group, or a substituted derivative thereof, and R_
5 and R_6 or R_7 and R_8 may form a ring. Further, R_5, R_6, R_7 and R_8 may be the same or different. ), and one or more compounds selected from antimony oxide or germanium oxide in an amount of 0.01 to 1000 ppm to a melt-kneaded product of polyalkylene terephthalate and polycarbonate. Method.