TWI522418B - Polyester compositions, they are obtained by the lens system and eyeglass - Google Patents

Description

Polyester composition, lens and glasses made therefrom

The present invention relates to a polyester composition and articles thereof, and more particularly to a polyester composition comprising polycarbonate (PC) and polybutylene terephthalate (PBT). And articles made therefrom.

In the existing plastic frame glasses market, cellulose acetate, which is light in weight, rich in gloss, easy to dye and environmentally friendly, is usually used as a frame material, and is matched with a lens made of polycarbonate or nylon.

Polycarbonate has high light transmission, low haze and other characteristics, in addition to being used as a lens material, it is also used in the fields of preparing touch films, advertising billboards or display windows. However, polycarbonate is a non-crystalline polymer with a tight molecular stack, which leads to defects in the subsequent preparation of the product, such as insufficient chemical resistance, that is, after contact with chemicals such as organic solvents or cellulose acetate. The occurrence of molecular break-offs becomes small molecules, and even deterioration phenomena such as swelling, cracking, or surface whitening occur.

Previous studies in other fields have pointed out that the addition of polybutylene terephthalate, which is a crystalline polymer, can improve the chemical resistance of polycarbonate, but due to the polycarbonate (non-crystalline polymer) and poly Butyric acid The lack of compatibility of the diol esters (crystalline polymers) leads to a decrease in the notched impact strength of the subsequently produced articles, and due to the transesterification between the polycarbonate and the polybutylene terephthalate during processing. The reaction is too intense and will cause the haze of the product to rise.

CN 1916076A, CN 101508834B, CN 101759985B and CN1789333A disclose the modification of polyester compositions comprising polycarbonate and polybutylene terephthalate by the addition of additives such as toughening agents, compatibilizers and the like. The above-mentioned improved polyester composition is mostly used for the production of automobile interior or exterior panels, household appliances and the like, and the main appeal of these products is high impact strength, high rigidity, high surface gloss and low temperature. Use and so on. However, based on the application of products such as lenses, the above products cannot simultaneously have a low melt flow index (MI), a high heat distortion temperature (HDT), a high notched impact strength, and a high light transmission. The characteristics of rate, low haze and high chemical resistance are not suitable for use in the preparation of lenses using cellulose acetate as a frame material or touch films, advertising panels, display windows, etc., which also require such characteristics.

Therefore, how to find a polyester composition, so that the subsequent products have the characteristics of low heat melt index, high heat distortion temperature, high notched impact strength, high light transmittance, low haze and high chemical resistance. Becoming the goal of current research.

Accordingly, a first object of the present invention is to provide a polyester composition which has a subsequent product having a low heat melt index, a high heat distortion temperature, a high notched impact strength, a high light transmittance, a low haze and high The characteristics of chemical resistance.

Thus, the polyester composition of the present invention comprises polycarbonate (PC), polybutylene terephthalate (PBT) and an antioxidant, wherein the polybutylene terephthalate has an intrinsic viscosity range of 0.9~ 1.25 dl/g, and the content of the polybutylene terephthalate is in the range of 1 to 3 parts by weight based on 100 parts by weight of the polycarbonate.

Furthermore, a second object of the present invention is to provide a lens having characteristics of low heat melt index, high heat distortion temperature, high notched impact strength, high light transmittance, low haze and high chemical resistance. It is made from the aforementioned polyester composition.

A third object of the present invention is to provide a spectacles comprising a frame and at least one lens made of cellulose acetate which is obtained from the aforementioned polyester composition.

The effect of the invention is to adjust the content of polybutylene terephthalate in the polyester composition comprising polycarbonate and polybutylene terephthalate to 1 to 3 parts by weight (by polycarbonate) 100 parts by weight) and defining the intrinsic viscosity of polybutylene terephthalate from 0.9 to 1.25 dl/g, and also adding an antioxidant, so that the polyester composition can be subsequently prepared. In addition to good chemical resistance, it can maintain low heat melt index, high heat distortion temperature and high notched impact strength, as well as prevent light transmittance and haze. Therefore, the article prepared by the polyester composition of the present invention can simultaneously have low heat melt index, high heat distortion temperature, high notched impact strength, high light transmittance, low haze and high chemical resistance, and is suitable for application. In the preparation of lenses using cellulose acetate as a frame material or a touch that also requires such characteristics Control film, advertising billboards, display windows and so on.

The contents of the present invention will be described in detail below:

[Polyester Composition]

The polyester composition of the present invention comprises polycarbonate (PC), polybutylene terephthalate (PBT), and an antioxidant. Preferably, the polyester composition of the present invention further comprises a release agent. More preferably, the polyester composition of the present invention further comprises an additive.

Preferably, the polyester composition is formed into a test piece having a thickness of 1/8 inch and tested according to ASTM D256, and the notched impact strength of the test piece is not less than 70 kg-cm/cm. More preferably, when the polyester composition is formed into a test piece having a thickness of 1/8 inch and tested in accordance with ASTM D256, the notched impact strength of the test piece ranges from 71 to 85 kg-cm/cm.

Preferably, the polyester composition is formed into a test piece having a thickness of 3.2 mm and tested according to ASTM D1003, and the test piece has a haze of not more than 1.3%. More preferably, when the polyester composition is formed into a test piece having a thickness of 3.2 mm and tested in accordance with ASTM D1003, the test piece has a haze ranging from 0.8 to 1.3%.

Preferably, when the polyester composition is formed into a test piece having a thickness of 0.8 mm and tested in accordance with ASTM D1003, the test piece has a haze of not more than 0.3%. More preferably, when the polyester composition is formed into a test piece having a thickness of 0.8 mm and tested in accordance with ASTM D1003, the test piece has a haze ranging from 0.2 to 0.3%.

Preferably, when the polyester composition is formed into a test piece having a thickness of 3.2 mm and tested according to ASTM D1003, the light transmittance of the test piece is not less than 80%. More preferably, when the polyester composition is formed into a test piece having a thickness of 3.2 mm and tested in accordance with ASTM D1003, the light transmittance of the test piece is not less than 88%.

Preferably, the polyester composition is made into a test piece and tested in accordance with ASTM D648, and the heat distortion temperature of the test piece is not lower than 125 ° C under a pressure of 1.82 MPa. More preferably, the polyester composition is made into a test piece and tested in accordance with ASTM D648, and the heat distortion temperature of the test piece ranges from 125 to 128 ° C under a pressure of 1.82 MPa.

Preferably, the polyester composition is made into a test piece and tested according to ASTM D1238, and the hot melt index of the test piece is not higher than the temperature of 300 ° C and the viscosity average molecular weight of the polycarbonate is 22,000. 14g/10 minutes.

Hereinafter, (a) polycarbonate, (b) polybutylene terephthalate, (c) antioxidant, (d) mold release agent, and (e) additive will be described.

(a) Polycarbonate:

Preferably, the polycarbonate is an aromatic polycarbonate, and particularly, the aromatic polycarbonate is, for example but not limited to, a phenol compound and a precursor such as phosgene (COCl ₂ ) or carbonate. Prepared by phosgene method (interfacial polymerization method) or melting method (transesterification method). Still more preferably, the polycarbonate is a bisphenol A type aromatic polycarbonate. In a specific embodiment of the present invention, the polycarbonate is an aromatic polycarbonate prepared by a phosgene method from a precursor of propylene glycol and phosgene (COCl ₂ ) or a carbonate (for example, by a tabular light) Manufactured by Petrochemical Co., Ltd., product name TARFLON FN-2200).

Preferably, the polycarbonate has a viscosity average molecular weight of from 15,000 to 40,000. The viscosity average molecular weight of the polycarbonate in the polyester composition When it is less than 15000, the physical strength (such as the notched impact strength) of the subsequently obtained product is low; when the viscosity average molecular weight is more than 40,000, the polycarbonate has poor fluidity and is difficult to be processed, and Heating to promote the flow of the polycarbonate also makes the hue of the subsequently produced product relatively yellowish. More preferably, the polycarbonate has a viscosity average molecular weight of 20,000 to 28,000.

It should be particularly noted that the viscosity average molecular weight (M) of the present invention is a solution of 0.5 g of polycarbonate dissolved in 100 mL of dichloromethane as a solvent, and the specific viscosity (η _sp ) of the solution is measured at 20 ° C. The obtained specific viscosity was obtained by converting <Form I> and <Formula II> (C is 0.5).

<Formula I>η _sp /C=[η]+0.45×[η] ² C

<Formula II>[η]=1.23×10 ^-4 M ^0.83

(b) Polybutylene terephthalate:

When the intrinsic viscosity of the polybutylene terephthalate in the polyester composition of the present invention is less than 0.9 dl/g, the physical strength (such as notched impact strength) and chemical resistance of the subsequently obtained products are significantly biased. low. Preferably, the polybutylene terephthalate has an intrinsic viscosity ranging from 1.15 to 1.2 dl/g.

It should be particularly noted that the intrinsic viscosity described in the present invention is determined in accordance with the ASTM D2857 standard test method.

The polyester composition of the present invention has a content of the polybutylene terephthalate in an amount of from 1 to 3 parts by weight based on 100 parts by weight of the polycarbonate. When the content of the polybutylene terephthalate is more than 3 parts by weight, subsequent The notched impact strength, chemical resistance and heat distortion temperature of the obtained product are both low and the haze is also high; when the content of the polybutylene terephthalate is less than 1 part by weight, the subsequent preparation The chemical resistance of the obtained product will be significantly reduced.

(c) Antioxidants:

Preferably, the antioxidant is a hindered phenol-based antioxidant, a phosphate-based antioxidant, a phosphite-based antioxidant, or a combination thereof. More preferably, the antioxidant is selected from a hindered phenol-based antioxidant containing a triethylene glycol structure, a hindered phenol-based antioxidant containing a neopentyl alcohol structure, and a hindered phenolic system having a 1,6-hexanediol structure. An antioxidant, a hindered phenol-based antioxidant containing an octadecyl structure, a phosphite-based antioxidant, a phosphate-based antioxidant, or a combination thereof. Still more preferably, the phosphate ester antioxidant is, for example but not limited to, dibutyl phosphate, diisopropyl phosphate, dioctyl phosphate, di(isopropylphenyl) phosphate, di(octylbenzene) Phosphate, bis(nonylphenyl)phosphate, trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tridecyl phosphate, triphenyl phosphate , tris(nonylphenyl)phosphate, butyl diphenyl phosphate, decyl diphenyl phosphate, octyl diphenyl phosphate or bis(2,6-di-t-butyl-4-methyl Pentaerythritol diphosphate; the phosphite antioxidant such as, but not limited to, tris(2,4-di-t-butylphenyl) phosphite; the hindered phenol-based antioxidant such as, but not limited to, triethyl Glycol-bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di Tributyl-4-hydroxyphenyl)propionate], pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] or octadecyl -3-(3,5-Di-t-butyl-4-hydroxyphenyl)propionate. Still more preferably, the antioxidant is selected from the group consisting of tris(2,4-di-t-butylphenyl)phosphite, octadecyl -3-(3,5-Di-t-butyl-4-hydroxyphenyl)propionate or a combination of the foregoing. Still more preferably, the antioxidant is tris(2,4-di-t-butylphenyl)phosphite and octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl) a combination of propionates.

Preferably, the polyester composition of the present invention has a content of the antioxidant in an amount of from 0.01 to 0.3 parts by weight based on 100 parts by weight of the polycarbonate. When the content of the antioxidant is less than 0.01 parts by weight, it is less likely to prevent cracking of the polycarbonate at a high temperature, resulting in a yellowish color of the subsequently produced product; when the content of the antioxidant is more than 0.3 parts by weight, subsequent Under the conditions of high temperature and high humidity, the physical strength (such as the notched impact strength) of the prepared product is relatively easy to decrease, so that the quality stability of the product after a long period of use is easily reduced.

(d) Release agent:

Preferably, the release agent is selected from the group consisting of glyceryl monostearate, pentaerythritol tetrastearate or a combination of the foregoing.

Preferably, when the polyester composition of the present invention further comprises a release agent, the release agent is contained in an amount ranging from 0.1 to 0.3 parts by weight based on 100 parts by weight of the polycarbonate.

(e) Additives:

The additive may be selected from any additive that does not affect the properties desired by the polyester composition (e.g., low heat melt index, high heat distortion temperature, high notched impact strength, high light transmittance, low haze, and high chemical resistance). Preferably, the additive is, for example but not limited to, an antibacterial agent, an ultraviolet light absorber (such as a UV 380 nm absorption type or a UV 400 nm absorption type), a dye, or a combination of the foregoing.

[Method for Preparing Polyester Composition]

The polyester composition of the present invention is obtained by mixing the components. Preferably, the polyester composition is prepared by mixing the ingredients at 250 to 280 °C.

[Application of polyester composition and preparation method thereof]

(i) Application of polyester composition:

The polyester compositions of the present invention are useful in the preparation of lenses.

The lens made from the polyester composition of the present invention can be combined with a frame made of cellulose acetate to form spectacles.

The polyester compositions of the present invention are also useful in the preparation of touch films, advertising panels or display windows.

(ii) Preparation method of the lens:

The aforementioned lenses can be prepared according to the following methods:

Step (1): the polyester composition of the present invention is granulated by a screw extruder to obtain a rubber granule; and the step (2): the rubber granules obtained in the step (1) are respectively formed by injection molding. It is made into a lens and can be surface-hardened as required.

Preferably, the screw extruder of the step (1) may be a single screw extruder or a twin screw extruder.

The invention will be further illustrated by the following examples, but it should be understood that this embodiment is for illustrative purposes only and should not be construed as Limitations of implementation of the invention.

<drug source>

<Examples 1 to 6>

Preparation of polyester composition

The polyester compositions of Examples 1 to 6 were prepared by first selecting the types and contents of the respective components according to the following Table 2, and then mixing the components at 250 to 280 °C.

<Comparative Examples 1 to 6>

Preparation of polyester composition

The polyester compositions of Comparative Examples 1 to 6 were obtained by first selecting the types and contents of the respective components according to the following Table 3, and then mixing the components at 250 to 280 ° C.

<Application Examples 1 to 6 and Comparative Application Examples 1 to 6>

Preparation of rubber particles and test pieces

The colloidal particles and the test pieces of Application Examples 1 to 6 and Comparative Application Examples 1 to 6 were sequentially prepared according to the following steps (1) and (2):

step 1):

Preparation of colloidal particles

The polyester compositions obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were each granulated by a twin-screw extruder, and then the rubber particles were obtained. In particular, this step can also be changed to a single screw extruder for granulation.

Step (2):

Preparation test piece

The rubber particles obtained in the above step (1) were respectively prepared into test pieces in accordance with the length, width and thickness required for each measurement method by a test piece injection machine.

<Hot Melt Index (MI) Analysis>

(a) Determination method:

10 g of the application examples 1 to 6 and the comparative application examples 1 to 6 were respectively taken, and then according to the ASTM D1238 standard test method, the hot melt index of the rubber particles was measured at 300 ° C by a hot melt index tester (DYNISCO D4003). The results obtained are shown in Table 4 below. The heat melt index is preferably not higher than 14 g/10 minutes as required for subsequent applications.

(b) Results and discussion:

As is apparent from Table 4, in Examples 1 to 6 obtained from the polyester compositions of Examples 1 to 6, the heat melt index (MI) at 300 ° C was not high and did not change much (11.6 to 13.3 g). /10 minutes), the article obtained by the polyester composition of the present invention is described, and its fluidity after melting is good to facilitate processing.

Further, Comparative Application Example 6, which was prepared from Comparative Example 6 having a PBT content of more than 3 parts by weight and containing a nucleating agent, had a heat melt index of 75 g/10 minutes, which was much higher than that of Examples 1 to 6. Application Examples 1 to 6 illustrate a system prepared by using a polyester composition containing a nucleating agent having a PBT content of more than 3 parts by weight. The product obtained by the polyester composition of the present invention has poor fluidity after melting and is not advantageous for processing.

<notched impact strength and heat distortion temperature (HDT) analysis>

(a) Determination method:

1. Notched impact strength:

Test pieces 1 to 6 and Comparative Application Examples 1 to 6 (length: 6.3 cm; width: 1.25 cm; thickness: 1/8 inch) were respectively used, and an impact resistance tester was used according to the ASTM D256 standard test method ( The notched impact resistance of the test piece was measured by CEAST Resil Junior 6963.000) and notched cutter (Notchvis 6950.000), and the results are shown in Table 5 below. The notched impact strength is preferably not less than 70 kg-cm/cm as required for subsequent applications.

2. Heat distortion temperature (HDT):

Test pieces 1 to 6 and Comparative Application Examples 1 to 6 (length: 12.7 cm; width: 1.25 cm; thickness: 1/8 inch) were respectively used, and the heat distortion temperature measuring machine was used according to the ASTM D648 standard test method. (TOYOSEIKI S6-MH) The heat distortion temperature of the test piece was measured under the conditions of a pressure of 1.82 PMa, and the results are shown in Table 5 below. The heat distortion temperature is preferably not lower than 125 ° C depending on the requirements of the subsequent application.

(b) Results and discussion:

1. Comparison and discussion of application example 2 and application examples 1 to 6:

As can be seen from Table 5, the application examples 1 to 6 obtained from Examples 1 to 6 in which the PBT has an intrinsic viscosity of 1.2 or 0.9 dl/g have a notched impact strength at a thickness of 1/8 inch of the test piece. 71~75kg-cm/cm, which is significantly higher than Comparative Application Example 2 prepared by Comparative Example 2 in which the inherent viscosity of PBT is 0.77 dl/g (less than 0.9 dl/g) (notch impact strength is 17 kg-cm/cm). ). Based on the above results, the polyester composition of the present invention (PBT inherent viscosity of 0.9 to 1.25 dl/g) is compared with the polyester composition of PBT having an inherent viscosity of less than 0.9 dl/g, and the polyester composition of the present invention is followed. The resulting article will have a higher notched impact strength.

2. Comparison and discussion of application examples 3~4 and application examples 1~6:

As can be seen from Table 5, the application examples 1 to 6 obtained in Examples 1 to 6 in which the PBT content was 1 to 3 parts by weight, the notched impact strength of the test piece when the thickness of the test piece was 1/8 inch was 71~. 75kg-cm/cm, both significantly higher than those by PBT Comparative Application Examples 3 to 4 (notched impact strengths of 14 and 6 kg-cm/cm, respectively) prepared in Comparative Examples 3 to 4 in a content of 5 and 11.11 parts by weight (more than 3 parts by weight). Further, in Application Examples 1 to 6, the HDT at a pressure of 1.82 MPa was 125 to 128 ° C, which was higher than Comparative Application Examples 3 to 4 (HDT was 121 ° C and 110 ° C, respectively), indicating the polyester composition of the present invention ( The PBT content is 1 to 3 parts by weight. Compared with the polyester composition having a PBT content of more than 3 parts by weight, the polyester composition of the present invention has a higher notched impact strength and heat distortion temperature. .

3. Compare and discuss application examples 5~6 with application examples 1~6:

Referring to Table 5, Comparative Application Example 5 prepared by Comparative Example 5 in which PBT has an intrinsic viscosity of less than 0.9 dl/g and a PBT content of more than 3 parts by weight and further contains a toughening agent, although the notched impact strength and application example 1~ 6 is not much different, but the HDT is lower than the application examples 1 to 6; in addition, the comparative application example 6 obtained by the comparative example 6 having a PBT content of more than 3 parts by weight and containing a nucleating agent, the notched impact strength and the HDT It is lower than the application examples 1 to 6, indicating that the PBT has an intrinsic viscosity of less than 0.9 dl/g or a PBT content of more than 3 parts by weight and the polyester composition containing the toughening agent or the nucleating agent is not produced by the present invention. The product obtained from the polyester composition has both high notched impact strength and high heat distortion temperature characteristics.

<Light transmittance and haze analysis>

(a) Determination method:

Test pieces 1 to 6 and Comparative Application Examples 1 to 6 (length: 6 cm; width: 6 cm; thickness: 3.2 mm or 0.8 mm) were respectively used, and a haze meter (TOKYO DENSHOKU) was used according to the ASTM D1003 standard test method. Haze Meter Mode TC-H3DPK) The light transmittance (test piece thickness: 3.2 mm) and haze (test piece thickness: 3.2 mm or 0.8 mm) of the test piece were measured, and the results are shown in Table 6 below. According to the subsequent application, the light transmittance of 3.2 mm in thickness is preferably not less than 80%, the haze of 3.2 mm in thickness is preferably not more than 1.3%, and the haze of 0.8 mm in thickness is preferably not more than 0.3%.

(b) Results and discussion:

1. Comparison and discussion of application examples 3~4 and application examples 1~6:

As can be seen from Table 6, the application examples 1 to 6 obtained in Examples 1 to 6 having a PBT content of 1 to 3 parts by weight all have high light transmittance (thickness 3.2 mm, 89.4 to 90.0%), and The haze at thickness of 3.2 mm and 0.8 mm is 1 to 1.3% and 0.2 to 0.3%, respectively. Comparative Application Examples 3 to 4 prepared by Comparative Examples 3 to 4 having a PBT content of 5 and 11.11 parts by weight (greater than 3 parts by weight) had a light transmittance of 86.1 to 88.9% and a thickness of 3.2 mm and 0.8. The haze at mm was higher than that of the application examples 1 to 6, which were 1.5% and 1.8% (3.2 mm) and 0.4% (0.8 mm), respectively. According to the foregoing results, the polyester composition of the present invention (PBT content of 1 to 3 parts by weight) is compared with the polyester composition having a PBT content of more than 3 parts by weight, and the polyester composition of the present invention is subsequently produced. Will have high light transmittance and low haze characteristics.

2. Comparison and discussion of application examples 5~6 and application examples 1~6:

Referring to Table 6, Comparative Application Example 5, which was prepared from Comparative Example 5 in which PBT has an intrinsic viscosity of less than 0.9 dl/g and a PBT content of more than 3 parts by weight and further contains a toughening agent, was in an opaque state, and thus the transmittance could not be measured. And haze; and Comparative Application Example 6 prepared by Comparative Example 6 having a PBT content of more than 3 parts by weight and containing a nucleating agent, the haze was significantly higher than that of the application examples 1 to 6, indicating that the inherent viscosity of the PBT was less than 0.9 dl/ An article made of a polyester composition containing g or a PBT content of more than 3 parts by weight and containing a toughening agent or a nucleating agent, unlike the polyester of the present invention The product obtained by the composition has high light transmittance and low haze characteristics at the same time.

<Method for measuring chemical resistance>

(a) Determination method:

1. Resistance to 99~100wt% glacial acetic acid determination:

The test pieces of Application Examples 1 to 6 and Comparative Application Examples 1 to 4 (dumbbell shape, length: 16.5 cm; width: 2 cm; thickness: 3.2 mm) were respectively subjected to stress, and were first bent to have a bending angle of 5 degrees (in terms of After the test piece of the length calculation, it was immersed in glacial acetic acid (concentration: 99 to 100% by weight), and the number of cracks on the test piece was observed. The results obtained are shown in Table 7 below.

2. Determination of sunscreen resistance:

The test pieces 1 to 6 and Comparative Application Examples 1 to 4 (dumbbell shape, length: 16.5 cm; width: 2 cm; thickness: 3.2 mm) were respectively subjected to stress to be bent to have a bending angle of 10 degrees (in terms of length). After calculating the test piece, apply a thin layer of sunscreen lotion (NIVEA SPF30+) on the surface, then re-coat a thin layer of sunscreen every 12 hours to observe the number of cracks on the test piece. The results are shown in Table 7 below. .

(b) Results and discussion:

1. Comparison and discussion of application example 1 and application examples 1 to 6:

As can be seen from Table 7, Comparative Application Example 1 obtained from Comparative Example 1 in which no PBT was added at all had good physical properties and high light transmittance, Low haze characteristics, but insufficient chemical resistance, whether it is after 10 minutes of glacial acetic acid infiltration or 72 hours after sunscreen cleaning, there will be cracks, and the present invention contains 1 to 3 parts by weight and has an inherent viscosity of The polyester composition of PBT of 0.9 to 1.25 dl/g will have good chemical resistance (no cleavage by glacial acetic acid infiltration or sunscreen cleaning).

2. Comparison and discussion of application examples 2 to 4 and application examples 1 to 6:

From Table 7, it can be found that the application examples 1 to 6 obtained by the examples 1 to 6 in which the PBT content is 1 to 3 parts by weight and the PBT inherent viscosity is 1.2 or 0.9 dl/g are infiltrated with glacial acetic acid or sunscreened. After the wiping, no cracks were generated, indicating that the chemical resistance of Application Examples 1 to 6 was good; however, Comparative Example 2 in which the inherent viscosity of PBT was 0.77 dl/g (less than 0.9 dl/g) or the PBT content was 5, respectively. And 11.1 parts by weight (greater than 3 parts by weight) of Comparative Application Examples 3 to 4 obtained by Comparative Examples 3 to 4, which were observed to be cracked after being immersed in glacial acetic acid for 60 minutes or after sunscreening for 72 hours. The results showed that the chemical resistance of Comparative Application Examples 2 to 4 was insufficient. Therefore, according to the foregoing results, the polyester composition of the present invention (PBT content of 1 to 3 parts by weight and PBT inherent viscosity of 0.9 to 1.25 dl/g) and PBT content of more than 3 parts by weight or PBT inherent viscosity of less than 0.9, respectively. Compared to the polyester composition of dl/g, the article obtained by the polyester composition of the present invention has better chemical resistance.

In summary, the polybutylene terephthalate of the polyester composition has an intrinsic viscosity of 0.9 to 1.25 dl/g and a content ranging from 1 to 3 parts by weight (100 parts by weight of polycarbonate). And also containing an antioxidant, so that the subsequent preparation of the polyester composition will have both a low heat melt index, a high heat distortion temperature, a high notched impact strength, a high light transmittance, The characteristics of low haze and high chemical resistance are indeed achieved by the object of the present invention.

However, the above is only the embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and the patent specification of the present invention are still It is within the scope of the patent of the present invention.

Claims (8)

A polyester composition comprising polycarbonate, polybutylene terephthalate and an antioxidant, wherein the polybutylene terephthalate has an intrinsic viscosity ranging from 0.9 to 1.25 dl/g, the poly The viscosity average molecular weight of the carbonate is 15,000 to 40,000, and the content of the polybutylene terephthalate is 1 to 3 parts by weight based on 100 parts by weight of the polycarbonate, and the content of the antioxidant is in the range of 1 to 3 parts by weight. 0.01 to 0.3 parts by weight. The polyester composition of claim 1, wherein the polycarbonate is an aromatic polycarbonate. The polyester composition according to claim 1, wherein the antioxidant is a hindered phenol-based antioxidant, a phosphate-based antioxidant, a phosphite-based antioxidant, or a combination thereof. The polyester composition according to claim 1, wherein the polyester composition is formed into a test piece having a thickness of 1/8 inch and tested according to ASTM D256, and the notched impact strength of the test piece is not less than 70 kg. -cm/cm. The polyester composition according to claim 1, wherein the polyester composition is formed into a test piece having a thickness of 3.2 mm and tested according to ASTM D1003, and the test piece has a haze of not more than 1.3%. The polyester composition of claim 1 further comprising a release agent. A lens produced by the polyester composition of any one of claims 1 to 6. A spectacles comprising a frame and at least one lens made of cellulose acetate, the lens being produced from the polyester composition of any one of claims 1 to 6.