KR20070071592A - Copolyester/polycarbonate resin composition and articles thereof - Google Patents

Abstract

Provided are a transparent polyester/polycarbonate copolymer resin composition having improved thermal stability, chemical resistance and process stability and having excellent in transparency, and an extrusion blow molded product prepared from the composition. The polyester/polycarbonate copolymer resin composition comprises 100 parts by weight of a mixture resin which comprises 1-99 wt% of a polyester copolymer resin and 1-99 wt% of a polycarbonate resin; and 0.01-20 parts by weight of a stearic acid-based compound. Preferably the polycarbonate resin has a viscosity molecular weight of 20,000-30,000; and the stearic acid-based compound is stearic acid, zinc stearate, calcium stearate, magnesium stearate, sodium stearate, aluminum stearate, barium stearate, or their mixture.

Description

 Copolyester / polycarbonate resin composition and articles thereof

The present invention relates to a copolyester / polycarbonate resin composition and a product thereof, and more particularly, to a stearic acid-based compound upon melt mixing of a copolymerized polyester resin and a polycarbonate having strong rigidity and excellent high temperature heat resistance. The present invention relates to a copolymerized polyester resin / polycarbonate resin composition and a product thereof which improve process stability by improving rheological mismatch between two polymers, and improve physical properties and appearance such as strength, chemical resistance, and transparency.

In general, in the case of a sheet and an injection molded product made of a transparent copolyester resin (hereinafter, referred to as polyester) as a raw material, the transparent and chemical resistance is strong, but the strength is weaker than that of polycarbonate. On the other hand, polycarbonate resin has been used for optical, electrical, electronic parts, automotive parts, etc. because of its excellent impact resistance and heat resistance, but its use has been limited because of its poor processability and chemical resistance. In order to solve this problem, many literatures have been studied to use a mixture of polycarbonate with strong heat resistance and mechanical properties and polyester with high chemical resistance. However, in the case of simple melt-mixing of polycarbonate and polyester, the process conditions between the two resins are different and the rheological properties are different, so the appearance and physical properties of the final product are often not effectively implemented.

U.S. Patent No. 4,522,979 discloses a method of adding polycarbonate, ABS (acrylonitrile / butadiene / styrene) copolymer and polyisocyanate to polyethylene terephthalate, but the resin composition prepared by such a method is polyisocyanate. Due to the poor flowability, workability was not excellent and transparency was poor. In addition, U.S. Patent No. 4,629,760 suggests a method of adding polyethylene terephthalate and impact modifier to polycarbonate, but this also has poor transparency, and Japanese Patent Laid-Open No. 3-195761 is a mixture of polycarbonate and polyester with ABS or ASA. Although polymer blends have been described, they also have poor appearance or physical properties and poor workability.

In the present invention, as a result of research to solve the problems of the conventional method, when the stearic acid compound is added when mixing the polyester resin and polycarbonate resin, the compatibility between the two resins of polyester and polycarbonate is increased It has been found that the physical properties and appearance can be improved by removing the difference in the heterogeneity or the rheology of the internal polymer domain, and the present invention has been completed based on this.

Accordingly, an object of the present invention is to provide a copolymerized polyester / polycarbonate resin composition having excellent physical properties and appearance such as strength, chemical resistance, transparency, and molding processability.

Another object of the present invention is to provide a product having excellent physical properties and appearance such as strength, chemical resistance, transparency and molding processability.

Transparent copolymer polyester / polycarbonate resin composition excellent in physical properties and appearance for achieving the object of the present invention is a mixed resin comprising 1 to 99% by weight of the copolymerized polyester resin and 1 to 99% by weight of polycarbonate resin; And 0.01 to 20 parts by weight of a stearic acid compound based on 100 parts by weight of the mixed resin.

Another object of the present invention can be obtained by extrusion molding the composition or release extrusion molding.

Hereinafter, the present invention will be described in more detail.

As described above, the present invention comprises a transparent copolyester resin and a polycarbonate as a main component, and by adding a stearic acid-based compound to prevent decomposition of the two resins by compatibility and reaction conditions, the polyester resin and the polycarbonate resin Increasing compatibility between the two, the increased compatibility allows the two materials to behave like a single material, eliminating the inhomogeneity or rheological differences between the internal polymer domains, improving process stability, strength, processability, chemical resistance and transparency It is to provide a polyester / polycarbonate resin composition having excellent physical properties and appearance.

The copolymerized polyester resin is prepared by copolymerizing 1,4-cyclohexanedimethanol. Specifically, the total glycol components including ethylene glycol and 1,4-cyclohexanedimethanol are added in an molar ratio of 1 to 3: 1, preferably 1: 1, to the aromatic dicarboxylic acid containing terephthalic acid. The esterification reaction was carried out under the conditions of 230 to 260 ° C and 1.0 to 3.0 kg / cm 2, and a carboxy phosphonic acid compound represented by the following formula (1) was used as a stabilizer using a titanium compound as a polycondensation catalyst for the esterification reaction product. Polycondensation under reduced pressure of 260 to 290 DEG C and 400 to 0.1 mmHg.

More specifically, the diol component contains 30-60% 1.4-cyclohexanedimethanol and 40-70% ethylene glycol, and the aromatic dicarboxylic acid component contains 70-100% terephthalic acid and 0-30% Isophthalic acid, and if the diol component and the aromatic dicarboxylic acid component are out of the above range, the transparency becomes poor and there is a problem in workability during extrusion kneading.

In general, polycondensation catalysts have been appropriately selected from titanium, germanium, and antimony compounds. Among these, suitable catalysts which are generally used as polycondensation catalysts of polyester resins in which 1,4-cyclohexanedimethanol is copolymerized with 15% or more by weight of terephthalic acid are tripropyl titanate, tetrapropyl titanate, tetra Butyl titanate etc. are mentioned. In addition to the titanium-based polycondensation catalyst may be used titanium dioxide and silicon dioxide copolymer described in US Patent No. 5,684,116, 10 to 100ppm based on the amount of titanium element relative to the weight of the final polymer. The amount of catalyst added affects the color of the final polymer and can vary depending on the desired color and the stabilizer and colorant used.

In addition, stabilizers and colorants may be added as other additives. Common stabilizers include phosphoric acid, trimethyl phosphate, and triethyl phosphate. In the present invention, a compound represented by the following Chemical Formula 1 is used as a stabilizer, and as a compound thereof The triethyl phosphono acetate may be mentioned, and the addition amount thereof is 10 to 150 ppm, preferably 10 to 100 ppm, and more preferably 40 to 80 ppm, based on the amount of the personnel. The stabilizer of the present invention has the advantage that the stabilization performance and thermal stability for the catalyst than the conventional stabilizer is improved, the volatility, which is the biggest disadvantage of the conventional stabilizer is lower. In addition, improved effects can be obtained in corrosion and toxicity. If the amount of the stabilizer is less than 10ppm there is a problem that the color is turned yellow because the stabilization effect is insufficient, and if it exceeds 150ppm there is a problem that does not reach the desired high degree of polymerization.

Formula 1

Wherein two of R1, R2, and R3 are hydrogen, and the other is selected from the group consisting of hydrogen, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group, and an aryl group having 6 to 10 carbon atoms, and R is selected from the group consisting of 1 to 10 carbon atoms It is selected from the group consisting of an alkylene group, a cycloalkylene group, and an arylene group having 6 to 10 carbon atoms.

In addition, examples of the colorant added to improve color include conventional colorants such as cobalt acetate and cobalt propionate, and the addition amount thereof is suitably 20 to 100 ppm relative to the weight of the final polymer.

In the resin composition of the present invention, the polyester resin is used in an amount of 1 to 99% by weight, preferably 30 to 70% by weight. If the content is less than 1% by weight, the chemical resistance and workability are poor, and more than 99% by weight. The heat resistance becomes poor.

On the other hand, the polycarbonate of the present invention can be prepared through a polycondensation reaction in which bisphenol A (Bisphenol A) is reacted with dichloro ketone as shown in Scheme 1, the hydrochloric acid is released. The raw material system of the polycarbonate includes the phosgene method (or solvent method) and the transesterification method (or melting method).

The phosgene method is a method of reacting bisphenol A with phosgene. That is, methylene chloride is added to the aqueous solution or suspension of phenol A sodium salt as a solvent, and phosgene is blown with stirring. The polycarbonate produced by the interfacial polycondensation reaction is obtained in a state of being dissolved in a solvent. After neutralization and washing to remove by-product inorganic salts, the product is precipitated into flakes using a petroleum or alcoholic non-solvent. Compared with the transesterification method, this production method has advantages such as obtaining a polymer having an arbitrary molecular weight from a low amount to a high molecular weight, and requiring no special device because of smooth reaction conditions. On the other hand, it requires an expensive solvent, a solvent recovery process, and a washing process to completely remove the inorganic salts mixed in the resin, and since the product is obtained in powder or flake form, it is usually a defect that must be pelletized through a melting process. There is this.

The transesterification method used in the present invention is a method in which bisphenol A and diphenyl carbonate are mixed at a suitable blending ratio and no solvent is used at all, so that the product is melted by heating and subjected to polycondensation by ester reaction under high temperature and reduced pressure. At the beginning of the reaction, 200 to 230 ° C. is maintained at 20 to 30 mm Hg, and at the end of the reaction, the melt viscosity of the system is increased to 290 to 300 ° C. to 1 mm Hg, thereby obtaining a high molecular weight product. The transesterification method does not require a solvent compared to the phosgene method, and thus, a solvent recovery process is not required. In addition, the resultant resin is obtained as a molten phase and is extruded from a reaction vessel with an inert gas to be pelletized. Is simple. On the other hand, the high cost and high molecular weight of the airtight reactor, such as maintaining a high temperature, high vacuum may have a drawback that cannot be manufactured.

Preferably, the polycarbonate has a melt index (MI) of 5 to 40. If the MI is outside the above range, workability may be deteriorated. In addition, it is preferable that the polycarbonate resin has a viscosity molecular weight of 20,000 to 30,000, and when the viscosity molecular weight is less than 20,000, mechanical properties are extremely low, and when the polycarbonate resin exceeds 30,000, the melt viscosity of the resin is high, thereby causing problems in processability. There is.

In the present invention, the polycarbonate resin is used in the range of 1 to 99% by weight, preferably 30 to 70% by weight. If the content is less than 1% by weight, the heat resistance does not improve. do.

According to the present invention in order to solve the inconsistency of the rheological properties of the internal polymer when the process of having a compatibility and thermal stability and antioxidant properties between the two polymers in the preparation of the resin composition mainly composed of the polyester resin and polycarbonate resin And stearic acid compound are mixed in an amount of 0.01 to 20 parts by weight, preferably 0.01 to 2 parts by weight, based on 100 parts by weight of the mixed resin of the polyester and polycarbonate. If it is out of the content range, such an effect cannot be obtained.

The stearic acid compound is not limited thereto, but stearic acid, stearate, zinc stearate, calcium stearate, magnesium stearate, and sodium stearate One or more are selected from the group consisting of Na stearate, Al Stearate, and Barium stearate, while the stearic acid compound may be added in the form of a master batch. .

As described above, the resin composition prepared according to the present invention not only has improved processability and chemical resistance compared to the conventional resin composition, but also has a high processing temperature, which is about 30 ° C. lower than the general processing temperature of polycarbonate, and has excellent transparency. It is very useful for automotive and electrical and electronic products.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

Preparation Example 1

(Preparation of polyester copolymerized with 1,4-cyclohexanedimethanol):

In more detail, 996 parts of terephthalic acid, 294 parts of 1,4-cyclohexanedimethanol and 618 parts of ethylene glycol were added to a 3 liter reactor equipped with a stirrer and an outlet condenser, and the pressure of the reactor was raised to 2.0 kg / cm 2, and the temperature of the reactor was increased. The reaction is gradually raised to 255 ° C. At this time, the generated water is allowed to flow out of the system to react with the ester. When the generation and outflow of water is completed, the reactant is transferred to a polycondensation reactor equipped with a stirrer, a cooling condenser, and a vacuum system. The C-94 catalyst (Acordis, Germany) was added to the esterification reaction so that 40 ppm of the final polymer was added based on the amount of titanium, and triethylphosphonoacetate was added to 80 ppm of the final polymer based on the small amount of phosphorus. After raising the internal temperature from 240 ° C to 275 ° C, the low pressure reaction was first performed at atmospheric pressure at 50 mmHg for 40 minutes to remove ethylene glycol, and then slowly depressurized to 0.1mmHg until the desired intrinsic viscosity was reached under high vacuum.

Preparation Example 2

200 g of bisphenol A and 150 g of diphenyl carbonate were mixed and melted without using a solvent at all to prepare a polycondensation by ester reaction under high temperature and reduced pressure. At the beginning of the reaction, 200 to 230 ° C. was maintained at 20 to 30 mm Hg. At the end of the reaction, the melt viscosity of the system was increased to 290 to 300 ° C. at 1 mm Hg, thereby obtaining a high molecular weight product.

Example 1

70 wt% polyester of Preparation Example 1 and 30 wt% of polycarbonate having a viscosity molecular weight of 20,000 were mixed, and a heat stabilizer and an antioxidant were added so that 1 part by weight of stearic acid, which is a stearic acid compound, based on 100 parts by weight of the mixed resin. 5 parts by weight of the master batch mixed together was kneaded and extruded with a melt kneading extruder at a temperature of 250 ° C. to measure the physical properties of the prepared specimen.

Example 2

The same procedure as in Example 1 was repeated except that 55 wt% of the polyester of Preparation Example 1 and 45 wt% of the polycarbonate having a viscosity of 25,000 were used.

Comparative Example 1

70% by weight of polyester of Preparation Example 1 and 30% by weight of polycarbonate having a viscosity molecular weight of 25,000 were mixed and kneaded and extruded with a melt kneading extruder at a temperature of 250 ° C. to measure the physical properties of the prepared specimen.

Comparative Example 2

Prepared by mixing 25 parts by weight of stearic acid with respect to 100 parts by weight of a resin obtained by mixing 70% by weight of polyester of Preparation Example 1 and 30% by weight of polycarbonate having a molecular weight of 25,000 and kneading and extruding with a melt kneading extruder at a temperature of 250 ℃ The physical properties of the prepared specimens were measured.

Comparative Example 3

To 5 parts by weight of Montanic acid wax was mixed with 100 parts by weight of a resin obtained by mixing 70% by weight of polyester of Preparation Example 1 and 30% by weight of polycarbonate having a viscosity molecular weight of 25,000. The physical properties of the prepared specimens were measured.

Comparative Example 4

The same procedure as in Example 1 was carried out except that 70 wt% of Preparation Example 1 and 30 wt% of polycarbonate having a viscosity molecular weight of 15,000 were used.

Comparative Example 5

The same procedure as in Example 1 was carried out except that 70 wt% of Preparation Example 1 and 30 wt% of polycarbonate having a viscosity molecular weight of 40,000 were used.

In Table 1, the glass transition temperature (Tg) was measured using a differential scanning calorimetry (TA instrument), tensile strength was measured according to ASTM D 638. In the chemical resistance test, the tensile specimen was immersed in gasoline and brake oil for 2 weeks, and the tensile strength was measured in accordance with ASTM D638, and the change rate of strength was less than 10%. The grade was determined. On the other hand, thermal stability was shown by measuring the (Tg) glass transition temperature using a differential scanning calorimeter.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Tg (℃) 97 102 96 89 91 94 96 Tensile Strength (kgf / ㎠) 572 583 570 570 575 531 577 Thermal stability Prize Prize Ha medium Prize medium Prize Chemical resistance Prize Prize medium medium medium Prize Prize Process stability Prize Prize medium Ha Prize Prize Ha Appearance (TT) 90 90 87 87 90 89 87 Haze 0.5 0.5 2.0 1.5 1.5 1.0 1.5 Appearance (Surface) Prize Prize Ha Ha medium medium Ha

As shown in Table 1, the use of a stearic acid compound according to the present invention increases the compatibility of the polyester resin and the polycarbonate resin to provide a resin having excellent strength, chemical resistance, transparency and molding processability at the same time In addition, there is an advantage that can produce an extruded blow molding or release extruded products excellent in appearance and physical properties.

Claims (8)

Mixed resin comprising 1 to 99% by weight of copolymerized polyester resin and 1 to 99% by weight of polycarbonate resin; And A transparent copolyester / polycarbonate resin composition comprising a stearic acid compound in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the mixed resin. The transparent copolyester / polycarbonate resin composition according to claim 1, wherein the mixed resin comprises 30 to 70 wt% of a copolyester resin and 30 to 70 wt% of a polycarbonate resin. The transparent copolyester / polycarbonate resin composition according to claim 1 or 2, wherein the content of the stearic acid compound is 0.01 to 2 parts by weight based on 100 parts by weight of the mixed resin. The transparent copolyester / polycarbonate resin composition according to claim 1, wherein the polycarbonate resin has a viscosity molecular weight of 20,000 to 30,000. The method of claim 1, wherein the copolyester resin 1: 1 diol component consisting of 1,4-cyclohexanedimethanol and 20 to 70 mol% ethylene glycol, aromatic dicarboxylic acid consisting of 0 to 30 mol% isophthalic acid and 70 to 100 mol% terephthalic acid It is a molar ratio, The transparent co-polyester / polycarbonate resin composition characterized by the above-mentioned. The method of claim 1, wherein the stearic acid-based compound is stearic acid, stearate, zinc stearate, calcium stearate, magnesium stearate, sodium stearate aluminum stearate, barium stearate and a mixture thereof Copolyester / Polycarbonate Resin Composition. An extrusion blow molded product comprising the extrusion composition of the resin composition according to any one of claims 1 to 6. A mold release extrusion molded product characterized by mold release extrusion molding the resin composition according to any one of claims 1 to 6.