Polysiloxane-polycarbonate copolymer with improved transparency and flame retardancy and method for producing same

Abstract

The present invention relates to a polysiloxane-polycarbonate copolymer having improved transparency and flame retardancy, and a method for producing the same. More specifically, the present invention relates to a polysiloxane having a specific structure having a side chain containing a randomly substituted hydroxyphenyl group, a polysiloxane-polycarbonate copolymer having the polysiloxane and a polycarbonate block as repeating units, exhibiting excellent flame retardancy and also excellent transparency, and a method for producing the same.

Claims

1. A polysiloxane of chemical formula 1: ##STR00011## wherein, R.sub.1 independently represents hydrogen atom, hydrocarbon group having 1 to 13 carbon atoms, or hydroxy group; R.sub.2 independently represents hydrocarbon group having 1 to 13 carbon atoms, or hydroxy group; R.sub.3 independently represents alkylene group having 2 to 8 carbon atoms; R.sub.4 independently represents hydrogen atom, halogen atom, hydroxy group, alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, or aryl group having 6 to 10 carbon atoms; k independently represents an integer of 1 to 4; each of l and m independently represents an integer of 0 to 4; n represents an integer of 1 to 4; and each of x and y independently represents an integer of 0 to 100.

2. The polysiloxane of claim 1, which is a reaction product of a polysiloxane of chemical formula 3 and a compound of chemical formula 4: ##STR00012## wherein R.sub.1, R.sub.2, l, m, n, x and y are the same as defined in chemical formula 1; ##STR00013## wherein R.sub.4 and k are the same as defined in chemical formula 1; and h represents an integer of 1 to 7.

3. A polysiloxane-polycarbonate copolymer comprising, as repeating units, a polysiloxane of chemical formula 1 and a polycarbonate block of chemical formula 2: ##STR00014## wherein, R.sub.1 independently represents hydrogen atom, hydrocarbon group having 1 to 13 carbon atoms, or hydroxy group; R.sub.2 independently represents hydrocarbon group having 1 to 13 carbon atoms, or hydroxy group; R.sub.3 independently represents alkylene group having 2 to 8 carbon atoms; R.sub.4 independently represents hydrogen atom, halogen atom, hydroxy group, alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, or aryl group having 6 to 10 carbon atoms; k independently represents an integer of 1 to 4; each of l and m independently represents an integer of 0 to 4; n represents an integer of 1 to 4; and each of x and y independently represents an integer of 0 to 100; ##STR00015## wherein R.sub.5 represents aromatic hydrocarbon group having 6 to 30 carbon atoms which is unsubstituted or substituted with alkyl group, cycloalkyl group, alkenyl group, alkoxy group, halogen atom, or nitro.

4. The polysiloxane-polycarbonate copolymer of claim 3, wherein the aromatic hydrocarbon group is derived from a compound of chemical formula 5: ##STR00016## wherein, X represents alkylene group; linear, branched or cyclic alkylene group having no functional group; or linear, branched or cyclic alkylene group comprising at least one functional group selected from the group consisting of sulfide, ether, sulfoxide, sulfone, ketone, naphthyl, or isobutylphenyl, each of R.sub.6 and R.sub.7 independently represents halogen atom, or linear, branched or cyclic alkyl group, and p and q independently represent an integer of 0 to 4.

5. The polysiloxane-polycarbonate copolymer of claim 3, wherein the amount of the polysiloxane of chemical formula 1 is 0.5 to 20% by weight, based on the total weight of the copolymer.

6. The polysiloxane-polycarbonate copolymer of claim 3, which has a viscosity average molecular weight of 15,000 to 200,000.

7. A method for preparing a polysiloxane-polycarbonate copolymer, comprising the steps of: reacting a polysiloxane of chemical formula 1 and an oligomeric polycarbonate under an interfacial reaction condition to form a polysiloxane-polycarbonate intermediate; and polymerizing the intermediate by using a first polymerization catalyst: ##STR00017## wherein, R.sub.1 independently represents hydrogen atom, hydrocarbon group having 1 to 13 carbon atoms, or hydroxy group; R.sub.2 independently represents hydrocarbon group having 1 to 13 carbon atoms, or hydroxy group; R.sub.3 independently represents alkylene group having 2 to 8 carbon atoms; R.sub.4 independently represents hydrogen atom, halogen atom, hydroxy group, alkyl group having 1 to 20 carbon atoms, alkoxy group having 1 to 20 carbon atoms, or aryl group having 6 to 10 carbon atoms; k independently represents an integer of 1 to 4; each of l and m independently represents an integer of 0 to 4; n represents an integer of 1 to 4; and each of x and y independently represents an integer of 0 to 100.

8. The method for preparing a polysiloxane-polycarbonate copolymer of claim 7, wherein the step of forming the polysiloxane-polycarbonate intermediate comprises a step of mixing a polysiloxane of chemical formula 1 and an oligomeric polycarbonate in a weight ratio of 0.5:99.5 to 20:80.

9. The method for preparing a polysiloxane-polycarbonate copolymer of claim 7, wherein the step of forming the polysiloxane-polycarbonate intermediate comprises a step of forming a mixture comprising a polysiloxane of chemical formula 1 and an oligomeric polycarbonate, wherein the mixture further comprises a phase transfer catalyst, a molecular weight-controlling agent and a second polymerization catalyst.

10. The method for preparing a polysiloxane-polycarbonate copolymer of claim 7, wherein the step of forming the polysiloxane-polycarbonate intermediate comprises a step of forming a mixture comprising a polysiloxane of chemical formula 1 and an oligomeric polycarbonate; and after completion of the reaction of the polysiloxane of chemical formula 1 and the oligomeric polycarbonate, a step of extracting an organic phase from the resulting mixture; and wherein the step of polymerizing the polysiloxane-polycarbonate intermediate comprises a step of providing the first polymerization catalyst to the extracted organic phase.

11. The method for preparing a polysiloxane-polycarbonate copolymer of claim 7, wherein the oligomeric polycarbonate has a viscosity average molecular weight of 800 to 20,000.

12. A molded article produced by using the polysiloxane-polycarbonate copolymer according to claim 3.

Description

EXAMPLES

Example 1

(1) <Preparation of Polysiloxane>

(2) In a 500 mL three-necked flask equipped with a condenser, under nitrogen atmosphere 50.44 g (0.1 mole) of a polysiloxane corresponding to the above chemical formula 3 (F5032, Dami Polychem, a colorless transparent liquid with a viscosity of 5 cP) was dissolved in 50 ml of toluene, and then 0.008 g (100 ppm) of platinum (Pt) catalyst (CP101, Dami Polychem) was added thereto. In a state of heating the resulting solution, 26.8 g (0.2 mole) of 2-allylphenol was slowly added thereto for 1 hour, and the resulting solution was refluxed for 5 hours. After the reaction was completed, the toluene solvent was removed from the solution, and the product was dried in a vacuum oven for 24 hours to prepare the polysiloxane of the following chemical formula 7:

(3) ##STR00008##

(4) <Preparation of Polysiloxane-Polycarbonate Copolymer>

(5) An interfacial reaction of bisphenol A in an aqueous solution and phosgene gas was conducted in the presence of methylene chloride to prepare an oligomeric polycarbonate mixture having a viscosity average molecular weight of about 1,000. An organic phase was extracted from the obtained oligomeric polycarbonate mixture, and thereto an aqueous solution of sodium hydroxide, the polysiloxane of the above chemical formula 7 (in amount of 2% by weight based on the total weight of the copolymer), tetrabutyl ammonium chloride (TBACl, in amount of 0.1% by weight based on the total weight of the copolymer), methylene chloride and p-tert-butylphenol (PTBP, in amount of 0.4% by weight based on the total weight of the copolymer) were admixed and reacted for 2 hours. After the phase separation, only the organic phase was collected, and thereto an aqueous solution of sodium hydroxide, methylene chloride and triethylamine (TEA, in amount of 0.015% by weight based on the total weight of the copolymer) were added and reacted for 3 hours. To the reacted organic phase, triethylamine (TEA, in amount of 0.02% by weight based on the total weight of the copolymer) was further added and reacted for additional 2 hours. After the phase separation, the organic phase with increased viscosity was collected, and thereto distilled water and methylene chloride were added, and the organic phase was washed with alkali and separated again. Next, the resulting organic phase was washed with 0.1N hydrochloric acid solution and then rinsed with distilled water 2 to 3 times. After the rinsing was completed, the organic phase was granulated by using a constant amount of pure water at 76 C. After the granulation was completed, the product was dried first at 110 C. for 8 hours and then at 120 C. for 10 hours. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

Example 2

(6) <Preparation of Polysiloxane>

(7) In a 500 mL three-necked flask equipped with a condenser, under nitrogen atmosphere 49.04 g (0.1 mole) of a polysiloxane corresponding to the above chemical formula 3 (F5032, Dami Polychem, a colorless transparent liquid with a viscosity of 5 cP) was dissolved in 50 ml of toluene, and then 0.008 g (100 ppm) of platinum (Pt) catalyst (CP101, Dami Polychem) was added thereto. In a state of heating the resulting solution, 40.2 g (0.3 mole) of 2-allylphenol was slowly added thereto for 1 hour, and the resulting solution was refluxed for 5 hours. After the reaction was completed, the toluene solvent was removed from the solution, and the product was dried in a vacuum oven for 24 hours to prepare the polysiloxane of the following chemical formula 8:

(8) ##STR00009##

(9) <Preparation of Polysiloxane-Polycarbonate Copolymer>

(10) A polysiloxane-polycarbonate copolymer was prepared by the same method as described in Example 1, except that the polysiloxane of the above chemical formula 8 (in amount of 2% by weight based on the total weight of the copolymer) was used instead of the polysiloxane of the above chemical formula 7. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

Example 3

(11) A polysiloxane-polycarbonate copolymer was prepared by the same method as described in Example 1, except that the polysiloxane of the above chemical formula 7 was used in amount of 5% by weight based on the total weight of the copolymer. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

Example 4

(12) A polysiloxane-polycarbonate copolymer was prepared by the same method as described in Example 1, except that the polysiloxane of the above chemical formula 7 was used in amount of 7% by weight based on the total weight of the copolymer. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

Example 5

(13) A polysiloxane-polycarbonate copolymer was prepared by the same method as described in Example 1, except that the polysiloxane of the above chemical formula 7 was used in amount of 10% by weight based on the total weight of the copolymer. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

Example 6

(14) A polysiloxane-polycarbonate copolymer was prepared by the same method as described in Example 2, except that the polysiloxane of the above chemical formula 8 was used in amount of 7% by weight based on the total weight of the copolymer. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

Example 7

(15) A polysiloxane-polycarbonate copolymer having a viscosity average molecular weight of 70,500 was prepared by the same method as described in Example 1, using the polysiloxane of the above chemical formula 7 in amount of 5% by weight based on the total weight of the copolymer. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

Comparative Example 1

(16) The properties of a linear polycarbonate having a viscosity average molecular weight of 21,200 (TRIREX 30221R, Samyang Corporation) were measured and are shown in the following Table 1.

Comparative Example 2

(17) A linear polycarbonate having a viscosity average molecular weight of 70,900 was prepared by the same method as described in Example 1, except that no polysiloxane was used. The properties of the prepared polycarbonate resin were measured and are shown in the following Table 1.

Comparative Example 3

(18) A polysiloxane-polycarbonate copolymer was prepared by the same method as described in Example 1, using a hydroxyl-terminated polysiloxane of the following chemical formula 9 in amount of 5% by weight based on the total weight of the copolymer. The properties of the prepared polysiloxane-polycarbonate copolymer were measured and are shown in the following Table 1.

(19) ##STR00010##

(20) TABLE-US-00001 TABLE 1 Examples Comparative Examples Properties 1 2 3 4 5 6 7 1 2 3 Siloxane content (wt %) 2 2 5 7 10 7 5 0 0 5 Viscosity average 21,800 27,100 22,200 21,500 22,100 27,800 70,500 21,200 70,900 21,100 molecular weight (Mv) Transmittance (%) 90 90 89 87 87 88 89 90 90 87 UL 94 flame 1.5 mm V1 V1 V1 V0 V0 V0 V0 V2 V2 V2 retardancy 2.0 mm V1 V0 V0 V0 V0 V0 V0 V2 V2 V1 Total flame 1.5 mm 97 88 67 45 38 35 33 250 250 124 time (sec) 2.0 mm 57 45 43 35 27 25 22 250 71 65

(21) As shown in the above Table 1, it can be known that the polysiloxane-polycarbonate copolymers prepared in Examples 1 to 7 showed remarkably superior flame retardancy, as compared with the linear polycarbonates of Comparative Examples 1 and 2 and the polysiloxane-polycarbonate copolymer prepared by using the hydroxyl-terminated polysiloxane of chemical formula 9 in Comparative Example 3.

(22) The methods of property measurement and evaluation used in the above Examples and Comparative Examples were as follows.

(23) (a) H-NMR (nuclear magnetic resonance spectroscopy): This analysis was conducted by using Avance DRX 300 (Bruker). The copolymer was confirmed by H-NMR analysis wherein the peak of methyl group of dimethylsiloxane was observed at 0.2 ppm, the peak of methylene group of the joint of polysiloxane-polycarbonate was observed at 2.6 ppm, and the peak of methoxy group of the joint of polysiloxane-polycarbonate was observed at 3.9 ppm.

(24) (b) Viscosity average molecular weight: The viscosity of methylene chloride solution was measured by using an Ubbelohde Viscometer at 20 C., and the limiting viscosity [] therefrom was calculated according to the following equation.
[]=1.2310.sup.5 Mv.sup.0.83

(25) (c) Transmittance: The transmittance was measured by using a haze meter (HAZE-GARD PLUS, BYK GARDNER).

(26) (d) Flame retardancy: Flame retardancy was measured according to UL-94 flame retardancy test method (UL: Underwriter's Laboratory Inc., US). The test evaluates flame retardancy from flame time or drips of flaming particles after burning on a vertically fixed specimen of a certain size for 10 seconds. Flame time is the time that the test specimen continued to flame after removal from the ignition source. Ignition of cotton layer was determined through the ignition of the cotton layer set about 300 mm under the specimen by any drips of flaming particles from the specimen. Flame retardancy ratings are shown in the the following table 2.

(27) TABLE-US-00002 TABLE 2 Rating V-2 V-1 V-0 1.sup.st/2.sup.nd flame time of 30 sec or less 30 sec or less 10 sec or less each specimen Total flame time of 250 sec or less 250 sec or less 50 sec or less 5 specimens Ignition of cotton Yes No No layer by drips