Polycarbonate compositions and articles formed therefrom, with matte surfaces and high light transmissions
View Patent ↗A composition is disclosed having a matte surface and high optical transmission characteristics. The composition comprises a polycarbonate and refractive index compatible polymer particles such as crosslinked polystyrene. The polycarbonate composition is useful for manufacture of anti-glare lenses, ATM screens, decorative articles, and housings for electronic appliances such as a computer.
1. A composition comprising:
(i) a polycarbonate with a refractive index α; and,
(ii) crosslinked polymer particles with a refractive index β;
wherein β is within the range of about 0.98α to about 1.02α;
wherein the polymer particles with a refractive index β consist of a copolymer of at least one mono-vinyl aromatic monomer and at least one multiple-vinyl aromatic monomer,
wherein the mono-vinyl aromatic monomer is selected from the group consisting of (i) styrene, (ii) ethylvinylbenzene, (iii) α-methyl-styrene, (iv) 1-vinyl naphthalene, (v) 2-vinyl naphthalene, (vi) vinyl toluene, (vii) methoxystyrene, (viii) t-butoxystyrene; (ix) alkyl, cycloalkyl, aryl, alkaryl, and aralkyl derivatives of (i)-(viii), in which the total number of carbon atoms in the monomer is not greater than 18; and (x) mixtures of two or more of (i)-(x); and
wherein the multiple-vinyl aromatic monomer comprises a compound having a general formula as shown below:
in which p is an integer from 2 to 6.
2. The composition of claim 1 , in which β is within the range of from about 0.99α to about 1.01α.
3. The composition of claim 1 , in which β is within the range of from about 0.995α to about 1.005α.
4. The composition of claim 1 , in which the mono-vinyl aromatic monomer comprises styrene.
5. The composition of claim 1 , in which the multiple-vinyl aromatic monomer comprises one or more of the following DVB isomers:
6. The composition of claim 1 , in which the loading ratio of multiple-vinyl aromatic monomer ranges from about 1% to about 50%.
7. The composition of claim 1 , in which the polymer particles consist of DVB crosslinked polystyrene.
8. The composition of claim 7 , in which the average mean diameter of the DVB crosslinked polystyrene is within a range of from about 2 microns to about 1000 microns.
9. The composition of claim 1 , in which the amount of the polymer particles is about 0.5% to about 50% by weight, based on the weight of the polycarbonate.
10. The composition of claim 1 , in which the amount of the polymer particles is about 1.5% to about 40% by weight based on the weight of the polycarbonate.
11. The composition of claim 1 , in which the polycarbonate comprises repeating structural carbonate units of the formula (A-1):
wherein each of A 1 and A 2 is a monocyclic divalent aryl radical and Y 1 is a bridging radical having one or two atoms that separate A 1 from A 2 .
12. The composition of claim 1 , in which the polycarbonate comprises repeating structural carbonate units of the formula (A-2):
wherein R a and R b each represent a halogen atom or a monovalent hydrocarbon group and may be the same or different; p and q are each independently integers of 0 to 4; and X a represents one of the groups of formula (5):
wherein R c and R d each independently represent a hydrogen atom or a monovalent linear or cyclic hydrocarbon group and R e is a divalent hydrocarbon group.
13. The composition of claim 1 , in which the polycarbonate comprises repeating structural carbonate units of the formula (A-3):
14. The composition of claim 1 , in which the polycarbonate comprises repealing structural carbonate units of the formula (A-3) and (E-1):
15. The composition of claim 1 , in which the polycarbonate has a weight average molecular night (Mw) of from about 1500 to about 100,000.
16. The composition of claim 1 , further comprising one or more optional additives selected from the group consisting of hydrolysis stabilizer, impact modifier, filler/reinforcing agent, visual effect enhancer, antioxidant heat stabilizer, light stabilizer, ultraviolet light absorber, plasticizer, mold release agent, lubricant, antistatic agent, pigment dye, flame retardant processing aid, radiation stabilizer, anti-drip agent and combinations thereof.
17. An article exhibiting a matte surface and high light transmission, which is made from the composition of claim 1 .
18. The article of claim 17 , which is selected from the group consisting of an anti-glare lens, an ATM screen, a decorative article, and a housing for electronic appliances.
19. The composition of claim 1 , wherein the composition has a gloss of from 42 to 114, according to ASTM D2457.
20. The composition of claim 1 , wherein the composition has a light transmission of from 80 to 90 percent, according to ASTM D1003, and a gloss of from 42 to 114, according to ASTM D2457.
21. A composition comprising:
(i) a polycarbonate with a refractive index α; and,
(ii) crosslinked polymer particles with a refractive index β;
wherein β is within the range of about 0.98α to about 1.02α;
wherein the polymer particles with a refractive index β consist of a copolymer of at least one mono-vinyl aromatic monomer and at least one multiple-vinyl aromatic monomer; and
wherein the composition has a light transmission of from 80 to 90 percent, according to ASTM D1003, and a gloss of from 42 to 114, according to ASTM D2457.