LIQUID CRYSTAL POLYMER COMPOSITIONS AND CORRESPONDING ARTICLES
Described herein are polymer compositions including a liquid crystal polymer (“LCP”) and 1 weight percent (“wt. %”) to 25 wt. % of a semi-aromatic, semi-crystalline polyester, relative to the total weight of the LCP and semi-aromatic, semi-crystalline polyester. It was surprisingly discovered that polymer compositions including an LCP in conjunction with a semi-aromatic, semi-crystalline polymer could be melt-extruded into desirable films, as opposed to corresponding polymer compositions. It was further surprisingly discovered that the polymer compositions described herein had improved mechanical performance (tensile strength and tensile elongation), relative to corresponding polymer compositions. Still further, the polymer compositions also unexpectedly had reduced (Tm-Tc) relative to corresponding polymer compositions and, therefore, provided faster cycle times for molded articles formed from the polymer compositions.
1 . A polymer compositions comprising:
a liquid crystal polymer (“LCP”) formed from the polycondensation of the following monomers: terephthalic acid, an aromatic diol, a first aromatic dicarboxylic acid, an aromatic hydrocarboxylic acid; and
1 wt. % to 25 wt. %, of a semi-aromatic, semi-crystalline polyester (“PE”) formed from the polycondensation of an aliphatic diol and a second aromatic dicarboxylic acid, relative to the total weight of the LCP and PE,
wherein at least one of the first aromatic dicarboxylic acid and aromatic hydroxycarboxylic acid are free of a napthyl group.
2 . The polymer composition of claim 1 ,
wherein the aromatic diol is selected from the group consisting of 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, 2,5-biphenyldiol, 4,4′-biphenol, 4,4′-(propane-2,2-diyl)diphenol, 4,4′-(ethane-1,2-diyl)diphenol, 4,4′-methylenediphenol, bis(4-hydroxyphenyl)methanone, 4,4′-oxydiphenol, 4,4′-sulfonyldiphenol, 4,4′-thiodiphenol, naphthalene-2,6-diol, and naphthalene-1,5-diol;
wherein the first aromatic dicarboxylic acid is selected from the group consisting of isophthalic acid, 4,4′-biphenyldicarboxylic acid, 4,4′-oxydibenzoic acid, 4,4′-(ethylenedioxy)dibenzoic acid, 4,4′-sulfanediyldibenzoic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, and naphthalene-2,3-dicarboxylic acid; and
wherein the aromatic hydroxycarboxylic acid is selected from the group consisting of 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 6-hydroxy-1-naphthoic acid, 2-hydroxy-1-naphthoic acid, 3-hydroxy-2-naphthoic acid, 1-hydroxy-2-naphthoic acid, 5-hydroxy-1-naphthoic acid, and 4′-hydroxy-[1,1′-biphenyl]-4-carboxylic acid.
3 . The polymer composition of claim 1 , wherein the aromatic diol is 4,4′-biphenol, the aromatic hydrocarboxylic acid is 4-hydroxybenzoic acid, and the first aromatic dicarboxylic acid is isophthalic acid.
4 . The polymer composition of claim 1 , wherein the aliphatic diol is selected from the group consisting of 1,4-cyclohexanedimethanol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 2,2,4-trimethyl 1,3-pentanediol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and neopentyl glycol.
5 . The polymer composition of claim 1 , wherein the second aromatic dicarboxylic acid is selected from the group consisting of terephthalic acid, isophthalic acid, and 2,6-napthalene dicarboxylic acid.
6 . The polymer composition of claim 1 , wherein the PE is selected from the group consisting of poly(cyclohexanedimethylene terephthalate) (“PCT”), polyethylene terephthalate (“PET”), polybutylene terephthalate (“PBT”), polyethylene naphthalate (“PEN”) and polybutylene naphthalate (“PBN”).
7 . The polymer composition of claim 1 , wherein the PE is PCT.
8 . The polymer composition of claim 1 , wherein the polymer composition is free of a fibrous reinforcing agent.
9 . The polymer composition of claim 1 , wherein the polymer composition is free of a reinforcing agent.
10 . The polymer composition of claim 1 , wherein the polymer composition has a tensile elongation of at least 4% and a tensile strength of from 100 MPa to 150 M.
11 . The polymer composition of claim 1 , wherein the polymer composition has a Tm-Tc of no more than 50° C., wherein Tm is the melting temperature and Tc is the crystallization temperature.
12 . An article comprising the polymer composition of claim 1 .
13 . The article of claim 12 , wherein the article is a mobile electronic device component.
14 . The article of claim 12 , wherein the article is a printed circuit board.
15 . A film comprising the polymer composition of claim 1 , wherein the film has an average thickness of from 5 μm to 200 μm, as measured according to DIN 53370.