Flame-retardant liquid crystal polyester composition, process for preparation thereof and injection-molded article composed thereof

Claim 2

A flame-retardant liquid crystal polyester composition which comprises (A) 100 parts by weight of a liquid crystal polyester comprising structural units represented by the following formulae (I), (II), (III) and (IV), in which the amount of structural units (I) and (II) is 77 to 95% by mole based on structural units (I), (II) and (III), the amount of structural units (III) is 23 to 5% by mole based on structural units (I), (II) and (III), and the structural units (I)/structural units (II) molar ratio is from 75/25 to 95/5, and (B) 0.5 to 30 parts by weight of a polymeric flame retardant having an average dispersed particle diameter not larger than 2.5 μm, wherein the aforementioned formulae are: ##STR22## wherein R 1 represents at least one group selected from the group consisting of ##STR23## and R 3 represents at least one group selected from the group consisting of ##STR24## in which X represents a hydrogen atom or a chlorine atom, and the amount of structural units (IV) is substantially equimolar to the sum of the amounts of structural units (II) and (III); and said polymeric flame retardant (B) being at least one compound selected from the group consisting of (a) polymeric organic bromine compounds containing at least 20% by weight of bromine and (b) polymeric organic phosphorous compounds comprised of structural units represented by at least one of the following formula (i) through (iv): ##STR25## wherein R 1 represents an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms and R 4 represents an alkylene group having 1 to 15 carbon atoms, a cycloalkylene group having 3 to 15 carbon atoms or an arylene group having 6 to 15 carbon atoms.

Claim 3

A flame-retardant liquid crystal polyester composition according to claim 1, which further comprises (C) 1 to 200 parts by weight of a filler per 100 parts by weight of the sum of the liquid crystal polyester (A) and the polymeric flame retardant (B).

Claim 4

A flame-retardant liquid crystal polyester composition according to claim 1, wherein the average dispersed particle diameter of the polymeric flame retardant is not larger than 2.0 μm.

Claim 5

A flame-retardant liquid crystal polyester composition according to claim 1, wherein the average dispersed particle diameter is not larger than 1.5 μm.

Claim 6

A flame-retardant liquid crystal polyester composition according to claim 1, wherein the amount of structural units (I) and (II) is 80 to 93% by mole based on the sum of structural units (I), (II) and (III), the amount of structural units (III) is 20 to 7% by mole based on the sum of structural units (I), (II) and (III), and the structural units (I)/structural units (II) molar ratio is from 78/22 to 93/7.

Claim 7

A flame-retardant liquid crystal polyester composition according to claim 1, wherein the amount of structural units (I) and (II) is 80 to 93% by mole based on the sum of structural units (I), (II) and (III), the amount of structural units (III) is 20 to 7% by mole based on the sum of structural units (I), (II) and (III), and the structural units (I)/structural units (II) molar ratio is from 91/9 to 93/7.

Claim 8

A flame-retardant liquid crystal polyester composition according to claim 1, wherein R 1 in structural units (II) comprises at least 70% by mole of ##STR26## and R 2 in structural units (IV) comprises at least 70% by mole of ##STR27##

Claim 9

A flame-retardant liquid crystal polyester composition according to claim 1, wherein R 1 in structural units (II) is ##STR28## and R 2 in structural units (IV) is ##STR29##

Claim 10

A flame-retardant liquid crystal polyester composition according to claim 1, wherein the melting point (Tm, °C.) of the liquid crystal polyester (A) satisfies the requirement represented by the following formula (1): -10<(Tm+5.89X-385.5)<10 (1) wherein X represents the ratio (% by mole) of structural units (III) to the sum of structural units (I), (II) and (III).

Claim 11

A flame-retardant liquid crystal polyester composition according to claim 1, wherein the polymeric flame retardant (B) is brominated polystyrene.

Claim 12

A flame-retardant liquid crystal polyester composition as set forth in claim 10, wherein at least 70% by mole of recurring units of the brominated polystyrene are units of ##STR30##

Claim 13

A flame-retardant liquid crystal polyester composition according to claim 10, wherein the weight average molecular weight of the brominated polystyrene is from 15×10 4 to 100×10 4 .

Claim 14

A flame-retardant liquid crystal polyester composition according to claim 10, wherein the weight average molecular weight of the brominated polystyrene is 20×10 4 to 100×10 4 .

Claim 15

A flame-retardant liquid crystal polyester composition according to claim 10, wherein the weight average molecular weight of the brominated polystyrene is 30×10 4 to 100×10 4 .

Claim 16

A flame-retardant liquid crystal polyester composition according to claim 2, wherein the filler (C) is a glass fiber.

Claim 17

A flame-retardant liquid crystal polyester composition according to claim 15, wherein the average filament diameter of the glass fiber is 4 to 15 μm.

Claim 18

A flame-retardant liquid crystal polyester composition according to claim 15, wherein the average filament diameter of the glass fiber is 4 to 11 μm.

Claim 19

A flame-retardant liquid crystal polyester composition according to claim 1, which further comprises at least one compound selected from the group consisting of epoxy compounds and epoxysilane compounds in an amount of 0.01 to 20 parts by weight per 100 parts by weight of the liquid crystal polyester (A).

Claim 20

An injection-molded article which is formed by injection-molding a flame-retardant liquid crystal polyester composition comprising (A) 100 parts by weight of a liquid crystal polyester comprising structural units represented by the following formulae (I), (II), (III) and (IV), in which the amount of structural units (I) and (II) is 77 to 95% by mole based on structural units (I), (II) and (III), the amount of structural units (III) is 23 to 5% by mole based on structural units (I), (II) and (III), and the structural units (I)/structural units (II) molar ratio is from 75/25 to 95/5, and (B) 0.5 to 30 parts by weight of a polymeric flame retardant having an average dispersed particle diameter not larger than 2.5 μm, wherein the aforementioned formulae are: ##STR31## wherein R 1 represents at least one group selected from the group consisting of ##STR32## and R 2 represents at least one group selected from the group consisting of ##STR33## in which X represents a hydrogen atom or a chlorine atom, and the amount of structural units (IV) is substantially equimolar to the sum of the amounts of structural units (II) and (III); and said polymeric flame retardant (B) being at least one compound selected from the group consisting of (a) polymeric organic bromine compounds containing at least 20% by weight of bromine and (b) polymeric organic phosphorous compounds comprised of structural units represented by at least one of the following formula (i) through (iv): ##STR34## wherein R 3 represents an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms and R 4 represents an alkylene group having 1 to 15 carbon atoms, a cycloalkylene group having 3 to 15 carbon atoms or an arylene group having 6 to 15 carbon atoms.

Claim 21

An injection-molded article which is formed by injection-molding a flame-retardant liquid crystal polyester composition comprising (A) 100 parts by weight of a liquid crystal polyester comprising structural units represented by the following formulae (I), (II), (III) and (IV), in which the amount of structural units (I) and (II) is 77 to 95% by mole based on structural units (I), (II) and (III), the amount of structural units (III) is 23 to 5% by mole based on structural units (I), (II) and (III), and the structural units (I)/structural units (II) molar ratio is from 75/25 to 95/5, and (B) 0.5 to 30 parts by weight of a polymeric flame retardant having an average dispersed particle diameter not larger than 2.5 μm, wherein the aforementioned formulae are: ##STR31## wherein R 1 represents at least one group selected from the group consisting of ##STR32## and R 2 represents at least one group selected from the group consisting of ##STR33## in which X represents a hydrogen atom or a chlorine atom, and the amount of structural units (IV) is substantially equimolar to the sum of the amounts of structural units (II) and (III); and said polymeric flame retardant (B) being at least one compound selected from the group consisting of (a) polymeric organic bromine compounds containing at least 20% by weight of bromine and (b) polymeric organic phosphorous compounds comprised of structural units represented by at least one of the following formula (i) through (iv): ##STR34## wherein R 3 represents an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms and R 4 represents an alkylene group having 1 to 15 carbon atoms, a cycloalkylene group having 3 to 15 carbon atoms or an arylene group having 6 to 15 carbon atoms.

Claim 22

An injection-molded article according to claim 19, wherein the flame retardant liquid crystal polyester composition further comprises (C) a filler in an amount of 1 to 200 parts by weight per 100 parts by weight of the sum of the liquid polyester (A) and the polymeric flame retardant (B).

Claim 23

An injection-molded article according to claim 19, wherein R 1 in structural units (II) comprises at least 70% by mole of ##STR35## and R 2 in structural units (IV) comprises at least 70% by mole of ##STR36##

Claim 24

An injection-molded article as set forth in claim 20, wherein R 1 in structural units (II) comprises at least 70% by mole of ##STR37## and R 2 in structural units (IV) comprises at least 70% by mole of ##STR38##

Claim 25

An injection-molded article according to claim 19, wherein the heat distortion temperature (HDT, °C.) satisfies the requirement represented by the following formula (2): -20<([HDT]-323+6.8X)<20 (2) wherein X represents the ratio (% by mole) of structural units (III) to the sum of structural units (I), (II) and (III).

Claim 26

An injection-molded article according to claim 19, wherein the heat distortion temperature (HDT, °C). satisfies the requirement represented by the following formula (2'): -10<([HDT]-323+6.8X)<10 (2') wherein X represents the ratio (% by mole) of structural units (III) to the sum of structural units (I), (II) and (III).

Claim 27

An injection-molded article according to claim 20, wherein the heat distortion temperature (HDT, °C.) satisfies the requirement represented by the following formula (3): -2< ([HDT]-Z+6.8X-85)<20 (3) wherein X represents the ratio (mole %) of structural units (III) to the sum of structural units (I), (II) and (III), and Z is a value defined by the following formula (4): ##EQU2## in which y represents the ratio (% by weight) of the filler (C) in the composition to the sum of the filler (C) and the liquid crystal polyester (A).

Claim 28

An injection-molded article according to claim 20, wherein the heat distortion temperature (HDT, °C.) satisfies the requirement represented by the following formula (3'): -10<([HDT]-Z+6.8X-85)<10 (3') wherein X represents the ratio (mole %) of structural units (III) to the sum of structural units (I), (II) and (III), and Z is a value defined by the following formula (4): ##EQU3## in which y represents the ratio (% by weight) of the filler (C) in the composition to the sum of the filler (C) and the liquid crystal polyester (A).