Flame resistant polyester compositions, method of manufacture, and articles therof

• US 8,686,072 B2
• Filed: 06/29/2010
• Issued: 04/01/2014
• Est. Priority Date: 06/29/2010
• Status: Expired due to Fees

• Current Assignee: SHPP Global Technologies BV
• Original Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Inventors: Ding, Tianhua, Fonseca, Rodney, van der Weele, Chris, Kim, Sung Dug
• Primary Examiner(s): Yoon, Tae H
• Application Number:
  US12/826,087
• Publication Number:
  US 20110319534A1
• Time in Patent Office: 1,372 Days
• Field of Search: 524/100, 524/101, 524/123, 524/504, 523/201, 523/210
• US Class Current: 524/100
• CPC Class Codes: C08K 5/34922 Melamine; Derivatives thereof
• CPC Class Codes: C08K 5/34928 Salts
• CPC Class Codes: C08K 5/5313 Phosphinic compounds, e.g. R2=P(:O)OR'
• CPC Class Codes: C08K 5/5399 Phosphorus bound to nitrogen
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 33/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 67/02 Polyesters derived from dicarboxylic acids and dihydroxy compounds C08L67/06 takes precedence
• CPC Class Codes: C08L 67/025 containing polyether sequences

Abstract

A thermoplastic polyester composition comprising, based on the total weight of the composition, a chlorine- and bromine-free combination of: from 40 to 60 wt % of a modified poly(1,4-butylene terephthalate); from 25 to 35 wt % of a reinforcing filler; from 2 to 8 wt % of a flame retardant synergist selected from the group consisting of melamine polyphosphate, melamine cyanurate, melamine pyrophosphate, melamine phosphate, and combinations thereof; from 5 to 15 wt % of a phosphinate salt flame retardant; from more than 0 to less than 5 wt % of an impact modifier component comprising a poly(ether-ester) elastomer and a (meth)acrylate impact modifier; from more than 0 to 5 wt % poly(tetrafluoroethylene) encapsulated by a styrene-acrylonitrile copolymer; from more than 0 to 2 wt % of a stabilizer; wherein the thermoplastic polyester composition contains less than 5 wt % of a polyetherimide.

Claims

1. A thermoplastic polyester composition comprising, based on the weight of the composition, a chlorine- and bromine-free combination of:

(a) from 40 to 60 wt % of a modified poly(1,4-butylene terephthalate) that (1) is derived from consisting of a poly(ethylene terephthalate) copolymer comprising a mixture of ethylene glycol groups, diethylene glycol groups, terephthalic acid groups, and isophthalic acid groups, and 1,4-butanediol, and (2) comprises a mixture of 1,4-butanediol groups, ethylene groups, diethylene glycol groups, terephthalic acid groups, and isophthalic acid groups;

(b) from 25 to 35 wt % of a glass fiber filler;

(c) from 2 to 8 wt % of a flame retardant synergist selected from the group consisting of melamine polyphosphate, melamine cyanurate, melamine pyrophosphate, melamine phosphate, and combinations thereof;

(d) from more than 10 to 15 wt % of a phosphorus flame retardant comprising;

a phosphinate of formula (I)

[(R¹)(R²)(PO)—

O]⁻

_mM^m+ 

 

(I),

a diphosphinate of formula (II)

[(O—

POR¹)(R³)(POR²—

O)]²⁻

_nM^m+_x 

 

(II), and/or

a polymer derived from the phosphinate of formula (I) or the diphosphinate of the formula (II),

wherein R¹ and R² are identical or different and are H, linear or branched C₁-C₆ alkyl, or C₆-C₁₀ aryl;

R³ is C₁-C₁₀, linear or branched alkylene, C₆-C₁₀ arylene, C₇-C₁₁ alkylarylene, or C₇-C₁₁ arylalkylene;

M is an alkaline earth metal, alkali metal, Al, Ti, Zn, Fe, or B;

m is 1, 2, 3 or 4;

n is 1, 2, or 3; and

x is 1 or 2;

(e) at least 1% to less than 5 weight % of impact modifier component comprising a combination of (i) a poly(ether-ester) elastomer and (ii) a core-shell (meth)acrylate impact modifier;

wherein the poly(ether-ester) elastomer comprises long-chain ester units of formula (III);

-GOCOR′

COO—

 

 

(III);

and short-chain ester units having units of formula (IV);

-DOCOR′

COO—

 

 

(IV),

wherein R′

is a divalent aromatic radical remaining after removal of carboxyl groups from terephthalic acid, isophthalic acid, or a combination of terephthalic acid and isophthalic acid;

G is a divalent polyalkylene oxide radical remaining after removal of terminal hydroxyl groups from a poly(alkylene oxide)glycol having a number-average molecular weight of 100 to 2500; and

D is a divalent alkylene radical remaining after removal of hydroxyl groups from aliphatic diols having a molecular weight from 62 to 286; and

wherein the core-shell meth(acrylate) impact modifier has a crosslinked poly(butyl acrylate) core with a grafted poly(methyl methacrylate) shell;

(f) from more than 0 to 5 wt % poly(tetrafluoroethylene) encapsulated by a styrene-acrylonitrile copolymer; and

(g) from more than 0 wt % to 2 wt % of a stabilizer;

wherein the thermoplastic polyester composition contains less than 3 wt % of a polyetherimide; and

wherein an article molded from the composition exhibits

(a) a flexural modulus that is more than 9800 MPa to less than or equal to 20,000 MPa, measured on 3.2 mm thick bars in accordance with ASTM D 790;

(b) a flexural stress that is more than 150 MPa to less than or equal to 190 MPa, measured on 3.2 mm thick bars in accordance with ASTM D 790;

(c) an unnotched Izod impact strength that is more than 470 Joules/meter to less than or equal to 700 Joules/meter, measured on 75 mm×

12.5 mm×

3.2 mm bars at 23 °

C. in accordance with ASTM D 256; and

(d) a V0 rating, measured on 0.8 m thick flame bars after conditioning for 48 hours at 23 °

C., and 0.8 mm thick flame bars after conditioning for 168 hours at 70 °

C., in accordance with UL 94.

2. The thermoplastic polyester composition of claim 1, wherein the poly(ether-ester) elastomer is a poly(butylene terephthalate-polytetrahydrofuran) block copolymer.

3. The thermoplastic polyester composition of claim 1, wherein the phosphorus flame retardant is present in an amount ranging from 11 to 12.5 wt %.

4. The thermoplastic polyester composition of claim 1, wherein the impact modifier is present in an amount ranging from 2 to 2.5 wt %.

5. The thermoplastic polyester composition of claim 1, wherein the composition contains no polyetherimide, and an article extruded from the composition exhibits a CTI (Comparative Tracking Index) of 600 volts.

6. The thermoplastic polyester composition of claim 1, wherein the flame retardant comprises the phosphinate of formula (I).

7. An article comprising the thermoplastic polyester composition of claim 1.

8. The article of claim 7, wherein the article is selected from the group consisting of computer fans, electrical connectors, automotive battery housings, and lighting sockets.

12. The thermoplastic polyester composition of claim 1, wherein the thermoplastic polyester composition contains less than 1 wt % of the polyetherimide.

13. The thermoplastic polyester composition of claim 1, wherein the impact modifier component comprises from 2 to 4 wt % of a combination of a poly(butylene terephthalate-polytetrahydrofuran) block copolymer and the core-shell (meth)acrylate impact modifier having a crosslinked poly(butyl acrylate) core with a grafted poly(methyl methacrylate) shell.

9. A thermoplastic polyester composition comprising, based on the weight of the composition, a halogen-free combination of:

(a) from 40 to 60 wt % of a modified poly(1,4-butylene terephthalate) that (1) is derived from consisting of a poly(ethylene terephthalate) copolymer comprising a mixture of ethylene glycol groups, diethylene glycol groups, terephthalic acid groups, and isophthalic acid groups, and 1,4-butanediol, and (2) comprises a mixture of 1,4-butanediol groups, ethylene glycol groups, diethylene glycol groups, terephthalic acid groups, and isophthalic acid groups;

(b) from 25 to 35 wt % glass fiber filler;

(c) from 2 to 8 wt % of a flame retardant synergist selected from the group consisting of melamine polyphosphate, melamine cyanurate, melamine pyrophosphate, melamine phosphate, and combinations thereof;

(d) from more than 10 to 15 wt % a phosphinate of formula (I)

[(R¹)(R²)(PO)—

O]⁻

_mM^m+ 

 

(I),

a diphosphinate of formula (II)

[(O—

POR¹)(R³)(POR²—

O)]²⁻

_nM^m+_x 

 

(II), and/or

a polymer derived from the phosphinate of formula (I) or the diphosphinate of the formula (II),

wherein R¹ and R² are identical or different and are H, or linear or branched C₁-C₆ alkyl;

R³ is C₁-C₁₀, linear or branched alkylene;

M is aluminum;

m is 3;

n is 3; and

x is 1 or 2;

(e) at least 1 to less than 5 wt % of impact modifier component comprising a combination of (i) a poly(butylene terephthalate-polytetrahydrofuran) block copolymer and (ii) a core-shell (meth)acrylate impact modifier having a crosslinked poly(butyl acrylate) core with a grafted poly(methyl methacrylate) shell;

(f) from more than 0 to 5 wt % poly(tetrafluoroethylene) encapsulated by a styrene-acrylonitrile copolymer; and

(g) from more than 0 wt % to 2 wt % of a stabilizer;

wherein the thermoplastic polyester composition contains less than 2 wt % of a polyetherimide; and

wherein an article molded from the composition exhibits

(a) a flexural modulus that is more than 9800 MPa to less than or equal to 20,000 MPa, measured on 3.2 mm thick bars in accordance with ASTM D 790;

(b) a flexural stress is more than 150 MPa to less than or equal to 190 MPa measured on 3.2 mm thick bars in accordance with ASTM D 790;

(c) an unnotched Izod impact strength that is more than 470 Joules/meter to less than or equal to 700 Joules/meter, measured on 75 mm×

12.5 mm×

3.2 mm bars at 23 °

C. in accordance with ASTM D 256; and

(d) a V0 rating, measured on 0.8 mm thick flame bars after conditioning for 48 hours at 23 °

C., and on 0.8 mm thick flame bars after conditioning for 168 hours at 70 °

C., in accordance with UL 94.

10. An article comprising the composition of claim 9.

11. The article of claim 10, wherein the article is selected from the group consisting of computer fans, electrical connectors, automotive battery housings, and lighting sockets.