EP0595850A1

EP0595850A1 - Polymer alloy made of polyetherimides and liquid-crystalline copolyesters

Info

Publication number: EP0595850A1
Application number: EP92914523A
Authority: EP
Inventors: Michael Römer; Andreas Schleicher
Original assignee: Hoechst AG
Current assignee: Hoechst AG
Priority date: 1991-07-25
Filing date: 1992-07-08
Publication date: 1994-05-11
Also published as: WO1993002144A1; JPH06504315A

Abstract

Un alliage polymère renferme 2 à 50 % en poids d'au moins un poly-étherimide et 50 à 98 % en poids d'au moins un copolyester à cristaux liquides, entièrement aromatique, dérivé de l'acide 2-hydroxy-6-naphtoïque ou de l'acide p-hydroxybenzoïque, et présente en outre des motifs structuraux d'un acide hydroxybenzoïque ou hydroxydiphénylcarboxylique, d'un acide aminocarboxylique aromatique et/ou d'un composé bishydroxy aromatique conjointement avec un acide dicarboxylique aromatique.A polymer alloy contains 2 to 50% by weight of at least one polyetherimide and 50 to 98% by weight of at least one fully aromatic liquid crystal copolyester derived from 2-hydroxy-6-naphthoic acid or p-hydroxybenzoic acid, and further has structural units of a hydroxybenzoic or hydroxydiphenylcarboxylic acid, an aromatic aminocarboxylic acid and/or an aromatic bishydroxy compound together with an aromatic dicarboxylic acid.

Description

description

Polymer alloy from polyetherimides and liquid crystalline copolyesters

Polymer alloys made from liquid crystalline copolyesters (LCP) and polyetherimides (PEI) have been known for some years.

By Kiss et al. (Polym. Eng. Sci. Volume 27 (1987), 410) and from EP-A-217 563 polymer alloys are known in which fiber-like crystallites of a liquid-crystalline polymer are incorporated into a polymer matrix, for example a polyetherimide. The proportion of the liquid crystalline polymer is not more than 30 or 2 to 20% by weight. The mechanical properties of these polymer alloys are improved compared to pure polyetherimides, but still do not meet the requirements for high loads.

EP-A-209 391 discloses polymer alloys containing 5 to 60% by weight of a fibrous liquid-crystalline polyester obtained by melt spinning and 40 to 95% by weight of a thermoplastic, which can also be a polyetherimide. The liquid crystalline copolyesters used in the only example of an LCP-PEI polymer alloy contain structural units derived from p-hydroxybenzoic acid, terephthalic and isophthalic acid and from dihydroxydiphenyl. The LCP: PEI ratio is 30:70% by weight. If the proportion of the copolyester is more than 60% by weight, the processing of the products is unsatisfactory.

Such polymer alloys are non-hygroscopic and have good electronic properties; however, the mechanical properties are in need of improvement. EP-A-278 066 describes polymer alloys made from polyetherimides and liquid-crystalline copolyesters, which structural units are derived from dihydroxyphenyl or diphenyl and dicarboxyphenyl or diphenyl and, if appropriate, from hydroxyphenyl or hydroxydiphenylmonocarboxylic acid or structural units are derived from 2-hydroxynaphthyl-6-carboxylic acid and 4-hydroxybenzoic acid contain.

Polymer alloys whose LCP content is more than 50% by weight could not be used to produce injection molded articles suitable for physical tests.

Polymer alloys with an LCP content of 5 to 50% by weight are characterized by higher tensile modulus of elasticity than pure PEI, however the mechanical properties such as elongation at break and impact resistance are still in need of improvement.

EP-A-291 323 describes polymer alloys composed of polyetherimides and liquid-crystalline copolyesters which contain 6-oxy-2-naphthoyl and 4-oxybenzoyl structural units. The LCP content can be 35 to 95% by weight or the PEI content 65 to 5% by weight. The physical properties are improved compared to LCP-PEI polymer alloys according to the prior art; The elongations at break achieved are unsatisfactory and therefore still in need of improvement.

The object of the invention is therefore to provide polymer alloys made from liquid-crystalline copolyesters or copolyesteramides and polyetherimides with improved mechanical properties with respect to elongation at break and impact strength and improved heat resistance.

The invention relates to polymer alloys containing at least one fully aromatic, liquid-crystalline copolyester (A) and at least one polyetherimide (B), characterized in that the liquid-crystalline copolyester (A) has structural units of the formula I.

or of formulas I and II

and structural units of at least one of the formulas III, IVa, IVb, V and VI

contains, with the proviso that structural units of the formula III can only be contained together with structural units of the formula V and vice versa, where q is zero or 1, s is zero or an integer from 1 to 4, the indices y, z, w , u, v, p and x are integers greater than 1, T is selected from hydrogen, an alkyl radical with 1 to 4 C atoms, an alkoxy radical with 1 to 4 C atoms or a halogen, M is selected from hydrogen, an alkyl radical with 1 to 4 carbon atoms, an aryl radical with 6 to 10 C atoms, an alkylaryl radical with 6 to 10 C atoms or a halogen, where the structural units can independently of one another contain identical or different radicals T or M, the proportion of copolyester (A) in the polymer alloy 50 to 98 wt .-% and the proportion of polyetherimide (B) is 2 to 50 wt .-%, so that the proportions of (A) and (B) add up relative to the total alloy to 100 wt .-% .

The liquid-crystalline copolyesters (A) have anisotropic melts and have average molar masses (weight average) of 2,000 to 20,000, preferably from 3,500 to 50,000, in particular from 4,000 to 30,000 g / mol.

The proportion of structural units of the formula I or of the formulas I and II in the copolyester (A) is 30 to 90 mol% and the sum of the structural units of the formulas III to VI is 10 to 70 mol%, the proportions totaling 100 Add mol%.

For the polymer alloy according to the invention, preference is given to using copolyesters (A) which are composed of structural units of the formulas I, II, III and V, the proportion of structural units of the formula I 15 to 1 mol% and that of the formula II 50 to 79 Mol%, the formula III is 20 to 10 mol% and the formula V 20 to 10 mol%.

Further preferred copolyesters (A) are those with structural units of the formulas I and VI, the proportion of structural units of the formula I being 40 to 80 mol% and of structural units of the formula VI being 60 to 20 mol%.

The copolyesters (A) are prepared by polycondensation according to known methods, which are described, for example, in US Pat. Nos. 4,161,470 and 3,637,595.

Liquid-crystalline copolyesters and copolyesteramides (A) suitable for the polymer alloy according to the invention can also be purchased commercially. you will be distributed for example by Hoechst Celanese Corporation as ^® Vectra ( ^® = registered trademark).

Polyetherimides (B) suitable for the polymer alloys according to the invention have structural units of the formula VII

where _ is an integer multiple of 1, especially 10 - 10,000, the group -O-A for

with R 'equal to hydrogen, halogen, _C. -C ^ alkyl or alkoxy, -Z- is a double-bonded structural unit selected from

is in which -R ^{1 is} C ¹ -C ₄ alkyl, preferably methyl, CC ₄ alkoxy, preferably methoxy, or halogen, preferably bromine, r is zero or an integer 1, 2, 3 or 4 and the radicals are -R ¹ and the indices r can be the same or different, -D- a group selected from -C _n H _2n -, preferably - C (CH ₃ ) ₂ - or -CH ₂ -, -SO-, -S0 ₂ -, - CO-, -O-, -S-, -C (CF ₃ ) ₂ - and n is an integer from 1 to 5 and -B- is a double-bonded structural unit selected from one unsubstituted or substituted by CC ₄ alkyl, C.-C ^ alkoxy or halogen Cs-Ca _j -aryl radical, C ₂ -C ₂₀ -alkylene or cycloalkylene, C ₂ -C ₈ -alkylene-terminated polydiorganosiloxane or

is, wherein R ¹ , r and D have the meaning given above.

Polyetherimides (B) with structural units of the following formula are preferably used:

wherein -B- and -Z- have the meaning given above.

The bonds of the -O-Z-O structural units can be in the 3,3'-, 3,4'-, 4,3'- or 4,4'-position.

Z is preferably Z3, in particular

B is preferably selected from m-phenylene is particularly preferred.

Particularly preferred polyetherimides (B) are those with structural units of the formula:

Such polyetherimides are commercially available, for example from the General Electric Company in unreinforced and glass and mineral reinforced form as ^® Ultem.

The polyetherimides are prepared by known methods, for example by reaction of aromatic bis (ether anhydrides) and organic diamines, which are described in detail in US Pat. Nos. 3,847,867, 3,847,869, 3,850,885, US -A-3 852 242, US-A-3 855 178, US-A-4 417 044 and EP-A-0 330 739.

Polyimides (B) with structural units of the following formulas are also suitable for the polymer alloys according to the invention:

or

where -P ¹ - for -0-, -S-, -CO-, -SO-, -S0 ₂ -, alkylene each having 1 to 9 carbon atoms, for example methylene, ethylene, propylene or butylene, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -C (CH ₃ ) (CF ₃ ) - or a direct bond, and P ² is a bivalent carbon radical selected from

(σ) a substituted or unsubstituted aromatic residue of the following formulas

or (ß) a radical of the general formula

where R ^{2 is} C 1 -C 6 -alkyl, such as methyl, ethyl, the various isomers of propyl, butyl, pentyl or hexyl, or halogen, and R ^{3 is} 0, S, CO, SO, S0 ₂ , alkylene each having 1 to 9 carbon atoms, for example methylene, ethylene, propylene or butylene, alkylidene each having 1 to 6 carbon atoms, for example ethylidene, isopropylidene, propylidene or isobutylidene, cycloalkylene or cycloaikylidene each having 4 to 9 carbon atoms and the Index h denotes integers zero, 1, 2, 3 or 4, or ( ^■ ) a radical of the general formula

where R ^{4 has} the meaning of a substituted or unsubstituted aromatic radical of the formulas mentioned in (a) and (ß) and the index h has the meaning given above, "E" for

stands for and "X" for

where R ^{5 is} independently hydrogen, alkyl having 1 to 6 carbon atoms, such as methyl, ethyl, the various isomers of propyl, butyl, pentyls or hexyls or alkoxy having 1 to 6 carbon atoms, for example methoxy, ethoxy or butoxy, and the index i stands for integers zero, 1, 2 or 3 and the index j stands for integers zero, 1 or 2.

Preferred polyimides of the invention are those with the following structural units:

N-P

or

where P ¹ and P ^{2 have} the meaning given above.

Particularly preferred polyimides (B) are those with the following structural units:

These polyimides can also be synthesized by known methods, which are described, for example, in "Polyimides - Materials, Chemistry and Characterization" (Elsevier, 1989) and in "Polyimides" (Consultants Bureau, 1987).

The term polyetherimides, as used here, includes homopolymers and copolymers, such as multipolymers or block polymers. The Staudinger indices of the polyetherimides used are 0.1-3 dl / g, preferably 0.3-1.5 dl / g, and particularly preferably 0.3-1 dl / g, measured at 25 ° C., for example in N-methylpyrrolidone or Methyl chloride.

In the polymer alloys according to the invention, the proportion of liquid-crystalline copolyesters (A) is preferably 55 to 95% by weight, in particular 75 to 95% by weight, and the proportion of polyetherimides (B) is preferably 45 to 5% by weight, in particular 25 to 5% by weight.

The polymer alloys according to the invention are produced and processed by known methods for thermoplastics at temperatures optimized for the respective material, such as. B. by extrusion or injection molding.

The polymer alloys according to the invention can contain additives, for example plasticizers, thermal stabilizers, UV stabilizers, impact modifiers or reinforcing additives such as glass, carbon, ceramic, mineral or high-modulus fibers.

The polymer alloys according to the invention can be used particularly advantageously as matrix materials for composite materials. They are also suitable for the production of moldings by the injection molding or extrusion process, for example in the form of fibers, films, lacquers and hoses.

The polymer alloys according to the invention have a variety of uses, for example as plug connections, electrical insulation in transformers, capacitors, cable and wire jackets, including glass fiber jackets in the electronics industry, the automotive and aerospace industries.

The following serves as a further explanation of the polymers used in the examples and the working methodology. The liquid-crystalline copolyesteramide (LCP) A1 contains structural units of the formula

wherein the proportion of structural units of oxynaphthoyl is 58 mol%, of terephthaloyl is 21 mol% and of aminophenoxy 21 mol%.

LCP A1 is available, for example, as Vectra B950 from Hoechst Celanese Corporation.

The liquid-crystalline copolyester (LCP) A2 contains structural units of the formula

wherein the proportion of the oxynaphthoyl structural units is 4 mol%, the proportion of the oxybenzoyl structural units is 60 mol%, the proportion of the bisoxydiphenylene structural units is 18 mol% and the proportion of the terephthaloyl structural units is 18 mol%.

LCP A2 is available, for example, as Vectra E950 from Hoechst Celanese Corporation.

The polyetherimide (PEI) B1 contains structural units of the formula

and has a Staudinger index of 0.55 dl / g, measured at 25 ° C in N-methylpyrrolidone.

For example, PEI B1 is available as Ultem from General Electric.

The polymers used for the alloys were first dried at 150 ° C. for 2-4 hours and after mixing in an LSM 30.34 GL extruder from Leistritz, Nuremberg, under protective gas (nitrogen) at temperatures of 310-330 ° C. (LCPA1 / PEIB1) or 330 - 360 ° C (LCPA2 / PEIB1) extruded and then granulated. The temperatures given here refer to the temperature profile from the feed to the extruder nozzle. The granules obtained were dried for 4 hours at 150 ° C. and injection molded into molded parts such as shoulder sticks, plates, etc. and examined for physical properties. A machine from Zwick, Ulm, was used for tensile and strain tests to determine the tensile strength, elongation at break according to DIN 53455 and the tensile modulus of elasticity according to DIN 53457.

The bending stresses, the edge fiber elongation according to DIN 53452 and the bending modulus of elasticity according to DIN 53457 were determined with a bending stretching machine from Zwick, Ulm. Furthermore, the heat resistance (HDT) was determined according to DIN 53 461 method A.

For comparison purposes, samples of pure polyetherimide or pure copolyester were produced under the optimal conditions for the respective polymer.

Example 1:

Mixtures of liquid-crystalline copolyesteramide A1 and polyetherimide B1 were extruded in the% by weight compositions 90/10, 80/20, 70/30 and 60/40.

Table 1 gives an overview of the mechanical and thermal properties of the polymer alloys and their individual components.

Table 1

Particularly noteworthy with LCP A1 / PEI B1 polymer alloys is the significant increase in heat resistance. σ ^* -

Example 2

Mixtures of the liquid crystalline copolyester A2 with polyetherimide B1 in the weight percent compositions 90/10 and 60/40 were extruded.

As can be seen from Table 2, the LCP A2 / PEI B1 blends show an excellent elongation at break, which is comparable to the elongation at break of pure LCP A2.

Particularly noteworthy is the increase in notched impact strength according to IZOD of the LCP A2 / PEI B1 blend and the 17% increase in tear strength achieved by adding only 10% by weight PEI / B1 to the pure LCP A2.

Table 2

Claims

Claims:

1. Polymer alloy containing at least one fully aromatic, liquid-crystalline copolyester (A) and at least one polyetherimide (B), characterized in that the liquid-crystalline copolyester (A) is structural units of the formula I.

or of formulas I and II

and structural units of at least one of the formulas III, IVa, IVb, V and VI

contains, with the proviso that structural units of the formula III can only be contained together with structural units of the formula V and vice versa, where q is zero or 1, s is zero or an integer from 1 to 4, the indices y, z, w , v, p and x are integers greater than 1, T is selected from hydrogen, an alkyl radical with 1 to 4 carbon atoms, an alkoxy radical with 1 to 4 carbon atoms or a halogen, M is selected from hydrogen, an alkyl radical with 1 to 4 carbon atoms, an aryl radical with 6 to 10 carbon atoms, an alkylaryl radical with 6 to 10 carbon atoms or a halogen, where the structural units can independently of one another contain identical or different radicals T or M, in which Polymer alloy, the proportion of copolyester (A) 50 to 98 wt .-% and the proportion of polyetherimide (B) is 2 to 50 wt .-%, so that the proportions of (A) and (B) relative to the Add the total alloy to 100% by weight.

Polymer alloy according to Claim 1, characterized in that the proportion of the copolyester (A) 55 to 95% by weight, in particular 75 to 95% by weight, and the proportion of the polyetherimide (B) 45 to 5% by weight, in particular 25 to 5% by weight.

Polymer alloy according to Claim 1, characterized in that the polyetherimide (B) has structural units of the formula VII

in which a is an integer, in particular an integer from 10 to 10,000, the group -OA for where -R 'is hydrogen, halogen, C 1 -C 4 alkyl or alkoxy, -Z- is a double-bonded structural unit selected from

is in which -R ^{1 is} C.-C ₄ -alkyl, C ₁ -C ₄ -alkoxy or halogen, r is zero or an integer 1,

2,

3 or 4 and the radicals -R ¹ and the indices r can be the same or different, -D- a group selected from -C ^^ -, -SO-, -S0 ₂ -, -CO-, -O-, -S-, -C (CF ₃₎ ₂ - and n is an integer from 1 to 5, and -B- is a divalent structural unit selected from an unsubstituted or substituted by C, -C ₄ alkyl, _C. -C ₄ alkoxy or halogen substituted Cg-C _j o-aryl radical, Cs-Ca _j alkylene or cycloalkylene, C ₂ -C ₈ alkylene-terminated polydiorganosiloxane or

is, wherein R ¹ , r and D have the meaning given above.

4. Polymer alloy according to claim 3, characterized in that the polyetherimide (B) structural units of the formula

contains, where -B- and -Z- have the meaning given above.

5. Polymer alloy according to claim 4, characterized in that the polyetherimide (B) structural units of the formula

contains.

6. Polymer alloy according to claim 1, characterized in that the polyetherimide (B) structural units of the following formulas

or

, where -P ¹ - for -0-, -S-, -CO-, -SO-, -S0 ₂ -, alkylene with 1 to 9 carbon atoms, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -C (CH ₃ ) (CF ₃ ) - or a direct bond, and P ^{2 is} a divalent carbon radical selected from (a) a substituted or unsubstituted aromatic radical of the following formulas

or (ß) a radical of the general formula

wherein R ² represents _C. -C ₆ alkyl or halogen, and R ^{3 is} O, S, CO, SO, S0 ₂ , alkylene with 1 to 9 carbon atoms, alkylidene with 1 to 6 carbon atoms, cycloalkylene or cycloalkylidene each with 4 to 9 C atoms and the index h denotes integers zero, 1, 2, 3 or 4, or (y) a radical of the general formula

where R ^{4 has} the meaning of a substituted or unsubstituted aromatic radical of the formulas mentioned in (σ) and (ß) and the index h has the above meaning,

"E" for

stands for and "X" for

where R ^{5 is} independently hydrogen, alkyl having 1 to 6 carbon atoms, or alkoxy having 1 to 6 carbon atoms, and the index i for integers zero, 1, 2 or 3 and the index j for integers zero, 1 or 2 stands.

7. polymer alloy according to claim 6, characterized in that the polyetherimide (B) structural units of the formulas

or

N-P

having,

where P and P ^{2 have} the meaning given above.

8. Polymer alloy according to claim 7, characterized in that the polyetherimide (B) has structural units of the following formulas:

9. Polymer alloy according to claim 1, characterized in that the copolyester (A) is composed of structural units of the formulas I, II, MI and V.

10. Polymer alloy according to claim 1, characterized in that the copolyester (A) contains structural units of the formulas I and VI.

11. Polymer alloy according to claim 1, characterized in that the copolyester (A) has the following structural units and the polyetherimide (B) structural units of the formula

having.

12. Polymer alloy according to claim 1, characterized in that the copolyester (A) has the following structural units

and the polyetherimide (B) structural units of the formula

having.

13. Use of a polymer alloy according to claim 1 for the production of moldings or as a matrix material for composites.