AU7938782A

AU7938782A - Clay filled polyphenylene ether compositions

Info

Publication number: AU7938782A
Application number: AU79387/82A
Authority: AU
Inventors: Visvaldis Abolins
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1980-11-24
Filing date: 1981-11-23
Publication date: 1982-06-17
Also published as: DE3173945D1

Description

Descrip tion

Clay Filled Polyphenylene Ether Compositions

This invention relates to clay filled polychenylene ether co-positions , and more specifically, to co-positions co-posed of polyphenylene ther , an impact modifier and a piasticizer which also contain clay particles characterized by a certain specified particle size and surface area .

Background of the Invention - The p olyphenylene ether resins are well known in the art a s comprising a family of thermoplastic material which are suitable for various engineering purposes. These m ay be made by catalyzed and non-catalyzed processes described in the patent literature.

such as in Hay. U. S. 3,306,874 and 3,306,875, and in Stasateff, U.S. 3,257,357 and U.S. 3,257,353, all of which are iscorporated herein by reference.

It ia knovn char the polyphenylene ether resins may be admixed with polystyrene, either unmodified or modified, to produce compositions having properties better than chose of either of the two polymers individually. Such compositions ere disclosed la Cizek, U.S. 3,383,435, which is incorporated herein by reference.

To reduce the cost, it has been proposed to add mineral fillers such as alumimmum silicate, calcium carbonate, magnesium silicate, calcium silicate, silica cr others, to compositions containing a polyphenylene ether resin and polystyrene. Compositions comprising a polyphenylene ether resin, a rubber modified high impact pelystyrene and aluminum silicate are disclosed in U.S. 4,156,312.

Copendiag application Serial Ho. 755,025, filed December 28, 1976, discloses compositions cosprising a polyphenylene ether resin, alone, or in combination vith an impact modifier which is not a high impact rubber modified polystyrene, a mineral filler and a piasticizer.

It is known that the addition of mineral fillers to polyphenylene ether resins can increase the rigidity and dimensional stability of the polymers. The toughness of the resulting composite is usually lover than that of the mineral filled-free polymer, hovever. It has been found that some mineral fillers increase the rigidity of. the polder and provide ductile composites having good impact resistance. Such benefits are sere pronounced in falling weight-type impact tests, such as Gardner impact resistance. This type of impact resistance is much sere important in actual practice than the ispact resistance as measured by other means such as the Izod impact test.

It has now been discovered that as among mineral fillers in general, particulate clay and specifically clay having a mean particle size of less than 0.6 micrometer (micron) and a surface area of 15 square meters per gram (m²/g) or more, dramatically improves the Gardner impact strength of certain polyphenylene ether compositions. These compositions are described below.

Description of the Invention_ - According to this invention, there are provided thermoplastic compositions having improved impact strength when molded, comprising:

(a) a polyphenylene ether resin, alone, or together with an impact modifier;

(b) an effective amount of a plasticizer; and

(c) a particulate clay filler having a mean particle size of less than 0.6 micron and a surface area of at least 15 square meters per gram.

Preferably, the particulate clay filler is substantially free of large, gritty particles and has been well dispersed to avoid the formation of limps. The presence of grit and clumps may cause stress concentrations in the clayresin composites which lower the impact resistance and also other physical properties.

The clay filler of the compositions of this invention can be prepared by conventional methods, using, e.g., sieving means to separate and collect clay particles having the appropriate size, preferably 0.1 to 0.5 micron and surface area, preferably 15 to 30.m²/g, and to separate gritty particles and clumps.

The preferred polyphenylene ether resins are those having the formula:

wherein the oxygen ether atom of one unit is connected to the benzene nucleus of the next adjoining unit, n is a positive integer and is at least 50, and each Q is a monovalent substituent selected from the group consisting of hydrogen halogen, hydrocarbon radicals free of a tertiary aipha-carhon atom, halohydrocarbon radicals having at least two carbon atoms between the halogen atom and the phenyl nucleus, hydrocarbonoxy radicals and halohydrocarbonoxy radicals having at least two carbon atoms between the halogen atom and the phenyl nucleus. The preparation of polyphenylene ether resins corresponding to the above formula is described in the abovementioned patents of Hay and Stama toff .

The test preferred polyphenylene ether resin for use in this invention is poly (2, 6-diaethyl-1,4-ρhenylene) ether.

The particular iispact modifier employed in the cospositions is not critical and can be selected from a vide variety of elastomeric materials . By way of illustration, the term "impact modifier" employed herein includes copolymers of styrene and elastomeric materials such as acrylonitrile, EPDM rubber, maleic anhydride or diene rubber, Exasples include copolymers of styrene and acrylonitrile, copolymers of styrene and butadiene, copolymers of styrene and maleic anhydride and copolymers of styrene and EPDM rubber. Other examples include terpolymers of styrene , acrylonitrile and butadiene, and terpolymers of styrene, butadiene and styrene of the A-3-A type or radial teleblock type, either hydrogenated or unhydrogenated.

Special mention is made of the A-B-A¹ block copolymers wherein terminal blocks A and A¹ are the same or different and are derived from a vinyl aromatic compound, e. g. , styrene,α-methyl styrene , vinyl toluene, vinyl sylene , vinyl naphthalene, and the like , and center block 3 is derived from a conjugated diene , i. e. , butadiene , isoprene , 1, 3-pentadiene , 2 , 3- dimethyl butadiene, and the like. Hydrogenated derivatives of the foregoing are also preferred. Both the unhydrogenated and hydrogenated forms can be prepared by methods described in the patent literature, e.g.. U.S. 3,251,905; U.S. 3.231.625; and U.S. 3,431,323, which are incorporated herein by reference.

The piasticizer can be selected from among any materials known to impart compatibility with polyphenylene ether resin. Preferably, the plasticizer is an aromatic phosphate, and especially a compound having the formula:

wherein R¹, R² and R³ are the same or different and are alkyl, haioalkyl, cycioalkyl, halocycloalkyl, aryl, haloaryl, alkyl substituted aryl, haioalkyl substituted aryl, aryl substituted alkyl, haloaryl substituted alkyl, hydroryalkyl, hydroxyaryl, hydroxyalkaryl, halogen and hydrogen.

Examples include cresyl diphenyl phosphate, 2-ethylhexyl diphenyl phosphate, tricresyl phosphate, triiscprcpylphenyl phosphate, triphenyl phosphate, triethyl phosphate, άibutyl phenyl phosphate, diethyl phosphate, cresyl diphenyl phosphate, isooctyl diphenyl phosphate, trihuryl phosphate, 2-ethylhexyl diphenyl phosphate, isodecyl diphenyl phosphate, isodecyl dicresyl phosphate, didecyl cresyl phosphate, tri-nhexyl phosphate, di-n-octyl phenyl phosphate, di-2-ethyl-hexyl phenyl and tri-2-ethylhexyl phosphate or mixtures thereof. Especially preferred is triphenyl phosphate. The ingredients in the compositions of this invention can vary widely. In preferred embodiments, the compositions contain from 5 to 95 parts by weight of polyphenylene ether, from 95 to 5 parts by weight of impact modifier, from 5 to 50 parts by weight of piasticizer and from 5 to 50 parts by weight of clay.

Other ingredients, such as stabilizers, flame retardant agents, drip retardands, antioxidants, antistatic agents, coloring agents, pigments, mold release agents, and the like, can also be included for their conventionally employed purposes.

The compositions of this invention are prepared in aay manner, usually, however, the ingredients are formed into a preblend by tumbling in a mixer, the preblend is extruded at a temperature of from 550º7. to 620ºF., the extrudate is cut into smaller pieces, and the pieces are injection molded at a temperature of from 530º7. to 640º7.

Description of the Preferred Embodiments. - The compositions of this indention are illustrated in the following examples, which are not intended to be limiting.

EXAMPLES 1-14

Compositions according to this invention are prepared by tumbling the ingredients , extruding the resulting blend in a Werner Pfleiderer 28 so twin screw machine , at a temperature of 590º7. and inj ection molding the extrudate in a Newbury injection molάias machine at 500º7. (mold temperature 18CºF.).

The molded compositions are evaluated for physical properties according to ASTM standards. The compositions and properties are reported in Tables I and II.

TABLE I. ComposIttone Comprising a Polyphenylene

Ether Reain, an A-B-A Block Copolymer, Triphenyl Phosphate and Clay Filler

Ingrudtents, parts by weight 1 2* 3* 4* 5* 6* 7*

Poly(2,6-dlmethyl- 1,4-phenylene)ether 95 95 95 95 95 95 95

Hydrogenated styreneliutadlene-atyrene copoiymer 5 5 5 5 5 5 5

Triphenyl phosphate 10 10 10 10 10 10 10

ASP-100^b (clny) 25 - - - - - -

ΛSF-105^b (clny) - 25 - - - - -

A3P-170^b (clay) 25 - - - - -

ASP-900^b (clay) - - 25 - - - -

ASP-400^b (clay) - - 25 - - -

Satlntone t. (clay) - 25 - - - - - an tin tone 1 (cl ay) - - - 25 - - - -

a Shell Chcmlcnl Company ' s KRATON C 1652 h Engelhard Minerals & Chemilcnls Corporat i on * comp artion exper iment

TABLE I. (cont'd)

Sample Designations Physical Properties 1 2* 3* 4* 5* 6* 7 * Filler ASP-100 ASP-105 ASP-170 ASP-900 ASP-400 Satintone Satintone No. it No. 1

Mean particle size of Ciller (microna) 0.55 0.55 0.55 1.5 4.8 1.0 20

Surface area of filler (m² /_g) 14.6-16.2 11.1-13.8 11.5-14.3 11 7.2 8.9-9.5 7.3-8.5

Gardner Impact streng th of composite (1n- 1bm) 235 63 27 9 2 12.5 6.5

TABLE II. Compositions Comprising a Polyphenylene Ether Reain, an A-B-A Block Copolymer, Triphenyl Phosphate and Clay Filler

Ingredients, parts by weight 8 9 10 11 12* 13* 14*

Poly(2,6-dinethyl- 1 ,4-phcnylene)ether 95 95 95 95 95 95 95

Hydrogenated styreneliutmilcue-ulyruie copolymer^a 5 5 5 5 5 5 5

Triphenyl phopphate 10 10 10 10 10 10 10

HG-90^b (clay) 25 - - - - - -

Suprex^b (clay) - 25 - - - - -

Hulok 321^b (clay) - - 25 - - - -

Nucap 200^b (clay) - - - 25 - - -

Al-Stl-Ate NCF^C (clay) - - - - 25 - -

Al-Sil-Atβ NC^C (clay) - - ^•- - - 25 -

Al-Sll-Ate HO₂ ^C (clay) - - - - - - 25

* compariaon experiment a Shell Chemical Company's KRATON G 1652 b J.M. Il-ther Corporation c Free port Kaollnn Company

TABLE II . (cont 'd)

Sample Designatlons

Physical Properties 8 9 10 11 12* 13* 14*

Filler 110-90 Suprex Hulok Nucap Al-Sll-Ate Al-Sil-Ate Al-Sli-Ate

No . 321 No . 200 NCF NC NO ₂

Mean particle βize of filler (microns) 0.3 0.3 0.3 0.3 97% 82% 82% below 2 below 2 below

Surface area of filler (m²/g) 22 22 22 22 1 4-16 12-14 12- 1 4

Gardner impact ntrrngth of coinposite (1n-1bs) 225 225 190 210 95 15 15

It can be seen that the compositions according to the invention, 1, 8, 9, 10 and 11, eaeh containing clay having a mean particle size no greater than 0.6 micron and a surface area of at least 15 m²/g. provide clearly better Gardner impact strength is comparison with the compositions containing a clay filler not is accordance with the invention, 2-7 inclusive and 12-14 inclusive.

Other modifications and variations of this invention are possible in view of the description. It is to be understood, therefore, that changes may be made in the particular embodiments shown herein without departing from the principles or scope of the invention defined is the appended claims and without sacrificing the chief benefits.

Claims

1. A thermoplastic composition comprising:

(a) a polyphenylene ether resin, alone, or together with as impact modifier;

(b) an effective amount of a plasticizer; and

(e) a particulate clay filler having a mean particle size of less than 0.6 micron and a surface area of at least 15 square meters per gram.

2. A composition as defined is Claim 1, is which the impact modifier is as A-B-A¹block copolymer wherein terminal blocks A and A ire derived from a vinyl aromatic compound and center block B is derived from a conjugated diene.

3. A composition as defined is Claim 2, is which the terminal blocks are polystyrene and the center block is polybutadiene.

4. A composition as defined is Claim 2, in which the A-B-A¹block copolymer has been hydrogenated.

5. A composition as defined in Claim 1, is which the polyphenylene ether resin has the formula

wherein the oxygen ether atom of one unit is connected to the benzene nucleus of the nest adjoining unit, n is a positive integer and is at least 50, and each Q is a monovalent substituent selected from the group eoasisting of hydrogen, halogen, hydrocarbon radicals free of a tertiary alpha-carbon atom, halohydrocarbon radicals having at least em carbon atoms between the halogen atom and the phenyl nucleus, hydrocarbonoxy radicals and halohydroeaxbonoxy radicals having at least two carbon atoms between the halogen atom and the phenyl nucleus.

6. A composition as defined is Claim 1, in which the polyphenylene ether resin is poly(2,6-dimethyl-1,4-phenylene) ether.

7. A composition as defined is Claim 1, is which the plasticizer is triaryl phosphate.

S. A composition as defined in Claim 1, in which the plasticizer is triphenyl phosphate.

9. A composition as defined is Claim 1. comprising from about 5 to about 95 parts by weight of said polyphenylene ether resin, from about 95 to 5 parts by weight of said impact modifier, from about 5 to about 50 parts by weight of said plasticizer and from about 5 to about 50 parts by weight of said clay.

10. A composition as defined is Claim 1, is which the particulate clay filler has a mean particle size of from to micron and a surface area of from to square meters per gram.

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