DE1669873B2 - Polymer compositions - Google Patents

Description

The invention relates to polymer compositions consisting of ethylene polymers and one therein contained finely divided metal powder.

It is known to convert powdered metal and other inorganic fillers into thermoplastic polymers add in order to improve certain properties of the polymers, in particular the module. However, other properties such as tensile strength and impact resistance are not achieved in an appropriate manner improved. In fact, at higher concentrations of the metal powder, these properties can decrease. Metal powder polymer masses that not only show an improved modulus, but also greater tensile strength and cable impact resistance therefore valuable.

For example, U.S. Patents 3,224,997 and 3,194,860, as well as French patents 1235 806 and 1384 603 mixtures of olefin polymers and metal powder described. The inventor has now surprisingly found that polymer compositions are obtained which have improved properties Modulus and a greater tensile strength and notched impact strength obtained when one special Selects ethylene polymers. From the values in Tables 1 and III, where the products of Examples 1 and 3 are compared - the product of Example 1 relates to a polymer composition according to the invention, while the product of Example 3 relates to a known polymer composition - it can be seen that the properties of both polymers are greatly changed by ίο the addition of metal particles. Both polymers have similar properties without metal particles. Surprisingly, they show Polymer compositions according to the invention have better elongation properties, higher notched impact strengths and Flexural strengths than the known masses. The polymer compositions according to the invention obtained by the Metal filler additive surprisingly properties that are similar to the properties of the known Way with fillers added polymers are far superior.

The invention relates to polymer compositions consisting of ethylene polymers and one therein contained finely divided metal powder, the metal particles in an amount between 40 and 60 percent by volume, based on the volume of the metal particles present in the entire polymer-metal mass, are present and wherein the ethylene polymer as a copolymer of 75 to 98 percent by weight Ethylene and from 2 to 25 percent by weight of a mono- or polybasic ethylenic Unsaturated carboxylic acid with 3 to 8 carbon atoms in which the carboxyl groups are partially esterified can be present.

According to a production method of a mass according to the invention, up to about 60 percent by volume a fine metal powder, such as aluminum, to a copolymer of ethylene and an ethylenic unsaturated carboxylic acid added. This mixture is in a conventional mixing device, for example a roller mill, a Banbury mixer or similar equipment, so that an intimate mixed polymer mixture results. Of course, other methods of production can also be used suitable metal-polymer mixtures are used. The mass can be easily poured, pressed, or otherwise into sheets, tubes or articles of a wide variety of shapes shapes that are suitable for many different uses and areas of application wherein the metal powder particles are uniformly distributed throughout the obtained article.

The polymer suitable for practicing the invention consists of a copolymer with a larger proportion of ethylene and up to 25 percent by weight, based on the copolymer, of an acidic comonomer, namely \, /? - ethylenic unsaturated aliphatic mono- and polycarboxylic acids and acid anhydrides with 3 to 8 carbon atoms per molecule and partial esters of such polycarboxylic acids, the acid content at least one Has carboxyl group and the alcohol contains 1 to 20 carbon atoms. Specific examples such acidic comonomers are acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, Itaconic acid, maleic anhydride, maleic acid monomethyl ester, Maleic acid monoethyl ester, fumaric acid monoethyl ester and fumaric acid monoethyl ester.

The copolymer used according to the invention preferably consists of a graft copolymer which consists essentially of a high-density polyethylene and an unsaturated aliphatic carboxylic acid. Such copolymers are prepared by known methods, for example by reaction of unsaturated aliphatic carboxylic acids having ^ a normally solid homopolymer of an olefin such as ethylene, at temperatures between about 65 and about 17O ⁰ C at atmospheric pressure. Above atmospheric pressure or below atmospheric pressure. Random interpolymers are also suitable for use in practicing the present invention.

Such copolymers can be prepared by known methods, for. B. by copolymerization of ethylenically unsaturated aliphatic carboxylic acids with ethylene at elevated temperatures and pressures and in the presence of a suitable catalyst. Both when using a copolymer with indiscriminate distribution, or a graft polymer is preferred that the unsaturated aliphatic carboxylic acid as a comonomer in an amount of between about 6 and about 12 ° _o by weight, based on the weight of Mischpolymeri- * 5, is present sates.

The metallic filler components for the copolymer consist of any finely divided metal particles, mixtures thereof, metal alloys or metal oxides. Examples of suitable fillers are aluminum, lead, iron and mixtures of Carbon black and metal powders.

Various sizes of metal particles can be used to obtain specific properties desired to reach. However, the most favorable particle sizes should be in the range of 5 to 300 microns and preferably between 13 and 20 microns. Mixtures of metal fillers can of course be used with other suitable conventional fillers also in the practical implementation of the Invention can be used.

The concentration of the metallic filler is in the range between 40 and 60 ", and preferably between 46 and 55 percent by volume, based on that present in the entire Polymer-Melall-Massc Volume of metal filler.

The mass according to the invention can e.g. B. for the production of shaped cups, magnetic cores for Electromagnets, machine parts, housings. Ornamental areas, gears, bearings or rollers are used will.

The following examples illustrate the invention.

example 1

55

75 g of a graft copolymer powder made from high density polyethylene and acrylic acid, the 8 " _o acrylic acid (mesh size 0.044 mm = 325 mesh) melt index = 3.1 according to ASTM test D1.238-57T condition E), which is produced by graft polymerisation by means of high energy radiation of Acrylic acid on high density polyethylene was dry mixed with 225 g of aluminum powder (average particle diameter = 19 to 20 microns) by rolling in a glass container at room temperature for 24 hours. 0.32 cm by forging between heated platters in a hydraulic preco press using a platen mold of 20 x 20 x 0.32 cm with an opening of 15 x 15 x 0.32 cm at 200 ^: C for 5 minutes with a Plate pressure of 9000 kg processed After the formed sheet was cooled in the press by passing water through the plates, it was removed and made into strips cut 1.27 x 15 x 0.32 cm for physical examination. The physical properties of this material are listed in Table 1. Table I also shows the properties of shaped sheets made in the same way and made from polymerizate that has not been filled with fillers.

Tabel

With reason filler polymer offset Polymer 239.4 Tensile strength, kg / cm ² 298.3 11249 Modulus of elongation, kg / cm ² 75931 313.1 Flexural Strength, kg / cm ² .... 541.9 9842 Flexural modulus, kg / cm ² .. 67494 9.0 Elongation, % 1.9 Notched impact strength, 3.4 kg / cm / cm notch 7.1

Example 2

A dry powder mixture of the same composition as in Example 1 was compounded on a heated two-roll mill Thropp for 5 minutes at 175 ^C C. The compounded mass was then ground by a Wiley mill, compression molded and examined. The properties of this composition are given in Table II.

Table II

Tensile strength wedge, kg / cm ²

Modulus of elongation, kg / cm ²
Flexural Strength, kg / cm ² ....
Flexural modulus, kg / cm ² . .

Elongation, " ₀

Notched impact strength,
ka / cm'cm notch

With

filler

offset

Polymer

301.8
71010

537.5
51324
1.5

7.1

Base polymer

232.1
11952

312.8
9842
7.9

Example 3

In a comparative experiment not corresponding to the present invention, that in Example 1 essentially repeated with the exception that a normal polyethylene of high density (melt index 3) instead of the graft copolymer made of high density polyethylene

and acrylic acid was used. The properties of this composition are summarized in Table HI. at A comparison of the values listed in Table 1 with those summarized in Table 111 result significant improvements in properties obtained when the graft copolymer is in bulk Made of high density polyethylene and acrylic acid is used.

Table 111

Tensile strength, kg / cm-

Modulus of elongation, kg / cm ²
Flexural Strength, kg / cm '-....
Flexural modulus, kg / cm ² ..

Elongation, " _u

Notched impact wedge,
ka / cm / cm notch

With
filler

offset
Polymer

Base polymer

218.6 217.4

55542! 11952
389.4 312.8

56949
0.9

2.3

9842
9.0

4.1

Example 4

For a number of masses of aluminum puKcr and the graft copolymer of high density polyethylene and acrylic acid accordingly Example 2 made with up to 60 percent by volume aluminum powder. The influence of the aluminum powder content The physical properties of selected samples are summarized in Table IV. From the values it is found that favorable improvements in properties are obtained when the Aluminum powder is present in the mixture in an amount / between about 40 and about 60 percent by volume is. Further investigations showed that the most favorable properties are obtained when the aluminum powder is present in an amount between about 46 and 55 percent by volume.

Table IV

Aluminum switch. Volume percentage

40 i 50 i 55 i M)

Impact strength, kg cm /
cm notch. .

Tensile strenght.
kg / cm ²

Elongation modulus.

46402 84368 87181 249.6 309.3 316.4 30232 65385 77479

56245

253.1

86477

Table ^v

Tensile Strength, kg / cm ² 229.2

Modulus of elongation, kg / cm ^{2 49215}

Flexural Strength, kg / cm ² 586.3

Flexural modulus, kg / cm ^{2 56245}

Elongation, ° _o 4.6

Notched impact strength,

kg cm cm notch 6.0

Example 6

The procedure was as in Example 1, with the exception that 89.0 g of fine iron powder and 11.0 g of a graft copolymer made of polyethylene of high density and acrylic acid (about 50/50 volume percent) were mixed and the mass formed became. The physical properties of this composition are listed in Table VI.

Table VI

Tensile strength, cm ² 370.5

Modulus of elongation, kg / cm ^{2 405671}

Flexural Strength, kg / cm- 922.3

Flexural modulus, kg'cm ² 104560

Strain. " ₀ 1.1

Notched impact strength

kg cm cm notch 6.2

Example 7

The procedure of Example 2 was repeated with the exception that 16 volume percent of the aluminum washer have been replaced by carbon black to produce an electrical to give conductive ground. The total amount of filler (aluminum and carbon black) was 50 percent by volume. The thin surface layer of the polymer was removed by sandblasting to remove to expose the conductive particles, whereupon successfully by a conventional Nickcl-Elekiroplattierverfahren was plated with nickel ("Chemical Engineer's Handbook", J. N. Perry. Ed .. p. 1798. 3rd ed. 1950. McGraw Hill).

Example 8

The procedure was as in Example 2, with the exception that the Pl'rupfmischpolymerisat made of polyethylene of high density and acrylic acid through a random copolymer of ethylene and acrylic acid, which had 10 "acrylic acid and a melt index of 5. The properties of these Masses are listed in Table 7 and compared with those of the polymer not mixed with fillers.

Table VIl Example 5

The procedure described in Example 1 was carried out in

essentially repeated with the exception that 92.1 g

of a fine lead powder and 7.9 g of a graft mix

Polyethylene polymers of high density and tensile strength, kg / cm ²

Acrylic acid (about 50/50 volume percent) was mixed 65 modulus of elongation. kgem ²

that to make up the crowd. The physical stretch. ",,

Properties of this mass are given in Table V - notched impact strength,

in summary. kg cm cm notch

! With

; l-iilkioiTcn Griind-

replaced
Polymer

164.7
1881
1.8

polymer

60.0
1409

8.3 j (too soft)

Example 9

The procedure of Example 2 was repeated with the exception that aluminum powder of different Particle size was used. The physical properties of those with aluminum from Masses produced with different particle sizes are summarized in Table VIII.

Table VIII

aluminum train
strength, Expansion
potential
module, Strain, Notch impact
strength, By-
sectional
Partial
size, kg cm / micron kg / cm ⁸ kg / cm ² cm notch diameter 297.7 87884 _ 4.6 297 297.2 66088 1.9 5.2 74 301.8 71010 1.5 7.0 20th 301.8 87181 1.5 7.7 18th 304.4 65385 1.6 7.3 13th 295.5 76635 1.5 3.4 4 to 6

Example 10

In Table IX the improved physical properties are one with 50 volume percent aluminum as a filler mixed polymer of polyethylene and acrylic acid compared to those of the copolymer shown without fillers.

Table IX

Tensile strength ¹ ), kg / cm ² ... With reason Modulus of elongation, kg / cm ² filler polymer 5 Flexural Strength, kg / cm ² .... offset Flexural modulus, kg / cm ² .. Polymer 239.4 Elongation, % 295.9 11530 Notched impact strength ² ), 72416 313.1 IO kg cm / cm notch 547.4 9984 Abrasion ³ ), weight loss 62573 9.0 Rockwell hardness ⁴ ) 2.0 Thermal conductivity ⁵ ), ^to 5 ^v 3.4 cal-cm / hr- ° C-cm ² 7.7 0.0146 15th Vicat HD ^e ), ⁰ C 0.0427 15 / 88-136 Tensile strength HD ⁷ ), 15 / 138-153 (66 psi) 4.64 kg / cm ² .. 22.7 Creep resistance ⁸ ), 77.8 129 126.7 kg / cm ² L / L 139 20th (100 hours) 118 Hours to break 124 126.7 kg / cm ² 0.12 0.01 * 5 50 800

*) ASTM D 638-58 T.

·) ASTM D 256, 56 method A.

») Drum, rollers CS 10 F, 2000 rev.

*) Rockweil surface hardness (Vi ") 0.63 cm ball 15 kg.

·) Room temperature, sheets of 15 X 15 χ 0.32 cm; heD

37.9 ° C. Cold 11 "C. ') ASTM 1525-58 T.') ASTM D 1637-59 T. ⁸ ) Compression molded test bars of 15 χ 1.27 χ 0.32 cm:

L = 5 cm, room temperature.

Example 11

The procedure described in Example 1 was essentially repeated except that 75 grams of a graft copolymer of high density polyethylene and acrylic acid, 204 g of aluminum powder and 21 grams of chopped fiberglass strands 0.67 cm in length were mixed together to form the mass. the improved physical properties of this mass compared to those of the base polymer are in Table X summarized.

Table X

With Reason- filler polymer offset Polymer 239.4 Tensile strength, kg / cm ² 408.5 11249 Modulus of elongation, kg / cm ² 84368 313.1 Flexural Strength, kg / cm ² .... 843.7 9843 Flexural modulus, kg / cm ² .. 65385 9.0 Strain, % 1.6

■ 409526/4

Claims (6)

Patent claims: 1. Polymer compositions, consisting of ethylene polymers and a finely divided one contained therein Metal powder, the metal particles in an amount between 40 and 60 percent by volume, based on the volume of the metal particles present in the entire polymer-Meiall mass, are present and wherein the ethylene polymer as a copolymer of 75 to 98 percent by weight Ethylene and 2 to 25 percent by weight of a mono- or polybasic ethylenically unsaturated Carboxylic acid with 3 to 8 carbon atoms in which the carboxyl groups are partially esterified can be present. 2. Polymer composition according to claim 1, characterized in that the ethylenically unsaturated Carboxylic acid is present as an aliphatic monocarboxylic acid. 3. Polymer composition according to claim 1, characterized in that the ethylenically unsaturated Carboxylic acid as an aliphatic polycarboxylic acid in which all but one carboxyl group Carboxyl groups esterified with an aliphatic alcohol having 1 to 20 carbon atoms can be present. 4. polymer composition according to claim 1 or 2, characterized in that the ethylenically unsaturated Carboxylic acid is present as acrylic acid. 5. polymer composition according to claim 1 to 4, characterized in that the metal particles 5 to 300 μ in diameter. 6. polymer composition according to claim 1 to 5, characterized in that together next a larger proportion of the metal particles, a smaller proportion of a non-metallic filler is present.