Construction of elastomeric biocomposite intended for insulating layers and pads with regard to flexible antenna

Abstract

The disclosure relates to a composition of biocomposite based on natural rubber containing sol-bioglass, which is used and intended for insulating layers and pads in flexible antennas which can be worn in close vicinity with regard to the human body without adversely affecting it. According to the invention, the composition of the biocomposite intended and designed for insulating layers and pads in flexible antennas based on natural rubber is filled with sol-gel derived bioglass amounting to a quantitative range starting from 8 to 50 parts by weight with regard to 100 parts by weight rubber and having following list of remaining ingredients: zinc oxide from 2.5 to 3.5, stearic acid from 1 to 2.5, bis (triethoxysilylpropyl) tetrasulfide from 4 to 6, tertiary butyl-benzothiazolyl sulfenamide from 1 to 2.5, sulfur from 1 to 3 and isopropyl-phenyl-β-phenylene diamine from 0.5 to 1.5.

Claims

1. A composition of an elastomeric biocomposite designed for insulating layers and pads with regard to flexible antennas, comprising natural rubber, and further comprising, per 100 weight parts of the natural rubber: 8 to 50 parts sol-gel derived glass; 2.5 to 3.5 parts zinc oxide; 1 to 2.5 parts stearic acid; 4 to 6 parts bis-(triethoxysilylpropyl)-tetrasulfide; 1 to 2.5 parts tertiary butyl-benzothiazolyl sulfenamide; 1 to 3 parts sulfur; and 0.5 to 1.5 parts isopropyl-phenyl-β-phenylene-diamine; wherein the sol-gel glass contains 49-51% CaO, 39-41% SiO.sub.2, 8% P.sub.2O.sub.5, and 0.1-4% Ag.sub.2O.

Description

DESCRIPTION OF THE ENCLOSED DRAWINGS

(1) FIG. 1a demonstrates a SEM image of an observed wide area of sol-gel derived bioglass containing 4% silver oxide.

(2) FIG. 1b demonstrates SEM images of relevant qualitative and quantitative distribution therein.

(3) FIG. 2a demonstrates a SEM image of sol-gel derived bioglass containing 4% silver oxide, at separate points of which (the latter being indicated within the images of FIG. 2 by means of a cross mark) EDX analysis was performed.

(4) FIG. 2b demonstrates a SEM image of sol-gel derived bioglass containing 4% silver oxide, at separate points of which (the latter being indicated within the images of FIG. 2 by means of a cross mark) EDX analysis was performed.

(5) FIG. 2c demonstrates a SEM image of sol-gel derived bioglass containing 4% silver oxide, at separate points of which (the latter being indicated within the images of FIG. 2 by means of a cross mark) EDX analysis was performed.

(6) FIG. 2d demonstrates a SEM image of sol-gel derived bioglass containing 4% silver oxide, at separate points of which (the latter being indicated within the images of FIG. 2 by means of a cross mark) EDX analysis was performed.

(7) FIG. 3a reveals the dependence of the storage modulus on the temperature for composites containing bioglass (NR0 denotes a composite that does not contain a filler).

(8) FIG. 3 b reveals the tangent on the mechanical loss angle on the temperature for composites containing bioglass (NR0 denotes a composite that does not contain a filler).

EXAMPLES OF EMBODIMENT OF THE INVENTION

(9) The invention is described in more detail by means of preferred embodiment's representation without limiting its scope.

Example Number 1

(10) The construction of the composite according to the invention comprises, expresses in parts by weight:

(11) Natural rubber STR 10-100

(12) Zinc oxide—2.5

(13) Stearic acid—1.0

(14) Sol-gel derived filler—8.00

(15) /Silane Si 69/Bis (triethoxysilylpropyl)tetrasulfide—4.00

(16) IPPD/isopropyl phenyl-p-phenylenediamine/anti-aging agent/—0.5

(17) TBBS/tertiary butyl-benzothiazolyl sulphenamid)—a vulcanization accelerator/—1.0

(18) Sulfur—1.00

(19) The composition of the sol-gel derived glass was CaO—49.00, SiO.sub.2—39.00, P.sub.2O.sub.5—8.00, Ag.sub.2O—0.1

(20) The sol-gel derived glass is prepared in advance by means of a specially designed procedure involving heating to 600° C. after which a mixing procedure is conducted involving addition of elastomer during the manufacture of the rubber mixture together with the other ingredients referred to above.

(21) The mixture is made in an open laboratory rolls mixing mill with roller dimensions of L/D 320×160 mm, friction 1.27 and slower roller speed 25 min.sup.−1. The vulcanization of the rubber mixture was carried out on an electrically hydraulic vulcanization press with plates of 400×400 mm at a temperature of 150° C., a pressure of 10 MPa and a time determined by the vulcanization isotherms of the mixtures taken on a MDR 2000 Rheometer manufactured by AlphaTechnology.

Example Number 2

(22) The composition of the biocomposite includes:

(23) Natural rubber STR 10-100

(24) Zinc oxide—3.5

(25) Stearic acid—2.5

(26) Filler—50

(27) /Silane Si 69/Bis (triethoxysilylpropyl)tetrasulfide—6

(28) IPPD/isopropyl phenyl-p-phenylenediamine/anti-aging agent/—1.5

(29) TBBS/tertiary butyl-benzothiazolyl sulphenamid)—a vulcanization accelerator/—2.5

(30) Sulfur—3.00

(31) The composition of the sol-gel derived glass was CaO—51, SiO.sub.2—41%, P.sub.2O.sub.5—8%, Ag.sub.2O—4.0 and is obtained in a manner identical to the one revealed in Example number one.

(32) The composition of the elastomer biocomposite is obtained by means of implementation of a technology identical to the one revealed in example 1.

Example Number 3

(33) The composition of the biocomposite includes:

(34) Natural rubber STR 10-100

(35) Zinc oxide—3

(36) Stearic acid—2

(37) Filler—20

(38) /Silane Si 69/Bis (triethoxysilylpropyl)tetrasulfide—5

(39) IPPD/isopropyl phenyl-p-phenylenediamine/anti-aging agent/—1

(40) TBBS/tertiary butyl-benzothiazolyl sulphenamid)—a vulcanization accelerator/—1.5

(41) Sulfur—2.00

(42) The composition of the sol-gel derived glass is identical to the one as revealed in Example Number 2.

(43) The composition of the elastomer biocomposite is obtained by means of implementation of a technology identical to the one revealed in example 1.