WO2010075825A1

WO2010075825A1 - Filler modified for polymeric systems with different polarity of polymer component and the method of its preparation

Info

Publication number: WO2010075825A1
Application number: PCT/CZ2009/000159
Authority: WO
Inventors: Jiri Malac; Martin Betik; Vlastimil Fryzelka
Original assignee: Tomas Bata University In Zlin
Priority date: 2008-12-29
Filing date: 2009-12-21
Publication date: 2010-07-08
Also published as: CZ303376B6; CZ2008847A3

Abstract

Subject matter of the invention is a filler modified to suit polymer systems containing a polymer component with a different polarity, which contains a modification additive comprising 0.1 to 50 mass percent of a chemical compound containing a sulphonyl functional group. The method of preparation of the filler according to the present invention consists in treating the filler surface with a chemical compound containing the sulphonyl functional group, advantageously at the temperature exceeding 100 °C.

Description

FILLER MODIFIED FOR POLYMERIC SYSTEMS WITH DIFFERENT POLARITY OF POLYMER COMPONENT AND THE METHOD OF ITS PREPARATION

Field of invention

The invention relates to a filler, particularly to a mineral filler, for polymer systems having a polymer component with a different polarity, to a method of preparation of the said filler and of polymer systems containing the said filler.

State of the art

Polymer systems contain polymeric molecules of various chemical composition, various structure and spatial arrangement. According to dependence of the basic properties of polymers on temperature, in applications the polymer systems are used as elastomers, thermoplastics or thermosetting plastics.

Frequently, separate components of the polymer systems possess different polarity. An example of such a polymer system is a non-polar polymeric matrix containing mineral fillers or a polymer system comprising polymers of various polarity. Application properties of the polymer systems containing components of various polarity depend to a great extent on interaction (i.e. mutual action) between the separate components. For instance, fillers exhibiting a higher degree of the filler-polymer interaction improve usually some properties of the polymer systems.

Mineral fillers, such as clay, talc, mica, calcium carbonate, silicone dioxide (silica), calcium silicate and aluminium trihydrate. are materials obtained by various procedures. Frequently, they are natural materials mined, ground and sorted to a required particle size. But also precipitated mineral fillers manufactured by precipitation of solutions are known.

For polar polymers the interaction between polar surface of the mineral filler and polar polymeric matrix is often sufficiently high even without surface treatment of the mineral filler.

However, non-polar polymers are often organic materials of hydrophobic nature while mineral fillers have hydrophilic surface. Therefore, the interaction between the non-polar polymers and polar mineral fillers is low. The low interaction results in poor properties of the polymer systems. The polymer systems possessing poor properties are unusable for An improvement of properties of a number of non-polar polymer systems is achieved by using mineral fillers treated with organosilanes, such as bis(3- triethoxysilylpropyl)tetrasulphane, γ-mercaptopropyltrimetoxysilane, γ-thiokyanato- propyltriethoxysilane, vinyltrialkoxysilane or γ-chlorpropyltrietoxysilane.

The organosilanes improve for instance properties of non-polar polymer systems containing silica, clay, mica, talc and calcium silicate. Surface treatment of the filler is carried out either before mixing (i e. a surface treated mineral filler is used during preparation of the polymer system) or in the course of preparation of the polymer system (i.e. silane and a non- treated mineral filler are added separately during preparation of the polymer system).

For a correct function of the silanes at the filler/polymer matrix interface the reaction between surface of the filler and the silane (known as a silanisation reaction) must reach the required degree of conversion, which is sometimes difficult.

Consequently, the main disadvantage of using silanes in non-polar polymer systems containing mineral fillers is dependence of properties of such polymer systems ori a complex kinetics of chemical reactions between the silane and the surface of the mineral fillers. Thus properties of the non-polar polymer systems containing mineral fillers and silarie depend not only on composition of the polymer systems but also on the achieved degree of conversion of the chemical reactions, which is undesirable.

Nature of the invention

The above shortcomings of the previous art are eliminated by employing a filler modified to suit polymer systems containing a polymer component of a different polarity" according to this invention. The nature of the invention can be described as follows. The filler contains a modification additive comprising 0.1 to 50 percent by mass, advantageously 0.25 to 25 percent by mass, of a chemical compound containing a sulphonyl functional group.

The modification additive can form advantageously a surface layer on the filler particles. It can primarily be a chemical compound containing a sulphonyl functional group selected from a group including dimethyl sulphone, methylethyl sulphone, diethyl sulphone, methylpropyl sulphone and tetramethylene sulphone.

The method of preparation of the filler according to the present invention consists in treating the filler surface with the modification additive - chemical compound containing the sulphonyl functional group - at the temperature exceeding 100 °C. The main advantage of this method according to this invention is the possibility to improve properties of the polymer systems without using the silanes and, consequently, also without affecting properties of the polymer system by a degree of conversion of the silanisation reaction.

An advantage of this invention is also the fact that the chemical compounds containing the sulphonyl functional group are often virtually non-toxic and, consequently, have no environmental impact.

Exemplary embodiment of invention

Two procedures for preparation of the modified filler according to the present invention were tested.

A. Modification of dried filler

- At first the filler was dried for a period of 2 hours at the temperature of 200 ⁰C in order to remove water absorbed on its surface.

- The modification agent was mixed into the dried filler at the temperature exceeding 100 ⁰C.

The mixture comprising the filler plus the modifier was heated at the temperature of 150 ⁰C for a period of 1 hour in order to assure a uniform wetting of the filler surface with the modification additive.

- Subsequently, the filler modified to suit the polymer systems according to the invention was cooled to the room temperature.

B. Modification of undried filler

- A mixture of the filler plus the modification agent was prepared at the room temperature:

- The mixture comprising the filler plus the modifier was dried at the temperature of 150 °C for a period of I hour in order to remove water absorbed on the filler surface and to assure a uniform wetting of the filler surface with the modification additive. Subsequently, the filler modified to suit the polymer systems according to the invention was cooled to the room temperature.

As a filler calcinated clay and silica were used in the example. Dimethyl sulphone at several concentrations (related to the filler) was used as the modification agent. In order to examine the effect of the modified fillers rubber compounds were prepared on a mill. The formulation of the rubber compound was as follows (phr = parts per hundred parts of rubber):

Rubber SBR 1500 100 phr

Filler 30 phr

Zinc oxide 5 phr

Blend of accelerators 2.4 phr

Sulphur 2 phr

Stearic acid (stearin) 1 phr

Vulcanised slabs were moulded from the rubber compounds prepared in this way to determine strength properties and tensile properties of the compounds containing unmodified and modified fillers were obtained.

The results shown in the exemplary embodiment of the invention indicate that the filler modified for polymer systems having a polymer component of a different polarity according to the present invention imparts the polymer system a higher strength and that strength values can be influenced also by method of preparation of the modified filler.

Claims

C L A I M S

1. A filler modified for polymer systems containing a polymer component with a different polarity characterized in that the said filler contains 0.1 to 50 mass percent of a chemical compound containing a sulphonyl functional group as a modification additive.

2. The filler according to claim 1 wherein the said filler contains 0.25 to 25 mass percent of a modification additive, the said modification additive being a chemical compound containing the sulphonyl functional group.

3. The filler according to claim 1, characterized in that the said chemical compound containing the sulphonyl functional group is at least one compound selected from a group including dimethyl sulphone, methylethyl sulphone, diethyl sulphone, methylpropyl sulphone and tetramethylene sulphone.

4. The filler according to claim 1, characterized in that the said modification additive forms a surface layer on the filler particles.

5. A method of preparation of the filler according to claim 1, characterized in that the filler surface is treated with the said modification additive - chemical compound containing the sulphonyl functional group.

6. The method of preparation of the filler according to claim 5, characterized in that the filler surface is treated with the said modification additive - chemical compound containing the sulphonyl functional group - at the temperature exceeding 100 ⁰C.

7. A polymer system comprising at least one polymer component and at least one filler, characterized in that at least one filler is a filler modified for polymer systems containing a polymer component with a different polarity according to claim 1.