WO2012159699A2

WO2012159699A2 - Composite material

Info

Publication number: WO2012159699A2
Application number: PCT/EP2012/001756
Authority: WO
Inventors: Michael Rohlmann
Original assignee: Thyssenkrupp Uhde Gmbh
Priority date: 2011-05-20
Filing date: 2012-04-25
Publication date: 2012-11-29
Also published as: WO2012159699A3; WO2012159699A4; DE102011102713A1; AR086431A1; TW201305256A

Abstract

The invention relates to a composite material comprising individual, short reinforcing fibres that are 0.1 - 50 mm in length, and a matrix that surrounds said reinforcing fibres and consists of a matrix material, said matrix material containing a thermoplastic material, and said reinforcing fibres containing polyphenylene sulfide.

Description

l

Composite material

The invention relates to a fiber-reinforced plastic structure

(Composite material), means made of the fiber-reinforced according to the invention

Plastic structure are made, and their use. Such plastic structures are materials which consist of reinforcing fibers which are embedded in a plastic matrix. These are found in a variety of applications in the form of short fiber reinforced,

Long fiber reinforced or continuous fiber reinforced components use.

The subgroup of glass fiber reinforced plastics is a composite of a plastic, such as polyester resin, epoxy or polyamide, and glass fibers. Glass fiber reinforced plastics are standard materials in the industry. Tubes of this type are standardized in the DIN and commercially available.

In the field of alkaline media glass fiber reinforced plastics are mainly used to absorb or to alkaline liquids

transported. These are typically made with a thermoplastic material, such as e.g. Polypropylene, provided as a chemical protective layer. This chemical protective layer is present on those surfaces which come into contact with the alkaline solutions and is intended to protect the glass fiber reinforced plastics. This additional protective layer is required above all when the alkaline solutions have temperatures of> 40 ° C and thus their corrosive effect is enhanced and surfaces are attacked and destroyed.

At temperatures below 40 ° C and low

Lye concentrations can be dispensed with a thermoplastic chemical protective layer and this is instead produced from the plastic matrix itself. The disadvantage of the glass fiber reinforced plastics known in the prior art is that if the chemical protection layer is damaged, the glass fibers are exposed and are exposed directly to a chemical attack by alkali.

Glass is a chemically highly resistant material, which is not laugebeständig and massively attacked by alkali and destroyed. By destroying the reinforcing fiber of the entire composite material is attacked, because the mechanical strength of the composite is achieved by the reinforcing fibers. The omission of the mechanical strength leads to the failure of the Material, since the pressure and temperature load, which prevails, for example, when operating an industrial plant, no resistance is opposed.

A glass fiber reinforced plastic pipe according to the prior art is known for example from DE 10 2008 033 577 A1. In particular, this document teaches a plastic tube which has improved properties in terms of tightness, rigidity, dimensional stability and abrasion in comparison to the prior art. The pipe wall is formed by at least one in the spin and / or

Centrifugal casting method produced spin coating and at least one in the

Winding process produced winding layer. Although such pipes have improved properties, but are very expensive to produce.

The use of pure thermoplastics, such as e.g. Polypropylene, as

Material for example containers or pipes, which are suitable for the transport of alkaline liquids, is known to be problematic due to the large thermal expansion and softening of thermoplastics at high temperatures.

A casing with glass fiber reinforced plastics or a

Embedding glass fibers in the thermoplastic to reduce thermal expansion and to ensure strength at higher temperatures up to 95 ° C, brings about the above-described problem with the use of alkaline media, that it decomposes and thus destroys the material of

Material comes.

In DE 2008 037 417 A1, for example, a thread is produced as a textile composite of different fibers, of which one fiber may be polyphenylene sulfide. This thread is used to reinforce an elastomer matrix material, so that at the end of the manufacturing process, an elastic workpiece, such as e.g. a hose is created. Disadvantage of this teaching is the elasticity of the product. This

Composite material is therefore not suitable as a material for example rigid

Pipelines or containers which must have high rigidity and hardness.

In EP 0 967 240 A2, fiber mats which may contain polyphenylene sulfide are used to reinforce the thermoplastic matrix material. The workpiece produced by this invention must be manufactured by means of pressing. The fiber mats are already contained in the mold before the introduction of the thermoplastic while the thermoplastic is introduced only in a second step. This approach has the disadvantage that a mixture of thermoplastic and fiber mats before the extrusion is not possible and also before Production of the material must first be generated mats, which is expensive.

The object of the present invention is therefore to provide an alternative composite material in which both the matrix material and the fiber material at temperatures> 60 ° C to 100 ° C resistant to alkaline media, and thus the probability of the occurrence of is reduced as described above. The invention has also set itself the task of providing appropriate means and uses of the composite material. The object is achieved by a composite comprising individual, reinforcing fibers having a length of 0.1 - 50 mm and a matrix surrounding these Verstärkungsfasem of a matrix material, wherein the

Matrix material contains a thermoplastic material and the reinforcing fibers contain polyphenylene sulfide. Surprisingly, it was found that a material containing short, randomly distributed in the matrix material single fibers of polyethylene sulfide has similar properties, such as a described in EP 0 967 240 A2 material containing elaborately prepared fiber mats, for a targeted distribution the fibers along the mats provide. Thus, this material can be made easier because it can be dispensed with a generation of mats.

In the manufacturing process of the matrix / fiber composite material is brought together in the extrusion or injection molding process in its respective form. The reinforcing fibers and the matrix material are first mixed and then processed. The processing temperature of the thermoplastic matrix material is about 210 ° C while the softening point of

Reinforcing fiber is at about 260 ° C. By this clear

Under temperature is ensured that the characteristics of the

Reinforcement fiber can not be changed.

Preferably, the composite reinforcing fibers of a length of 10 - 25 mm.

In an advantageous embodiment of the invention, the composite material additionally comprises the additives which influence the composite properties. These are selected from the group of stabilizers adhesion promoters and lubricants and are known to the person skilled in the art. In this case, the composite preferably comprises 0.05 to 5% by weight of additives. These can either be in the matrix material and / or in the

Be contained fiber material. According to the invention, the matrix material comprises 95 to 100% by weight of thermoplastic and 0 to 5% by weight of additives. The fiber material advantageously comprises 95 to 100% by weight of polyphenylene sulfide and 0 to 5% by weight of additives.

According to the invention, the matrix material from the group polyvinyl chloride, polyphenylene sulfide, polysulfone, polyethylene, polyamide, polyoxymethylene and

Polymethylpenten selected. Here are the thermoplastic materials

Polyvinyl chloride, polyphenylene sulfide and polysulfone provided with a polyphenylene sulfide reinforcing fiber, especially for use up to 95 ° C, also in

Presence of alkaline media, suitable. In contrast, the

thermoplastics polyethylene, polyamide, polyoxymethylene and

Polymethylpenten, which are provided with a polyphenylene sulfide reinforcing fiber, suitable for use up to 60 ° C.

Advantageously, the composite material according to the invention is resistant to> 20% - concentrated alkaline media, wherein the alkaline medium is in particular> 20% NaOH. It goes without saying that the

Composite also has a resistance to other chemicals. The composite of the present invention is resistant to alkaline media such as NaOH and other corrosive media at temperatures> 60 ° C to 100 ° C according to the choice of thermoplastic

Matrix material.

The present invention also includes means for receiving and / or transport of alkaline liquids, comprising the inventive

Composite material. These are advantageously pipes or containers.

In this case, the pipes and containers are made by a method known to those skilled in the art from the composite material. The known processes are in detail: Extrusion process: For this purpose, the plastic or the extrudate is first melted by an extruder (also called screw press) by means of heating and internal friction and homogenized. Furthermore, in the extruder necessary for the flow of the nozzle pressure is built up. After leaving the nozzle, the plastic usually solidifies in a water-cooled calibration. The mooring Vacuum causes the profile to press against the caliber wall and thus complete the shaping. This is often followed by a cooling section in the form of a cooled water bath. The cross section of the resulting geometric body corresponds to the nozzle or calibration used. Injection molding process: The thermoplastic injection molding is the basis for all other injection molding and the most commonly used

Plastic processing process at all.

The usual today Schneckenenkolbenspritzgießmaschine usually attracts plastics in the form of granules from a funnel in the screw threads, cuts and shears them. The resulting friction heat in conjunction with the heat supplied by the heated cylinder ensures a relatively homogeneous melt. This gathers in front of the top of the receding snail. In the so-called injection phase, the screw is pressurized hydraulically on the rear or by mechanical force. The melt is pressed under high pressure (usually between 500 and 2000 bar) through the nozzle pressed against the injection mold, possibly a hot runner system (common in modern series tools) and the sprue in the shaping cavity of the tempered injection mold. A reduced pressure acts as a reprint on the melt until the connection (sprue) solidifies (frozen). As a result, the volume shrinkage arising during cooling is largely compensated. By this measure, the dimensional accuracy and the desired surface quality is achieved. Thereafter, the rotation of the screw begins. While in this way the shot composition is prepared for the following molding, the molding in the tool can still cool until the soul (liquid core) is solidified. The tool opens and ejects the finished molding. The composite material according to the invention finds above all things

Use as a material for pipelines and / or containers, wherein the

Piping and / or the containers are brought into contact with alkaline media. Even at elevated temperatures of> 60 ° C of alkaline media, the piping and tanks are used. In a preferred use of the composite material, it is used in devices of an electrolysis process in which alkaline media are produced and / or supplied. The use is conceivable especially in inflows and outflows, as well as in the reaction chambers of electrolysis cells.

Further uses of the invention

Composite material will be explained below. These are for example Devices of a metal extraction process in which alkaline media are supplied and / or used, this being advantageously an aluminum extraction from bauxite. Furthermore, the invention relates generally to apparatuses of methods known in the art in which alkaline media are supplied and / or used. The use is conceivable especially in inflows and outflows, as well as in the reaction chambers of electrolysis cells.

Advantages resulting from the invention:

Composite material with good alkali resistance - composite material at high temperatures, even in the presence of

alkaline media resistant

Claims

claims

Composite comprising single, short reinforcing fibers having a length of 0.1 to 50 mm and a matrix of a matrix material surrounding these reinforcing fibers, wherein the matrix material is a

contains thermoplastic and the reinforcing fibers

Contain polyphenylene sulfide.

2. Composite material according to claim 1, characterized in that the

Reinforcing fibers have a length of 10 to 25 mm.

3. Composite material according to one of claims 1 or 2, characterized

in that the composite comprises as modifier the additives selected from the group of stabilizers, adhesion promoters and lubricants.

4. Composite material according to one of claims 1 to 3, characterized

characterized in that the composite comprises 0.05 to 5% parts by weight of additives.

5. Composite material according to one of the preceding claims, characterized

in that the matrix material comprises 95 to 100% by weight of thermoplastic and 0 to 5% by weight of additives.

6. Composite material according to one of the preceding claims, characterized

characterized in that the fiber material 95 to 100% by weight

Polyphenylene sulfide and 0 to 5% by weight of additives.

7. Composite material according to one of the preceding claims, characterized

in that the matrix material is selected from the group consisting of polyvinyl chloride, polyphenylene sulfide, polysulfone, polyethylene, polyamide, polyoxymethylene and polymethylpentene.

8. Composite material according to one of the preceding claims, characterized

characterized in that the composite is resistant to> 20% concentrated alkaline media.

9. Composite material according to claim 8, characterized in that the composite is resistant to> 20% NaOH.

10. Composite material according to one of the preceding claims, characterized

characterized in that the composite material at temperatures> 60 ° C to 100 ° C is alkali-resistant.

11. An agent for receiving and / or transporting alkaline liquids, comprising the composite material according to claim 1.

12. means for receiving and / or transport of alkaline liquids according to claim 11, characterized in that it is a tube.

13. means for receiving and / or transport of alkaline liquids according to claim 11, characterized in that it is a container.

14. Use of the composite material according to claim 1 as a material for

Pipelines and / or containers, wherein the pipelines and / or the containers are brought into contact with alkaline media.

15. Use of the composite material according to claim 1 as a material for

Pipelines and / or containers, wherein the composite material with alkaline media at a temperature of> 60 ° C is brought into contact.

16. Use of the composite material according to claim 1 in apparatuses of processes in which alkaline media are supplied and / or used.

17. The use of the composite according to claim 16, wherein the devices are devices of an electrolysis process in which alkaline media are produced and / or supplied.

18. The use of the composite of claim 16, wherein the devices are devices of a metal extraction process in which alkaline media are supplied and / or used.