JPH026657A - Highly oriented ultrahigh molecular weight polyolefin product, and its production and use - Google Patents

Abstract

PURPOSE: To obtain a reinforcing material for a composite material having improved wetting property and adhesion property by subjecting ultrahigh mol.wt. highly oriented polyolefin filaments, fibers, fabrics or films to plasma surface treatment under specified conditions and further subjecting to chemical treatment. CONSTITUTION: Filaments, fibers, fabrics, films or the like consisting of ultrahigh mol.wt. highly oriented polyethylene having >=600,000 g/mol weight average mol.wt. are preliminarily cleaned and then subjected to plasma treatment under conditions of 0.5 to 2 mmHg pressure, preferably 1 mmHg, 5 to 10 kw/m<2> energy density, preferably 15 to 50 kw/m<2> , at room temp. for 5 to 200 sec by using inert gas and/or reactive gas, preferably using reactive gas. Further, the material is subjected to chemical treatment to improve the wetting property and adhesion property.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to 600. OOOg1 mol (weight average molecular weight)
Products, which are filaments, fibers, yarns, fabrics and films, in particular on conventional 7-trinox materials, consisting of highly oriented polyolefins with ultra-high molecular weights of at least 10%, characterized by good wetting and adhesion properties, these products - JIS and their use for the production of composite materials.

BACKGROUND OF THE INVENTION European patent EP-A 0006 275 discloses a method for improving the adhesion of aromatic polyamide fibers, which comprises plasma-treating the fibers.

A disadvantage of this method is that the tensile strength of the fibers is reduced by plasma treatment.

European Patent EP-A 0 062 491 discloses that a reinforcing material is embedded within a conventional polymer matrix, the reinforcing material can consist of filaments and fibers of polyolefins having a molecular weight of up to 300,000, A method of manufacturing a composite material is disclosed that includes plasma treatment to improve adhesion. Again, a decrease in the tensile strength of the plasma-treated reinforced material is observed.

DISCLOSURE OF THE INVENTION It is an object of the present invention to improve the performance of polymers, especially in conventional matrix materials, such as filaments, fibers, yarns, fabrics and films, without at the same time reducing their tensile strength. In this case, polymeric matrix materials such as phenolic resins, epoxy resins, vinyl ester resins, polyester resins, acrylic acid resins, etc. or other thermoplastic resin matrix materials such as glass fiber carbon fiber, etc., such as polymethyl methacrylate can be used. It is particularly used in the production of composite materials in such a way that it is embedded as a reinforcing material together with conventional reinforcing materials. As a result of the plasma treatment of the invention, the filaments, fibers, etc. of the invention do not suffer from a decrease in tensile strength and exhibit good adhesion to the matrix material, so that their high tensile strength is fully utilized.

In the case of filaments, or fibers, yarns and fabrics produced from them, the highly oriented products of the present invention are produced by stretching the filaments, particularly at a draw ratio of 20 or more, preferably 30 or more; are produced in such a way that they are uniaxially or biaxially stretched at similar stretching ratios.

The object of the present invention is to improve the wettability and adhesion of the reflex product, which consists of highly oriented polyolefins.

The present invention is characterized by the plasma treatment of the surface of products, especially filaments, fibers, yarns, fabrics and films, made of highly oriented polyolefins with ultra-high molecular weights of 600.000 g/mol (weight average molecular weight) or more. This goal can be achieved.

Surprisingly, the tensile strength of the plasma-treated products is very high due to the high degree of orientation and ultra-high molecular weight, and as a result does not decrease, making the products according to the invention superior to the conventional 7. It is very suitable as a reinforcing material for the production of composite materials.

Preferably, the product of the invention has a
00. It consists of polyethylene, in particular linear polyethylene, with an ultra-high molecular weight of 1 mol OOOg and more.

The products of the invention are in particular filaments, fiber yarns,
The plasma-treated products, which are fabrics and films, are preferably produced by dissolving a specific ultra-high molecular weight polyolefin, particularly polyethylene, in a solvent and molding the solution at a temperature above the melting temperature of the polyolefin to form filaments or filaments. It is produced by the so-called gelling process, which consists of obtaining a tape, cooling the filament or tape below the melting temperature for gelation or solvent removal, and then stretching. Methods for producing such filaments are disclosed, for example, in British patents CB-A 2,042,414 and 2,051,667, while highly oriented, biaxially oriented films from ultra-high molecular weight polyolefins The production of is disclosed, for example, in German Patent No. 3.724.434.

Preferably, the product of the invention consists of polyethylene, especially linear polyethylene, copolymerizable with it of napropyrene,
phthylene, pentene, hexane, 4-methylpentane,
It may contain small amounts, preferably at most 5 mol %, of one or more alkenes such as octene and the like. Preferably, the polyethylene contains 1 to 10.0% carbon per 1000 carbon atoms. Especially 2
It can contain up to 6 methyl or ethyl groups. However, as mentioned above, other polyolefins can be used, such as homopolymers and copolymers, and the polyolefins can also contain small amounts of one or more polymers, especially 1-alkene polymers.

According to the invention, the filaments or the products and filaments made therefrom may be porous;
In this case they are preferably 01-0,9 g/c
m'' density. They can be produced by controlling the evaporation of solvent from gelling filaments or tapes in such a way that porosity remains.

The method for producing plasma-treated products of ultrahigh molecular weight, highly oriented polyolefins according to the invention comprises, if desired, subjecting the surface of these products to a plasma treatment after preliminary cleaning.

Pre-cleaning consists of, for example, a solvent treatment that serves to remove sizing agents adhering to its surface and to enable a clean surface of the product to be processed for plasma treatment.

Use drugs. For example, such a chemical treatment can be carried out by introducing the plasma-treated product into a solution of one of the aforementioned unsaturated compounds, for example an acrylic acid solution, but without chemical post-treatment in the gas phase. You can also do this. Chemical methods of this type for improving the adhesion of polyolefins are known.

In an advantageous manner, polyolefin filaments from which fibers, yarns and fabrics can be produced are used to carry out the method of the invention. The device for plasma treatment of filaments is covered by European patent EP-A 0 006 2.
It is disclosed in No. 75.

This device each consists of one or a number of narrow inlets and outlets through which the filament is continuously drawn and subjected to the plasma treatment. However, it is also possible to use a device in which the filament circulates inside the plasma chamber and is then wound around bending rollers in any desired number of loops, depending on the desired residence time.

The solvent treatment is carried out using inert and/or reactive gases, the use of reactive gases being preferred.

Inert gases include nitrogen and helium, and reactive gases include air, carbon dioxide, and ammonia.

Preferably 0.2-5 mm/g, especially about] mm
Under pressure of l+g, 5~I OKW/m3, especially 15~5
The plasma treatment is carried out at a density of 0 KW/m3, in particular at room temperature and with a residence time of 5 seconds to 200 seconds.

Immediately after the plasma treatment, a chemical treatment may be carried out to further impart active groups, such as carboxyl, hydroxyl or carbonyl groups, to the surface of the plasma-treated product in order to improve its wettability and adhesion. It's advantageous. Such treatments can be carried out using unsaturated compounds such as acrylic acid, acrylamide, maleic acid, glycyl methacrylate, hydroxyethyl methacrylate, itaconic acid, vinyl acetate, and the like.

In order to avoid polymerization of the unsaturated compounds, in this case preferably polymerization inhibitors such as iron (Il+) compounds are used.
Large areas of fabric or film can also be processed in a correspondingly sized plasma processing apparatus.

Composite materials produced using the filaments, fibers, yarns and fabricators of the present invention as reinforcing materials, in particular, can be used to manufacture sporting goods such as tennis rackets and golf clubs, and these composite materials can also be used to manufacture helmets, ports, etc. We can manufacture bulletproof products, high pressure hoses, etc.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

A yarn of 800 dtex consisting of about 400 monofilaments of polyethylene with a molecular weight of about 1.9 x 100 and having a strength of 2.4 GPa and a modulus of elasticity of 90 GPa is washed in carbon tetrachloride for size removal. .

This yarn was then dried at 25° C. under a pressure of 1 mm 11 g.
Due to the action of air plasma, the mechanical strength is 30 K.
Plasma treatment is performed at W/m3 for 50 seconds.

Using this yarn, 50% by volume yarn and 50% by volume resin (Eurepox 730 manufactured by Scher ing)
(trade name) 100 parts, and 2 parts of curing agent (XE278)
A composite material sample consisting of 0 parts) with a width of 3 mm and a height of /1
．． lnm.

Manufactured with a length of 150mm. This sample was heated to 1/
After fully curing for 2 hours at 80'C for 1 hour, the sample
It is cut to a length of 8 mm and its interlaminar shear strength is determined by ASTM method D2344 (accelerated bending test) at a bending speed of 2 mm/min.

For comparison, a similar sample is prepared using yarn without plasma treatment.

Interlaminar shear strength for plasma treated yarn is 30
．． 6 ± 0.7 MPa, and 1 for untreated yarn.
It is 2.9±0.8 MPa.

The corresponding tensile strengths are 2.50, ]5 GPa and 2.4±0.05 GPa, respectively.

These values indicate that the yarns of the present invention have twice the adhesion and the same tensile strength as the untreated yarns.

Claims (7)

[Claims] (1) Consisting of highly oriented polyolefin having an ultra-high molecular weight of 600,000 g/mol (weight average molecular weight) or more,
Products, especially filaments, fibers, yarns, fabrics and films, especially on common matrix materials, having good wettability and adhesion properties, whose surfaces have been plasma treated. (2) A product according to claim (1) consisting of polyethylene, in particular linear polyethylene. (3) Claims (1) or (2) of the invention, which comprises plasma-treating the surfaces of highly oriented filaments, fibers, fabrics, and films made of ultra-high molecular weight polyolefins, if necessary after preliminary cleaning. method of manufacturing the product. (4) The method according to claim (3), wherein the plasma treatment is performed using an inert gas and/or a reactive gas, particularly a reactive gas. (5) Under a pressure of 0.2 to 5 mmHg, especially about 1 mmHg, 5 to 10 KW/m^3, especially 15 to 50 KW/m^3
Claim 3, in which the plasma treatment is carried out at an energy density of 5 seconds to 200 seconds, particularly at room temperature.
) or the method described in (4). (6) The method according to any one of claims (3) to (5), further comprising a chemical treatment to improve wettability and adhesion. (7) Claims (1) to (6) for manufacturing composite materials
) Use of the products listed in any one of the above items.