JPS6268833A - Polyethylene based composition and molded article thereof - Google Patents

Abstract

PURPOSE:The titled composition, consisting of metal powder consisting essentially of copper, polyethylene and ethylenic polymer containing carboxyl groups, having improved antimicrobial and antifungal properties and melt moldable into filaments, sheets, films, etc. CONSTITUTION:A polyethylene based composition obtained by incorporating (A) 15-40wt% metal powder selected from metallic copper having 1-20mum average particle diameter with <=8wt% oversize on a 250-mesh screen or alloy powder containing >=60wt% copper which may be oxidized with (B) 60-85wt% polyethylene having preferably 0.1-50 melt index (MI) and, as necessary, (C) 1-10wt% ethylenic polymer having >=1, preferably 5-50, based on 1,000 carbon atoms in the polymer, carboxyl groups, preferably by incorporating the components (B) with (C) and then component (A) therewith. The resultant composition is melt molded while heating and cold-drawn to afford the aimed molded article.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a polyethylene resin composition that has excellent antibacterial and antifungal properties and can be melt-molded into filaments, sheets, films, or pipes, and molded products thereof.

It is well known that as we enter the era of the 200 nautical mile limit on conventional technology, the number of marine resources that can be caught between islands has decreased significantly, and as a countermeasure, fisheries have shifted from fishing to cultivating fisheries, and in particular, aquaculture fisheries are becoming more popular. It is exactly as it is written. At the same time, the development of fishing gear necessary for aquaculture has become more active, and there are problems in particular with fishing gear being corroded in seawater or having various deposits attached to it. Research is underway to control the deposits.

Traditionally, ropes and fishing nets used in fishing have been made of synthetic resins such as polyethylene, polypropylene, or nylon;
m caused by marine bacteria than those manufactured using natural fibers such as linen thread! ! Although II is said to be small, it is well known that a considerable number of microorganisms still grow in spots on the synthetic resin fishing gear, causing the surface of the fishing gear to corrode in a concave shape. When shellfish (such as ropes or fishing nets) are immersed in seawater for a certain period of time, organic and inorganic suspended matter suspended in the seawater will first adhere to them, and then snails, seaweed, or sea lettuce. Algae and hydrozoa, such as these, settle on the ground, and a large number of minute deposits grow densely.
Furthermore, as time passes, moss insects attach to the area, creating areas where the water flow is stagnant, and floating larvae such as Fujibbo grow and easily attach, which stagnates the water flow within the aquaculture net and causes pests and diseases. It induces outbreaks and damages the growth of aquaculture.

In order to deal with the above-mentioned problems, various antifouling agents have been commercially available, such as i'! Nets are soaked in these antifouling agent solutions and then air-dried to adhere the antifouling agents to the fishing nets, giving them an antifouling effect, but the effect lasts for several months at most. However, there is a problem in that fishing nets must be frequently coated with antifouling agents. The damage caused by the marine organisms described above is not limited to fishing nets, but is also observed in sheets, films, pipes, etc. used in devices and equipment that use seawater, and is still a major problem.

Problems to be Solved by the Invention However, the conventional anti-lη methods described above have poor long-term effects, and fishing gear such as fishing nets, as well as equipment and equipment that use seawater, require antifouling agents and anti-fouling agents. There was a problem in that dirty paint had to be frequently applied for maintenance management.

Problems The problems of the prior art described above are, for example, 4 in accordance with the present invention.
This problem can be solved by using ropes, nets, sheets, films, etc. made of monofilaments made from the No. 64 resin composition. That is, when these ropes, nets, sheets, films, etc. are immersed in seawater, the metal powder mixed into the resin composition of the present invention is ionized in the seawater, and its antibacterial effect is reduced. 41 of Bacteria]
Ikuo r! 11 and exhibits a bactericidal action that kills algae lamps 1 such as Aomidoji 1.

That is, the polyethylene resin composition according to the present invention has (1) an average particle size of 1 μm and 20. +jm or less, 25
At least one metal, which may be oxidized, selected from the group of metallic copper whose residual sieve content is 8% or less and alloy powder containing at least 6% copper Powder 15-40% and (ii) polyethylene 60-](5%) and, if necessary, (ii)
i) 100011 carbon atoms in the polymer? There is provided a polyethylene resin composition comprising 1 to 10 M% of an ethylene polymer containing at least one carboxyl group based on IL.

The polyethylene non-based resin composition according to the present invention is, for example, melt-molded and cooled and stretched to form filaments 1-,
It can be used in any form such as sheet, film, pipe, etc.

The metal powder blended into the resin composition of the present invention has an average particle size of more than 1 μm and 20 μm or less, preferably more than 1 μm and 15 μm.
Hereinafter, it is particularly preferably more than 1 μm and not more than 12 μm. That is, in order to obtain appropriate mechanical performance by melt-molding the resulting resin composition, it is necessary to
m or less metal powder must be used. However, even if the average particle size of the metal powder is 20 μm or less, 250 μm or less
If the amount of Iff powder remaining on the mesh sieve exceeds 8% by weight of the metal powder, the molded product obtained by melt-molding the resin composition will not exhibit sufficient mechanical performance, which is not preferable.

The preferred metal powder has an average particle size of 2 pm or less per month, and 25
The amount of coarse powder remaining on the sieve of 0 methane is less than 5% by weight of the metal powder. Particularly preferred metal powders have an average particle size of 8 μm or less, an amount of coarse powder remaining on a 250 sieve sieve of 2% by weight or less, and an amount of compatible powder remaining on the sieve of 0.5 weight %. Particularly excellent performance is exhibited when the following conditions are met.

The smaller the average particle size of the metal powder, the better its dispersibility in resin.
The mechanical performance of the resin composition is also excellent, and when the average particle size is 1 μm or less, not only is there no significant increase in the improvement effect on properties and mechanical performance, but the price of the metal powder increases significantly, 1 in terms of economy for the purpose of the invention.
The use of metal powders having an average particle size of pm or less cannot be said to be preferable.

Can be used as metal powder in the present invention,
As the alloy powder containing at least 60% by weight of copper,
Examples include brass, bronze, and nickel-copper alloys.

The amount of metal powder in the resin composition of the present invention is 40% by weight.
If the amount exceeds 15% by weight, it is undesirable because the mechanical performance of the resin molded product will deteriorate without particularly increasing the antibacterial and antibacterial properties.On the other hand, if the amount of metal powder is less than 15% by weight, This is not preferable because the antibacterial and antifouling effects will be lost. Moldability, mechanical performance and antibacterial properties of resin compositions,
In order to obtain a resin composition that is excellent in both anti-scaly effects, the preferred amount of metal powder is 15 to 35% by weight, particularly preferably 20 to 30% by weight.

The polyethylene used in the resin composition of the present invention is:

Homopolymers of ethylene or ethylene and other comonomers containing at least 80% by weight of units consisting of ethylene (e.g. propylene, butene-1, hexene-1,
It is a copolymer with 4-methylpentene-1, octene-1) and can be produced by conventional radical polymerization or ionic polymerization. The polyethylene may be a mixture of ethylene alone or a copolymer obtained by the radical polymerization or ionic polymerization, or may be a mixture of other thermoplastic resins (for example, nylon, polypropylene) in an amount of 20% by weight or less. It can be anything.

The polyethylene used in the present invention is preferably M
T 0.1-50, more preferably M I 0.3-50
It is 20. Furthermore, the polyethylene for the resin composition used for the filament is preferably one produced by ionic polymerization, particularly preferably one having an M of 10.3 to 2, and furthermore one having an M of 10.3 to 2.
Particularly preferred is one between 0.5 and 1. Furthermore, HL old/Ml
is preferably 38 or less, and particularly preferably 33 or less. Further, the density of the polyethylene is 0.9
Preferably, it is 45 g/cc or more. On the other hand, as the polyethylene for the resin composition used for films and sheets, it is preferable to use polyethylene having an MI of 0.5 to 20.

If the amount of polyethylene blended into the resin composition according to the present invention is too large, the desired antibacterial and antifungal effects will be poor, which is undesirable.On the other hand, if the amount is too small, molding of filaments, sheets, films, pipes, etc. This is not preferable because the mechanical performance of the product deteriorates.

The ethylene polymer containing at least one carboxyl group per 1000 carbon atoms of the polymer, which is blended in the second embodiment of the resin composition according to the present invention, refers to an ethylene polymer containing ethylene monomer in the polymer. A polymer containing at least 70% by weight of units derived from. This polymer can be produced by a conventional ionic polymerization method, radical polymerization method, or the like. Furthermore, a carboxyl-containing ethylene polymer can also be obtained by producing an ethylene polymer and then modifying the polymer with a compound having a carboxyl group. The carboxyl group in the carboxyl-containing ethylene polymer can be introduced using the compounds exemplified below. Maleic anhydride, acrylic acid, methacrylic acid, crotonic acid, maleic acid, methyl hydrogen maleate, itaconic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, α-
Cyanoisopropyl acrylate, β-cyanoethyl acrylate, 0-(3-phenylpropane-1,3-dionyl) phenyl acrylate, glycidyl acrylate, methyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, 2-ethyl Hexyl methacrylate, stearyl methacrylate, glycidyl methacrylate, β-hydroxypropyl methacrylate, 3-hydroxy-4
-carbomethoxyphenylmethacrylate-1-1N,
N-dimethylaminoethyl methacrylate-1., diethyl fumarate, di-n-butyl fumarate, diethyl maleate, and methyl crotonate. According to the present invention, one or more of the compounds exemplified above.
By copolymerizing 2 with ethylene, the desired carboxyl group-containing polymer can be obtained.

Other comonomers (e.g. styrene,
(vinyl acetate, vinyl ether monomers, fluorine-substituted olefins) may also be present. Further, the desired carboxyl group-containing polymer can be obtained by grafting one or more of the compounds listed above to the ethylene polymer.

Preferred examples of the exemplified compounds listed under 1-1 include maleic anhydride, methacrylic acid, acrylic acid, methyl hydrogen maleate, methyl acrylate, and ethyl acrylate-I.
, methyl methacrylate, glycidyl methacrylate,
Glycidyl acrylate, methacrylic acid, acrylic acid, methyl hydrogen maleate, glycidyl methacrylate
Particular preference is given to using 1. glycidyl acrylate.

By using the carboxyl group-containing polymer in the resin composition of the present invention, the mechanical performance of the resulting resin composition is significantly improved. Although the cause of this effect is not clear, it is thought to be due to improved wetting of the interface between polyethylene and metal powder.

The number of carboxyl groups in the carboxyl group-containing polymer used in the present invention is preferably 70 or less, particularly preferably 5 to 50, per 1000111iI of carbon atoms in the polymer.

This carboxyl group-containing polymer contains 1 to 1
However, if this amount is less than 1% by weight, the effect of improving the interface will be poor, and if it exceeds 10% by weight, the performance of the carboxyl group-containing polymer will be affected by the mechanical performance of the target resin composition. is reflected in the image, which is not desirable. The preferred range of the amount of the carboxyl group-containing polymer incorporated into the resin composition is 3 to 7% by weight. The carboxyl-containing polymer has an average molecular weight of 2,000 to 200,000, preferably 5,000 to 100,000.

In the resin composition containing metal powder, polyethylene, and carboxyl-containing polyethylene polymer according to the present invention, the excellent effect of improving wetting with the carboxyl-containing polyethylene polymer is obtained by oxidizing the metal powder. It will be done.

Any conventionally known method can be used for the oxidation treatment of the metal powder. Examples of such methods include flame treatment, chromic acid treatment, and ozone treatment.

By subjecting the metal powder to oxidation treatment according to the present invention, the interaction with the carboxyl group-containing ethylene polymer is enhanced, so it is assumed that the excellent effects described above can be obtained.

To produce the resin composition according to the present invention, the two or three components can be mixed by a conventionally known mixing method. For example, the metal powder and the polyethylene (and the carboxyl group-containing polyethylene) can be mixed according to a conventional method for mixing fillers and polyolefins such as polyethylene.

As a specific example, a predetermined amount of metal powder and polyethylene powder (and carboxyl-containing ethylene polymer) are mixed in a Henschel mixer with appropriate additives as necessary, and then melt-mixed using an extruder. It can be a beret.

This pellet can be made into any shape such as a filament, sheet, or film using a molding machine. In addition, when blending three components, the three components may be blended at the same time, but it is also possible to blend two of the three components in advance and then blend and mix the remaining components, In this case, it is preferable to first mix the polyethylene and the carboxyl group-containing ethylene polymer, and then mix the metal powder.

The resin composition according to the present invention can be made into filaments, tapes, and pipes having excellent antibacterial and antifungal properties by, for example, heating and melting using a general-purpose extruder, extrusion molding, cooling and stretching, and spinning or molding. and films can be easily produced.

The various molded products manufactured by the method of the present invention have the advantage that even if their surfaces are abraded by seawater, for example, the antibacterial and anti-mildew effects will not be diminished because the metal powder is dispersed and kneaded throughout the molded product. have

The resin composition according to the present invention can also be used for applications other than fishing, such as antibacterial shoe insoles, sanitary sheets, anti-fouling packaging films, and nets for outdoor use.

Examples of Embellishment - The present invention will be described in detail below with reference to Examples, but it goes without saying that the technical scope of the present invention is not limited to these Examples.

A polyolefin (Mlo, 8 kg) obtained by ionic polymerization of 2.8 kg of metallic copper powder with an average particle size of 5 μm (residual amount on a 250 sieve: 0.3%, 1%) using a titanium catalyst.
, anal old/MI31, density 0.950 g/cc)
7.2 kg, 20 g of di-t-butylhydroxytoluene and 30 g of calcium stearate were uniformly mixed using a Henschel mixer, and then this mixture was mixed with
Pellets of the resin composition were obtained by melt-mixing using an Oryu φ twin-screw extruder.

The strength and elongation of the obtained resin composition were measured using a tensile measuring machine. In addition, antifouling properties were measured as follows. The results were as shown in Table 1.

That is, monofilament obtained from resin composition pellets (
The drawn yarn) was made into a net, which was immersed 1.5 m below the sea surface in a southward direction, and the degree of contamination after 3 months was visually determined.

◎: Almost no stain ○: Slight stain □ ×: Stain XX: Very dirty Examples 2 to 3 and Comparative Examples 1 to 3 Polyethylene and copper powder with the physical properties and amounts shown in Table 1 were used. A resin composition was obtained in the same manner as in Example 1. The physical properties of the obtained resin composition were as shown in Table 1.

Example 4 Metallic copper powder with an average particle size of 5 μm (250 mesh sieve)
2.5 kg of polyethylene obtained by ion desorption using a titanium catalyst (M+0
．． 8.111. Old/MI31, density 0.9508/
cc) 7.1 kg, ethylene-acrylic acid copolymer (
Molecular weight 80,000, carboxyl group content 15117.
0.4 kg of 1/+000 carbon 1 < 4 carbons), 20 g of di-t-butylhydroquinol-1-luene, and 30 g of calcium stearate were uniformly mixed using a Henschel mixer.
Then, this mixture was melt-mixed using a 30-diameter 1φ twin-screw extruder to obtain resin composition pellets. The breaking strength and elongation of the obtained) 61 fatty silk composition were measured using a tensile tester (JI56760). The results are shown in Table 2.
It was an illusion. A monofilament die having six small holes of 1 m/m was attached to this. Using a 40ml 1φ extruder, the drawn yarn was stretched 8 times in a 5100°C drawing bath, which was anti-filtered and cooled in a cooling bath, to obtain a drawn yarn.The stain resistance of this drawn yarn was measured in the same manner as in Example 1.Results were as shown in Table 2.

Examples 5 to 7 and Comparative Examples 5 to 9 Resin compositions were obtained in the same manner as in Example 4 using polyethylene, copper powder, and carboxyl-containing ethylene copolymer having the physical properties and amounts shown in Table 2.

The results were as shown in Table 2.

(Left below) Harm - Treatment (7+11-) 2.50 kg of metallic copper powder with an average particle size of 5 μm (residual amount on a 250 mesh sieve was 0.3% by weight) was treated with an oxidizing flame. As a result, 2.65 kf 2.5 kg of this oxidized copper powder was obtained.
Polyethylene obtained by ionic polymerization using a titanium catalyst (M+0.8, Ml/Ml 31. Density 0.95
0g/cc) 7.1 kg, ethylene-acrylic acid copolymer (molecular weight 80,000, carboxyl group content 1
5/1000 carbon atoms), 0.4 kg of di-1-butyl hydroxide/l/1720 g, and 30 μg of calcium histearate were uniformly mixed using a Henschel mixer. Next, the obtained mixture was melt-mixed using a 30 mmφ twin-screw extruder to obtain pellets of the resin composition. The breaking strength and elongation of this resin composition were measured using a tensile tester (JIS 6760). The results obtained are shown in Table 3. Next, a monofilament die having six small holes of 1 m/m was attached to this. 40 seal ■φ
After being yarn-proofed in an extruder and cooled in a cooling bath, the yarn was stretched 8 times in a 100° C. stretching bath to obtain a drawn yarn, and the antifouling property was measured in the same manner as in Example 1.

Harm - Example 9 c'-0 Harassment Example 1 Shooting: U In the same manner as in Example 8 using polyethylene, copper powder and carboxyl group-containing ethylene polymer having the physical properties and amounts shown in Table 3. A resin composition was obtained.

The results obtained are shown in Table 3.

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Claims (1)

[Claims] 1. (i) The average particle size is more than 1 μm and not more than 20 μm, and 250
15 to 40% by weight of at least one metal powder, which may be oxidized, selected from metallic copper whose residual amount on a mesh sieve is 8% by weight or less and alloy powder containing at least 60% by weight of copper. , (ii) polyethylene 60
~85% by weight and, if necessary, (iii) 1 to 10% by weight of an ethylene polymer containing at least one carboxyl group per 1000 carbon atoms of the polymer. thing. 2. (i) The average particle size is more than 1 μm and less than 20 μm, and 250
15 to 40% by weight of at least one metal powder, which may be oxidized, selected from metallic copper whose residual amount on a mesh sieve is 8% by weight or less and alloy powder containing at least 60% by weight of copper. , (ii) polyethylene 60
~85% by weight and, if necessary, (iii) 1 to 10% by weight of an ethylene polymer containing at least one carboxyl group per 1000 carbon atoms of the polymer. A molded product made by heating, melting, and then cooling and stretching.