DESCRIPTION
RESIN COMPOSITIONS AND FILAMENTS
TECHNICHAL FIELD
This application was filed claiming Paris Convention priority of Japanese Patent Application No. 2007-091216, the entire content of which is herein incorporated by reference . The present invention relates to a resin composition comprising a high density polyethylene, a high-pressure- processed low density polyethylene, an insect-controlling agent and a support, and a filament shaped of the resin composition.
BACKGROUND OF INVENTION
Resin compositions comprising polyethylene-based resins and insect-controlling agents are processed into various shaped articles for use as materials for controlling insects such as ticks, sucking lice, mosquitoes, flies, etc. For example, there is proposed in JP-A-8- 302080 (Patent Publication 1) a resin composition prepared by blending, to a high density polyethylene, an ethylene- based polymer to which an insect-controlling agent is highly migratory, such as a low density polyethylene or a linear low density polyethylene, and an insect-controlling agent, and this publication discloses in its Example a resin composition comprising a commercially available low density polyethylene as an ethylene-based polymer to which an insect-controlling agent is poorly migratory, and an inflation film formed of the resin composition. Patent Publication 1: JP-A-8-302080
DISCLOSURE OF INVENTION
However, the above-described resin composition prepared by blending to the high density polyethylene, the low density polyethylene and the insect-controlling agent has difficulties in the shaping of filaments thereof such as cutting of the filaments, and therefore is insufficient in its shaping property.
Under such a situation, an object of the present invention is to provide a resin composition comprising a high density polyethylene, an ethylene-based polymer to which an insect-controlling agent is highly migratory, and an insect-controlling agent, the use of the resin composition for shaping of filaments being effective to decrease a filament-cutting frequency in process of shaping the filaments of the resin composition. Another object of the invention is to provide filaments shaped of the same resin composition.
Firstly, the present invention relates to a resin composition which comprises a high density polyethylene, a high-pressure-processed low density polyethylene, an insect-controlling agent and a support, wherein the melt flow rate (MFR) of the high density polyethylene is from 0.1 to 10 g/10 mins . ; wherein the high-pressure-processed low density polyethylene satisfies the following conditions (al) and (a2) : (al) the melt flow rate (MFR) thereof is from 5 to 50 g/10 mins., and (a2) the proportion of a component having a molecular weight of not smaller than 1,000,000 is from 1 to 12% by weight; and wherein the content of the high-pressure-processed low density polyethylene is from 1 to 15 parts by weight, the content of the insect-controlling agent, from 0.1 to 10 parts by
weight, and the content of the support, from 0.1 to 20 parts by weight, per 100 parts by weight of the high density polyethylene.
Secondly, the present invention relates to filaments shaped of the same resin composition.
According to the present invention, there are provided a resin composition which comprises a high density polyethylene, an ethylene-based polymer to which an insect- controlling agent is highly migratory, and an insect- controlling agent, the use of the same resin composition for shaping filaments being effective to decrease a filament-cutting frequency in process of shaping the filaments; and the filaments shaped thereof.
BEST MODE FOR CARRYING OUT THE INVENTION
The high density polyethylene to be used in the present invention is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms (an ethylene-α-olefin copolymer) . Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 4-methyl-l- penetene, 4-methyl-l-hexene, etc. Each of these α-olefins may be used alone, or at least two selected therefrom may be used in combination. The content of the ethylene-based monomer unit in the high density polyethylene is usually not smaller than 90% by weight based on the entire weight of the high density polyethylene as 100% by weight.
Examples of the high density polyethylene include an ethylene homopolymer, an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, an ethylene-1-octene copolymer, an ethylene-l-butene-1-
hexene copolymer, etc. Preferable examples thereof are copolymers of ethylene and α-olefins each having 4 to 8 carbon atoms. More preferable examples thereof are an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, an ethylene-1- octene copolymer and an ethylene-1-butene-l-hexene copolymer. Still more preferable examples thereof are an ethylene-propylene copolymer, an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer and an ethylene- 1-octene copolymer.
The melt flow rate (MFR) of the high density polyethylene is from 0.1 to 10 g/10 mins . When this MFR is too high, the filament-cutting frequency tends to increase. The MFR is preferably not larger than 6 g/10 mins., more preferably not larger than 4 g/10 mins., still more preferably not larger than 2 g/10 mins. Again, the MFR is preferably not smaller than 0.3 g/10 mins., more preferably not smaller than 0.6 g/10 mins. from the viewpoint of decreasing a load on the motor of an extruder for use in the shaping of filaments. This MFR is measured under the conditions of a load of 21.18 N and a temperature of 190°C according to the method regulated in JIS K7210-1995.
The melt flow rate ratio (MFRR) of the high density polyehtylene is preferably not larger than 50, more preferably not larger than 45, still more preferably not larger than 40, from the viewpoint of an increase in the tenacity of the resultant filaments. Again, the MFRR of the high density polyehtylene is preferably not smaller than 10, more preferably not smaller than 15, still more preferably not smaller than 20, from the viewpoint of decreasing a load on the motor of the extruder for use in the shaping of filaments. The MFRR is calculated as
follows: a melt flow rate (MFR-H, g/10 mins . in unit) measured under the conditions of a test load of 211.83 N and a temperature of 190°C according to the method regulated in JIS K7210-1995 is divided by a melt flow rate (MFR) measured under the conditions of a load of 21.18 N and a temperature of 190°C according to the method regulated in JIS K7210-1995.
The density of the high density polyethylene is usually from 940 to 965 kg/m3. It is preferably from not lower than 945 kg/m3 from the viewpoint of improvement of the insect-controlling property of the filaments. It is preferably not higher than 960 kg/m3, more preferably not higher than 955 kg/m3, from the viewpoint of a decrease in the filament-cutting frequency. In this regard, this density is measured according to a method regulated in the method A among the methods of JIS K7112-1980, using a test piece annealed according to JIS K6760-1995.
The high density polyethylene is produced by a known process such as the solution polymerization process, the slurry polymerization process, the vapor phase polymerization process, the high-pressure ionic polymerization process or the like, using a known olefin polymerization catalyst such as a Ziegler-Natta catalyst, a chromium-based catalyst, a metallocene-based catalyst or the like. This polymerization process may be of batch type or of continuous type, or may be a multi-step polymerization process comprising two or more steps. As the Ziegler-Natta catalyst, for example, the following catalysts (1) and (2) are given: (1) a catalyst which comprises a component obtained by supporting at least one selected from the group consisting of titanium trichloride, vanadium trichloride, titanium
tetrachloride and haloalcoholate on a magnesium-based compound, and an organic metal compound as a co-catalyst, and
(2) a catalyst which comprises a co-precipitate or an eutectic crystal of a magnesium compound and a titanium compound, and an organic metal compound as a co-catalyst.
As the chromium-based catalyst, for example, a catalyst which comprises a component obtained by supporting a chromium compound on silica or silica-alumina, and an organic metal compound as a co-catalyst is given.
As the above-described metallocene-based catalyst, for example, the following catalysts (1) to (4) are given:
(1) a catalyst which comprises a component containing a transition metal compound having a cyclopentadiene framework, and a component containing an almoxane compound,
(2) a catalyst which comprises the above transition metal compound-containing component and a component containing an ionic compound such as trityl borate, anilinium borate or the like, (3) a catalyst which comprises the above transition metal compound-containing component, the above ionic compound- containing component and a component containing an organic aluminum compound, and (4) a catalyst obtained by supporting or incorporating the above respective components on or into a particle-shaped inorganic compound such as SiO2, Al2Cb or the like, or a particle-shaped polymer such as an olefin polymer of ethylene, styrene or the like.
As the process for producing the high density polyethylene to be used in the present invention, a process using a Ziegler-Natta-based catalyst or a metallocene-based catalyst is preferred. Also, a narrower residence time
distribution in process of the polymerization is preferred from the viewpoint of an improvement on the melt spinning property of the resin composition. To narrow the residence time distribution, a single-step polymerization is preferable, or a process using a plurality of reactors is preferable in which the plurality of the reactors are operated in parallel for the polymerization.
The melt flow rate (MFR) of the high-pressure- processed low density polyethylene to be used in the present invention is from 5 to 50 g/10 mins . When this MFR is too high, the filament-cutting frequency tends to increase. The MFR is preferably not larger than 30 g/10 mins., more preferably not larger than 25 g/10 mins. Again, when the MFR is too low, the filament-cutting frequency is likely to increase. The MFR is preferably not smaller than 7 g/10 mins., more preferably not smaller than 10 g/10 mins. The MFR is measured under the conditions of a load of 21.18 N and a temperature of 190°C according to the method regulated in JIS K7210-1995. The density of the high-pressure-processed low density polyethylene is usually from 910 to 935 kg/m3. It is preferably not higher than 930 kg/m3, more preferably not higher than 925 kg/m3, from the viewpoint of improvement of the insect-controlling property of the resultant filaments. It is preferably not lower than 915 kg/m3, from the viewpoint of improvement of the insect-controlling property of the resultant filaments. The density is measured according to a method regulated in the method A among the methods of JIS K7112-1980, using a test piece annealed according to JIS K6760-1995.
The proportion of a component of the high-pressure- processed low density polyethylene, which has a molecular
weight of not smaller than 1,000,000, is from 1 to 12% by weight. When the proportion of this component is too small, the filament-cutting frequency tends to increase. The proportion is preferably not smaller than 2% by weight, more preferably not smaller than 6% by weight. Again, when this proportion is too large, the filament-cutting frequency tends to increase. The proportion is preferably not larger than 10% by weight, more preferably not larger than 9% by weight. In this regard, the molecular weight of 1,000,000 is a molecular weight in terms of polystyrene. This proportion can be determined from a molecular weight distribution curve in terms of polystyrene, found by gel permeation chromatography.
The high-pressure-processed low density polyethylene is produced by polymerizing ethylene at a high temperature under a high pressure, using a radical-generating agent.
Examples of the radical-generating agent include organic peroxides such as di-t-butyl peroxide, t-butyl hydroperoxide, t-butyl-peroxy-2-ethyl hexanate, dicumyl peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxy benzoate, di-t-amyl peroxide, cumyl hydroperoxide, t- butylperoxy pivalate, etc. and oxygen.
It is preferable to use at least two kinds of radical- generating agents from the viewpoint of increasing the proportion of the component having a molecular weight of not lower than 1,000,000. The two or more kinds of the radical-generating agents may be sequentially used or may be mixed for use. Polymerization reactor (s) may be introduced from one site or a plurality of sites. The high-pressure-processed low density polyethylene may be produced in the presence of a chain transfer agent in order to control the molecular weight of the high-
pressure-processed low density polyethylene. Examples of the chain transfer agent include saturated hydrocarbons, aromatic hydrocarbons and alcohols. Examples of the saturated hydrocarbons include alkanes such as ethane, propane, n-butane, n-hexane, n-heptane and isobutane, and cycloalkanes such as cyclohexane, etc. Examples of the aromatic hydrocarbons include benzene, toluene, xylene, ethyl benzene, etc. Examples of the alcohols include methanol, ethanol, etc. Examples of the chain transfer agent further include organic compounds containing hetero atoms, such as tetrahydrofuran, acetone, etc. and hydrogen. Preferable examples of the chain transfer agent are ethane, propylene and propane.
As for the polymerization temperature, it is preferable to raise the highest polymerization temperature in order to increase the proportion of the component having a molecular weight of not lower than 1,000,000. The highest polymerization temperature is more preferably not lower than 240°C, still more preferably not lower than 260°C. The highest polymerization temperature is usually not higher than 310°C.
As for the polymerization pressure, it is preferable to lower the highest polymerization pressure in order to increase the proportion of the component having a molecular weight of not lower than 1,000,000. The highest polymerization pressure is more preferably not higher than 170 MPa, still more preferably not higher than 150 MPa. The highest polymerization pressure is usually not lower than 50 MPa. As the reactor (s) for use in the production of the high-pressure-processed low density polyethylene, tank type reactor (s), tube type reactor (s) or the like is used, and
preferably, the tank type reactor (s) is used. The high- pressure-processed low density polyethylene may be produced in a single reactor or may be produced in a plurality of reactors in combination. From the viewpoint of an increase in the proportion of the component having a molecular weight of not lower than 1,000,000, it is preferable to produce the high-pressure-processed low density polyethylene, using a plurality of reactors in combination. Examples of the insect-controlling agent to be used in the present invention include insect-controllable compounds such as insecticides, insect growth-controlling agents, insect-repelling agents, etc.
Examples of the insecticides include pyrethroid-based compounds, organophosphorus-based compounds, carbamate- based compounds, phenyl pyrazole-based compounds, etc. Examples of the pyrethroid-based compounds include permethrin, allethrin, d-alethrin, dd-alethrin, d- tetramethrin, prallethrin, cifenothrin, d-pfenothrin, d- resmethrin, empenthrin, fenvalerate, esfenvalerate, fenpropathrin, cyhalothrin, cyfluthrin, etofenprox, tralomethrin, esbiothrin, benfluthrin, terallethrin, deltamethrin, cypermethrin, fenothrin, tefluthrin, bifenthrin, cyfluthrin, cyphenothrin, cypermethrin, alphacypermethrin, etc. Examples of the organophosphorus- based compounds include fenitrothion, dichlorovos, naled, fenthion, cyanophos, chlorpyrifos, diazinon, carcrofos, salithion, diazinon, etc. Examples of the carbamate-based compounds include methoxydiazon, propoxur, fenobucarb, carbaryl, etc. Examples of the phenyl pyrazole-based compound include fipronyl, etc.
Examples of the insect growth-controlling agent include pyriproxfen, methoprene, hydroprene, diflubenzuron,
cyromazine, phenoxycarb, lufenuron (CGA 184599), etc.
Examples of the insect-repelling agent include diethyl-toluamide, dibutyl phthalate, etc.
Each of these insect-controlling agents may be used alone, or at least two selected therefrom may be used as a mixture. As the insect-controlling agent, the insecticides are preferable, and the pyrethroid-based compounds are more preferable. Some of the pyrethroid-based compounds, showing vapor pressures of lower than 1 X ICT6 mmHg at 25°C, are still more preferable. As the pyrethroid-based compounds which show vapor pressures of lower than 1 X ICT6 mmHg at 25°C, resmethrin, permethrin, etc. are exemplified.
The resin composition of the present invention may contain a compound which acts to improve the insect- controlling effect. As such a compound, piperonyl butoxide, MGK 264, octachlorodipropylether, etc. are exemplified.
As the support for use in the resin composition of the present invention, a support capable of supporting the insect-controlling agent is used. Examples of the support include silica-based compounds, zeolites, clay minerals, metal oxides, micas, hydrotalcites, organic supports, etc. As the silica-based compounds, amorphous silica and crystalline silica are exemplified, and examples thereof include silicic acid powder, fine silicic acid powder, acidic china clay, diatom earth, quartz, white carbon, etc. As the zeolites, A type zeolite, mordenite, etc. are given. As the clay minerals, montmorillonite, saponite, bidellite, bentonite, kaolinate, halloysite, nacrite, deckite, anauxite, illite, sericite, etc. are given. As the metal oxides, zinc oxide, magnesium oxide, aluminum oxide, iron oxide, copper oxide, titanium oxide, etc. are given. As the mica, mica, vermiculite, etc. are given. As the
hydrotalcites, smectite, etc. are given. As the organic supports, charcoals (charcoal, marl, grass peat, etc.), polymer beads (microcrystal cellulose, polystyrene beads, acrylate beads, methacrylate beads, polyvinyl alcohol-based beads, etc.) and their crosslinked polymer beads are given. In addition to these supports, perlite, gypsum, ceramics, volcanic rocks, etc. are given.
As the support, amorphous inorganic compounds are preferable, and amorphous silica is more preferable. The resin composition of the present invention is a resin composition which comprises a high density polyethylene, a high-pressure-processed low density polyethylene, an insect-controlling agent and a support.
The content of the high-pressure-processed low density polyethylene is from 1 to 15 parts by weight per 100 parts by weight of the high density polyethylene. When this content is too small, the insect-controlling effect of the resultant composition tends to lower. The content is preferably not smaller than 1 part by weight, more preferably not smaller than 3 parts by weight. Again, when this content is too large, the insect-controlling effect of the resultant composition tends to lower. The content is preferably not larger than 10 parts by weight.
The content of the insect-controlling agent is from 0.1 to 10 parts by weight per 100 parts by weight of the high density polyethylene. When this content is too small, the insect-controlling effect of the resultant composition tends to lower. The content is preferably not smaller than 0.5 parts by weight, more preferably not smaller than 1 part by weight. Again, the content is preferably not larger than 5 parts by weight, more preferably not larger than 3 parts by weight, from the viewpoint of a decrease in
the stickiness of the resultant filaments.
The content of the support is from 0.1 to 20 parts by weight per 100 parts by weight of the high density polyethylene. When this content is too small, the insect- controlling effect of the resultant composition tends to lower. The content is preferably not smaller than 0.5 parts by weight, more preferably not smaller than 1 part by weight. Again, the content is preferably not larger than 10 parts by weight, more preferably not larger than 5 parts by weight, from the viewpoint of an increase in the tenacity of the resultant filaments.
If needed, the resin composition of the present invention may contain additives such as an antioxidant, an anti-blocking agent, a filler, a lubricant, an antistatic ' agent, a weather resistant agent, a pigment, a processability-improving agent and a metal soap, and at least two additives in combination may be added to the resin composition.
As the antioxidant, phenol-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, etc. are given.
Examples of the phenol-based antioxidants include 2,6- di-t-butyl-4-methylphenol (BHT), n-octadecyl-3- (3, 5-di-t- butyl-4-hydroxyphenyl) propionate (Irganox 1076® manufactured by Ciba Specialty Chemicals K.K.), pentaerythrityl-tetrakis [3- (3, 5-di-t-butyl-4- hydroxyphenyl) propionate] (Irganox 1010® manufactured by Ciba Specialty Chemicals K.K.), 1, 3, 5-tris (3, 5-di-tert- butyl-4-hydroxybenzyl) isocyanurate (Irganox 3114® manufactured by Ciba Specialty Chemicals K.K.), 1,3,5- trimethyl-2, 4, 6-tris (3, 5-di-t-butyl-4-hydroxybenzyl) benzene, 3, 9-bis [2-{3- (3-t-butyl-4-hydroxy-5-
methylphenyl)propionyloxy}-l, 1-dimethylethyl] -2,4,8,10- tetraoxaspyro [5.5] undecane (Sumilizer GA80® manufactured by Sumitomo Chemical Company, Limited), etc.
Examples of the phosphorus-based antioxidants include distearylpentaerythritol diphosphate (ADK STAB PEP8®) , tris (2, 4-di-tert-butylphenyl) phosphite (Irgafos 168® manufactured by Ciba Specialty Chemicals K.K.), bis (2, 4-di- tert-butylphenyl ) pentaerythritol diphosphite, tetrakis (2, 4- di-tert-butylphenyl) 4,4' -biphenylene diphosphonite (Sandostab P-EPQ® manufactured by Clariant (Japan) K.K.), bis (2-t-butyl-4-methylphenyl) pentaerythritol diphosphite, etc.
Examples of an antioxidant having both of a phenol structure and a phosphorus structure include 6- [3- (3-tert- butyl-4-hydroxy-5-methyl) propoxy] -2,4,8, 10-tetra-tert- butyldibenz [d, f] [1, 3, 2] -dioxaphosphebine (Sumilizer GP® manufactured by Sumitomo Chemical Company, Limited), etc.
Example of the sulfur-based antioxidant include 4,4'- thiobis (3-methyl-6-tert-butylphenol) (Sumilizer WXR® manufactured by Sumitomo Chemical Company, Limited), 2,2- thiobis- (4-methyl-6-tert-butylphenol) (IRGANOX 1081® manufactured by Ciba Specialty Chemicals K.K.), etc.
Examples of other antioxidants include vitamin E, vitamin A, etc. Preferable antioxidants are antioxidants having phenol structures, and more preferable antioxidants are phenol- based antioxidants. Still more preferable examples of the antioxidant include 2, 6-di-t-butyl-4-methylphenol (BHT), n- octadecyl-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionate, and pentaerythrityl-tetrakis [3- (3, 5-di-t-butyl-4- hydroxyphenyl) propionate] .
It is preferable to use the antioxidant from the viewpoints of improvement on the stability of the insect- controlling agent and a decrease in the filament-cutting frequency. The content of the antioxidant is preferably not smaller than 0.01 part by weight, more preferably not smaller than 0.03 parts by weight, still more preferably not smaller than 0.05 parts by weight, per 100 parts by weight of the high density polyethylene. Again, the content is preferably not larger than 1 part by weight, more preferably not larger than 0.5 parts by weight, still more preferably not larger than 0.2 parts by weight, from the viewpoint of a decrease in the coloring of the resultant filaments.
The resin composition of the present invention is produced by melt-kneading the high density polyethylene, the high-pressure-processed low density polyethylene, the insect-controlling agent and the support in a known kneader such as an extruder, a roll molding machine, a kneader or the like. In the production of the resin composition, the insect-controlling agent may be previously supported on the support before the melt-kneading; or the insect-controlling agent and the support may be melt-kneaded into the high- pressure-processed low density polyethylene or the high density polyethylene as a base resin for the preparation of a master batch. Specifically, the insect-controlling agent and the support are mixed to support the insect-controlling agent on the support, and then, the support having the insect-controlling agent supported thereon and the high- pressure-processed low density polyethylene are melt- kneaded to prepare a master batch, and the resulting master batch is melt-kneaded with the high density polyethylene. The resin composition of the present invention is
suitably, used to shape filaments, since the filament- cutting frequency in process of shaping the filaments is low.
An example of methods for shaping the resin composition of the present invention is as follows: an extruder or the like is used to melt the resin composition; the molten resin composition is extruded from a die or a nozzle through a gear pump; the extruded resin composition is taken up to form a strand-like resin composition; the strand-like resin composition is cooled using a cooling medium such as water or an air for spinning; and then, if needed, the resultant spun filament of the resin composition is drawn under heating, heat-treated and coated with an oil and is then wound up. The resultant filament has a sectional shape of, for example, a circle, ellipse, triangle, rectangle, hexagon, star or the like.
A monofilament shaped of the resin composition of the present invention is used for nets such as a mosquito net, screen, insect-controlling net, etc.; ropes; yarns; and filters. A multifilament shaped of the resin composition of the present invention is used for ropes, nets, carpets, non-woven cloth, filters, shoes, clothing, etc. In particular, they are suitably used for applications required for insect-controlling effects, such as mosquito nets, screens, insect-controlling nets, filters, carpets, shoes and clothing.
Examples of insects as objects to be controlled by the filaments shaped of the resin composition of the present invention are Arthropoda such as spiders, ticks and insects. The following are examples thereof: Ormithonyssus sylviarum, citrus red mite, Tyrophagus putrescentiae, etc. belonging
to Acarina; and Atypus karshi, Pholcus phalangioides, etc. belonging to Araneae, in Arachnida: Thereuopoda clunifera, etc. belonging to Scutigeromorpha; and Bothropolys asperatus, etc. belonging to Lithobiomorpha in Chilopoda: and axidus gracilis, Nedyopus tambanus, etc. belonging to Polydesmoidea, in Chilopoda.
As the insects, the following are given: Ctenolepisma villosa Escherich, etc. belonging to Thysanura; cave cricket, mole cricket, Teleogryllus emma, locusta migratoria, Schistocerca gregaria, locust, etc. belonging to Orthoptera; earwig, etc. belonging to Dermaptera; Blattella germanica, Periplaneta fuliginosa, Periplaneta Japonica, Periplaneta americana, etc. belonging to Blattaria; Japanese subterranean termite, Formosan subterranean termite, Incisitermes minor HAGEN, etc. belonging to Isoptera; Liposcelis entomophilus Enderlein, Liposcelis bostrychophilus Badonnel, etc. belonging to Psocoptera; Trichodectes canis, Felicola subrostratus, etc. belonging to Mallophaga; Pediculus humanus corporis, Pthirus pubis, Pediculus humanus, etc. belonging to
Anoplura; Nilaparvata lugens Stal, Nephotettix cincticeps, Greenhous white fly, Myzus persicae, Cimex lectularius Linnaeus, Halyomorpha halys, etc. belonging to' Hemiptera; dermestid beetles, Aulacophora femoralis, Sitophilus zeamais, Lyctus brunmeus, Ptinus japonicus, Popillia japonica Newman, etc. belonging to Coleoptera; cat flea, dog flea, human flea, etc. belonging to Siphonaptera; Culex pipiens pallens couguillett, Aedes aegypti, anopheles, Simuliidae, Chironomus, Psychodidae, House fly, Glossina palpalis, Tabanus trigonus, Syrphinae, etc. belonging to Diptera; Vespa, Polistes, Nesodiprion japonicus Marlatt, Dryocosmus kuriphilus, Sclerodermus nipponicus, Monomorium
pharaonis, etc. belonging to Hymenoptera; and the like.
EXAMPLES
Hereinafter, the present invention will be described by way of Examples thereof and Comparative Examples. In Examples and Comparative Examples, the physical properties were measured according to the following methods.
(1) Melt Flow Rate (MFR, g/10 mins . in unit)
A melt flow rate was measured at 190°C under a load of 21.18 N according to the method regulated in JIS K7210-1995,
(2) Melt Flow Rate Ratio (MFRR)
A MFRR was found by dividing a melt flow rate (MFR-H, g/10 mins. in unit) measured at 190°C under a test load of 211.83 N according to the method regulated in JIS K7210- 1995 by a melt flow rate (MFR) measured at 190°C under a load of 21.18 N according to the method regulated in JIS K7210-1995.
(3) Density (kg/m3 in unit)
A density was measured according to the method regulated in the method A among the methods described in JIS K7112-1980. A test piece to be measured was annealed according to the method regulated in JIS K6760-1995.
(4) Proportion of Component with Molecular Weight of 1,000,000 or more (% by weight in unit) The gel permeation chromatograph (GRC) was employed to measure a molecular weight distribution curve under the following conditions (1) to (8). Next, the proportion of the area of a region indicating molecular weights of not lower than 1,000,000 in terms of polystyrene was determined from the molecular weight distribution curve
(1) Apparatus: Waters 150C manufactured by Water
(2) Column: TOSOH TSKgelGMH-HT
( 3 ) Measuring temperature : 145°C
( 4 ) Carrier : ortho-dichlorobenzene
( 5 ) Flow rate : 1 . 0 itiL/min .
(6) Charged amount: 50 μL (7) Detector: Differential refraction
(8) Molecular weight standard substance: standard polystyrene (TSK STANDARD POLYSTYRNE of TOSOH CORPORATION) Example 1 (1) Preparation of Resin Composition
An antioxidant (2, β-di-t-butyl-4-methylphenol, hereinafter referred to as BHT) (1.5 parts by weight) was dissolved in permethrin (Eksmin® of Sumitomo Chemical Company, Limited) (51 parts by weight) . Next, the solution (52.5 parts by weight) of permethrin containing BHT was stirred and mixed with amorphous silica (Porous Silica® of SUZUKI YUSHI CO., LTD.) (47.5 parts by weight) to prepare a support having an insect-controlling agent supported thereon. Pellets of a high-pressure-processed low density polyethylene (Sumikathene CE4506 of Sumitomo Chemical
Company, Limited, hereinafter referred to as LD-I) (59.42 parts by weight), BHT (0.06 parts by weight), the support having the insect-controlling agent supported thereon (31 parts by weight), zinc stearate (5 parts by weight) and a blue coloring agent (available from Sumika Color) (4.52 parts by weight) were melt-kneaded at a set temperature of 200°C with a twin-screw extruder to prepare a master batch. Next, pellets of a high density polyethylene (HI-ZEX 5000S® of PRIME POLYMER; MFR = 0.8 g/10 min., density = 948 kg/m3, and MFRR = 35) (100 parts by weight), the master batch (16.5 parts by weight) and zinc stearate (7.0 parts
by weight) were melt-kneaded at a set temperature of 260°C with a single screw extruder to obtain a resin composition. The results of the physical properties of the pellet of LD- 1 are shown in Table 1. (2) Shaping of Filament
The resultant resin composition was extruded from the die with 6 holes of 1 mmf of a 35 itimf extruder, at a discharge rate of 0.7 kg/hr. and at a die set temperature of 220°C, and the resulting strand was taken up at a line speed of 14 m/min., allowed to pass through a heated water tank and was taken up at a rate of 112 m/min., to shape monofilaments with a fineness of 170 deniers. The filament-cutting frequency in process of the shaping of the filaments was 1/hr. Example 2
(1) Preparation of Resin Composition
A resin composition was prepared in the same manner as in Example 1, except that, instead of the pellets of the high-pressure-processed low density polyethylene LD- 1, pellets of Sumikathene G801 of Sumitomo Chemical Company, Limited (hereinafter referred to as LD-2) were used. The measurement results of the physical properties of the pellet of LD-2 are shown in Table 1.
(2) Shaping of Filament Monofilaments of the resultant resin composition were shaped in the same manner as in the shaping of the filaments of Example 1. The filament-cutting frequency in process of the shaping of the filaments was 0/hr.
Comparative Example 1 (1) Preparation of Resin Composition
A resin composition was prepared in the same manner as in Example 1, except that, instead of the pellets.
of the high-pressure-processed low density polyethylene LD- 1, pellets of Sumikathene CE5502 of Sumitomo Chemical Company, Limited (hereinafter referred to as LD-3) were used. The measurement results of the physical properties of the pellet of LD-3 are shown in Table 1.
(2) Shaping of Filament
Monofilaments of the resultant resin composition were shaped in the same manner as in the shaping of the filaments of Example 1. The filament-cutting frequency in process of the shaping of the filaments was 3/hr.
Comparative Example 2
(1) Preparation of Resin Composition
A resin composition was prepared in the same manner as in Example 1, except that, instead of the pellets of the high-pressure-processed low density polyethylene LD-I, pellets of Sumikathene CE5503 of Sumitomo Chemical Company, Limited (hereinafter referred to as LD-4) were used. The measurement results of the physical properties of the pellet of LD-4 are shown in Table 1.
(2) Shaping of Filament
Monofilaments of the resultant resin composition were shaped in the same manner as in the shaping of the filaments of Example 1. The filament-cutting frequency in process of the shaping of the filaments was 5/hr.
Table 1