JP2003038626A - Stretched molding of active carbon-containing polyolefin resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stretched molding of an active carbon-containing polyolefin resin which is formed by coating the surface of the active carbon with the resin to prevent the closing of the pores of the active carbon, utilizes the intrinsic adsorption effect of the active carbon to the maximum possible extent, is provided with a function to decompose the adsorptive material thereto and is usable continuously for a long time to malodorous gas. SOLUTION: The polyolefinic resin which is compounded with the active carbon having a specific surface area of >=1,700 m<2> /g is extrusion molded and is then subjected to stretching treatment, by which the stretched molding of the active carbon-containing polyolefin resin, such as a monofilament or composite monofilament, is obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an activated carbon-containing stretched polyolefin resin molded article. More specifically, it relates to a stretched molded product of activated carbon-containing polyolefin resin that removes various malodorous gases such as hydrogen sulfide, various mercaptans, ammonia and amines.

[0002]

2. Description of the Related Art In recent years, trace amounts of hydrogen sulfide, ammonia, mercaptan, which are present in living spaces due to changes in living environment,
There is increasing interest in malodorous gases such as amines and aldehydes. In order to remove these malodorous gases and maintain a comfortable living environment, a deodorant is required, and various malodorous gas adsorbents are also used in home life. For deodorizing these malodorous gases, a deodorant mainly containing activated carbon is generally used.

[0003]

The above-mentioned deodorant for activated carbon is due to the adsorption action of activated carbon, and has a limited adsorption capacity. When used for a long period of time, activated carbon becomes dusty,
There was a problem that the activated carbon had to be replaced frequently. Further, in order to prevent dusting of the activated carbon, impart strength, and effectively utilize the specific surface area, when the activated carbon is molded in the resin, the resin covers the surface of the activated carbon, There is a problem in that the pores of the activated carbon are clogged and the original adsorption capacity of the activated carbon is lost.
The present invention, the resin covers the surface of the activated carbon, prevents the pores of the activated carbon from being blocked, can maximize the adsorption action of the activated carbon to the maximum, and also has a function of decomposing the adsorbed substance, An object is to provide an activated carbon-containing stretched polyolefin resin molded product that can be continuously used for a long time against a malodorous gas.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a composition obtained by blending a polyolefin resin with specific activated carbon is extruded and then stretched. By stretching the resin-coated portion of the surface of the activated carbon, the blockage of the pores can be released, whereby the adsorption capacity inherent in the activated carbon can be expressed, and the adsorbed substance is decomposed by using the specific activated carbon. The inventors have found that an activated carbon-containing stretched polyolefin resin stretched product having a high deodorizing effect can be obtained, and the present invention has been completed. That is, the present invention is a stretched molded product of activated carbon-containing polyolefin resin obtained by extruding a mixture of activated carbon having a specific surface area of 1700 m ² / g or more with respect to 100 parts by weight of a polyolefin-based resin, and then performing a stretching treatment. Exist in.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The polyolefin resin used in the present invention includes high-density polyethylene, linear low-density polyethylene, branched low-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic ester copolymer. Examples thereof include polymers, polypropylene, and propylene-ethylene copolymers, and these polyolefin resins may be used alone or in combination of two or more kinds. Of these, high-strength high-density polyethylene or polypropylene is preferable. As the above-mentioned polyolefin resin, melt fluorate (hereinafter abbreviated as MFR)
Is usually 1 to 30 g / 10 min. , Preferably 2-3
Those in the range of 0 g / 10 min. Are used. The MFR of the polyolefin resin is 1 g / 10 min. If it is less than the above range, the fluidity of the composition is poor, and the thickness of the stretch-molded product may change irregularly. On the other hand, the MFR is 30 g /
10 min. If it exceeds, it adversely affects the molding stability and the production efficiency and is not desirable.

Activity incorporated into the above polyolefin resin
Specific surface area of charcoal is 1700m ^Two / G or more, preferred
1700-3000m^Two / G range,
The carbonization rate is 90% or more, preferably 90 to 95%.
It is a range. Adsorption of odorous substances when the specific surface area is less than the lower limit
Capacity is reduced, and the ability to decompose adsorbed substances is remarkable
descend. Ordinary activated carbon, such as coconut shell activated carbon,
Specific surface area is 1200m^Two/ G and the carbonization rate is 70
%, The odor substance adsorption capacity is insufficient, and
Second, it has no ability to decompose adsorbed materials. For use in the present invention
The activated carbon raises the carbonization rate of the palm shell activated carbon to 90% or more,
Specific surface area of activated carbon is 1700m^Two / G or more
Manufactured by.

The activated carbon is used in an amount of 1 to 50 parts by weight, preferably 3 to 100 parts by weight, based on 100 parts by weight of the polyolefin resin.
Add 50 parts by weight. If the blending amount of the activated carbon is less than the lower limit, the effect of the activated carbon cannot be sufficiently expressed, and if it is more than the upper limit, a problem occurs in the dispersibility with the polyolefin resin, and the mechanical strength tends to be insufficient as a molded product and insufficient. is there.

The content of water in the activated carbon used above is 0.
Less than 10% by weight, preferably 0.01-0.08% by weight
Is the range. When the water content is 0.10% by weight or more, a foaming phenomenon is apt to occur during extrusion molding, and when the obtained resin molded product is stretched, stretch breakage is likely to occur, which is not preferable.

As the stretch-molded article obtained by blending the above-mentioned polyolefin resin with the above-mentioned activated carbon and extrusion-molding, various forms such as a film, a sheet, a flat yarn, a monofilament, a composite monofilament, etc. can be adopted and formed by a known molding method. it can. Among these, a monofilament that is easy to mold and can maintain high strength, particularly a composite monofilament is preferable.

The case of a monofilament as the stretch-molded product will be described. The molding method is not particularly limited, and a known monofilament molding method is adopted. That is, using a monofilament molding die, the resin composition was extruded at a melting temperature of 170 to 240 ° C., cooled and solidified at a cooling water temperature of 30 to 70 ° C., and then stretched to obtain 5 to 15 of the stretched monofilaments.
% Relaxation heat treatment can be applied to form a monofilament. The stretching treatment is carried out by a hot stretching method, that is, at a temperature not higher than the melting point of the polyolefin resin and not lower than the softening point, usually at a stretching temperature of 90 to 150 ° C. and a stretching ratio of 3 to.
The range is 12 times, preferably 5 to 10 times. As the hot stretching method, a hot roll method, a hot plate method, an infrared irradiation method, a hot air oven method, a hot water method, or the like can be adopted. When the draw ratio is less than 3 times, the effect of drawing is not obtained and the strength of the monofilament is insufficient, and when the draw ratio exceeds 12 times, breakage of the drawing is likely to occur and the monofilament is liable to be longitudinally cracked, which is not preferable. The stretching method can be one-stage stretching or multi-stage stretching of two or more stages, and two-stage stretching is better than one-stage stretching.

The monofilaments obtained above can be used as woven or knitted fabrics as warp and weft. The woven or knitted structure of the woven or knitted fabric is not particularly limited, and specifically, as the woven fabric, a plain weave, a twill weave, a woven fabric, a dummy weave, a leno weave, etc. can be adopted, and a tricot knit, a Milanese knit, and
Russell edition etc. can be adopted. As the fineness of the warp and weft, a filament of 80 to 500 decitex (hereinafter abbreviated as dt) is used, and its weaving density, that is, driving density is 5 to 50 yarns / inch, preferably 5 to 30. The range is books / inch. When used as an element of an air filter such as an air conditioner or an air purifier, it is desirable to use a honeycomb structure.

Further, it is preferable to use a composite monofragment instead of the monolayer monofilament because the strength characteristics are further improved and the core layer and the sheath layer can be added with functions. The composite monofilament has a core-sheath structure in which the polyolefin resin containing the activated carbon is used as a sheath layer and the polyolefin resin is used as a core layer. With this core-sheath structure, the core layer imparts strength characteristics and the sheath layer does not block the pores of the activated carbon, but imparts the original function of the activated carbon. The polyolefin resin used for the core / sheath of the composite monofilament is not particularly limited, and the above-mentioned polyolefin resin is used. The type of active carbon to be blended in the sheath layer, the blending amount, and the water content are used within the ranges described above. Also,
The cross-sectional area ratio of the sheath layer / core layer of the composite filament is 2 /
It is in the range of 8 to 6/4. If the cross-sectional area ratio of the sheath layer / core layer is less than 2/8, it becomes difficult for the sheath component to cover the entire cross-section of the core layer,
The sheath layer is easily separated from the core layer, and powder is easily generated. Also,
If the cross-sectional area ratio is larger than 6/4, the tensile strength of the filament yarn is reduced, which is not desirable.

Further, by forming a composite monofragment, it is possible to separately add a function that cannot be added with a monolayer monofilament into a core layer and a sheath layer. For example, a flame retardant is added to the core layer. By adding a weathering agent to the sheath layer, it is possible to combine the function of flame retarding treatment and weatherability in the composite monofractor.

As the flame retardant used by adding it to the sheath layer, halogen type, phosphorus type, inorganic type and the like flame retardants are appropriately used. Examples of bromine flame retardants include aromatic bromine flame retardants such as tetrabromobisphenol A, decabrom diphenyl oxide, octabromodiphenyl oxide, bisdibromopropyl ether tetrabromobisphenol S, hexabrom cyclododecane, dibromoethyl dibromocyclohexane, etc. Alicyclic bromine flame retardant,
Liquid bromine-based flame retardants such as pentabromodiphenyl oxide and tetrabromodiphenyl oxide, and phthalimide-based brominated flame retardants such as ethylene bis (tetrabromophthalimide). Further, as the phosphorus-based, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, octyl diphenyl phosphate, tricresyl phosphate, tris [chloroethyl] phosphate, tris [2-chloropropyl] phosphate, tris [2, 3-Dichloropropyl] phosphate, and further, as the inorganic type, antimony trioxide barium aluminum metaborate aluminum hydroxide, red phosphorus and the like can be mentioned. If necessary, two or more flame retardants selected from the above may be used in combination. It is preferable to use antimony trioxide as a flame retardant auxiliary together with the brominated flame retardant from the viewpoint of improving the flame retarding effect. The mixing ratio of the brominated flame retardant and antimony trioxide is not particularly limited, but it is 2: 1 to
3: 1 is preferable

The blending ratio of the flame retardant is in the range of 3 to 50% by weight, preferably 5 to 5% by weight, based on the polyolefin resin.
It is in the range of 40% by weight. If the blending ratio is less than 3% by weight, the flame retardancy becomes insufficient, and if it exceeds 50% by weight, the effect of the flame retardancy is not further improved, and conversely the cost is increased, which is not preferable.

On the other hand, as a method of imparting weather resistance to the sheath layer, a method of adding a weather resistance agent such as an ultraviolet absorber or a light stabilizer can also be adopted. Specific examples of the ultraviolet absorber include 2-ethylhexyl-2-cyano-3,3'-diphenyl acrylate, ethyl-2-cyano-3,3'-diphenyl acrylate, octyl-2-cyano-3,3 '. -Cyanoacrylate UV absorbers such as diphenyl acrylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4
-Benzophenone-based UV absorbers such as octoxybenzophenone, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole, 2- (2'-hydroxy-5'-
Benzotriazole-based UV absorbers such as t-octylphenyl) benzotriazole, resorcinol monobenzoate, 2,4-di-t-butylphenyl-3'-5'-di-t-
Examples thereof include benzoate-based UV absorbers such as butyl-4'-hydroxybenzoate. The blending ratio of the ultraviolet absorber is preferably 0.05 to 5 with respect to polyethylene.
%, More preferably 0.1 to 1% by weight.

The hindered amine light stabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) -1, 2,3,4-butanetetracarboxylate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) di (tridecyl) -1,2,3,4-butanetetracarboxylate, 1- (2-hydroxyethyl) -2,2,
Examples thereof include polycondensates of 6,6-tetramethyl-4-piperidinol and diethyl succinate. The content of the light stabilizer is preferably 0.05 to 5% by weight, more preferably 0.1 to 1% by weight, based on polyethylene.

The method for producing the above composite monofilament is not particularly limited, and the above-mentioned polyolefin resin containing the activated carbon and the anti-resistance agent and the polyolefin resin containing the flame retardant are melt-kneaded in an extruder, respectively, and 17
At the melting temperature of 0 to 240 ° C., a core layer made of a polyolefin resin mixed with a flame retardant is supplied from the center discharge hole of a die in which two discharge holes are provided on substantially concentric circles, and the activated carbon and resistance to resistance are provided on the outer surface thereof. It is possible to form a composite monofilament by extruding a sheath layer made of a polyolefin resin mixed with an agent to cover it to form a composite, and subjecting it to a stretching treatment or the like. The stretching treatment is performed by a hot stretching method at a temperature not higher than the melting point of the polyolefin resin and not lower than the softening point, usually at a stretching temperature of 90 to 150 ° C. and a stretching ratio of usually 3 to 12 times, preferably 5 to 10 times. It is a double range.

The polyolefin resin used in the present invention includes, if necessary, an antioxidant, an ultraviolet absorber, a light stabilizer, a dispersant, a lubricant, an antistatic agent, and a pigment within a range not departing from the gist of the present invention. , Inorganic filler, cross-linking agent,
You may mix | blend normally used additives, such as a foaming agent and a nucleating agent.

[0020]

Example 1 Example 1 Activated carbon (carbonization rate 93%, specific surface area 1800 m
² / g) 20 parts by weight of polypropylene and 100 parts by weight of polypropylene were mixed and dried for 24 hours to adjust the water content in the activated carbon to 0.05% by weight. Next, polypropylene (MFR = 4.0g / 10m
in., Tm = 163 ° C.) 100 parts by weight, the composition containing 50 parts by weight of the above master batch containing activated carbon was melt extruded from a circular nozzle at 220 ° C. from a circular nozzle to form a monofilament, which was cooled. A monofilament having a fineness of 150 dt was obtained by drawing with a hot air oven type drawing machine at a drawing temperature of 115 ° C. at a draw ratio of 8 times, and then subjected to heat relaxation treatment. The monofilament obtained above was used as a warp and a weft to woven a honeycomb woven structure having a driving density of 10 × 12 filaments / inch.

The honeycomb structure obtained above was subjected to a deodorization test by the following evaluation method, and the evaluation results are shown in Table 1. (1) Ammonia deodorization test 290 mm in length and 290 mm in width on one side in a cubic closed container having a length of 300 mm, a width of 300 mm and a height of 300 mm.
The honeycomb structure containing the activated carbon obtained in the above is attached and sealed. Ammonia gas was injected into this with a gas-tight syringe, and the inside of the container was allowed to stir at room temperature while stirring with a fan to stabilize the initial concentration, 1 hour, 4 hours, 24 hours, 48 hours later. After that, the residual ammonia concentration after 72 hours was measured with a detector tube. The results are shown in Table 1. (2) Repeat test (second time) The repeat test of (1) above was performed. The results are shown in Table 1.

Example 2 In Example 1, the obtained monofilament was used as a warp and a weft, and a plain weave with a driving density of 20 × 25 yarns / inch.
The same procedure was carried out except that the (mesh) structure was woven. The results are shown in Table 1.

Comparative Example 1 The same procedure as in Example 1 was carried out except that no activated carbon was added. The results are shown in Table 1.

[0024]

[Table 1]

Example 3 Activated carbon (carbonization rate 93%, specific surface area 1800 m
² / g) 20 parts by weight and high density polyethylene (MFR =
1.0 g / 10 minutes, density = 0.950 g / cm ³ ) 80 parts by weight of the activated carbon blended master batch was blended at 105 ° C.
Dry for 24 hours to reduce the water content in the activated carbon to 0.0
Adjusted to 5% by weight. High-density polyethylene (MFR = 1.0 g / 10 min, density = 0.950 g / c)
6% by weight as a bromine flame retardant obtained by mixing phthalimide flame retardant ethylenebis (tetrabromophthalimide) and antimony trioxide in m ³ ), and a black pigment 3
In the sheath layer, a high-density polyethylene (MFR = 1.0 g / 10 min, density =
0.950 g / cm ³ ) using the above activated carbon-blended masterbatch, 8% by weight as activated carbon and 0.3% by weight of bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate as weathering agent From the composite high density polyethylene monofilament molding die in which two layers of discharge holes connected to two extruders are concentrically provided, the composition of The composition of the high-density polyethylene of the sheath layer, the activated carbon and the weatherproofing agent was extruded, and the drawing temperature was 99 ° C and the draw ratio was 5
The composite monofilament was molded by stretching the film twice and annealing it at a treatment temperature of 115 ° C. The fineness of the obtained composite polyolefin monofilament was 350 in the core layer / sheath layer.
At dt / 150 dt, the total fineness was 500 dt. The composite monofilament thus obtained has, as its strength,
3 cN / dt, and in the flame retardancy test, JI
In the combustion test according to SA1322, the carbonization length was 45 mm, and the flame-proof grade 1 was passed.

Using the monofilament obtained above as a warp and a weft, a plain weave structure (A) having a striking density of 58 × 33 yarns / inch and a honeycomb woven structure having a striking density of 38 × 38 yarns / inch ( B) was woven.

The plain weave structure and the honeycomb weave structure obtained above were subjected to a deodorizing test by the following evaluation methods, and the evaluation results are shown in Table 1. (1) Test gas deodorizing test A plain weave structure or honeycomb weave structure containing 280 mm in length and 52 mm in length and containing the activated carbon obtained above in one side in a cubic closed container having a length of 300 mm, a width of 300 mm and a height of 300 mm. Attach and seal. After injecting a test gas (ammonia, formaldehyde or hydrogen sulfide) into the container and allowing it to stir at room temperature while stirring with a fan, the initial concentration was adjusted to 1 hour, 4 hours and 24 hours. After 48 hours and 72 hours, the residual gas concentration was measured with a gas detector tube. The results are shown in Table 2.

Comparative Example 2 The procedure of Example 3 was repeated except that no activated carbon was added to the sheath layer. The test gas deodorization test was performed using a plain weave structure (placing density: 58 × 33 / inch), and the results are shown in Table 2.

[0029]

[Table 2]

[0030]

As described above, the activated carbon-containing polyolefin resin stretch-molded article of the present invention is extrusion-molded using a specific activated carbon, and then stretched to obtain an activated carbon-containing polyolefin resin such as a monofilament or a composite monofilament. By forming a stretch-molded body, the resin-coated portion of the activated carbon surface can be subjected to a stretching treatment to open the blockage of its pores, whereby the original adsorption capacity of the activated carbon can be expressed, and a specific activated carbon can be obtained. By using it, it is possible to impart a function of decomposing the adsorbed substance, and it is possible to continuously use the malodorous gas for a long time. Therefore, the activated carbon-containing stretched polyolefin resin molded product of the present invention is suitable as a deodorant for malodorous gas, particularly as an element of an air filter.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideo Shiozawa             1-25-8, Nihonbashi Kyokicho, Chuo-ku, Tokyo               Asahi Industrial Fiber Co., Ltd. (72) Inventor Miyuki Tokuda             2-38 Wakamatsucho, Fuchu-shi, Tokyo Stocks             Company NMG F-term (reference) 4C080 AA05 AA07 BB02 CC04 CC05                       CC08 CC09 HH05 JJ05 KK08                       LL03 MM05 NN27 QQ03

Claims (6)

[Claims] 1. A polyolefin resin having a specific surface area of 17
An activated carbon-containing polyolefin resin stretch-molded article obtained by extrusion-molding a mixture of activated carbon of 00 m ² / g or more, and then subjecting it to a stretching treatment. 2. The activated carbon-containing stretched polyolefin resin molded article according to claim 1, wherein the blending amount of the activated carbon is in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the polyolefin resin. 3. The stretched molded product of activated carbon-containing polyolefin resin according to claim 1, wherein the content of water in the activated carbon is less than 0.1% by weight. 4. The stretched and molded product of activated carbon-containing polyolefin resin according to claim 1, wherein the stretched and molded product obtained by the stretching treatment is a monofilament. 5. A stretched molded product obtained by a stretching treatment is a composite monofilament comprising a polyolefin resin containing a activated carbon having a specific surface area of 1700 m ² / g or more as a sheath layer and a polyolefin resin as a core layer. An activated carbon-containing polyolefin resin stretched molded article according to any one of 3 to 3. 6. A composite comprising a stretched and molded product obtained by a stretching treatment, comprising a polyolefin resin containing a activated carbon having a specific surface area of 1700 m ² / g or more as a sheath layer and a polyolefin resin containing a flame retardant as a core layer. The activated carbon-containing polyolefin resin stretch-molded article according to claim 1, which is a monofilament.