JP3395902B2 - Laminated product of fibrous activated carbon knit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fibrous activated carbon knitted product obtained by carbonizing and activating a knitted raw material organic fiber knitted fabric, which has excellent processability such as lamination and is torn or bent. The present invention relates to a laminated product obtained by stacking a fibrous activated carbon knitted fabric and a front cloth / back cloth on top of each other, which is durable, easy to handle, and has a high breathability and an excellent adsorption performance for organic gas. More specifically, the present invention relates to a laminated product obtained by stacking a fibrous activated carbon knitted fabric and a front cloth / back cloth on top of each other for quilting, which is used for a mask, a deodorizing pad, a medical product such as a deodorizing sheet, and a protective suit for protecting the body from harmful gases. . In particular, when the fibrous activated carbon knitted fabric is used in a quilting-processed medical article or protective clothing such as a quilting laminated product, it is highly flexible and highly breathable. It relates to a laminated product.

[0002]

2. Description of the Related Art Hitherto, it has been proposed to obtain a fibrous activated carbon by subjecting a carbonizable raw material organic fiber to a carbonization treatment and an activation treatment. In addition, as a method for obtaining a cloth-like fibrous activated carbon in which the fibrous activated carbon forms a sheet shape, after the raw material organic fiber is made into a nonwoven fabric such as felt or a woven fabric,
Examples thereof include a method of carbonizing and activating treatment, and a method of carbonizing and activating the raw material organic fiber to obtain fibrous activated carbon and then processing it into a nonwoven fabric such as felt.

[0003] These have a pore structure which the fibrous activated carbon originally has, and also have weak strength due to shrinkage during carbonization and activation, causing wrinkles and cracks, handling and lamination with other materials. During processing, the activated carbon cloth breaks or breaks, powdering and falling off, making it unsuitable for practical use.

In order to solve these problems
In 24725, a knitted fabric fibrous activated carbon cloth is proposed. According to this, a knitted fabric-like activated carbon cloth that is flexible, has excellent workability, resistance to pulling, tearing, bending, and has good handleability can be obtained. However, it is not possible to satisfy the recent high demands such as high performance as an activated carbon cloth and high-order processability in combination with other materials. In particular, the balance between adsorption performance, air permeability and tear strength was not sufficient. That is, when the absolute dry mass of the fibrous activated carbon knitting is increased in order to increase the adsorption performance for the organic solvent gas per unit area, the density increases, the pressure loss increases, the air permeability decreases, and the degree of freedom between fibers increases. Are lost to increase rigidity, resulting in reduced strength, especially tear strength.

Further, assuming continuous industrial production, tension is applied due to shrinkage in the course direction during firing, so that when the strength of the activated carbon cloth is weak, it breaks or breaks. Further, it is difficult to obtain a fibrous activated carbon cloth having a constant and stable width because both ends are curled and curling in the width direction is unstable. Further, the fluctuation of shrinkage was large, the fluctuation of absolute dry mass was large, and the stitch was bent, resulting in poor quality of the product.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems in the prior art. In other words, a fibrous activated carbon with excellent quality and quality due to its high adsorption performance for organic solvent gas per unit area, high air permeability, and stable shrinkage even in the continuous carbonization / activation process during industrial production. It is intended to provide a laminated product in which a knitted fabric and a front cloth / a back cloth are stacked and quilted.

[0007]

Means for Solving the Problems The present inventors have completed the present invention as a result of extensive studies to solve the above problems. That is, in the present invention, a fibrous activated carbon knitted product obtained by filamentizing and knitting a fibrous polymer precursor, and then carbonizing and activating, has a toluene adsorption performance of 25 g / m ² or more and an air permeability of 250 cm ^3. / Cm ² · s or more and tear strength is 2.
5N or more, and the fibrous polymer precursor is a phenolic fiber whose filament is 197d
A fibrous activated carbon knitted product obtained by carbonizing and activating a fibrous polymer precursor having a thickness of tex or more. Furthermore, absolute dry mass is 80~250g / m ^2, specific surface area by BET method is the 1000~3000m ² / g, the activated carbon fiber knit and table cloth, a knit structure is ribbed or both sides knitting
It is a laminated product in which backing fabrics are stacked and quilted.

Since the fibrous activated carbon sheet has excellent flexibility, it is used as various filters and elements for adsorbing gases of various organic solvents. As described above, in the method for forming the sheet, the raw material organic fibers are made into a non-woven fabric or a woven fabric such as felt, and then carbonized and activated, or the raw material organic fibers are carbonized and activated to obtain fibrous activated carbon. A method of later processing it into a non-woven fabric such as felt may be mentioned, but a knitted fibrous activated carbon sheet is excellent because of its flexibility and workability. When the sheet itself is handled in a place involving movement, such as laminating with other fiber materials or the like, and protective clothing, it is particularly advantageous to have a knitted shape because of its flexibility. Regarding the step of obtaining the fibrous activated carbon knitted product, it is preferable to first knit the fibrous polymer precursor into a knitted product, and then carbonize and activate the activated carbon knitted product to knit the activated carbon fibrous product. Since the strength is weak, it is not industrially possible.

[0009] As the adsorption performance of the activated carbon knit, JIS
K1477 “Fibrous Activated Carbon Test Method” has a toluene adsorption performance of 25 g / m ² or more (25 ° C., 1 /
10 conditions, preferably 40 g / m ² or more. If it is less than this adsorption amount, practical performance cannot be sufficiently exhibited when used as a filter or protective clothing.
The breathability of the activated carbon knitted fabric is JIS L101.
8. Air permeability of the method described in “Test method for knit fabric” must be 250 cm ³ / cm ² · s or more. If it is less than this, there is a problem that the pressure loss increases when the filter is used and the wearing feeling is deteriorated when the protective clothing is used.

When the fibrous activated carbon knitted fabric is processed according to the purpose, for example, when it is laminated with another fiber aggregate such as a woven or knitted fabric or a non-woven fabric, it is necessary to industrially process it so that the fibrous activated carbon knitted fabric is subjected to mechanical stress. Joining, tearing and tearing occur.
To prevent this, at least JIS L1096
The tear strength (trapezoid method) described in Section 8.15.4 is 2.5.
N or more is required. If it is less than this, productivity is greatly reduced when it is subjected to lamination processing or other processing for commercialization, which is not practical.

In order to obtain such a fibrous activated carbon knitted fabric having a high tear strength, it is desirable that the precursor fiber is a phenol fiber. Cellulose-based, pitch-based and PAN-based fibers are also known as precursor fibers for fibrous activated carbon. When cellulosic fibers are used as the total precursor, carbonized / activated carbon fiber gives a fibrous activated carbon having a specific surface area that exhibits sufficient adsorption performance, but the yield is low and the shrinkage rate is large, so the rigidity is high and the fabric The strength, especially the tear strength, is small. When a PAN-based fiber is used as the precursor fiber, a fiber having a relatively high fabric strength can be obtained, but it is difficult to obtain a fibrous activated carbon having a large adsorption performance.
When pitch-based fibers are used, strength and adsorption performance intermediate between those of cellulose-based and PAN-based fibers can be obtained, but both properties are not always satisfied.

[0012]

In the present invention, in view of the above situation, the precursor fiber may be in the form of spun yarn or filament yarn obtained from staples, or may be a mixed filament yarn in which both are mixed. Absent. The single fiber fineness is 1.1 dtex to 5.5 dtex, and the fineness of the twisted thread is 197 dtex or more, preferably 2
95-590 dtex is good. If it is 197 dtex or less, the density of the knitted, carbonized and activated knitted fibrous activated carbon becomes dense, and sufficient air permeability cannot be obtained. In addition, the flexibility is insufficient, which leads to tearing or tearing during post-processing or during use.

In knitting a raw material knitted fabric using such a filament, the elongation percentage of the fabric after being made into fibrous activated carbon,
In order to maintain flexibility and air permeability, rib knitting or double-sided knitting is preferable as the knitting structure. Among them, milling and smooth knitting are preferable in that the selvage of the dough is hardly caught by the stress in the course direction due to the shrinkage of the dough during continuous firing, and the effective width of the fibrous activated carbon knit is secured.

The mechanical strength of the fibrous activated carbon cloth is lowered by being carbonized and activated. In particular, if the tear strength is extremely reduced, it may cause damage during post-processing or during use, which is inconvenient. Here, in order to maintain the flexibility and strength of the fibrous activated carbon knitting as much as possible, it can be solved by having the elongation at break of the raw material knitting before carbonization and activation be 100% or more in both the course and wale directions. Found by the present invention. The present invention also includes a fibrous activated carbon knitted product that is carbonized and activated using a raw material knitted product that is designed to have an elongation at break of 100% or more.

When the raw material knitted fabric thus obtained is made into activated carbon, it can be obtained by subjecting the fibrous activated carbon knitted fabric to uniform dough characteristics and adsorption performance, though it can be obtained by performing a carbonization / activation process in a batch or continuous manner. It is preferable to carry out the carbonization and activation continuously in consideration of obtaining the property and industrial productivity. The raw material knitted fabric is carbonized in an inert atmosphere at a temperature of 350 ° C. or more and 1000 ° C. or less, and then activated in an active atmosphere containing steam, oxygen, carbon dioxide, etc. that reacts with carbon at a temperature of 500 ° C. or more and 1000 ° C. or less, and activated carbonization. To do. In some cases, carbonization and activation can be performed simultaneously by controlling the atmospheric conditions. In addition, if the maximum temperature reached during activation treatment, that is, active carbonization is 1000 ° C. or higher, wrinkles may occur due to abnormal shrinkage, and the maximum temperature reached is preferably 1000 ° C. or lower. As a result, a knitted fibrous activated carbon having a specific surface area of 1000 to 3000 m ² / g is obtained. Further, the dry mass of the obtained activated carbon cloth is 80 to 250 g / m ² , preferably 1
It is preferably from 0 to 150 g / m ² . If the amount is 80 g / m ² or less, the tear strength of the activated carbon is weak, and if the amount is 250 g / m ² or more, the air permeability is deteriorated. When processing a fibrous activated carbon knitted fabric according to the purpose, for example, when laminating with another fiber aggregate such as a woven or knitted fabric or a non-woven fabric, a method of laminating with a non-woven fabric hot melt adhesive is known. When this method is used when the weight of the activated carbon cloth is large, the rigidity of the laminated product increases and the wearing feeling becomes poor when it is used as protective clothing, and the surface of the activated carbon cloth is covered with an adhesive to lower the adsorption performance. And problems such as reduced breathability occur. Therefore, in order to solve these problems, it is preferable to make a laminated product by quilting.

[0016]

EXAMPLES The present invention will be described in detail below based on examples. However, the following examples do not limit the present invention, and any modification and implementation without departing from the gist of the preceding and the following are included in the technical scope of the present invention. The measuring method of each characteristic value of the knitted fabric is as follows. Absolute dry mass of fabric,
The basis weight, thickness, apparent specific gravity, breathability, tensile strength, elongation and bending resistance are in accordance with JIS L1018, tear strength is in accordance with JIS L1096, and the toluene adsorption performance of fibrous activated carbon is JIS K1477. Compliant with.

Example 1 A milling knitted fabric was knitted by a 22-gauge double-sided circular knitting machine using a phenolic fiber having a single fiber fineness of 2.2 dtex and a thread-like fineness of 295 dtex. This knitted fabric has a basis weight of 225 g /
m ² , thickness 1.65 mm, apparent specific gravity 0.14 g / cm ³ , breathability 320 cm ³ / cm ² · s, tensile strength 37.2 N / cm in course direction, 53.9 N / wale direction. cm, elongation was set to 147% in the course direction and 160% in the wale direction. The knitted fabric was carbonized from room temperature to 890 ° C for 30 minutes in an inert atmosphere, and then activated at a temperature of 890 ° C for 90 minutes in an atmosphere containing 12 wt% of steam. The obtained knitted fibrous activated carbon cloth contracted 20% in the course direction and 28% in the wale direction, but had no curl in the ears, and was supple without wrinkles or distortion. The obtained knitted fabric fibrous activated carbon cloth has an absolute dry weight of 120 g /
m ² , thickness 1.05 mm, specific gravity 0.11 g / cm ³ , breathability 330 cm ³ / cm ² s, tensile strength course direction 2.0 N /
cm, wale direction 1.5 N / cm, elongation is course direction 3
5%, wale direction 95%, tear strength course direction 3.
8N, wale direction 4.0N, bending resistance is course direction 6.
It was 4 mN · cm and 6.2 mN · cm in the wale direction. Also, the toluene adsorption performance of this fibrous activated carbon cloth is 5
It had a very high adsorption performance of 6 g / m ² and a BET specific surface area of 1380 m ² / g. The obtained knitted fibrous activated carbon cloth was sandwiched between 82.5 dtex and 65 g / m ² tricot cloth using 22 dtex ester, and 9
2.54c with 8.5 dtex ester spun yarn
The diamond pattern was quilted. During processing, there was no trouble such as tearing or cutting of the activated carbon cloth, and the obtained laminated product was very flexible.

Comparative Example 1 Using a 22-gauge double-sided circular knitting machine, a milling knitted fabric was knitted using a phenolic fiber having a single fiber fineness of 2.2 dtex and a thread-like fineness of 295 dtex. This knitted fabric has a basis weight of 225 g /
m ² , thickness 1.65 mm, apparent specific gravity 0.14 g / cm ³ , breathability 320 cm ³ / cm ² · s, tensile strength 37.2 N / cm in course direction, 53.9 N / wale direction. cm, elongation was set to 147% in the course direction and 160% in the wale direction. The knitted fabric was carbonized from room temperature to 890 ° C for 30 minutes in an inert atmosphere, and then activated at a temperature of 890 ° C for 90 minutes in an atmosphere containing 12 wt% of steam. The obtained knitted fibrous activated carbon cloth contracted 20% in the course direction and 28% in the wale direction, but had no curl in the ears, and was supple without wrinkles or distortion. The obtained knitted fabric fibrous activated carbon cloth has an absolute dry weight of 120 g /
m ² , thickness 1.05 mm, specific gravity 0.11 g / cm ³ , breathability 330 cm ³ / cm ² s, tensile strength course direction 2.0 N /
cm, wale direction 1.5 N / cm, elongation is course direction 3
5%, wale direction 95%, tear strength course direction 3.
8N, wale direction 4.0N, bending resistance is course direction 6.
It was 4 mN · cm and 6.2 mN · cm in the wale direction. Also, the toluene adsorption performance of this fibrous activated carbon cloth is 5
It had a very high adsorption performance of 6 g / m ² and a BET specific surface area of 1380 m ² / g. The obtained knitted fibrous activated carbon cloth was sandwiched between 82.5 dtex and 65 g / m ² tricot cloth using 22 dtex ester, and laminated with a non-woven fabric hot melt adhesive made of an amide resin. During processing, there was no trouble such as tearing or cutting of the activated carbon cloth, but the obtained laminated product was a little stiff and stiff.

Comparative Example 2 Single fiber fineness of 2.2 dtex, thread-like fineness of 590 dtex
Using a 14-gauge single-sided circular knitting machine using knot-based fibers
A knitted fabric is knitted. This knitted fabric has a basis weight of 220 g /
m², Thickness 0.94mm, apparent specific gravity 0.23g / cm³, Through
210cm temper³/ M ²・ S, tensile strength is 20.
6 N / cm, wale direction 13.7 N / cm, elongation is
The direction was set to 84% in the rolling direction and 177% in the wale direction. this
Knitted fabric from room temperature to 890 ℃ in an inert atmosphere for 30 minutes
In an atmosphere containing 12 wt% steam.
Activation was carried out at a temperature of 890 ° C. for 90 minutes. The resulting knitted form
Fibrous activated carbon cloth is 30% in the course direction and 25% in the transverse direction.
Caused the contraction of. The obtained knitted fabric fibrous activated carbon cloth is
Absolute dry mass 125g / m², Thickness 0.89 mm, specific gravity 0.
14 g / cm³, Tensile strength is 2.9 N / cm in the course direction,
1.1 N / cm in the wale direction, 26% elongation in the course direction,
85% wale direction, tear strength 2.5N course direction,
Wale direction 2.0N, bending resistance 6.7mN course direction
cm, the direction of wale was 6.1 mN · cm, which was flexible.
Also, the toluene adsorption performance of this fibrous activated carbon cloth is 59 g /
m², BET specific surface area 1380m²/ G very high adsorption
Although it had performance, breathability was 175 cm3 / cm2
・ It was as low as s, and curls occurred in the ears. The obtained edition
82.5 dtex and 22 dte of fibrous activated carbon cloth
65 g / m using x ester²Sandwiched between the tricot land
Using an ester spun yarn of 98.5 dtex.
54 cm diamond pattern was quilted. The laminated product is
It was very flexible, but when quilted, it became fibrous.
It has very poor workability due to the curl of the ears of the charcoal cloth.
there were.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

As described above, the fibrous activated carbon knitted fabric of the present invention is a rib in which the filaments are phenolic fibers having a thickness of 197 dtex or more and elongation at break of 100% or more in both the course direction and the wale direction. The carbonaceous or double-sided knitted fibrous polymer precursor is activated and carbonized by carbonization and activation, so that it has a large adsorption performance for organic solvent gas per unit area, high air permeability, and tear strength. It is possible to provide fibrous activated carbon that is strong, excellent in quality, and excellent in quality, and by providing a quilted material on top of the front cloth / back cloth, it is possible to provide a flexible and highly breathable laminated product.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-11-267244 (JP, A) JP-A-8-308945 (JP, A) JP-A-2-190328 (JP, A) JP-A-2001-149501 (JP, A) JP 2002-235247 (JP, A) JP 2002-235248 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B32B 1/00-35/00 D04B 1/00-1/28 D04B 21/00-21/20

Claims (5)

(57) [Claims] 1. A fibrous polymer precursor having a thickness of 197 dtex or less.
In a fibrous activated carbon knitted product obtained by carbonizing and activating after knitting and knitting in the range of 590 dtex or less , the toluene adsorption performance is 25 g / m ² or more and the air permeability is 25.
0 cm ³ / cm ² · s or more , tear strength ^2.5 N or more, and excellent
A laminated product characterized in that a front cloth and a back cloth are laid and quilted on the front and back of a fibrous activated carbon knitted fabric having a dry mass of 80 to 250 g / m ² . 2. A specific surface of a fibrous activated carbon knitted fabric by the BET method.
Characterized in that the product is 1000 to 3000 m ² / g
The laminated product according to claim 1, wherein 3. The phenolic fiber is used as the fibrous polymer precursor.
3. The method according to claim 1, wherein there is
Laminated products. 4. A fibrous polymer precursor knitted fabric before carbonization / activation
Elongation at break is 100% in both course and wale directions
It is above, It is any one of Claim 1 thru | or 3 characterized by the above-mentioned.
The laminated product described in. 5. The knitting structure is rib knitting or double-sided knitting.
Laminate according to any one of claims 1 to 4, characterized in that
Goods.