KR20140134874A - Electroconductive Aramid Paper Having Excellent Tensile Strength - Google Patents
Electroconductive Aramid Paper Having Excellent Tensile Strength Download PDFInfo
- Publication number
- KR20140134874A KR20140134874A KR20130054811A KR20130054811A KR20140134874A KR 20140134874 A KR20140134874 A KR 20140134874A KR 20130054811 A KR20130054811 A KR 20130054811A KR 20130054811 A KR20130054811 A KR 20130054811A KR 20140134874 A KR20140134874 A KR 20140134874A
- Authority
- KR
- South Korea
- Prior art keywords
- aramid
- weight
- para
- meta
- slurry
- Prior art date
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F1/00—Wet end of machines for making continuous webs of paper
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F5/00—Dryer section of machines for making continuous webs of paper
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21G—CALENDERS; ACCESSORIES FOR PAPER-MAKING MACHINES
- D21G1/00—Calenders; Smoothing apparatus
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/26—Polyamides; Polyimides
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/20—Macromolecular organic compounds
- D21H17/33—Synthetic macromolecular compounds
- D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
- D21H17/55—Polyamides; Polyaminoamides; Polyester-amides
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Paper (AREA)
Abstract
The present invention relates to a method for producing a slurry by preparing a slurry from an aqueous dispersion solution comprising para-aramid flocs, meta-aramid fibrids, and conductive fillers, forming a web through the wet pasting method, dehydrating the slurry through a nip roller, Wherein the para aramid floc is present in an amount of 10 to 60% by weight, the meta-aramid fibrid is contained in an amount of 20 to 70% by weight, and the conductive filler is contained in an amount of 5 to 20% by weight, And an electrically conductive aramid paper excellent in tensile strength, and a method for producing the same.
Description
The present invention relates to aramid paper. More particularly, the present invention relates to an electrically conductive aramid paper having low surface resistance and exhibiting electrical conductivity properties, excellent tensile strength and good durability.
A number of sheets called meta aramid paper have already been developed and used. The main uses of this paper include electrical insulation and honeycomb structural materials. Such a sheet as an electric insulator is widely used for insulators of coils such as a transformer and an electric motor, a printed board, etc. A sheet having a certain degree of conductivity is used for a heating element and a conductive tape for electrostatic discharge according to the degree of conductivity thereof.
The meta-aramid paper is produced by wet-laid paper by mixing and slurrying fibrids and flocs, usually made of heat-resistant fibers.
Examples of the heat-resistant fiber include organic heat-resistant fibers such as meta-aramid fiber, para-aramid fiber, and arylate fiber, and inorganic fibers such as glass fiber and asbestos. The aramid paper can be used for a heating element, an electromagnetic shielding material, a conductive tape or the like by imparting conductivity thereto. In order to impart conductivity to the aramid paper, Japanese Patent Laid-Open No. 4-65226 and Japanese Patent Laid-Open No. 4-153399 disclose that carbon fiber, metal fiber, or the like is used as the heat resistant fiber. In the case of imparting conductivity to the aramid paper as described above, the specific gravity of the conductive fiber is larger than that of the aramid fiber, and the dispersibility in the process of making the web state using the wet paper machine is poor.
WO 2006-127819 discloses a method for producing a conductive aramid paper by mixing meta aramid floc, meta-aramid fibrids and conductive filler (carbon fiber) to prepare a web, In which a paper is produced without a calendering step of compressing the paper. In the case of imparting conductivity to the aramid paper as described above, the surface resistance is lowered to exhibit conductivity to some extent, but the tensile strength is lowered and the durability is lowered.
In order to solve the above problems, the inventor of the present invention has found that a web is formed using a carbon fiber as a para-aramid floc, a meta-aramid fibrid and a conductive filler, and then subjected to a calendaring process, It has come to develop electrically conductive aramid paper with excellent strength.
An object of the present invention is to provide an aramid paper having electrical conductivity.
Another object of the present invention is to provide an aramid paper having excellent tensile strength.
It is still another object of the present invention to provide a method for producing aramid paper excellent in electrical conductivity and tensile strength.
These and other objects of the present invention can be achieved by the present invention described in detail below.
The present invention relates to a method for producing a slurry by preparing a slurry from an aqueous dispersion solution comprising para-aramid flocs, meta-aramid fibrids, and conductive fillers, forming a web through the wet pasting method, dehydrating the slurry through a nip roller, Wherein the aramid flock comprises 10 to 60% by weight of para-aramid flakes, 20 to 70% by weight of meta-aramid fibrids and 5 to 20% by weight of conductive fillers.
The para-aramid floc may be a poly (paraphenylene terephthalamide) flock, and the methallylide fibrid may be a poly (metaphenylene isophthalamide) fibrid. The conductive filler may be carbon fiber.
The aramid may have a tensile strength of 40 to 65 N / cm measured according to ASTM D 828 and a surface resistance of 200 to 400 Ω / sq measured according to ASTM D 257.
The present invention also provides a method of making a slurry from an aqueous dispersion solution of 10 to 60% by weight of para-aramid flock, 20 to 70% by weight of meta-aramid fibrids and 5 to 20% by weight of conductive filler, And a step of dewatering the mixture through a nip roller, and calendaring the resultant mixture, thereby providing an electrically conductive aramid paper having excellent tensile strength.
The aramid fabric according to the present invention is made by adding carbon fiber as a conductive filler to lower the surface resistance to provide electrical conductivity and to provide aramid paper with excellent tensile strength by using para-aramid flock.
The present invention relates to an electrically conductive aramid paper having low surface resistance and exhibiting electrical conductivity properties and having excellent tensile strength and good durability.
The aramid paper according to the present invention comprises para-aramid flock, meta-aramid fibrid and conductive filler, and has electrical conductivity and excellent tensile strength. Hereinafter, the details will be described in detail.
Aramid paper
The electrically conductive aramid having excellent tensile strength according to the present invention can be produced by forming a web by a wet pasting method by adding carbon fiber as a para-aramid flock, a meta-aramid fibrid or a conductive filler, and calendering at a high temperature and a high pressure. The aramid according to the present invention comprises 10 to 60% by weight of para-aramid flock, 20 to 70% by weight of meta-aramid fibrid and 5 to 20% by weight of conductive filler.
The aramid yarns of the present invention may comprise fibers made from aramid polymers. Para-aramid flocs can be produced by cutting para-aramid filaments to a certain length. The flock length is preferably about 2 to 7 mm, and the diameter is preferably about 5 to 14 μm. If the length of the floc is less than 2 mm, it is difficult to form a strong paper. If the length is more than 7 mm, it is difficult to form a uniform web by the wet grass method. If the diameter of the floc is less than 5 占 퐉, it is not easy to produce para-aramid fibers for producing the flock, and if the diameter of the flock exceeds 14 占 퐉, the thickness of the paper becomes thick.
The aramid of the present invention comprises 10 to 60% by weight of para-aramid flock. When the para-aramid flock is less than 10% by weight, the aramid paper tends to be broken and the tear strength is lowered. On the other hand, when the para-aramid floc is more than 60% by weight, the content of the fibrids constituting the aramid paper relatively decreases and the tensile strength is lowered.
The aramid paper of the present invention also includes meta-aramid fibrids. The fibrids have a length of about 100 to 1000 μm and a diameter of about 0.1 to 1 μm. As described in U.S. Pat. No. 3,756,908, fibrids can be prepared by causing the polymer solution to undergo precipitation and strong shear stress while contacting the polymer in solution in a fibridater.
The aramid paper of the present invention comprises 20 to 70% by weight of meta-aramid fibrids. When the meta-aramid fibrid is less than 20% by weight, the floc is not properly bound and the tensile strength is lowered. When the meta-aramid fibrid is more than 70% by weight, the aramid paper tends to be broken, have.
The aramid paper of the present invention further comprises a conductive filler for imparting conductivity. The conductive filler means a fibrous or particulate form having a conductivity of at least 10 2 S / m.
In the present invention, the aramid paper comprises 5 to 20% by weight of the conductive filler. When the conductive filler is less than 5% by weight, there is a problem that the produced aramid paper has a high surface resistance and is difficult to exhibit conductivity. On the other hand, when the amount of the conductive filler is more than 20% by weight, fractions of floc and fibrids are lowered when the aramid paper is produced, which deteriorates the mechanical properties of the aramid paper. A preferred conductive filler in the present invention is carbon fiber.
Aramid Manufacturing method
An electrically conductive aramid having excellent tensile strength is prepared by preparing a slurry from an aqueous dispersion solution containing 10 to 60% by weight of para-aramid flocs, 20 to 70% by weight of meta-aramid fibrids, and 5 to 20% by weight of conductive fillers, And then dehydrating and calendering the web through a nip roller after the web is formed.
The step of calendaring is a process of thermocompression and can be easily performed by a person having ordinary skill in the art to which the present invention belongs.
The present invention is characterized by having a surface resistance of 400 Ω / sq or less, preferably 200 to 400 Ω / sq, measured according to ASTM D 257, after calendering, and a tensile strength of 40 N / cm Or more, preferably 40 to 65 N / cm.
The para-aramid flocs, meta-aramid fibrids, and conductive fillers used in the production of the aramid paper of the present invention are the same as those described in the above-mentioned aramid paper, and are omitted in order to avoid duplication.
The present invention may be better understood by the following examples, which are for the purpose of illustrating the invention and are not intended to limit the scope of protection defined by the appended claims.
Example And Comparative Example
The components used in Examples and Comparative Examples are as follows.
(1) Para-aramid flock
Based on the Korean Patent Application No. 2008-0047150, a para-aramid multifilament was prepared. The multifilament properties showed a fineness of 840 denier, a single filament fineness of 1.5 denier, a tensile strength of 23 g / d and an elongation of 3.5%. The multi-filaments were cut to an average length of 4 mm to produce para-aramid flocs.
(2) Meta-aramid fibrids
Methylphenylenediamine (MPD) is dissolved in the polymerization solvent to prepare a mixed solution. N, N-Dimethylacetamide (DMAc) was used as a heavy solvent.
Next, isobutyryl chloride (IPC) is added to the mixed solution in two portions while stirring the above-mentioned mixed solution to be polymerized. Calcium hydroxide is added to neutralize the hydrochloric acid generated as a by-product in the polymethenylene isophthalamide (PMIA) solution obtained through the polymerization process.
The neutralized dope (polymer solution) was contacted with the non-solvent in the Fibrid data as described in US Pat. No. 3,756,908, and the precipitate was ground with strong shear stress to produce fibrids. The freeness of the prepared fibrids was 110 ml.
(3) Meta-aramid flock
Methylphenylenediamine (MPD) is dissolved in the polymerization solvent to prepare a mixed solution. N, N-Dimethylacetamide (DMAc) was used as a heavy solvent.
Next, isobutyryl chloride (IPC) is added to the mixed solution in two portions while stirring the above-mentioned mixed solution to be polymerized. Calcium hydroxide is added to neutralize the hydrochloric acid generated as a by-product in the polymethenylene isophthalamide (PMIA) solution obtained through the polymerization process.
The dope (polymer solution) which had been subjected to the neutralization process was filtered and defoamed to prepare a radiation coating suitable for spinning, and then the methacrylamide fiber was formed by wet spinning and cut into an average length of 4 mm to prepare a meta-aramid floc .
(4) Conductive filler
The carbon fiber was cut into 4 mm of commercially available Doraic acid T300.
Example One
The above-described meta-aramid fibrids were prepared and dispersed in an aqueous solution to prepare an aqueous dispersion. After the carbon fiber was added to the dispersion, stirring was continued for 15 minutes, followed by addition of water and para-aramid flocs and stirring for 15 minutes to obtain a slurry with a final concentration of 0.4% by weight. The slurry consisted of 55% by weight of para-aramid flock, 35% by weight of meta-aramid fibrids, and 10% by weight of carbon fibers as described in Table 1 below. The slurry was formed into a web by a wet laid-in method, dehydrated through a nip roller, and dried to produce aramid paper. The aramid paper was obtained through calendering at a temperature of 280 캜, a pressure of 80 kg / cm, and a roller speed of 6 m / min, and the electrically conductive aramid paper obtained by the above production method.
Example 2
The rest of the process was carried out in the same manner as in Example 1, except that the slurry was composed of 35% by weight of para-aramid flock, 55% by weight of meta-aramid fibrids and 10% by weight of carbon fibers as shown in Table 1 below.
Comparative Example One
The meta-aramid fibrids were prepared by the above-described preparation method and then dispersed in an aqueous solution to prepare an aqueous dispersion. After the carbon fibers were added to the dispersion, stirring was continued for 15 minutes, followed by addition of water and meta aramid floc and stirring for 15 minutes to obtain a final 0.4 wt% slurry. The slurry consisted of 55% by weight of meta-aramid flock, 35% by weight of meta-aramid fibrids, and 10% by weight of carbon fibers, as described in Table 1 below. This slurry was formed into a web by a wet laid-on method and then subjected to the above-described thermal compression process to obtain an aramid paper.
Comparative Example 2
The rest of the process was carried out in the same manner as in Example 1, except that the slurry was composed of 60% by weight of para-aramid flock and 40% by weight of meta-aramid fibrids, as shown in Table 1 below.
Comparative Example 3
The rest of the process was carried out in the same manner as in Example 1, except that the slurry was composed of 56% by weight of para-aramid flock, 40% by weight of meta-aramid fibrids and 4% by weight of carbon fibers as shown in Table 1 below.
The properties of the produced aramid paper were measured in the following manner, and the results are shown in Table 2.
Property measurement
1) Thickness measurement: Measured according to ASTM D 374 for Example 1-2 of the present invention and Comparative Example 1-3. In the thickness measurement, the test piece was measured under a pressure of 172 Kpa.
2) Density (apparent density): measured according to ASTM D 202.
3) Tensile Strength: Measured on a tensile test on an Instron test machine using specimens of 2.54 cm wide and 12.7 cm gauge length according to ASTM D 828.
4) Surface resistance: Measured according to ASTM D 257.
As shown in Table 2 above, Example 1 using para-aramid floc shows excellent tensile strength, but Comparative Example 1 using meta-aramid floc shows lower tensile strength than Example 1.
Examples 1 and 2 according to the content range of the present invention show desirable tensile strength and surface resistance. Further, it can be seen from Examples 1 and 2 that the higher the content of para-aramid flocs is, the more the tensile strength is improved. However, it can be seen that Comparative Examples 2 and 3, which did not use carbon fibers or were used in an amount less than the content range, had a high surface resistance and a poor electrical conductivity effect.
It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
The slurry is formed into a web through a wet grass method and then dehydrated through a nip roller; And
Calendaring;
Wherein the electrically conductive aramid paper has an excellent tensile strength.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20130054811A KR20140134874A (en) | 2013-05-15 | 2013-05-15 | Electroconductive Aramid Paper Having Excellent Tensile Strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR20130054811A KR20140134874A (en) | 2013-05-15 | 2013-05-15 | Electroconductive Aramid Paper Having Excellent Tensile Strength |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| KR20140134874A true KR20140134874A (en) | 2014-11-25 |
Family
ID=52455756
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| KR20130054811A KR20140134874A (en) | 2013-05-15 | 2013-05-15 | Electroconductive Aramid Paper Having Excellent Tensile Strength |
Country Status (1)
| Country | Link |
|---|---|
| KR (1) | KR20140134874A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101662023B1 (en) * | 2015-04-30 | 2016-10-14 | 주식회사 엔바이오니아 | manufacturing process of aramid paper for enhancing dispersion force |
| KR20170023297A (en) * | 2015-08-20 | 2017-03-03 | 주식회사 휴비스 | Aramid Paper Having Excellent Withstand Voltage and Method for Preparing the Same |
| KR101866526B1 (en) * | 2015-09-17 | 2018-06-14 | 주식회사 휴비스 | Meta aramid paper with high basis weight |
| CN113293640A (en) * | 2021-06-28 | 2021-08-24 | 山东聚芳新材料股份有限公司 | Para-aramid nanofiber and high-performance carbon fiber composite paper and preparation method thereof |
-
2013
- 2013-05-15 KR KR20130054811A patent/KR20140134874A/en not_active Application Discontinuation
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101662023B1 (en) * | 2015-04-30 | 2016-10-14 | 주식회사 엔바이오니아 | manufacturing process of aramid paper for enhancing dispersion force |
| KR20170023297A (en) * | 2015-08-20 | 2017-03-03 | 주식회사 휴비스 | Aramid Paper Having Excellent Withstand Voltage and Method for Preparing the Same |
| KR101866526B1 (en) * | 2015-09-17 | 2018-06-14 | 주식회사 휴비스 | Meta aramid paper with high basis weight |
| CN113293640A (en) * | 2021-06-28 | 2021-08-24 | 山东聚芳新材料股份有限公司 | Para-aramid nanofiber and high-performance carbon fiber composite paper and preparation method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103282412B (en) | Electrically-insulating paper | |
| EP1885953B1 (en) | Electroconductive aramid paper | |
| RU2656226C2 (en) | Electrical insulation paper | |
| JP6251392B2 (en) | Flame retardant sheet material | |
| KR20140134874A (en) | Electroconductive Aramid Paper Having Excellent Tensile Strength | |
| JP2007308836A (en) | Heat-resistant electrical insulating paper | |
| KR101538190B1 (en) | Papers containing floc derived from diamino diphenyl sulfone | |
| JP2023518231A (en) | Paper containing airgel powder and aramid polymer fibrils | |
| EP3305982B1 (en) | Aramid paper, manufacturing method therefor, and use thereof | |
| JPWO2016103966A1 (en) | Insulating paper | |
| US8168039B2 (en) | Electroconductive aramid paper and tape made therefrom | |
| TWI702326B (en) | Polyaramide (aramide) paper and its manufacturing method | |
| JP2001207335A (en) | Fibrillar material and method for producing the same | |
| CN111295479A (en) | Insulating sheet | |
| JP6405583B2 (en) | Insulating paper | |
| KR101515307B1 (en) | Meta aramid paper with high basis weight and manufacturing method thereof | |
| JP2003096698A (en) | Heat-resistant insulating paper sheet and method for producing the same | |
| KR101537453B1 (en) | Meta aramid paper with low density and enhanced Tear strength and manufacturing method thereof | |
| CN110088371B (en) | Aramid paper suitable for electronic applications | |
| JP2020133028A (en) | Finer meta-type wholly aromatic polyamide fiber and method for producing the same | |
| KR101700827B1 (en) | Aromatic polyamide laminated sheet and manufacturing method thereof | |
| KR20180022751A (en) | Aromatic polyamide paper for electrical insulation and manufacturing method thereof | |
| JP2010102893A (en) | Meta-type wholly aromatic polyamide electric insulating paper | |
| JP2018145567A (en) | High-strength heat-resistant paper | |
| JP2012233266A (en) | Organic fiber fibrid, sheet material using the same, and sound absorbing structural material in which the sheet material is arranged |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A201 | Request for examination | ||
| E902 | Notification of reason for refusal | ||
| E601 | Decision to refuse application |