KR102486278B1 - Method of manufacturing graphene coated fabric - Google Patents

Abstract

The present invention relates to a method for producing a graphene-coated fiber fabric. It becomes possible to produce a coating liquid with uniform dispersion and high content.
Textile fabrics coated with such a graphene-resin coating solution can be suppressed from deterioration of antibacterial properties even after a lot of washing.

Description

Manufacturing method of graphene-coated textile fabric {Method of manufacturing graphene coated fabric}

The present invention relates to a manufacturing method of coating graphene on a textile fabric to exhibit antibacterial properties.

Graphene is a carbon allotrope with a two-dimensional structure in which carbon atoms form a hexagonal honeycomb lattice structure, the thickness of which is the size of one atom.

Graphene has tensile strength 311 times stronger than steel, electron mobility 1000 times faster than silicon, thermal conductivity 10 times better than copper, transparent enough to pass 98% of light, and characteristics even when bent or stretched. has this property.

Graphene has excellent electrical, thermal, and mechanical properties, and due to these properties, it is applied to conductive materials, electromagnetic wave shielding materials, solar cells, and polymer composite materials.

Graphite is a structure in which these graphenes are stacked in layers, and is a starting material for producing graphene.

An example of a method for chemically producing graphene using graphite will be described as follows.

First, graphite is treated with strong acid to oxidize it.

When carbon and acid react, graphene oxide containing oxygen functional groups such as hydroxyl group, epoxide group, carboxyl group, and lactol group is produced.

Since graphene oxide is an oxygen functional group, it is well dispersed in an aqueous solution.

Graphene is produced by transforming the aqueous dispersion of graphene oxide into a desired pattern and removing oxygen by using a reducing agent or treating at a high temperature.

Graphene is prepared by reacting using hydrogen sulfide, hydrazine, hydroquinone, sodium hydroxide, potassium hydroxide, etc. as a reducing agent.

Republic of Korea Patent Registration No. 1233818 describes a method for producing graphene-treated fibers.

According to the above patent, a method for producing graphene-treated fibers is described by treating cationized fibers with a dispersion containing graphene oxide and reducing the fibers treated with graphene oxide.

At this time, the method for preparing the dispersion containing graphene oxide is as follows,

After putting the graphite in sulfuric acid, while maintaining the temperature of the reactor not to exceed 20 ° C, potassium permanganate is added and stirred at 30 to 40 ° C for 60 to 120 minutes, and deionized water is added in portions while stirring.

Next, add deionized water and hydrogen peroxide and stir until the solution turns golden. Thereafter, filtering is performed using filter paper, and the paste collected on the filter paper is vacuum dried. When the vacuum-dried paste is again placed in deionized water and ultrasonically dispersed, a dispersion containing graphene oxide is prepared.

According to the above patent, the fibers treated with the graphene oxide aqueous dispersion have improved electrical conductivity, chargeability, deodorization and antibacterial properties by graphene.

However, this manufacturing method has a problem in that the coating force and adhesion to the fiber surface are low, and the quality deteriorates when used for a long time, resulting in poor durability.

The present invention is to solve the above problems, and a manufacturing method using a graphene oxide water dispersion but using a coating method so that the properties expressed by graphene are maintained for a long time in the graphene-coated fiber fabric. intended to provide

In order to solve the above problems, the present invention is to manufacture a graphene-coated textile fabric obtained by coating a graphene-resin containing coating solution including a graphene oxide dispersion, polyurethane, and an organic solvent on a textile fabric and drying it by heat. In the method, the graphene oxide dispersion may include: a first step of concentrating a graphene oxide aqueous dispersion to obtain a graphene oxide slurry; A second step of applying shock waves to a solution obtained by adding an amphoteric solvent miscible with water to the graphene oxide slurry; A third step of concentrating after the second step to obtain an amphoteric solvent-containing graphene oxide slurry; and a fourth step of adding an organic solvent to the amphoteric solvent-containing graphene oxide slurry, wherein the graphene oxide dispersion is prepared by repeating the second and third steps two or more times. It provides a method for producing this coated fiber fabric.

According to the present invention, by replacing water with an organic solvent in a graphene oxide aqueous dispersion and mixing it with an organic solvent solution of a binder resin, it is possible to prepare a coating solution having a uniform dispersion of graphene oxide and a high content of the graphene oxide.

Textile fabrics coated with such a graphene-resin coating solution can be suppressed from deterioration of antibacterial properties even after a lot of washing.

The present invention relates to a method for producing a graphene-coated textile fabric by preparing a graphene-resin coating solution using a graphene oxide aqueous dispersion and coating the graphene-resin coating solution on a textile fabric.

The present invention is to prepare a resin coating solution containing graphene using a graphene oxide aqueous dispersion.

In general, a resin coating solution containing graphene using water as a dispersion solvent is difficult to uniformly disperse graphene and has limitations in increasing the content of graphene. There is a problem of quality that deteriorates, and the coating force and adhesive force on the surface of the fiber fabric are lowered.

The present invention solves the above problems by using an organic solvent as a dispersion solvent by substituting a non-aqueous solvent for water adsorbed on graphene oxide in an aqueous dispersion of graphene oxide, and at the same time improves mixing with a binder dispersed in an organic solvent. it has improved

To this end, shockwaves are repeatedly applied to the aqueous dispersion of graphene oxide to desorb water attached to the surface of graphene oxide, and at the same time replace the desorbed water with an amphoteric solvent in excess of water to obtain graphene substituted with an organic solvent. to use oxide.

A method of providing the shock wave is based on a physical energy application method.

The physical energy application method is a micro cavity explosion induction method, an ultrasonic application method, a molecular unit shear force application method (high pressure jetting method in which high pressure is discharged with a fine nozzle, high speed homogenizer, etc.), ultra high speed blading, ultra high speed stirring ( stirring), beads ball stirring (a method of inserting fine bead balls and stirring them together), a high-pressure ejection method (compression/ejection method with fine gaps), and a high-speed homogenizer method.

The ampholytic solvent is a solvent having an amphoteric property that is miscible with water, and methanol, ethanol, isopropyl alcohol (IPA), butanol, acetone, NMP (1-methyl-2-pyrrolidinone), glycol, TEG (tetraethylene glycol) ), dioxane, and tetrahydrofuran (THF).

Examples of organic solvents that are dispersing solvents of the present invention include acetone, methanol, ethanol, isopropyl alcohol (IPA), butyl alcohol, ethylene glycol, polyethylene glycol, dimethyl sulfoxide (DMSO), dimethyl formamide, DMF), N-Methylpyrrolidone (NMP), tetrahydrofuran (THF), toluene, benzene, xylene, dichloromethane, etc. Considering this, dimethylformamide is more preferable.

In the coating composition of the present invention, the binder serves to bind the components to be mixed.

As a binder, since acrylics are hard when cured by heat and have dyes that may blow into water when washed, polyurethane can be used as a binder in the present invention. In addition, polyurethane resin can be preferably used in the present invention because it has excellent transparency and adhesion to graphene materials.

When polyester diol is used as a polyol in the production of polyurethane resin, it has excellent adhesion to the fiber surface and is inexpensive when coating fabric fabric.

In the production of polyurethane resin, using polycarbonate diol as a polyol can improve mechanical properties and durability, and using poly tetramethylene glycol can improve hydrolysis resistance. There are advantages.

When producing polyurethane resin, if aliphatic isophorone diisocyanate or cyclohexylmethane diisocyanate is used as isocyanate, it is finally coated on the textile fabric so that discoloration by ultraviolet rays does not occur after coating. There are advantages to not

However, polycarbonate-based polyurethane has a problem in that the texture becomes hard.

To solve this problem, the polyurethane of the present invention may more preferably be prepared by including a copolymerized polycarbonate diol, a polycarbonate diol, an organic diisocyanate, and a chain extender.

The copolymerized polycarbonate diol may include a structural unit derived from an alkanediol having 3 to 5 carbon atoms and a structural unit derived from an alkanediol having 8 to 12 carbon atoms. In addition, it is a copolymerized polycarbonate diol having a heat of fusion (ΔH) of 40 to 100 J/g as determined by the melting point measurement method specified in JIS K7121-1987 as crystallinity.

The alkanediol having 3 to 5 carbon atoms is selected from among 1,3-propanediol, 1,4-butanediol and 1,5-pentanediol, and is preferably 1,4-butanediol.

The alkanediol having 8 to 12 carbon atoms is selected from 1,9-nonanediol, 1,10-decanediol and 1,12-dodecanediol, preferably 1,10-decanediol.

Copolymerization polycarbonate diols include, for example, 1,10-decanediol/1,4-butanediol (mol% ratio: 81/19) copolymerization polycarbonate diol.

The polycarbonate diol is an amorphous polycarbonate diol containing a structural unit derived from an alkane diol having 4 to 6 carbon atoms and having a heat of fusion (ΔH) defined above of 0 J/g.

The alkanediol having 4 to 6 carbon atoms is 1,6-hexanediol or 3-methyl-1,5 pentanediol, and a mixture thereof may also be used.

It can be confirmed that the polycarbonate diol of the present invention is amorphous, and no melting peak is observed in the melting point measuring method using a differential scanning calorimeter specified in JIS K7121-1987. If the polycarbonate diol is crystalline, it may damage the texture of textile fabrics.

As for polycarbonate diol, 1, 6- hexanediol polycarbonate diol etc. are mentioned, for example.

The content of the copolymerized polycarbonate diol of the present invention is preferably 50 to 80% by weight based on the total diol because durability and texture can be exhibited in a balanced manner due to the combination ratio of crystallinity and non-crystallinity.

At this time, if it is less than 50% by weight, durability and abrasion resistance are lowered, and if it exceeds 80% by weight, the touch is deteriorated, which is not preferable.

Examples of the method for producing copolymerized polycarbonate diols and polycarbonate diols include transesterification of diols with carbonate esters such as diphenyl carbonate and dimethyl carbonate.

Organic diisocyanates include aromatic diisocyanates having 6 to 20 carbon atoms (excluding carbon in NCO groups), aliphatic diisocyanates having 2 to 18 carbon atoms, alicyclic diisocyanates having 4 to 15 carbon atoms, and aromatic aliphatic diisocyanates having 8 to 15 carbon atoms. , modified products of these diisocyanates (modified carbodiimide, modified urethane, modified uretdione, etc.), mixtures of two or more of these, and the like are included.

The chain extender is selected from, for example, water, ethylene glycol, 1,4-butanediol, 4,4'-diaminodiphenylmethane, and mixtures of two or more thereof.

Examples of organic solvents used for production of polyurethane resins include amide solvents [N,N-dimethylformamide (DMF), N,N-dimethylacetamide, N-methylpyrrolidone, etc.]; Sulfoxide solvents [such as dimethyl sulfoxide (DMSO)]: ketone solvents (such as methyl ethyl ketone); etheric solvents (dioxane, THF, etc.); ester solvents (such as methyl acetate, ethyl acetate and butyl acetate); Aromatic solvents (toluene, xylene, etc.), etc., and mixtures of 2 or more types of these are mentioned. Among these, a preferred organic solvent is an amide-based solvent, and a particularly preferred organic solvent is DMF.

The number average molecular weight of the polyurethane resin is preferably 30,000 or more from the viewpoint of resin strength, and preferably 150,000 or less from the viewpoint of viscosity stability and workability.

The polyurethane resin used in the present invention is obtained by a one-shot method in which copolymerized polycarbonate diol, polycarbonate diol, organic diisocyanate, and chain extender are simultaneously reacted, or a method in which a chain extender is additionally reacted after obtaining a urethane prepolymer. can be manufactured

The graphene-resin-containing coating solution of the present invention can be prepared by uniformly mixing a composition comprising graphene oxide, polyurethane, and an organic solvent by a conventional method.

At this time, it is preferable that the graphene oxide is 1 to 10 parts by weight compared to 100 parts by weight of the polyurethane. If it is less than 1 part by weight, it is difficult to exhibit functional properties (eg, antimicrobial properties) by graphene, and if it exceeds 10 parts by weight, graphene distribution can be difficult.

In addition, since the graphene oxide dispersion of the present invention substituted with a non-aqueous solvent and polyurethane are dispersed in an organic solvent as a dispersion solvent, mixing is easy and graphene can be uniformly dispersed.

The graphene-resin-containing coating solution of the present invention preferably has a viscosity of 1,000 to 10,000 cps because it can be applied to textile fabrics using gravure, offset, kiss bar, knife, meyer bar, combing, and roll coating methods.

In the present invention, knife coating is more preferable because graphene can be arranged flat.

In the present invention, the coating liquid is applied to form a coating layer of 5 to 30 g / m 2, dried at 140 to 160 ° C for 1 to 3 minutes, set at 150 to 200 ° C for 1 to 5 minutes to harden, and the cured fiber fabric is 50 It can be manufactured by further performing smoothing to give a finishing effect by calendering by passing between rolls heated to ~ 100 ° C.

The graphene-coated textile fabric of the present invention exhibits an antibacterial effect by graphene, and since the graphene is uniformly and strongly attached to the textile fabric, washing resistance is improved, so that the antibacterial effect can be continuously maintained.

As a result, it can be applied to bedding and clothing, and can be applied to various fields of household goods manufacturing.

Hereinafter, the present invention will be described in more detail based on the following Examples and Comparative Examples.

However, the following examples are only for exemplifying the present invention, and the present invention is not limited by the following examples, and can be substituted and replaced by other equivalent examples without departing from the technical spirit of the present invention. It will be clear to those skilled in the art to which the present invention belongs.

[Example 1]

The aqueous dispersion of graphene oxide was centrifuged to remove water from the supernatant, and isopropyl alcohol was added to the precipitated concentrated graphene oxide slurry so that its volume was 5 times greater, and ultrasonic shock was applied for 20 minutes to remove the remaining water and isopropyl alcohol. After sufficiently mixing, the mixture was centrifuged again, and the supernatant was discarded to obtain a concentrated graphene oxide slurry at the bottom.

Inject isopropyl alcohol into the concentrated precipitate at the bottom, apply ultrasonic shock for 20 minutes, centrifuge to discard the supernatant, and repeat the process of obtaining a concentrated graphene oxide slurry at the bottom twice more to remove water attached to the graphene oxide. and substituted with isopropyl alcohol to prepare a graphene oxide concentrated slurry containing isopropyl alcohol.

Dimethylformamide was added to the isopropyl alcohol-containing graphene oxide slurry to 5 times its volume, and ultrasonic shock was applied for 20 minutes so that the remaining isopropyl alcohol and dimethylformamide were sufficiently mixed, and centrifuged again to obtain the supernatant. was discarded and the process of obtaining the concentrated precipitate at the bottom was repeated three times to remove isopropyl alcohol and substituted with dimethylformamide to prepare a graphene oxide concentrated slurry containing dimethylformamide.

The polyurethane resin binder and the graphene oxide slurry containing dimethylformamide were mixed so that 2 parts by weight of pure graphene oxide were mixed with 100 parts by weight of the polyurethane resin binder, and dimethylformamide was added and mixed in a mixer to obtain a coating having a viscosity of 2,000 cps. A composition solution was prepared.

The coating liquid is applied to the gray-dyed modal fiber fabric by the knife edge coating method using a knife, keeping the distance between the knife and the surface of the fabric at 0.05 mm, dried at 150 ° C for 1 minute, and then treated in a tenter at 180 ° C for 5 minutes and cured to prepare a fiber fabric coated with graphene.

[Example 2]

A graphene-coated fiber fabric was prepared in the same manner as in Example 1, except for using the polyurethane prepared as follows in Example 1.

200 parts of 3-methyl-pentanediol/1,6-hexanediol (mol% ratio: 85/15) copolymerization polycarbonate diol having a number average molecular weight of 1,979 (hydroxyl value: 57.5), 12.8 parts of BG, 67.1 parts of MDI, and 653 parts of DMF The mixture was introduced and reacted at a temperature of 70°C for 15 hours in a dry nitrogen atmosphere to prepare a polyurethane resin solution having a resin concentration of 30 wt% and a viscosity of 82,000 mPa·s/20°C.

[Example 3]

A graphene-coated fiber fabric was prepared in the same manner as in Example 1, except for using the polyurethane prepared as follows in Example 1.

120 parts of 1,10-decanediol/1,4-butanediol (mol% ratio: 81/19) copolymerized polycarbonate diol with a number average molecular weight of 2,018 (hydroxyl value: 556), 1 with a number average molecular weight of 2,000 (hydroxyl value: 561), 80 parts of 6-hexanediol polycarbonate diol, 12.6 parts of BG, 66.0 parts of MDI, and 650 parts of DMF were added and reacted at a temperature of 70°C for 15 hours under a dry nitrogen atmosphere to obtain a resin concentration of 30 wt% and a viscosity of 82,000 mPa s/ A solution of polyurethane resin at 20° C. was prepared.

[Comparative Example 1]

The aqueous dispersion of graphene oxide was centrifuged to remove water from the supernatant to prepare a precipitated concentrated graphene oxide slurry.

A coating composition having a viscosity of 2,000 cps was prepared by mixing the concentrated graphene oxide slurry so that the polyurethane resin binder and 100 parts by weight of the polyurethane resin binder were 2 parts by weight of pure graphene oxide, and dimethylformamide was added and mixed in a mixer.

After that, a fiber fabric coated with graphene was prepared using the same method as in Example 1.

Appearance (staining degree), antibacterial property, and touch were evaluated for the graphene-coated fiber fabrics prepared in the above Examples and Comparative Examples, and the results are shown in Table 1 below.

According to the KS K 0693:2011 test method for the antibacterial property, Staphylococcus aureus (ATCC 6538) was used as a test strain, and the antibacterial level was evaluated immediately after preparation and after washing 30 times.

The tactile sensation was evaluated by the sensory test method of 10 experts. If more than 8 out of 10 experts judged the tactile sensation to be “excellent”, if 5 to 7 experts out of 10 experts judged the tactile sensation to be good, it was “normal”, and less than 4 out of 10 experts judged the tactile sensation to be good. When judged to be good, it was classified as "defect".

division Example 1 Example 2 Example 3 Comparative Example 1 Exterior Uniform appearance without stains Uniform appearance without stains Uniform appearance without stains Partial staining observed Bacteriostatic reduction rate -1 (%)* 99.9 99.9 99.9 98.5 Bacteriostatic reduction rate -2 (%)* 99.6 99.4 99.5 92.4 touch commonly commonly Great error * Bacteriostatic reduction rate-1 is measured immediately after fabric manufacturing, and bacteriostatic reduction rate-2 is measured after washing 30 times

On the other hand, after washing the manufactured fabric 30 times using a washing machine, as a result of visually checking whether or not graphene is detached and damage to the coating layer containing graphene (whether or not cracks occur), as a result of graphene desorption and It was confirmed that the coating layer was hardly damaged.

From the results of Table 1, it can be confirmed that the dispersion of graphene in the coating solution is uniform since the appearance of the fiber fabric of the embodiment according to the present invention shows a uniform appearance without stains.

In addition, it is confirmed that the degree of antibacterial change is not great even after washing, and the function is expressed without graphene being detached from the coated fiber fabric.

On the other hand, when using a polycarbonate-based polyurethane in which crystallinity and non-crystallinity are combined in the coating solution, it is confirmed that the tactile feeling of the coated fiber fabric is improved.

Claims (5)

In the manufacturing method of graphene-coated textile fabric, which is obtained by coating a graphene-resin containing coating solution comprising a graphene oxide dispersion, polyurethane, and dimethylformamide as a dispersion solvent on a textile fabric and drying it by heat,
The graphene oxide dispersion,
A first step of concentrating the aqueous dispersion of graphene oxide to obtain a graphene oxide slurry;
a second step of applying shock waves to a solution obtained by adding an isopropyl alcohol solvent to the graphene oxide slurry;
A third step of concentrating after the second step to obtain the isopropyl alcohol solvent-containing graphene oxide slurry; and
A fourth step of obtaining a graphene oxide dimethylformamide dispersion by adding dimethylformamide as a dispersion solvent to the isopropyl alcohol solvent-containing graphene oxide slurry and removing the isopropyl alcohol solvent;
A graphene oxide dispersion prepared by repeating the second and third steps two or more times,
The polyurethane is a polycarbonate-based polyurethane, which is polymerized by including a copolymerized polycarbonate diol, a polycarbonate diol, an organic diisocyanate, and a chain extender,
The organic diisocyanate is a method for producing a graphene-coated textile fabric, characterized in that isophorone diisocyanate or cyclohexylmethane diisocyanate. delete delete delete According to claim 1,
The polyurethane is a method for producing a graphene-coated fiber fabric, characterized in that the content of the copolymerized polycarbonate diol is 50 to 80% by weight of the total diol.