KR900004240B1 - The manufacturing method of chemical resistant cloth - Google Patents

Abstract

A method for mfg. a cloth having an excellent chemicalresistance comprises (a) precuring a resin soln. comprising 8-35% fluorin- polymer resin, 0.1-3% crosslinking agent, 0.1-3% crosslink promoting agent and solvent, (b) coating one surface of the cloth with the resin soln, (c) drying the coated layer at 60-150≰C for 0.5-5 min., (d) crosslinking it at 150-230≰C for 5-20 min., amd (e) treating it with antistatic agent. The fluorine-polymer resin is prepd. by copolymerizing at least one monomer of PVF, PVDF, ECTFE or ETFE and at least one monomer of PTFE, PCTFE or PHFP.

Description

Process for producing textile pouch with excellent chemical resistance.

The present invention relates to a method for producing a fiber cloth having chemical resistance, heat resistance and antistatic function required in the field of high-tech industries that require an antistatic function as well as handling chemicals and high heat.

Recently, the necessity of multifunctional special work clothes is increasing in the field of chemicals handling and new material manufacturing. In the past, multifunctional special work clothes were not required. Forge made of asbestos with chemical resistance and heat resistance as a work clothes material, and forge made by coating a thick layer of tarpaulin and / or filler containing rubber on some inorganic solvents to the fabric Mainly used. However, the forge has a number of problems as follows. First, asbestos is resistant to heat, but not only causes dermatitis in the human body, but is also known as a carcinogen, and there is a problem that absorption of the drug occurs because it is not waterproof. In addition, asbestos cloth is not drape-free and has poor activity due to the weight of asbestos itself. Therefore, it is not suitable for work clothes or special clothes.

Tarpaulin has strong resistance to some chemicals, but it does not have stability to organic solvents and strong alkalis. Especially, it is weak to high temperatures and easily cracks even at small lattice below the secondary transition temperature. The thick coated rubber forge is heavy, poor drape and heat resistant. Therefore, the present inventors have studied the forge which is stable to various chemicals such as acid, alkali and organic solvent, is resistant to heat, has antistatic properties and has excellent drape property.

The present invention is described in detail as follows. In terms of structure, the fluorine resin has a high C-F bonding strength and a strong C-C bonding strength, which is excellent in heat resistance, chemical resistance and acid resistance.

The fluorine-based resin as described above was coated on one side and subjected to an antistatic treatment to prepare excellent chemical resistance, heat resistance and antistatic tarpaulin. In general, the fluorine resin can be classified into Groups A and B as follows.

(Group A)

Polyvinyl fluoride (PVF) [CH ₂ -CHF] m... … … … … … … … … … … … … … (One)

PVDF (polyvinylidene fluoride) [CF ₂ —CH ₂ ] _m . … … … … … … … … … … … (2)

ECTFE (ethylene chlorotri plottoethylene) [CClF-CF ₂ ] _m [CH ₂ -CH ₂ ] _m . … (3)

ETFE (ethylene tetrafluoro ethylene) [CF ₂ -CF ₂ ] _m [CH ₂ -CH ₂ ] _n . (4)

(Group B)

PTFE (polytetrafluoroethylene) [CF ₂ -CF ₂ ] _m . … … … … … … … … … … … (5)

PCTFE (polychloro trifluoroethylene) [CClF-CF ₂ ] _m . … … … … … … … … (6)

Group A has high melting point and mechanical strength because hydrogen and fluorine are regularly arranged closely so that the bonding force between molecules is high. However, it is soluble in polar solvents and is reactive with base, resulting in poor chemical resistance than group B. In addition, group B has a low cohesion between molecules due to the repulsion of fluorine atoms, so that the molecules are easily slipped due to external pressure, and the mechanical strength is slightly decreased. However, the surface energy is very low and does not penetrate water or organic solvents. Therefore, the present inventors selected a copolymer that can utilize the advantages of each of Group A and Group B resins. That is, a fluorine-based resin copolymerized with at least one monomer selected from group A and at least one monomer selected from group B was used. Next, a method of coating the fluorine-based resin on fiber cloth will be described.

In order to make the copolymerized fluororesin suitable for coating, it must first be dissolved in a solvent. Examples of the solvent include DMF, MEK, toluene, DM and mixed solution.

And using a stirrer to dissolve the fluorine resin in the solvent to give a solution of 5-50%.

And a crosslinking agent is added to the solution containing a fluororesin in order to bridge | crosslink a fluororesin. Crosslinkers include hexamethylene carbamate, N, N'-dicinnamylidene-1.6, hexanediamine (N, N'-dicinnamy lidene-1.6, hex-anediamine), 4.4'-methylene-bis- (cyclohexylamine) -Carbaate {4.4'-methylene-bis- (Cyclohex-ylamine) cabamate}, etc., the amount is 0.5-5% by weight of the resin solid content.

Methyl oxide was used as a crosslinking promoter during the heat treatment, and the dosage was 0.5-5% by weight based on fluorine-based vertical solids.

Then, the mixture is stirred using a stirrer to allow the crosslinking accelerator to penetrate into the fine part of the fluorine resin and mill to remove bubbles.

On the other hand, after the milling process, the precure time is required for the crosslinking agent and the crosslinking accelerator to occur in the microregions, and the precure time is 3 hours to 47 hours. In order to increase the crosslinking density after the curing process after coating, the precure time should be long.

If the crosslinking agent penetrates into the microstructure and the crosslinking density is high, the physical properties such as chemical resistance and heat resistance are excellent, but if the crosslinking density is low, the crosslinking agent is not only poor in terms of physical properties but also odor due to the unreacted crosslinking agent. However, if the precure time is longer than 48 hours, the color changes out of color and becomes gel, which makes the coating unsuitable. In addition, even when the coating is performed, the surface of the coating layer is rough and large pores are formed to easily penetrate the chemicals. The physical properties of the back drops sharply. A suitable precure time will result in a viscosity of 20-260 Poise. The coating is a floating coating using a knife on the raw unit water-repellent 0.5-5%.

When applying a knife coating, fix the gauge so that the thickness of the film after drying is 5-60 micro.

When the coating layer has a thickness of 5μ or less, the chemical resistance is inferior, and when the thickness is 60μ or more, the drape resistance may be deteriorated and the touch may become hard.

And after coating it is dried at a temperature of 60-150 ℃.

When drying, the drying time is 0.5-5 minutes and the solvent must be completely removed from the coating layer.

Crosslinking resin by heat treatment after drying. When heat treatment is not completely done, chemical resistance, heat resistance, water resistance, etc. are inferior, and the remaining crosslinking agent causes odor. Next, the heat treatment process used a tenter and the process temperature was 150-230 degreeC, and it bridge | crosslinked for 5 to 20 minutes.

Next, antistatic treatment is performed using an antistatic agent.

Suitable antistatic agent is used according to the type and process condition of the base forge coated with fluorine resin, and the amount of use is used for the type and process condition of the base forge, and the amount of use is slightly different depending on the type and process condition of the base forge. It treated with the method of padding and drying as 0.1-1.0% aqueous solution.

The chemical resistant forge prepared by the present invention is stable in methanol and ethanol, stable in organic solvents such as DMF, toluene, MEK xylene and cyclohexane, and is inorganic solvent 98% sulfuric acid and 63% nitric acid. It is stable in formic acid, acetic acid, 30% sodium hydroxide solution and 25% ammonia water and excellent in cresol.

The measurement method of chemical resistance is as follows.

The chemical was placed on fibrous paper with 3-5 drops of supoid, left for 60 minutes, and washed with water to determine the area where the chemical was buried. Ordinary polyester or nylon fabrics are readily soluble in 98% concentrated sulfuric acid, 50% sulfuric acid, etc., but the forge of the present invention is stable. The heat resistance was compared as a melting test for cigarettes.

The general polyester fabric was punctured by a cigarette after 2-3 seconds, but the coating fabric of the present invention was stable even after 10 minutes. The water resistance was measured by the high water pressure method according to JIS-L0109. The result is 0.5 kg / cm ² or more, and the peeling strength of the coating layer is 1,000 g / cm or more.

The chargeability test was conducted in accordance with JIS-L 1094. As a result, the counter voltage is 400 V or less and the half life is 6 seconds or less.

The excellent functionality of the fiber cloth of the present invention was confirmed by the stability test, the reactivity test, the test against water pressure, and the test against chargeability for the pharmaceuticals.

Example 1

A 75 manne polyester fabric (inclined density of 170ol / inch, weft density of 100ol / inch) was water-repellent in an aqueous solution of 1.5% of fluorine-based water repellent material. Next, a resin solution having the following composition was prepared on one side of the fabric, precure for 12 hours, and then coated.

Resin liquid composition

25 parts of fluorine resin

(Copolymer of Polyvinyl Polide with Polytetrafluoroethylene)

Solvent (mixed solvent of DMF and MEK) 75 parts

0.3 part of crosslinking agents (N, N'-discinnamilide-1.6 hexanediamine)

0.3 parts of crosslinking accelerator (metal oxide)

The coating was coated to a thickness of 40μ using a floating knife, dried at 120 ° C. for 2 minutes, crosslinked at 180 ° C. for 8 minutes using a tenter, and subjected to an antistatic treatment using an aqueous solution of an antistatic agent at 2%. As a result, the coating layer was stable even in a 98% sulfuric acid solution heated to 150 ℃.

Table 1 shows the excellent chemical resistance of Example 1. The large voltage is under 400V and the half life is under 6 seconds.

TABLE 1

Chemical resistance of Example 1

* After dropping 2-3 drops with dropper on coated paper, leave it at room temperature for 60 minutes.

Comparative Example 1

Treatment was carried out under the same conditions as in Example 1, but the precure time was reduced to 2 hours. As a result, a crosslinking agent that did not form a cross-linking odor, decomposed in 98% sulfuric acid solution, swelling in the DM, MK, toluene, etc. in the organic solvent significantly reduced the chemical resistance and also severely lowered the heat resistance.

Comparative Example 2

The treatment was carried out in the same manner as in Example 1, but the precure time was 48 hours. As a result, the resin gels and is not evenly applied.

Comparative Example 3

The same treatment as in Example 1 was performed, but no relay treatment was performed. As a result, the large voltage was over 1,800-2,000V and the half life was over 10 seconds, which was excellent in chemical resistance but poor in antistatic function.

Claims (4)

The resin solution prepared by copolymerizing at least one monomer selected from Group A and at least one monomer selected from Group B and a solvent, a crosslinking agent and a crosslinking accelerator is precured for 3 hours to 47 hours. A method for producing a fiber bag having excellent chemical resistance, which is coated on one side of the fiber bag, dried and heat treated, and then subjected to normal antistatic processing. Group A PVF (polyvinyl fluoride) … … … … … … … … … … … … … (One) PVDF (polyvinylidene fluoride) … … … … … … … … … … (2) ECTFE (ethylene chlorotrifluoroethylene)... … … … … … … … … (3) ETFE (ethylene tetrafluoroethylene)... … … … … … … … … … … (4) Group B PTFE (polytetrafluoroethylene)... … … … … … … … … … … … (5) PCTFE (Polychlorotrifluoroethylene)…. … … … … … … … … … (6) PHFP (Polyhexafluoropropylene)…. … … … … … … … … … … … (7) The method of claim 1, wherein the crosslinking agent is a diamine-based carbamate and the crosslinking promoter is a metal oxide. The method for producing a fiber cloth having excellent chemical resistance according to claim 1, wherein the thickness of the coated film after drying is 5-60 mu. The method of claim 1, wherein the resin liquid has a composition of 8-35% fluorinated copolymer resin, 0.1-3% crosslinking agent, 0.1-3% crosslinking accelerator and solvent with excellent chemical resistance.