KR101855618B1

KR101855618B1 - Functional film and preparing method thereof

Info

Publication number: KR101855618B1
Application number: KR1020170064746A
Authority: KR
Inventors: 이재웅; 안다정
Original assignee: 영남대학교 산학협력단
Priority date: 2017-05-25
Filing date: 2017-05-25
Publication date: 2018-06-08

Abstract

The present invention relates to a functional film and a method for preparing the same, and more particularly, to a method for preparing a functional film and a polyurethane dope solution, which comprises: preparing an m-aramid dope liquid and a polyurethane dope liquid; Preparing a first mixed dope solution by mixing the m-aramid dope liquid and the polyurethane dope liquid; Adding a plasticizer to the first mixed dope solution to prepare a second mixed dope solution; Shaking the second mixed dope solution to remove bubbles present in the second mixed dope solution; Depositing a second mixed dope solution from which the bubbles have been removed on a release paper; Dipping the release paper on which the second mixed dope liquid is laminated in a coagulation bath to obtain a functional film composed of a second mixed dope solution; And washing and drying the functional film. The present invention also provides a method for producing a functional film.
The functional film according to the present invention has a uniform pore size at a low cost and simple cost by using m-aramid and cellulose pulp, and can be applied to various textile industries because it can replace expensive ePTFE film.

Description

TECHNICAL FIELD [0001] The present invention relates to a functional film and a manufacturing method thereof,

The present invention relates to a functional film made of m-aramid and polyurethane which can replace ePolytetrafluoroethylene (hereinafter 'ePTFE') film, and a method for manufacturing the functional film.

Recently, the demand for high functional fiber has been increasing. Especially, Medical Textile, which has become a blue ocean of the textile industry, has grown 4.5% annually and will be worth US $ 22 billion by 2020 do.

In particular, high-performance fibers have been used in a variety of fields such as surgical filters, sutures, bands, and the like. Medical fibers suitable for local manufacturers such as sanitary hygiene products, household products, hospital consumables, .

In the case of mattress covers used in hospitals, it is manufactured by combining functional films and fabrics. While the functional film and the fabric are bound together, the functional film can be applied in various ways due to the wider boundaries of the bonding fabric.

The patient's mattress cover inner film, which is a medical product, is made to be resistant to heat when sterilized with mites, bacteria and high temperature steam by applying the film to a bed sheet which is not easy to wash.

However, ePolytetrafluoroethylene (ePTFE) film, which is used as a cover film inside the patient's bed in existing hospitals, has been attracting attention due to its excellent chemical resistance and heat resistance. However, in order to realize commercialization in domestic market, ePTFE film It is difficult because of relatively high price.

Therefore, it is urgent to research and develop a fusion film that can meet the price competitiveness and the properties required for existing bed cover.

Korean Patent No. 1506236

It is an object of the present invention to provide a functional film that can replace expensive ePTFE films used in conventional textile industries and a method of manufacturing the same.

In order to achieve the above object, the present invention provides a functional film made of m-aramid and polyurethane.

The present invention also provides a method for preparing a polyurethane dope comprising the steps of: preparing an m-aramid dope solution and a polyurethane dope solution; Preparing a first mixed dope solution by mixing the m-aramid dope liquid and the polyurethane dope liquid; Adding a plasticizer to the first mixed dope solution to prepare a second mixed dope solution; Shaking the second mixed dope solution to remove bubbles present in the second mixed dope solution; Depositing a second mixed dope solution from which the bubbles have been removed on a release paper; Immersing the release paper on which the second mixed dope solution is laminated in a coagulation bath to obtain a functional film made of a second mixed dope solution; And washing and drying the functional film. The present invention also provides a method for producing a functional film.

The functional film according to the present invention has a uniform pore size at a low cost and simple cost by using m-aramid and cellulose pulp, and can be applied to various textile industries because it can replace expensive ePTFE film.

1 is a SEM image of a functional film according to the present invention;
2 is a graph showing a result of measurement of liquid permeability of the functional film according to the present invention;
3 is a SEM image of a functional film according to the present invention;
4 is a graph showing the results of measurement of liquid permeability of the functional film according to the present invention;
5 is a SEM image of the functional film according to the present invention; And
6 is a view showing a result of measurement of liquid permeability of the functional film according to the present invention.

Hereinafter, the functional film of the present invention and a method for producing the same will be described in more detail.

The inventors of the present invention have found that when polyurethane is added to m-aramid having excellent heat-resistance characteristics while it is being developed to replace ePTFE film, uniform pores can be formed and a film having a function can be produced. Thus, an expensive ePTFE film The present invention has been completed.

The present invention provides a functional film composed of m-aramid and polyurethane.

The functional film may include pores of 0.02 to 0.25 탆, but is not limited thereto.

The functional film may be composed of 25 to 75% by weight of m-aramid and 25 to 75% by weight of polyurethane, but is not limited thereto.

The functional film may further include a plasticizer, but is not limited thereto.

The plasticizer may be any one selected from the group consisting of dioctyl phthalate (DOP), dioctyl adipate (DOA), and dibutyl phthalate (DBP), but is not limited thereto .

The functional film may include 1 to 5 parts by weight of plasticizer per 100 parts by weight of m-aramid and polyurethane, but is not limited thereto.

The m-aramid dope and the polyurethane dope may be m-aramid dope having a viscosity of 7,000 to 10,000 cps and polyurethane dope having a viscosity of 7,000 to 10,000 cps.

The step of preparing the first mixed dope may include preparing 25 to 75% by weight of the m-aramid dope and 25 to 75% by weight of the polyurethane dope to prepare the first mixed dope, It is not.

The preparation of the second mixed dope may include preparing a second mixed dope by adding 1 to 5 parts by weight of a plasticizer to 100 parts by weight of the first mixed dope.

Specifically, when the plasticizer is added, the inherent thermal properties of the m-aramid may be decreased. As the amount of the plasticizer added increases, the diameter of the pores formed in the functional film may increase. Therefore, To 5 parts by weight of a plasticizer.

Specifically, when bubbles are present in the second mixed dope liquid, problems such as tear strength, moisture permeability, and water pressure lowering due to the formation of pores on the surface of the film may occur, so that bubbles present in the second mixed dope liquid are preferably removed .

The removing of the bubbles may include, but is not limited to, shaking the second mixed dope at 100 to 120 rpm for 20 to 40 minutes to remove bubbles present in the second mixed dope.

The release paper may be any one selected from the group consisting of polyethylene terephthalate (PET) fabric, PET film, and paper, but is not limited thereto.

In particular, when a release paper is used, the permeability in the coagulation bath is better than when a glass plate is used, so that pores of a uniform degree can be formed on the upper and lower surfaces of the functional film, and the release paper preferably uses a polyethylene terephthalate (PET) Do.

In the step of obtaining the functional film, when using a coagulation bath having a volume ratio of 80:20 of distilled water and dimethylacetamide, it is possible to include pores having the most effective size. The pores having an effective size may be 0.02 to 0.25 μm, But is not limited thereto.

In the step of obtaining the functional film, when moisture comes in contact with the release paper on which the second mixed dope liquid is laminated, care should be taken since the solidification of the second mixed dope liquid may progress rapidly.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by these examples.

&Lt; Example 1 > Preparation of functional film

100 g of m-aramid (Yantai) was added to 30 ml of dimethylacetamide (DMAc) solvent to prepare an m-aramid dope having a viscosity of 8,000 cps.

25 g of polyurethane (molecular weight: 3,850) was added to 100 ml of dimethylacetamide (DMAc) solvent to prepare a polyurethane dope solution.

75% by weight of the m-aramid dope solution and 25% by weight of the polyurethane dope solution were mixed to prepare a mixed dope solution.

The mixed dope solution was shaken in a shaker (Wisebath, Science) at 110 rpm for 30 minutes to remove bubbles present in the mixed dope solution.

Thereafter, a mixed dope solution in which air bubbles were removed on a polyethylene terephthalate (hereinafter, referred to as 'PET') fabric to serve as a release paper was applied to a film maker (Baker Applicator, YBA-4, Yoshimitsu Seiki, Tokyo , Japan) was poured evenly into a suitable amount and slowly pushed using a film maker to thinly mix the mixed dope solution on the PET fabric.

A coagulation bath consisting of distilled water and DMAc in a volume ratio of 80:20 was prepared by allowing to stand at room temperature or lower (25 ° C or less) for at least 1 hour.

The PET fabric in which the mixed dope liquid was laminated was immersed in a coagulating bath and solidified for 30 minutes to obtain a film composed of the second mixed dope solution.

The film obtained by solidification was taken out from the coagulation bath, immersed in distilled water at room temperature (25 ° C), and allowed to stand for 6 hours.

Thereafter, the process of immersing in 80 DEG C distilled water for 30 minutes was repeated twice to remove residual DMAc in the film to obtain a film having pores. After removing the water, the film was dried naturally for a day or dried for 30 minutes in a 20 DEG C dryer, A film was prepared.

&Lt; Example 2 > Preparation of functional film

25 g of polyurethane (molecular weight: 3,850) was added to 100 ml of dimethylacetamide (DMAc) solvent to prepare a polyurethane dope having a viscosity of 8,000 cps.

75% by weight of the m-aramid dope solution and 25% by weight of the polyurethane dope solution were mixed to prepare a first mixed dope solution.

2.5 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of the first mixed dope solution to prepare a second mixed dope solution.

The second mixed dope solution was shaken in a shaker (Wisebath, Science) at 110 rpm for 30 minutes to remove bubbles present in the second mixed dope solution.

Thereafter, a second mixed dope solution in which air bubbles were removed on a polyethylene terephthalate (hereinafter, referred to as 'PET') fabric serving as a release paper was applied to a film maker (Baker Applicator, YBA-4, Yoshimitsu Seiki , Tokyo, Japan) was poured evenly into a suitable amount and slowly pushed using a film maker to thinly laminate the second mixed dope on the PET fabric.

The PET fabric in which the second mixed dope liquid was laminated was immersed in a coagulating bath and solidified for 30 minutes to obtain a film composed of the second mixed dope solution.

&Lt; Example 3 > Preparation of functional film

Except that 5 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of the first mixed dope solution to prepare a second mixed dope solution. A film was prepared.

&Lt; Example 4 > Preparation of functional film

A functional film was prepared under the same conditions as in Example 1, except that 50% by weight of the m-aramid dope solution and 50% by weight of the polyurethane dope solution were mixed to prepare a mixed dope solution.

&Lt; Example 5 > Preparation of functional film

2.5 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of the first mixed dope solution prepared by mixing 50% by weight of m-aramid dope solution and 50% by weight of polyurethane dope solution, 2 mixed dope solution was prepared in the same manner as in Example 2,

Example 6 Production of Functional Film

5 parts by weight of dioctyl phthalate (hereinafter referred to as "DOP") as a plasticizer was added to 100 parts by weight of a first mixed dope prepared by mixing 50% by weight of an m-aramid dope solution and 50% by weight of a polyurethane dope solution, 2 mixed dope solution was prepared in the same manner as in Example 2,

&Lt; Example 7 > Preparation of functional film

A functional film was prepared under the same conditions as in Example 1, except that 25% by weight of the m-aramid dope solution and 75% by weight of the polyurethane dope solution were mixed to prepare a mixed dope solution.

&Lt; Example 8 > Preparation of functional film

2.5 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of a first mixed dope prepared by mixing 25% by weight of an m-aramid dope solution and 75% by weight of a polyurethane dope solution, 2 mixed dope solution was prepared in the same manner as in Example 2,

&Lt; Example 9 > Preparation of functional film

5 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of a first mixed dope solution prepared by mixing 25% by weight of m-aramid dope solution and 75% by weight of polyurethane dope solution, 2 mixed dope solution was prepared in the same manner as in Example 2,

&Lt; Comparative Example 1 &

A functional film was prepared under the same conditions as in Example 1, except that 100 wt% of the m-aramid dopa solution was used.

&Lt; Comparative Example 2 &

A functional film was prepared under the same conditions as in Example 1, except that 100 wt% of the polyurethane dope solution was used.

&Lt; Comparative Example 3 &

Except that 10 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of the first mixed dope solution to prepare a second mixed dope solution. A film was prepared.

&Lt; Comparative Example 4 &

Except that 20 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of the first mixed dope solution to prepare a second mixed dope solution. A film was prepared.

&Lt; Comparative Example 5 &

10 parts by weight of dioctyl phthalate (hereinafter referred to as "DOP") as a plasticizer was added to 100 parts by weight of a first mixed dope prepared by mixing 50% by weight of an m-aramid dope solution and 50% by weight of a polyurethane dope solution, 2 mixed dope solution was prepared in the same manner as in Example 2,

&Lt; Comparative Example 6 >

20 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer was added to 100 parts by weight of a first mixed dope prepared by mixing 50% by weight of an m-aramid dope solution and 50% by weight of a polyurethane dope solution, 2 mixed dope solution was prepared in the same manner as in Example 2,

Experimental Example 1 Scanning Electron Microscopy (SEM) analysis

SEM analysis (S-4100, Hitachi, Japan) was performed to analyze the cross section of the functional film produced according to the present invention, and the results are shown in Figs. 1, 3 and 5.

FIG. 1 is an SEM image of the cross-sectional area of a film in order to observe a change in the pore size of the film due to a change in the mixing ratio of m-aramid and polyurethane.

Referring to FIG. 1, it can be seen that the pore size existing in the film increases as the content of the polyurethane dope solution increases.

3 and 5 are SEM images of the cross-sectional area of the film in order to observe the change in the pore size of the film due to the change in the content of dioctyl phthalate (DOP).

Referring to FIGS. 3 and 5, DOP, which is a plasticizer, is used to impart softness of the film. It can be seen that the higher the DOP content in the film, the larger the average size of the pores. 100 weight parts of the first mixed dope solution prepared by mixing 75 weight% of the m-aramid dope liquid and 25 weight% of the polyurethane dope solution in consideration of the tear strength was used as a plasticizer. Dioctyl phthalate (hereinafter referred to as DOP) ), 2.5 parts by weight or 5 parts by weight of a film (Examples 2 and 3), and 50% by weight of an m-aramid dope solution and 50% by weight of a polyurethane dope solution, (Example 5 and Example 6) prepared with 2.5 parts by weight or 5 parts by weight of dioctyl phthalate (hereinafter referred to as 'DOP') as a plasticizer with respect to 100 parts by weight of the ePTFE film Respectively.

<Experimental Example 2> Measurement of liquid permeability

The liquid permeability measurement of the functional films prepared according to the present invention was performed.

After impregnating the film with a low surface tension liquid, Galwick solution, the pores existing in the film are closed and then the pressure is applied, and the Galwick solution is released as much as the gas exists in the pores.

At this time, the permeability is measured using the initial pressure at which the gallwick solution clogged in the pores of the film penetrates. This value depends on the difference in condition variables (mixing ratio, degree of plasticizer, etc.) of the film.

Fig. 2 is a view showing a measurement result of the liquid permeability of the film according to the change of the mixing ratio of m-aramid and polyurethane.

Referring to FIG. 2, as the ratio of polyurethane increases, the average pore size of the film increases and the liquid permeability increases.

4 and 6 are graphs showing the measurement results of the liquid permeability of the film according to the content of dioctyl phthalate (DOP).

Referring to FIGS. 4 and 6, it can be seen that the liquid permeability also increases because the average size of the pores increases as the content of DOP in the film increases.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood that various modifications and changes may be made without departing from the scope of the appended claims.

Claims

From 25 to 75% by weight of m-aramid and from 25 to 75% by weight of polyurethane, and comprising pores of 0.02 to 0.25 占 퐉.

delete

The method according to claim 1,
In the functional film,
A functional film, further comprising a plasticizer.

The method of claim 4,
The above-
Wherein the functional film is any one selected from the group consisting of Dioctyl Phthalate (DOP), Dioctyl Adipate (DOA), and Dibutyl Phthalate (DBP).

The method of claim 4,
In the functional film,
1 to 5 parts by weight of a plasticizer based on 100 parts by weight of m-aramid and polyurethane.

preparing an m-aramid dope solution and a polyurethane dope solution;
Preparing 25 to 75 wt% of the m-aramid dope solution and 25 to 75 wt% of the polyurethane dope solution to prepare a first mixed dope solution;
Adding a plasticizer to the first mixed dope solution to prepare a second mixed dope solution;
Shaking the second mixed dope solution to remove bubbles present in the second mixed dope solution;
Depositing a second mixed dope solution from which the bubbles have been removed on a release paper;
Immersing the release paper on which the second mixed dope solution is laminated in a coagulation bath to obtain a functional film made of a second mixed dope solution; And
Washing and drying the functional film;
And a pore size of 0.02 to 0.25 占 퐉.

The method of claim 7,
The above-mentioned m-aramid dope liquid and polyurethane dope liquid,
Aramid dope liquid having a viscosity of 7,000 to 10,000 cps and a polyurethane dope liquid having a viscosity of 7,000 to 10,000 cps.

delete

The method of claim 7,
Wherein preparing the second mixed dope comprises:
Wherein 1 to 5 parts by weight of a plasticizer is added to 100 parts by weight of the first mixed dope solution to prepare a second mixed dope solution.

The method of claim 7,
The above-
Wherein the functional film is any one selected from the group consisting of Dioctyl Phthalate (DOP), Dioctyl Adipate (DOA), and Dibutyl Phthalate (DBP).

The method of claim 7,
The step of removing the bubbles includes:
Wherein the second mixed dope solution is shaken at 100 to 120 rpm for 20 to 40 minutes to remove bubbles present in the second mixed dope solution.

The method of claim 7,
Wherein the release paper comprises:
Wherein the film is any one selected from the group consisting of polyethylene terephthalate (PET) fabric, PET film, and paper.

delete