KR20210042606A - Surface modified substrate and Process for producing the same - Google Patents

Abstract

The present invention relates to a substrate, wherein a part or all of the surface of a substrate including hydrophilic resin particles in a hydrophobic polymer matrix is removed by external energy, and some or all of the hydrophilic resin particles are exposed to add hydrophilic surface properties, and to a manufacturing method thereof.

Description

Substrate to which hydrophilic surface properties are added and its manufacturing method {Surface modified substrate and Process for producing the same}

The present invention relates to a substrate to which hydrophilic surface properties are added and a method of manufacturing the same.

Various methods have been developed to modify the hydraulic properties of the PDMS surface. One of them is a method of reducing the contact angle by changing the chemical structure of the surface through ozone or plasma treatment. That is, a functional group having hydrophilic properties such as -OH or -COOH was introduced on the surface of the PDMS to secure hydrophilicity with external water droplets. In addition, a method of changing the PDMS surface to hydrophilicity using a method of coating or grafting polyethylene glycol (PEG) or polyvinylalcohol (PVA), which is a hydrophilic material, has been suggested. These methods are known to be very effective temporarily, but have poor persistence and cannot be used in a long-term, high-humidity environment (“Durable Antifog Films from Layer-by-Layer Molecularly Blended Hydrophilic Polysaccharides” N. Nuraje, R. Asmatulu, RE Cohen, and MF Rubner Langmuir 2011, 27(2), 782-791). In addition, in order to solve this problem, the above paper proposed a method of laminating dozens of layers of hydrophilic polymers such as chitosan or carboxyl cellulose on a glass substrate or a polycarbonate slide substrate by a layer-by-layer (LBL) method to have hydrophilicity. . On the other hand, although this method is transparent, has excellent mechanical properties, and maintains hydrophilicity for a long period of time, it is evaluated as an unfavorable method in the process because it requires a complicated step of laminating dozens of layers.

As described above, the aforementioned prior art documents have problems in that the holding time of hydrophilicity is short, durability is poor, and the process of surface treatment with hydrophilicity is complicated.

Accordingly, there is a need for a method for manufacturing a substrate with hydrophilic surface properties added at low cost based on a very simple process, while maintaining hydrophilicity over a long period of time and having excellent durability against external conditions.

“Durable Antifog Films from Layer-by-Layer Molecularly Blended Hydrophilic Polysaccharides” N. Nuraje, R. Asmatulu, R. E. Cohen, and M. F. Rubner Langmuir 2011, 27(2), 782-791

The present invention has been conceived to solve the problems of the above-described background technology, and an object thereof is to provide a method of making hydrophilicity through a simple process and a very inexpensive method capable of maintaining the hydrophilicity for a long time.

One aspect of the present invention for achieving the above object is that a part or all of the surface of the substrate including the hydrophilic resin particles in the hydrophobic polymer matrix is removed by external energy, so that some or all of the hydrophilic resin particles are exposed. It features a substrate to which surface properties are added.

As an aspect of the present invention, the external energy may be one or more types of plasma, ion beam, chemical etching, sanding, laser beam, and the like.

As an aspect of the present invention, the substrate may have a light transmittance of 50% or more in a visible light region of 500 to 700 nm.

As an aspect of the present invention, the hydrophilic resin particles may be contained in the hydrophobic polymer resin matrix at a concentration of 0.1 to 1% by weight.

As an aspect of the present invention, the substrate may have a water contact angle change rate of 35° or more according to Equation 1 below.

[Equation 1]

△WA1 = (WA _base -WA ₂₅ )/ WA _base × 100

(The WA ₂₀₀ is the water contact angle of the substrate measured 25 hours after plasma treatment, the WA _base is the water contact angle of the substrate before plasma treatment, and the unit is °.)

As an aspect of the present invention, the substrate may have a water contact angle change value of 30° or less according to Equation 2 below.

[Equation 2]

△WA2 = WA ₃₀₀ -WA ₀

(Wa ₃₀₀ is the water contact angle of the substrate measured 300 hours after plasma treatment, WA ₀ is the water contact angle of the substrate measured immediately after plasma treatment, and the unit is °.)

As an aspect of the present invention, the hydrophilic resin particles in the substrate may be formed in a uniform concentration as a whole.

As an aspect of the present invention, the concentration of the hydrophilic resin particles in the substrate may be decreased from the surface of the substrate in an inward direction.

Another aspect of the present invention is a first step of preparing a substrate including a surface in which hydrophilic resin particles are mixed with a hydrophobic polymer matrix; A second step of applying external energy to a part of the surface of the substrate or the entire surface of the substrate; And a third step in which a part of the surface of the substrate or the entire surface of the substrate is removed by the external energy so that a part of the hydrophilic resin particles is exposed to the surface of the hydrophobic polymer matrix. It features a method of manufacturing a substrate to which hydrophilic surface properties are added, including.

As an aspect of the present invention, the external energy may be one or more selected from plasma, ion beam, chemical etching, sanding, laser beam, and the like.

As an aspect of the present invention, the plasma may be performed for 0.1 to 10 seconds at an intensity of 5 W to 1000 W.

As an aspect of the present invention, the substrate may be formed of a single hydrophobic polymer matrix resin or may be formed of two or more types of hydrophobic polymer matrices.

As an aspect of the present invention, in the first step, a pattern may be formed on the surface of the substrate.

As an aspect of the present invention, in the second step, hydrophilic patterning may be formed on a substrate using a mask.

As an aspect of the present invention, a part or all of the surface of the substrate may be that the hydrophilic resin particles are formed in a uniform concentration as a whole inside the substrate.

As an aspect of the present invention, in some or all of the substrate, the concentration of the hydrophilic resin particles may decrease in an inward direction from the surface of the substrate.

The present invention can be treated for hydrophilicization in an economical and simple process, and the long-term stability and durability of the hydrophilic property are excellent.

1 shows a schematic diagram of manufacturing a substrate to which the hydrophilic surface property of the present invention is added.
Figure 2 is a water contact angle and a pure polydimethylsiloxane substrate (hereinafter referred to as pure PDMS substrate) before and after plasma treatment of a substrate (hereinafter referred to as a PDMS/PEG substrate) containing polyethylene glycol in a polydimethylsiloxane according to an embodiment of the present invention. It shows the measurement of the water contact angle.
2(a) shows the water contact angle of the PDMS/PEG substrate treated with plasma, FIG. 2(b) shows the water contact angle of the PDMS/PEG substrate without plasma treatment, and FIG. 2(c) shows the pure PDMS. It shows the water contact angle.
3 shows the surface roughness values before and after plasma treatment of a substrate (PDMS/PEG substrate) containing polyethylene glycol in polydimethylsiloxane, which is an aspect of the present invention, and the surface roughness of a pure polydimethylsiloxane substrate (pure PDMS substrate). .
3(a) shows the surface roughness of the PDMS/PEG substrate treated with plasma, FIG. 3(b) shows the surface roughness of the PDMS/PEG substrate without plasma treatment, and FIG. 3(c) It shows the surface roughness.
Figure 4 shows the optical transparency according to the concentration of the polyethylene glycol and the thickness of the substrate containing polyethylene glycol in the polydimethylsiloxane according to an aspect of the present invention.
5 is a cross-sectional view of a substrate to which hydrophilic surface properties are added, which is an aspect of the present invention.
5(a) shows that the concentration of the hydrophilic resin particles 120 in the substrate 100 is uniform as a whole, and FIG. 5(a) shows that the hydrophilic resin particles 120 are distributed on the surface of the substrate 100. 5(c) shows a form in which the concentration of the hydrophilic resin particles 120 decreases from the surface of the substrate 100 to the inner direction.
6 is a schematic diagram of a method for manufacturing a patterned substrate to which hydrophilic surface properties are added, which is an aspect of the present invention.
7 is a schematic diagram of a method for manufacturing a patterned substrate to which hydrophilic surface properties are added, which is an aspect of the present invention.
8 is an enlarged view of a hydrophilic region after plasma treatment of a substrate to which a hydrophilic surface property is added, which is an aspect of the present invention.
9 is an exemplary view of a hydrophilic pattern formed on a substrate to which hydrophilic surface properties have been added after plasma treatment, which is an aspect of the present invention.

Hereinafter, the present invention will be described in more detail through specific examples or examples including the accompanying drawings. However, the following specific examples or examples are only one reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms.

In addition, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. The terms used in the description in the present invention are merely for effectively describing specific embodiments and are not intended to limit the present invention.

In addition, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

In addition, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

In the present invention, a substrate with hydrophilic surface properties capable of maintaining hydrophilicity for a long period of time can be manufactured by a simple and inexpensive process.

The present invention is a substrate in which a part or all of the surface of a substrate containing hydrophilic resin particles in a hydrophobic polymer matrix is removed by external energy, and a part or all of the hydrophilic resin particles are exposed to add hydrophilic surface properties, and a method for manufacturing the same It is about.

The substrate to which the hydrophilic surface property of the present invention is added includes a first step of preparing a substrate including a surface in which hydrophilic resin particles are mixed with a hydrophobic polymer matrix; A second step of applying external energy to a part of the surface of the substrate or the entire surface of the substrate; And a third step in which a part of the surface of the substrate or the entire surface of the substrate is removed by the external energy so that a part of the hydrophilic resin particles is exposed to the surface of the hydrophobic polymer matrix. It can be manufactured by a manufacturing method including.

The hydrophilic resin particles and the hydrophobic polymer matrix are physical properties of a relative concept, meaning that the hydrophilic resin particles are less hydrophobic than the hydrophobic matrix, or the hydrophilic resin particles are more hydrophilic than the hydrophobic matrix.

The substrate may include a hydrophobic polymer matrix formed of a single resin or formed of two or more types of hydrophobic polymer matrices. In FIG. 7, the substrate includes a second resin different from the hydrophobic matrix including the hydrophilic resin particles, and the substrate formed of the two or more resins is not limited thereto.

The hydrophobic polymer matrix may include all polymer matrices that are relatively hydrophobic than the hydrophilic resin particles. Specifically, it may include a silicone-based polymer, a urethane resin, an epoxy resin, a fluorine resin, and a polycarbonate resin, and various resins may be used depending on the purpose. Examples of the silicone-based polymer include polydimethylsiloxane (PDMS) and polyhydroxymethylsiloxane (PHMS), but are not limited thereto.

The hydrophilic resin particles are not limited as long as the resin is hydrophilic compared to the hydrophobic polymer matrix, but may specifically include polyethylene glycol (PEG), polyvinylalcohol (PVA), and the like.

In the substrate to which the hydrophilic surface property is added, the hydrophilic resin particles may be included in the hydrophobic polymer matrix at a concentration of 0.1 to 2% by weight, and preferably may be included at a concentration of 0.1 to 1% by weight. In the above concentration range, it is preferable to realize hydrophilicity without affecting the transparency of the hydrophobic polymer matrix and the transparency of the entire substrate to which the hydrophilic surface properties are added.

The substrate may be prepared including the hydrophobic polymer matrix, hydrophilic resin particles, and initiator. The initiator is added for the purpose of curing the hydrophobic polymer matrix, and may be used without limitation as long as it is capable of curing the hydrophobic polymer matrix to be used. When using PDMS as the substrate, the curing agent may specifically use Sylgard 184B manufactured by Dow-corning.

The initiator may be included in an amount of 0.1 to 60% by weight, preferably 1 to 30% by weight, based on the total weight of the hydrophobic polymer matrix and the hydrophilic resin particles.

The hydrophilic resin particles in the substrate may be formed in a uniform concentration as a whole.

The concentration of the hydrophilic resin particles in the substrate may decrease from the surface of the substrate in an inward direction.

The substrate including the hydrophilic resin particles may have hydrophilic resin particles distributed on the surface thereof, and the hydrophilic resin particles on the surface of the substrate may have a very thin surface covered by the hydrophobic polymer matrix.

The hydrophobic polymer matrix formed thinly on the surface of the hydrophilic resin particles is removed by the external energy, so that the hydrophilic resin particles are exposed to the outside, thereby expressing hydrophilicity.

The external energy may be used without limitation as long as it can remove the hydrophobic polymer matrix, and specifically may include at least one selected from plasma, ion beam, chemical etching, sanding, laser beam, and the like. Preferably, it may include a plasma, an ion beam, and the like, and more preferably, a plasma.

The external energy may remove only the hydrophobic polymer matrix formed on the surface of the hydrophilic resin particles, or may remove a part of the hydrophobic polymer matrix and a part of the hydrophilic resin particles together. The method, time, intensity, etc. of imparting the external energy may be controlled without limitation as long as the hydrophilic resin particles are exposed on the surface of the hydrophobic polymer matrix to express hydrophilicity.

The external energy may preferably use plasma, and the intensity of the plasma may be adjusted and used according to the type of the hydrophobic polymer matrix used as the base material. Specifically, the intensity of 5 W to 1000 W when the base material is PDMS It can be done with. The plasma may be performed for 0.1 to 60 seconds, preferably 0.1 to 40 seconds.

The substrate to which the hydrophilic surface property is added may implement excellent effects in hydrophilic properties, long-term retention of hydrophilicity, and optical transparency.

The substrate to which the hydrophilic surface property is added may have a light transmittance of 50% or more in a visible light region of 500 to 700 nm.

The substrate to which the hydrophilic surface property is added may have a water contact angle of 90° or less, preferably 70° or less, more preferably 50° or less, and even more preferably 35° or less.

The substrate to which the hydrophilic surface property of the present invention is added implements excellent hydrophilicity, can maintain the hydrophilicity for a long time, and implements a hydrophilic effect that satisfies the following Equations 1 and 2.

The substrate to which the hydrophilic surface property is added may have a water contact angle of 35° or more according to Equation 1 below.

[Equation 1]

△WA1 = (WA _base- WA ₂₅ )/ WA _base × 100

(The WA ₂₀₀ is the water contact angle of the substrate measured 25 hours after plasma treatment, the WA _base is the water contact angle of the substrate before plasma treatment, and the unit is °.)

The substrate to which the hydrophilic surface property is added may have a water contact angle change value of 30° or less according to Equation 2 below.

[Equation 2]

△WA2 = WA ₃₀₀ -WA ₀

(Wa ₃₀₀ is the water contact angle of the substrate measured 300 hours after plasma treatment, WA ₀ is the water contact angle of the substrate measured immediately after plasma treatment, and the unit is °.)

The substrate to which the hydrophilic surface property of the present invention is added may implement patterning by various methods.

In the first step, since the substrate is patterned, it is possible to implement hydrophilic patterning in the same manner as the pattern by external energy.

Alternatively, in the second step, hydrophilic patterning may be implemented on the substrate by using a mask.

In the first step, a part or all of the substrate may be formed in which the hydrophilic resin particles in the hydrophobic polymer matrix are formed at a uniform concentration throughout the inside of the hydrophobic polymer matrix. In addition, a part or all of the substrate may be that the concentration of the hydrophilic resin particles in the hydrophobic polymer matrix decreases from the surface of the hydrophobic polymer matrix in the inner direction.

The degree of hydrophilization and transparency can be controlled by controlling the concentration distribution of the hydrophilic resin particles in the hydrophobic polymer matrix.

The hydrophilic resin particles in the hydrophobic polymer matrix may be included in a range that does not deteriorate the physical properties of the hydrophobic polymer matrix, and preferably may be included in an amount of 0.1 to 1.0% by weight, and the optical transparency of the hydrophobic polymer matrix is maintained within the range. It can be desirable.

Hereinafter, specific technical details of the present invention will be described in more detail based on the accompanying drawings.

1 is a schematic diagram of manufacturing a substrate to which hydrophilic surface properties of the present invention are added. As shown in FIG. 1, by stirring the hydrophobic polymer prepolymer and the hydrophilic resin, a mixture in which the hydrophilic resin is sufficiently dispersed in the hydrophobic polymer prepolymer may be prepared. An initiator may be added to the mixture for crosslinking. The hydrophobic polymer matrix may include a silicone-based polymer, a urethane resin, an epoxy resin, a fluorine resin, and a polycarbonate resin, and various resins may be used depending on the purpose. Examples of the silicone-based polymer include polydimethylsiloxane (PDMS) and polyhydroxymethylsiloxane (PHMS), but are not limited thereto.

The hydrophobic polymer matrix may be used for preparation in the form of a prepolymer. Specifically, the hydrophilic resin may include polyethylene glycol (PEG), polyvinylalcohol (PVA), and the like. The hydrophilic resin may be expressed as hydrophilic resin particles in an aggregated form in the hydrophobic polymer matrix.

The initiator may be used without limitation as long as it is capable of curing the hydrophobic polymer matrix, and a thermal initiator, a photoinitiator, and the like may be used without limitation. Specifically, when the hydrophobic polymer matrix constituting the substrate is PDMS, Sylgard 184B may be used as the initiator. The initiator may be included in an amount of 0.1 to 60% by weight, preferably 1 to 30% by weight, based on the total weight of the hydrophobic polymer matrix and the hydrophilic resin particles.

The mixture may be poured into a mold and cured by heating to prepare a substrate. The substrate is prepared in such a manner that the hydrophobic polymer matrix is covered on the surface of the hydrophilic resin particles because the hydrophilic polymer matrix is not compatible with each other. In this case, when PDMS is used as a substrate, the water contact angle may have a hydrophobicity of 110° to 120°.

The hydrophilic resin particles in the hydrophobic polymer matrix may mean a form in which the hydrophilic resin is aggregated.

When plasma treatment of a substrate including hydrophilic resin particles in the hydrophobic polymer matrix, the hydrophobic polymer matrix thinly covered with the hydrophilic resin particles is removed, and the hydrophilic resin particles are exposed on the substrate surface. Accordingly, the substrate after plasma treatment exhibits hydrophilicity, and in this case, the water contact angle may be 90° or less, preferably 70° or less, more preferably 50° or less, and even more preferably 35° or less.

Figure 2 shows the measurement of the water contact angle before and after plasma treatment of a substrate (PDMS/PEG substrate) containing polyethylene glycol in polydimethylsiloxane, as shown in FIG. 2(a), in the PDMS/PEG substrate The contact angle after plasma treatment has a hydrophilicity of 10° or less, and the contact angle of the PDMS/PEG substrate before plasma treatment is 114°, as shown in FIG. 2(b), and has hydrophobicity, as shown in FIG. 2(c). Likewise, it can be seen that the contact angle of pure polydimethylsiloxane (hereinafter referred to as pure PDMS) has 114° the same as before plasma treatment.

The degree of hydrophilization of the PDMS/PEG substrate before and after plasma treatment may be satisfied as a water contact angle change rate of 35° or more according to Equation 1 below.

[Equation 1]

△WA1 = (WA _base- WA ₂₅ )/ WA _base × 100

(The WA ₂₅ is the water contact angle of the substrate measured 25 hours after plasma treatment, the WA _base is the water contact angle of the substrate before plasma treatment, and the unit is °.)

In addition, the degree of maintaining hydrophilicity after the plasma treatment may be satisfied as a water contact angle change value of 30° or less according to Equation 2 below.

[Equation 2]

△WA2 = WA ₃₀₀ -WA ₀

(Wa ₃₀₀ is the water contact angle of the substrate measured 300 hours after plasma treatment, WA ₀ is the water contact angle of the substrate measured immediately after plasma treatment, and the unit is °.)

The surface roughness of the substrate may be changed before and after plasma treatment.

3 shows the surface roughness values before and after plasma treatment of a substrate (PDMS/PEG substrate) containing polyethylene glycol in polydimethylsiloxane. The surface roughness was observed using an optical profiler (ContourGT, Bruker, Germany).

3(a) shows the surface roughness of the plasma-treated PDMS/PEG substrate, FIG. 3(b) shows the water contact angle of the non-plasma-treated PDMS/PEG substrate, and FIG. 3(c) shows the pure PDMS. It shows the water contact angle.

In FIG. 3, FIG. 3(a) shows a value of 36.3 nm as a surface roughness (Ra) after plasma treatment, and FIG. 3(b) shows a value of 28.3 nm as a surface roughness of the substrate before plasma treatment, and FIG. 3 (c) The surface roughness of pure polydimethylsiloxane is 23.1 nm. Through the surface roughness of the substrate before plasma treatment, it can be seen that the surface roughness slightly increases due to the addition of polyethylene glycol to the polydimethylsiloxane, and the surface roughness after the plasma treatment is very increased. The surface roughness may increase as protrusions having a diameter of 1 to 2 μm and a height of several hundred nm, which were not observed in pure polydimethylsiloxane, are formed by plasma treatment. In addition, since the polydimethylsiloxane on the surface of the polyethylene glycol aggregated by the plasma treatment is removed, the polyethylene glycol protrudes to the outside and directly contacts the water droplets, thereby converting the surface to a surface having hydrophilic properties.

FIG. 4 shows optical transparency according to the thickness of a substrate (PDMS/PEG substrate) containing polyethylene glycol in polydimethylsiloxane and the concentration of polyethylene glycol.

The substrate containing polyethylene glycol in the polydimethylsiloxane may include 0.1 to 1% by weight of the polyethylene glycol in the polydimethylsiloxane, and preferably 0.1 to 0.5% by weight. In the above range, it may have a transmittance of 50% or more in a region of 500 nm to 700 nm, which is a visible light region. The substrate may have a thickness of 0.1 mm to 5 mm, preferably 0.1 mm to 1 mm. In the above range, it may have a transmittance of 50% or more in a region of 500 nm to 700 nm, which is a visible light region. By controlling the thickness of the substrate and the content of the polyethylene glycol, it can be applied to various fields by adjusting optical transparency and hydrophilicity according to the intended purpose.

The substrate to which the hydrophilic surface property of the present invention is added does not deteriorate mechanical properties due to the inclusion of the hydrophilic resin particles, and can maintain mechanical properties such as warpage and elasticity of the pure hydrophobic polymer matrix. Therefore, it can be used without limitation in its applicability in various fields.

5 shows an example of the concentration of the hydrophilic resin particles 120 in the hydrophobic polymer matrix 110. 5(a) shows that the concentration of the hydrophilic resin particles 120 in the substrate 100 is uniform throughout, and FIG. 5(a) shows that the hydrophilic resin particles 120 are distributed on the surface of the substrate 100. 5(c) shows a form in which the concentration of the hydrophilic resin particles 120 decreases from the surface of the substrate 100 to the inner direction. The concentration of the hydrophilic resin particles 120 inside the substrate 100 is not limited thereto and may be variously implemented. By controlling the distribution or concentration of the hydrophilic resin particles 120 inside the substrate 100, transparency or mechanical properties of the substrate 100 may be controlled.

The substrate to which the hydrophilic surface property of the present invention is added can be prepared by patterning. 6 and 7 are schematic diagrams of a method for manufacturing a patterned substrate to which hydrophilic surface properties are added.

In FIG. 6, a substrate 100 including hydrophilic resin particles 120 is formed in the hydrophobic polymer matrix 110 on the substrate 200. As a method of forming the substrate 100, as described in FIG. 1, after preparing a mixture by mixing a hydrophobic polymer prepolymer, a hydrophilic resin, and an initiator, the mixture is applied onto the substrate 200 using a known coating method. It can be prepared after applying and curing. Plasma treatment is performed by shielding selected portions of the surface of the substrate 100 by using a mask 300 on the upper layer of the substrate 100 so that plasma treatment is performed in the open area of the mask 300, so that the hydrophilic resin The hydrophobic polymer matrix 100 formed on the surface of the particles 120 is removed to expose the hydrophilic resin particles 120 to the outside, thereby forming a region A to which hydrophilic surface properties are imparted. The area protected by the mask 300 remains hydrophobic. The thickness of the hydrophobic matrix 100 to be removed is very thin and can be adjusted according to the type of the hydrophobic matrix 100 and the intensity of plasma. When the hydrophobic matrix 100 is PDMS, the thickness to be removed may be about 100 nm or less than 100 nm.

In FIG. 7, the substrate 100 includes a hydrophobic polymer matrix 110, a hydrophilic resin particle 120, and a hydrophobic polymer 130 of a different type from the hydrophobic polymer matrix 110. The substrate 100 includes a region (B) in which a part of the substrate has been removed by plasma treatment, and the hydrophilic resin particles 120 are exposed to the outside on the surface of the substrate 100 by the removed region (B). As a result, a hydrophilized region (A) is formed.

In the region B from which a part of the substrate has been removed by the plasma, a range of the thickness to be removed may be adjusted according to the type of the hydrophobic matrix 100 and the intensity of the plasma. When the hydrophobic matrix 100 is PDMS, the thickness to be removed may be about 100 nm or less than 100 nm.

The region (A) to which the hydrophilic surface property is provided in FIGS. 6 and 7 is formed by exposing the hydrophilic resin particles 120 to the outside, and will be described in detail in FIG. 8 below.

8 shows a cross-section of a substrate to which hydrophilic surface properties are added. When the substrate 100 formed of the hydrophobic polymer matrix 110 including the hydrophilic resin particles 120 is plasma-treated to form the hydrophilic region A, the hydrophobic matrix 110 as shown in 1) of FIG. 8 The hydrophilic resin particles 120 and the hydrophilic resin particles 120 are removed together to expose a part of the hydrophilic resin particles 120 on the surface of the substrate 100 to become hydrophilic. In addition, as shown in 2) of FIG. 8, only the hydrophobic polymer matrix 110 formed on the surface of the hydrophilic resin particles 120 is removed, and the hydrophilic resin particles 120 may be exposed to the outside in a protruding form to become hydrophilic.

9 shows various shapes of a hydrophilic pattern formed on a substrate to which hydrophilic surface properties are added after plasma treatment, which is an aspect of the present invention, and FIG. 9(a) shows the hydrophilization of a substrate without patterning, 9(b) and 9(c) show the patterning of the hydrophilized region. The present invention is not limited to the patterning form shown above, and patterning may be implemented in various forms.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the following Examples and Comparative Examples are only one example for describing the present invention in more detail, and the present invention is not limited by the following Examples and Comparative Examples.

[Example]

In the examples, stability data was put into the data given by the inventor, and the degree of hydrophilization and stability were judged and compared by numerical comparison.

[How to measure]

1. Contact angle

The contact angle was measured with an optical contact angle meter (OCA30, Dataphysics, Germany).

2. Young's modulus

The shape and test method of the specimen were measured according to ASTM D 412-06 standard.

[Example 1]

PDMS pre-polymer (Sylgard 184A from Dow-corning) and polyethylene glycol (PEG, Mw = 570 ~ 630, Junsei Chemical, Japan) are stirred with a hydrophilic resin so that PEG is sufficiently dispersed in the PDMS pre-polymer. With respect to the mixture of the PDMS prepolymer and PEG, the concentration of PEG is mixed in a weight ratio of 0.1% by weight. After that, the mixture of Sylgard 184A and PEG was mixed with Dow-corning's Sylgard 184B as a crosslinking curing initiator in a weight ratio (Sylgard 184A + PEG): Sylgard 184B = 10:1. Poured and cured by heating at 80° C. for 2 hours to prepare a PDMS/PEG substrate in which PEG is dispersed in the PDMS.

[Example 2]

It was prepared in the same manner as in Example 1, except that the mixture of PDMS prepolymer and PEG was prepared by mixing the concentration of PEG to 0.25% by weight in a weight ratio.

[Example 3]

It was prepared in the same manner as in Example 1, except that the mixture of PDMS prepolymer and PEG was prepared by mixing the concentration of PEG to be 0.5% by weight in a weight ratio.

[Example 4]

It was prepared in the same manner as in Example 1, except that the mixture of PDMS prepolymer and PEG was prepared by mixing the concentration of PEG to be 1.0% by weight in a weight ratio.

[Comparative Example]

100 g of PDMS pre-polymer (Sylgard 184A from Dow-corning) was mixed with 10 g of Sylgard 184B from Dow-corning as a crosslinking curing initiator, poured into a rectangular polycarbonate mold with a thickness of 5 mm, and heated at 80°C for 2 hours. Cured to prepare a pure-PDMS substrate.

In Table 1 below, plasma was treated on each of the substrates of Examples 1 to 4 and Comparative Example 1 at an intensity of 100 W for 10 seconds, and the change value of the water contact angle according to time was measured and shown.

Water contact angle (°) plasma
Before processing Time after plasma treatment (hrs) 0 25 50 100 300 Example 1 104 75 90 90 90 90 Example 2 104 40 45 54.2 54.2 54.2 Example 3 104 28 30 30 44.5 44.5 Example 4 104 15 28 40.6 40.6 40.6 Comparative example 104 80 104 104 104 104

In Examples 1 to 4, it can be seen that the value of Equation 1 below is satisfied with 35° or more, and the value of Equation 2 below is satisfied with 30° or less.

[Equation 1]

△WA1 = (WA _base -WA ₂₅ )/ WA _base × 100

(The WA ₂₅ is the water contact angle of the substrate measured 25 hours after plasma treatment, the WA _base is the water contact angle of the substrate before plasma treatment, and the unit is °.)

[Equation 2]

△WA2 = WA ₃₀₀ -WA ₀

(Wa ₃₀₀ is the water contact angle of the substrate measured 300 hours after plasma treatment, WA ₀ is the water contact angle of the substrate measured immediately after plasma treatment, and the unit is °.)

As can be seen from Table 1 and Equations 1 and 2, in Examples 1 to 4, as the concentration of PEG increases, the water contact angle decreases, that is, it can be seen that hydrophilicity is excellently expressed. Alternatively, it was found that the hydrophilization of the surface of the hydrophilized PDMS/PEG substrate was kept constant even for a long time. From this, it can be seen that the plasma-treated PDMS/PEG substrate, that is, the PDMS/PEG substrate to which the surface hydrophilic property is imparted, has very excellent hydrophilicity and stability.

In Table 2 below, the Young's Modulus of Examples 1 to 3 was measured and shown.

Modulus of elasticity (MPa) Example 1 1.35 Example 2 1.35 Example 3 1.3 Comparative Example 1 1.3

In Table 2, the modulus of elasticity of Examples 1 to 3 could not be found to be significantly different compared to Comparative Example 1. From the above results, it was found that the mechanical properties of the PDMS/PEG substrate were equivalent to that of pure PDMS.

Summarizing the above results, it is shown that the substrate to which the hydrophilic surface property of the present invention is imposed is maximizing the hydrophilicization efficiency in terms of long-term stability of the degree of hydrophilicity and an economical and simple process. In addition, it can be seen that the properties of the fabricated material such as optical transparency and mechanical Young's modulus maintain similar properties compared to the existing pure PDMS. This enables excellent hydrophilicity while maintaining the mechanical properties of pure PDMS, such as excellent bending and elasticity. In application and use as a coating agent, it can be seen that it is possible without additional technology development. In addition, it is possible to expand the applicability to various fields through spatial control of hydrophobicity and hydrophilicity through the expansion of the above-described hydrophilicization concept to a fine area, and thus the application field can be expected to expand.

100: base
110: polymeric polymer matrix
120: hydrophilic resin particles
200: substrate
300: mask

Claims (16)

A substrate to which hydrophilic surface properties are added by partially or entirely removing a surface of a substrate including hydrophilic resin particles in a hydrophobic polymer matrix by external energy, thereby exposing part or all of the hydrophilic resin particles. The method of claim 1,
The external energy is at least one selected from plasma, ion beam, chemical etching, sanding, and laser beam. The method of claim 1,
The substrate is a substrate to which a hydrophilic surface property having a light transmittance of 50% or more in a visible region of 500 to 700 nm is added. The method of claim 1,
The hydrophilic resin particles are contained in a concentration of 0.1 to 1% by weight of the substrate to the hydrophilic surface property is added. The method of claim 1,
The substrate is a substrate to which hydrophilic surface properties having a water contact angle change rate of 35° or more according to the following Equation 1 are added.
[Equation 1]
△WA1 = (WA _base- WA ₂₅ )/ WA _base × 100
(The WA ₂₅ is the water contact angle of the substrate measured 25 hours after plasma treatment, the WA _base is the water contact angle of the substrate before plasma treatment, and the unit is °.) The method of claim 1,
The substrate is a substrate to which a hydrophilic surface property is added having a water contact angle change value of 30° or less according to the following Equation 2.
[Equation 2]
△WA2 = WA ₃₀₀ -WA ₀
(The WA ₃₀₀ is the water contact angle of the substrate measured 300 hours after plasma treatment, WA ₀ is the water contact angle of the substrate measured immediately after plasma treatment, and the unit is °.) The method of claim 1,
A substrate to which hydrophilic surface properties are added, wherein the hydrophilic resin particles in the substrate are formed in a uniform concentration as a whole. The method of claim 1,
A substrate to which hydrophilic surface properties are added, wherein the concentration of the hydrophilic resin particles in the substrate decreases from the surface of the substrate in an inward direction. A first step of preparing a substrate including a surface in which hydrophilic resin particles are mixed in a hydrophobic polymer matrix;
A second step of applying external energy to a part of the surface of the substrate or the entire surface of the substrate; And
A third step in which a part of the surface of the substrate or the entire surface of the substrate is removed by the external energy so that a part of the hydrophilic resin particles is exposed to the surface of the hydrophobic polymer matrix;
Method for producing a substrate to which hydrophilic surface properties are added, including. The method of claim 9,
The external energy is at least one selected from plasma, ion beam, chemical etching, sanding, and laser beam. The method of claim 10,
The plasma is a substrate to which hydrophilic surface properties are added, which is performed for 0.1 to 10 seconds at an intensity of 5 W to 1000 W. The method of claim 9,
The method of manufacturing a substrate to which hydrophilic surface properties are added, comprising the substrate being formed of a single hydrophobic polymer matrix resin or formed of two or more types of hydrophobic polymer matrices. The method of claim 9,
In the first step, the surface of the substrate is a method of manufacturing a substrate to which hydrophilic surface properties are added, wherein a pattern is formed. The method of claim 9,
In the second step, a method of manufacturing a substrate to which hydrophilic surface properties are added, wherein hydrophilic patterning is formed on the substrate using a mask. The method of claim 9,
A method of manufacturing a substrate with hydrophilic surface properties, wherein a part or all of the surface of the substrate is formed in a uniform concentration of the hydrophilic resin particles as a whole inside the substrate. The method of claim 9,
A method of manufacturing a substrate with hydrophilic surface properties, wherein the concentration of the hydrophilic resin particles decreases from the surface of the substrate in an inward direction to part or all of the substrate.

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