WO2014171592A1

WO2014171592A1 - Mechanoluminescence colour-tunable complex film and method for tuning colour thereof

Info

Publication number: WO2014171592A1
Application number: PCT/KR2013/007545
Authority: WO
Inventors: 정순문; 이수근; 송성규
Original assignee: 재단법인대구경북과학기술원
Priority date: 2013-04-18
Filing date: 2013-08-22
Publication date: 2014-10-23
Also published as: KR101501525B1; KR20140125116A

Abstract

Provided are a colour-tunable complex film which emits light in a mechanical manner and a method for tuning colour thereof. Modes of embodiment of the present invention comprise a mixture of at least two mechanoluminescence materials which emit light by applied mechanical energy and a stress transfer material which transfers mechanical energy applied from the outside to the mechanoluminescence materials, wherein among the at least two mechanoluminescence materials, a first emission spectrum of the first mechanoluminescence material is different from a second emission spectrum of the second mechanoluminescence material.

Description

Mechanical light-emitting composite film with color control and its color control method

The present invention relates to a light emitting composite film, and more particularly, to a composite film and a color control method for emitting light in a mechanical manner capable of color control.

The phenomenon of light emission in a mechanical manner, i.e. light generated by applying force to a material, has long been known under the name of Mechanoluminescence (mechanical light emission; higher concepts including triboluminescence, fractoluminescence, deformation-luminescence, etc.). Is not only certain but is only treated as an academic interest.

For example, X-ray emission from Scotch tape delamination under vacuum (Camara et al. Nature 2008) and ultraviolet radiation from ultrasound (Eddingsaas et al. Nature 2006) have been shown to have great academic repercussions. Due to the fundamental problem that light is generated by friction and destruction, the possibility of industrial application is very low.

In order to solve these problems related to industrial applications, the Xu Group of the Japan Institute of Industrial Technology (AIST) has developed elastic or plastic deformation in some materials instead of triboluminescence and fractoluminescence caused by friction or fracture. In this study, non-destructive mechanical luminescence phenomenon called deformation luminescence, which generates light, was applied to some stress sensors.

Brightness, lifespan, and color control are very important factors to apply such mechanical luminescence to various industries, but until now, many studies have not been conducted due to the limitations of the material itself. In particular, due to the limitation of the brightness and life (or reproducibility) of the light expressed in the material, there is no technical development of color control.

An object of the present invention is to provide a method for independently adjusting two or more colors by uniformly mixing at least two or more stress luminescent materials with a stress transfer material in order to solve the above problems of the prior art.

The object of the present invention is not limited to the above-mentioned object, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention for achieving the above object of the present invention, the color-controlled mechanically luminescent composite film has at least two stress luminescent materials that emit light by mechanical energy applied thereto, and is external to the stress luminescent material Wherein the first emission spectrum of the first stress luminescent material and the second emission spectrum of the second stress luminescent material of the at least two stress luminescent materials It is characterized by different from each other.

In one embodiment, the intensities of the first and second emission spectra may be independently adjusted based on the amounts of the first and second stress luminescent materials.

In one embodiment, as the mixing ratio of the first stress luminescent material and the second stress luminescent material is changed, the color expressed in the mechanical light emitting composite film may be controlled.

In one embodiment, as the transmission period of the mechanical energy applied to the first and second stress light-emitting material is changed, the color expressed in the mechanical light emitting composite film can be adjusted.

In one embodiment, the stress transmission material is an elastic organic material having a transmittance of 80% or more in the visible light region, the elastic organic material is polydimethylsiloxane (PDMS), silicone rubber, UV curable epoxy It may be composed of at least one of.

As described above, according to the embodiment of the present invention, the field of application of the mechanical luminescence phenomenon limited to the existing academic research can be expanded to the industry. The embodiments can be applied to lighting and display through color control, and can be applied to bio and imaging such as artificial skin.

1 is a block diagram showing the internal configuration of a mechanical light-emitting composite film capable of color adjustment according to an embodiment of the present invention.

Figure 2 shows the spectral characteristics of the light generated in the composite film according to the present invention at a tensile-restoration rate of 200 cpm (cycle per minute).

3 is a view for explaining an aspect in which the emission color is changed in accordance with the composition ratio of the stress light-emitting material constituting the composite film according to the present invention.

4 is a view for explaining an aspect that the spectrum is changed according to the composition ratio of the stress light-emitting material constituting the composite film according to the present invention.

5 is a view for explaining an aspect in which the emission spectrum is changed when changing the generation period of the stress applied to the stress light-emitting material constituting the composite film according to the present invention.

6 is a view for explaining an aspect in which the emission spectrum is changed when changing the generation period of the stress applied to the stress light-emitting material at various composition ratios of the stress light-emitting material constituting the composite film according to the present invention.

7 is a view for explaining a method of manufacturing a composite film including a letter pattern having a variety of colors shown in FIG.

8 is a view showing a composite film including a letter pattern having a variety of colors according to an application of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Meanwhile, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used to refer to the same components even though they are shown in different drawings. In describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

1 is a block diagram showing the internal configuration of the mechanical light-emitting composite film is color control according to an embodiment of the present invention.

As shown in FIG. 1, the mechanically luminescent composite film of which color adjustment is possible delivers at least two or more stress luminescent materials that emit light by mechanical energy applied thereto, and mechanical energy applied to the stress luminescent materials from outside. It consists of a mixture of stress transfer materials. The first emission spectrum of the first stress light-emitting material and the second emission spectrum of the second stress light-emitting material may be different from each other.

That is, according to the embodiment of the present invention, the two types of stress luminescent materials are uniformly mixed with an elastic organic material (stress transmission material), which is based on the principle of independently controlling the two types of colors.

In FIG. 1, the two stress luminescent materials include copper-doped zinc sulfide (hereinafter referred to as Zns: Cu) that expresses green light, and copper and manganese doped zinc sulfide that express red light. Hereinafter, polydimethylsiloxane (hereinafter, referred to as PDMS) is used as a stress transfer material for transferring ZnS: Cu, Mn to the light emitting material, but is not limited thereto.

In another embodiment, the stress luminescent material is ZnS: Mn, ZnS: Cu, Mn, ZnS: Cu, Pb, ZnS: Cu, Pb, Mn, MgF2: Mn, La2O2S: Eu, Y2O2S: Cu, EuD4TEA, EuD4TEA +1.25 mL DMMP, ZnS: Cu, Cl, ZnS: Cu, Mn, Cl, SrAl2O4: Eu, SrAl2O4: Ce, SrAl2O4: Ce, Ho, SrMgAl6O11: Eu, SrCaMgSi2O7: Eu, SrBaMgSi2O7O7O7O7O7 : Eu, Dy, CaYAl3O7: Eu (Ba, Ca), TiO3: Pr3 +, ZnGa2O4: Mn, MgGa2O4: Mn, Ca2Al2SiO7: Ce, ZrO2: Ti, ZnS: Mn, Te etc. can be used, and organic materials (stress transfer Materials include optically transparent (over 80% transmittance in the visible region) including PDMS, and can be widely used for durable silicone rubber and UV curable epoxy.

In addition, the inventive idea of the present invention can be found in controlling color of a wide area by using a light emitting material that expresses various light emission colors that can be displayed on color coordinates, without being limited to materials that express green and red light. .

In order to produce a color-controlled composite film according to an embodiment of the present invention, improved mechanical emission intensity and lifespan of material properties should be ensured. To this end, in the embodiment of the present invention, a transparent PDMS having a very strong elasticity and excellent durability may be used as the stress transfer material.

The PDMS has three advantages as a stress transfer material.

1. PDMS does not adhere to the stress luminescent material when it is mixed with the stress luminescent material because of its low interfacial free energy. In the case of strong adhesion between the stress luminescent material and the stress-transfer material, the interface state may be destroyed as the adhesive surface slips under various deformation states. In the case of PDMS, the surface of the stress luminescent material is stably and repeatedly It can transmit phosphorus stress.

2. Since PDMS is optically transparent, mechanically emitted light can be transmitted to the outside without light loss.

3. PDMS is durable and does not break down even if it is repeatedly stressed for a long time.

2 is a view showing the spectral characteristics of the light generated in the composite film according to the present invention at a tensile-restore rate of 200 cpm (cycle per minute).

As shown in FIG. 2, the mechanical emission spectrum of green light is observed in the Zns: Cu stress luminescent material and the mechanical emission spectrum of red light is observed in the ZnS: Cu, Mn stress luminescent material due to externally applied mechanical energy.

As an embodiment for controlling the color of the light expressed in the composite film having the above-described configuration, a method of changing the composition ratio of two or more stress light-emitting materials constituting the composite film is proposed. In an actual experiment, Zns: Cu and ZnS: Cu, Mn were mixed in a ratio of red: green (O: G), and the ratio was 10: 0, 9: 1, 8: 2, 7: 3, 6 : 4, 5: 5, 0:10. In addition, the ratio of the overall light emitting material and PDMS was maintained at 7: 3.

In order to observe the optical properties of the mechanical luminescence emitted by the composite film, a stretching-releasing system was used, and the result is shown in FIG. 3.

3 is a view for explaining an aspect in which the emission color is changed according to the composition ratio of the stress light-emitting material constituting the composite film according to the present invention. As shown in FIG. 3, as the G (green) ratio increases in the O: G ratio, the color of light expressed in the composite film may be changed from red to green. It can be seen in FIG. 4 that the spectrum of light expressed in the composite film also increases in intensity of the spectrum corresponding to green as the G ratio increases.

As another embodiment for controlling the color of the light expressed in the composite film according to the present invention, a method of changing the transmission period (or tensile-recovery rate) of the mechanical energy applied to the composite film is proposed. That is, the color of the light is different depending on how quickly the stress applied to the composite film. This will be described in detail with reference to FIGS. 5 to 6.

5 is a view for explaining an aspect in which the emission spectrum is changed when changing the generation period of the stress applied to the stress light-emitting material constituting the composite film according to the present invention. Referring to FIG. 5, it can be seen that when the tensile recovery rate is increased from 200 cpm to 500 cpm, the emission spectrum is shifted to the left. This is because the doping position of Cu in ZnS: Cu is located at various energy levels. That is, as the rate of change of stress increases, light of a high energy wavelength band is emitted.

On the other hand, the color control in the composite film according to the present invention may be used in the two methods described above. This will be described in detail with reference to FIG. 6. 6 is a view for explaining an aspect in which the emission spectrum is changed when changing the generation period of the stress applied to the stress luminescent material at various composition ratios of the stress luminescent material constituting the composite film according to the present invention.

6 shows the results of indirectly measuring the results of color change and spectral change for a high stress change rate (500 cpm or more) by fabricating a composite film according to the present invention with a thick film inorganic EL and applying an electrical frequency. do.

Referring to FIG. 6, the spectrum (a) of Zns: Cu and Mn is kept constant as the frequency is changed, whereas the spectrum (b, c, d, e, f) of Zns: Cu is higher in frequency. It can be seen that the left side shift. This result means that the light emitted on the color coordinates is blue shifted. In addition, it can be seen that the spectrum of light expressed according to the composition ratio of Zns: Cu, Mn: Zns: Cu (O: G) is different.

On the other hand, when only Zns: Cu and Mn are used as stress luminescent materials, the spectrum is kept constant even though the frequency is changed. This is because in the case of Cu in Zns: Cu and Mn, it acts only as a sensitizer. This is because Mn maintains a constant state even though Cu has various energy levels.

As such, in the composite film according to the present embodiment, not only the composition ratio of the stress luminescent material constituting the composite film but also various cycles of stress applied to the composite film may be varied to implement a wide color control range.

An example of applying the above-described characteristics (spectral change according to composition ratio or stress generation cycle) of the composite film according to the present invention will be described with reference to FIGS. 7 and 8. 7 is a view for explaining a method of manufacturing a composite film including a letter pattern having a variety of colors shown in Figure 8, Figure 8 includes a letter pattern having a variety of colors according to an application of the present invention It is a figure which shows a composite film.

As shown in FIG. 7 to implement letters having various color patterns as shown in FIG. 8, a composite film was manufactured using a screen printing technique. First, a mask for silk screen printing is formed on a glass substrate in a predetermined pattern, and a paste in which at least two stress luminescent materials are mixed is applied onto the mask (a). In FIG. 7, paints (mixing by selecting two or more of the above-described stress luminescent materials) were used to express green, orange, and yellow colors, respectively.

Next, the applied paint is pushed with a squeegee (stick) to allow the paint to soak into the mask gap to form a letter pattern (b). Then, PDMS is applied as a transparent material on the formed letter pattern as a transparent substrate (c) and subjected to a curing process for 30 minutes in an environment of 70 ℃ (d). Thereafter, when curing of the PDMS is completed, the glass substrate is separated to complete the composite film (e).

Those skilled in the art will appreciate that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The protection scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the claims and their equivalents should be construed as being included in the scope of the present invention.

Claims

A mixture of at least two stress luminescent materials that emit light by mechanical energy applied and a stress transfer material that delivers mechanical energy applied externally to the stress luminescent material,

Among the at least two stress luminescent materials, the first luminescence spectrum of the first stress luminescent material and the second luminescence spectrum of the second stress luminescent material are different from each other.

Mechanical light-emitting composite film, characterized in that the color control.
The method of claim 1,

Intensities of the first emission spectrum and the second emission spectrum are independently adjusted based on the amounts of the first and second stress luminescent materials.

Mechanical light-emitting composite film, characterized in that the color control.
The method of claim 1,

As the mixing ratio of the first stress luminescent material and the second stress luminescent material is changed, the color expressed in the mechanical light emitting composite film is controlled.

Mechanical light-emitting composite film, characterized in that the color control.
The method of claim 1,

The color expressed in the mechanically luminescent composite film is controlled by changing the transmission period of the mechanical energy applied to the first stress luminescent material and the second stress luminescent material.

Mechanical light-emitting composite film, characterized in that the color control.
The method of claim 1,

The stress transfer material is an elastic organic material having a transmittance of 80% or more in the visible light region,

The elastic organic material is composed of at least one of polydimethylsiloxane (PDMS), silicone rubber, UV curable epoxy

Mechanical light-emitting composite film, characterized in that the color control.
A method for color control in a mechanically luminescent composite film comprising a mixture of at least two stress luminescent materials that emit light by mechanical energy applied and a stress transfer material that delivers mechanical energy applied externally to the stress luminescent material. To

Among the at least two stress luminescent materials, the first luminescence spectrum of the first stress luminescent material and the second luminescence spectrum of the second stress luminescent material are different from each other,

Changing a mixing ratio of the first stress luminescent material and the second stress luminescent material

Color control method of a mechanical light-emitting composite film characterized in that.
The method of claim 6,

Changing a transfer period of mechanical energy applied to the first stress luminescent material or the second stress luminescent material

Color control method of a mechanical light-emitting composite film further comprising.
A method for color control in a mechanically luminescent composite film comprising a mixture of at least two stress luminescent materials that emit light by mechanical energy applied and a stress transfer material that delivers mechanical energy applied externally to the stress luminescent material. To

Among the at least two stress luminescent materials, the first luminescence spectrum of the first stress luminescent material and the second luminescence spectrum of the second stress luminescent material are different from each other,

Changing the transmission period of mechanical energy applied to the first or second stress luminescent material

Color control method of a mechanical light-emitting composite film characterized in that.
Providing a first stress luminescent material that emits light by mechanical energy applied and a second stress luminescent material having a different emission spectrum than the first stress luminescent material;

Forming a composite film by providing a stress transfer material that transfers mechanical energy applied externally to the first stress luminescent material and the second stress luminescent material;

Generating stress in the composite film at a first cycle; And

Changing the stress from the first period to the second period

Color control method of a mechanical light-emitting composite film comprising a.
The method of claim 9, wherein providing the stress luminescent material comprises:

Changing a mixing ratio of the first stress luminescent material and the second stress luminescent material

Color control method of phosphorescent mechanical light emitting composite film.