KR102556641B1 - Varifocal lens composition comprising internal plasticized PVC and varifocal lens having the same - Google Patents

Abstract

The present invention relates to a composition for a variable focus lens comprising PVC internally plasticized with at least one of TBC, PDMS, and oleic acid, and a variable focus lens including the same.
A composition for a variable focus lens according to an embodiment of the present invention may include PVC in which at least one of TBC, PDMS, and oleic acid is internally plasticized; And a plasticizer; includes.

Description

A composition for a varifocal lens comprising PVC internally plasticized with at least one of TBC, PDMS, and oleic acid, and a varifocal lens composition comprising the same

The present invention relates to a composition for a variable focus lens comprising PVC internally plasticized with at least one of TBC, PDMS, and oleic acid, and a variable focus lens including the same.

A variable focus lens refers to a lens capable of changing its focal length by changing its external appearance or internal structure by a current, voltage, electric field, or magnetic field provided from the outside. Such a variable focus lens may be in a liquid or gel state, and can be operated with less power than conventional lenses, and can be miniaturized due to a small space required for changing the focus.

Korean Patent Publication No. 10-2018-0114382, which is a prior art document below, discloses a variable focus lens capable of independently controlling the focal length of both sides by applying a light-transmissive polymer resin and a plasticizer.

Korean Patent Publication No. 10-2018-0114382

An object of the present invention is to provide a composition for a variable focus lens having improved relative permittivity characteristics, a variable focus lens including the composition, and a manufacturing method thereof.

Also, the ductility of the variable focus lens may be improved.

Also, focus shift is possible in a weak electric field.

Also, it is excellent in durability.

A composition for a variable focus lens according to an embodiment of the present invention may include PVC in which at least one of TBC, PDMS, and oleic acid is internally plasticized; And a plasticizer; includes.

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The weight ratio of the internally plasticized PVC and the plasticizer may be 1:8 to 1:10.

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The plasticizer may be dibutyl adipate (DBA).

A variable focus lens according to an embodiment of the present invention includes the composition for a variable focus lens described above.

A composition for a variable focus lens according to an embodiment of the present invention, a variable focus lens including the same, and a manufacturing method thereof have improved relative permittivity characteristics.

Also, the ductility of the variable focus lens may be improved.

Also, focus shift is possible in a weak electric field.

Also, it is excellent in durability.

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1, 2 and 4 show a reaction scheme for a manufacturing process of a composition for a variable focus lens according to an embodiment of the present invention.
5 is a conceptual diagram of a variable focus lens according to an embodiment of the present invention, wherein (a) is a perspective view and (b) is an exploded perspective view.
6 illustrates a state in which a variable focus lens behaves as current is applied.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention may be modified in various forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art. Therefore, the shape and size of elements in the drawings may be exaggerated for clearer description, and elements indicated by the same reference numerals in the drawings are the same elements. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. In addition, "include" a component throughout the specification means that other components may be further included without excluding other components unless otherwise stated.

Composition for varifocal lenses

A composition for a variable focus lens according to an embodiment of the present invention may include PVC in which at least one of TBC, PDMS, and oleic acid is internally plasticized; And a plasticizer; includes.

PVC in which at least one of TBC, PDMS, and oleic acid is internally plasticized refers to a polymer material formed by connecting at least one of TBC, PDMS, and oleic acid and PVC chains to each other.

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PVC serves to provide high light transmittance and processability to the variable focus lens composition, and the molecular weight of the PVC may be 150,000 or more in consideration of ductility and the like.

PVC can be represented by the molecular formula 1 below.

[Molecular formula 1]

(Where n is a natural number.)

The tributyl citrate (TBC) can be represented by molecular formula 2 below.

[Molecular Formula 2]

PVC in which tributyl citrate is internally plasticized (PVC-TBC ₁ ) can be expressed by the molecular formula 3 below.

[Molecular formula 3]

(Where n and m are natural numbers.)

The manufacturing method of PVC (PVC-TBC ₁ ) in which tributyl citrate is internally plasticized is as follows. First, azide-functionalized PVC (PVC-N ₃ ) is manufactured by synthesizing sodium azide (NaN ₃ ) in PVC and substituting N for Cl in PVC. At this time, after dissolving PVC and sodium azide in a solvent (such as DMF), stirring, precipitating in an organic solvent (such as methanol), and vacuum drying, Azide-functionalized PVC can be produced. Next, Azide-functionalized PVC, Propargyl ether tributyl citrate (PrTBC) is dissolved in a solvent (DMF, etc.), stirred, precipitated in an organic solvent, and vacuum-dried to obtain tributyl citrate internally plasticized PVC (PVC-TBC ₁ ) can be manufactured. The reaction diagram of the manufacturing process of this embodiment is shown in FIG.

The polydimethylsiloxane (PDMS) may be represented by molecular formula 4 below.

[Molecular Formula 4]

PVC in which PDMS is internally plasticized (PVC-PDMS) can be expressed by the molecular formula 5 below.

[Molecular Formula 5]

(Where n, m and x are natural numbers.)

The manufacturing method of PVC (PVC-PDMS) in which PDMS is internally plasticized is as follows. First, PVC-DEA is prepared by synthesizing PVC with diethanolamine (DEA), and then PVC-PDMS is prepared by synthesizing PDMS. The reaction diagram of the manufacturing process of this embodiment is shown in FIG. In PVC in which PDMS is internally plasticized (PVC-PDMS), the molar ratio of PVC and PDMS may be 1:2.

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The oleic acid can be represented by molecular formula 8 below.

[Molecular Formula 8]

PVC (PVC-Oleic) in which oleic acid is internally plasticized can be expressed by the molecular formula 9 below.

[Molecular Formula 9]

(Where n and m are natural numbers.)

The manufacturing method of PVC (PVC-Oleic) in which oleic acid is internally plasticized is as follows. First, diethanolamine (DEA) is synthesized in PVC to produce PVC-DEA, hexamethylene diisocyanate is synthesized to produce PVC-HDI, and then oleic acid is added to synthesize it. The reaction diagram of the manufacturing process of this embodiment is shown in FIG. In PVC (PVC-Oleic) in which oleic acid is internally plasticized, the mole ratio of PVC and oleic acid may be 1:2.

Looking at the internal plasticization reaction equation of at least one of PVC and TBC, PDMS and Oleic acid, when the internally plasticized material is at least one of Polydimethylsiloxane (PDMS) and Oleic acid, PVC and internally plasticized PDMS and Oleic acid The molar ratio of at least one of the acids may be 1:2. Through this, at least one of PVC, PDMS, and oleic acid is stably internally plasticized, enabling detailed operation even at low current.

The plasticizer performs a function of curing the light-transmitting polymer resin and P(VC-VA) and converting them into a gel phase. Through this, the plasticizer may lower leakage current. The plasticizer is not particularly limited, but may be DBA (Dibutyl Adipate).

The DBA may be represented by the following molecular formula 10.

[Molecular Formula 10]

A weight ratio of the plasticizer and PVC in which at least one of the TBC, PDMS, and oleic acid is internally plasticized may range from 1:8 to 1:10. If the plasticizer content is too low, the effect of adding the plasticizer may not appear, and if the plasticizer content is too high, the plasticizer may flow out and deformation does not occur easily, so a lot of power is consumed for deformation or there is a risk of damage. .

varifocal lens

The variable focus lens 100 according to an embodiment of the present invention includes the composition for a variable focus lens described above. Referring to FIG. 5 , the variable focus lens 100 includes a lens unit 110 made of a composition for a variable focus lens, an upper substrate 120 disposed above and below the lens unit 110, and a lower portion. A substrate 130 may be included. The upper substrate 120 and the lower substrate 130 may include a hollow in which the curved surface of the lens unit 110 is disposed, and may include an electrode contacting the lens unit 110 to allow current to flow. FIG. 6 is a cross-sectional view of the variable focus lens of FIG. 5, illustrating deformation of a lens unit according to supply of power. 6(a) shows a case where current is not applied, FIG. 6(b) shows a case where current is applied through an electrode of the lower substrate, and FIG. 6(c) shows a case where current is applied through an electrode of the upper substrate 6(d) is a case where current is applied through the electrodes of the upper substrate and the lower substrate. As such, the variable focus lens according to an embodiment of the present invention can control the shape of both sides according to the current application method.

Example: Preparation of composition for variable focus lens

Production of PVC internally plasticized with TBC

First, to prepare propargyl ether tributyl citrate (PrTBC), 8.0 ml of tributhyl citrate (TBC), 2.8 ml of propargyl bromide solution, and 3.18 g of potassium carbonate were dissolved in 30 ml of acetone to synthesize the mixture. The compound was sonicated for 15 minutes to uniformly disperse potassium carbonate, and then the compound was stirred at 65° C. for 12 hours under reflux. The compound was washed 3 times with deionized water and purified by vacuum distillation. Next, to prepare azide-functionalized PVC (PVC-N ₃ ), 2.0 g of PVC and 2.0 g of NaN 3 were dissolved in 50 ml of DMF. The reaction mixture was stirred at 30° C. for 24 hours, then precipitated in a methanol/water mixture (2/1 volume ratio), washed with methanol, and dried in a vacuum oven to obtain PVC-N ₃ . 0.64 g of PVC-N ₃ and 2.39 g of Propargyl ether tributyl citrate thus obtained were dissolved in 20 ml of DMF. 19.2 mg of copper(II) sulfate and 0.12 g of sodium ascorbate were dissolved in 2 ml of deionized water and added dropwise to the reaction mixture. The reaction mixture was stirred at 30° C. for 24 hours, then filtered and dried in a vacuum oven to obtain PVC-TBC ₁ .

Preparation of PVC with internal plasticization of PDMS

First, 5.0 g of PVC powder was dissolved in 20 ml of THF, diluted with 30 ml of DMF, and then 4.21 g of diethanolamine (diethanolamine) and 1.68 g of sodium bicarbonate (NaHCO ₃ ) were added to the reaction vessel. The mixture was stirred and heated at 80° C. for 12 hours under a nitrogen atmosphere. After cooling the reaction mixture to room temperature, it was filtered and PVC-DEA was purified by precipitation in excess methanol and then re-precipitation from THF solution. The PVC-DEA thus prepared was filtered and dried in a vacuum oven. 0.64 g dried PVC-DEA was dissolved in 15 ml dry THF and 4.85 ml PDMS was added to the reaction mixture. The mixture was stirred at 30° C. for 24 hours, precipitated in excess methanol and dried in a vacuum oven to obtain PVC-PDMS.

Production of PVC internally plasticized with TBT

First, 5.0 g of PVC powder was dissolved in 20 ml of THF and diluted with 30 ml of DMF, and then 4.21 g of diethanolamine and 1.68 g of sodium bicarbonate (NaHCO ₃ ) were added to the reaction vessel. The mixture was stirred and heated at 80° C. for 12 hours under a nitrogen atmosphere. After cooling the reaction mixture to room temperature, it was filtered and PVC-DEA was purified by precipitation in excess methanol and then re-precipitation from THF solution. PVC-DEA was filtered and dried in a vacuum oven. 2.0 g of PVC-DEA was dissolved in 25 ml of anhydrous THF, and 4 ml of hexamethylene diisocyanate (hexamethylene diisocyanate) was added dropwise to the reaction mixture under an inert atmosphere. The mixture was stirred at room temperature for 1 hour, and the resulting PVC-HDI product was precipitated in dry hexane, washed several times with the same solvent, filtered and dried in a vacuum oven. 0.64 g of the prepared PVC-HDI was dissolved in 15 ml of THF, and 2.1 ml of tributyl citrate was added to the reaction mixture under a nitrogen atmosphere. The reaction was carried out at 30 °C for 24 hours, and PVC-TBT was prepared by precipitation in an excess of dried diethyl ether.

Production of PVC internally plasticized with oleic acid

First, 5.0 g of PVC powder was dissolved in 20 ml of THF and diluted with 30 ml of DMF, and then 4.21 g of diethanolamine and 1.68 g of sodium bicarbonate (NaHCO 3 ) were added to the reaction vessel. The mixture was stirred and heated at 80° C. for 12 hours under a nitrogen atmosphere. After cooling the reaction mixture to room temperature, it was filtered and PVC-DEA was purified by precipitation in excess methanol and then re-precipitation from THF solution. PVC-DEA was filtered and dried in a vacuum oven. 2.0 g of PVC-DEA was dissolved in 25 ml of anhydrous THF, and 4 ml of hexamethylene diisocyanate (hexamethylene diisocyanate) was added dropwise to the reaction mixture under an inert atmosphere. The mixture was stirred at room temperature for 1 hour, and the resulting PVC-HDI product was precipitated in dry hexane, washed several times with the same solvent, filtered and dried in a vacuum oven. 0.64 g of PVC-HDI was dissolved in 15 ml dry THF, 1.9 ml of oleic acid (oleic acid) was added to the reaction mixture under an inert atmosphere, and the reaction was carried out at 30° C. for 24 hours. It was precipitated in an excess of dry diethyl ether and dried in a vacuum oven to obtain PVC-Oleic.

Preparation of variable focus lens unit using composition for variable focus lens

THF (Sigma-Aldrich, 99.9%, CAS: 109-99-9) was prepared as a solvent, PVC powder (Scientific Polymer Products, Inc., Mw 275,000, CAS: 9002-86-2) and the previously prepared PVC- TBC, PVC-PDMS, PVC-TBT, and PVC-Oleic powders were prepared. To purify PVC powder, PVC-TBC, PVC-PDMS, PVC-TBT, and PVC-Oleic powder, 1 g of each was dissolved in 20 ml of THF solvent and then precipitated in methanol. Next, it was dried and purified to obtain a purified powder. The prepared PVC powder and 1 g of PVC-TBC, PVC-PDMS, PVC-TBT, and PVC-Oleic powder were mixed and completely dissolved in 10 ml of THF solvent. Next, DBA (Sigma-Aldrich, CAS: 105-99-7) was prepared as a plasticizer, mixed with the above solution, and stirred for 4 hours at 400 rpm with a stirrer. Next, the mixed solution was poured into a glass dish and stored at room temperature for 3 days to remove the solvent. The gelled mixed solution was put into a vacuum oven and treated for 24 hours to remove the solvent, thereby preparing a lens unit using a composition for a variable focus lens.

In the above production example, at least one of PVC, TBC, TBT, PDMS, and Oleic acid was internally plasticized, and the comparative examples and examples were classified as shown in Table 1 according to the contents of PVC and DBA. Comparative examples use PVC, and examples use PVC internally plasticized with the materials listed in the table below.

classification PVC or internally plasticized PVC content (g) Types of internal plasticizing materials DBA content (g) Comparison example 1 One doesn't exist 9 Example 1 One Tributyl citrate (TBC) 9 Example 2 One Polydimethylsiloxane (PDMS) 9 Example 3 One Tributyltin (TBT) 9 Example 4 One Oleic acid 9

Tensile strength measurement experiment

Examples and Comparative Examples were manufactured as dumbbell-shaped specimens and performed according to the ASTM D638 test method using a general-purpose tester (Tinius Olsen, H5KT). Table 2 shows the tensile strength measurement results. Referring to Table 2, it can be seen that the tensile strength is different depending on the type of internally plasticized material, and in particular, it can be seen that polydimethylsiloxane (PDMS) has a high tensile strength.

classification PVC or internally plasticized PVC content (g) Types of internal plasticizing materials DBA content (g) tensile strength
(kPa) Comparison example 1 One doesn't exist 9 322 Example 1 One Tributyl citrate (TBC) 9 255 Example 2 One Polydimethylsiloxane (PDMS) 9 634 Example 3 One Tributyltin (TBT) 9 225 Example 4 One Oleic acid 9 250

Elongation measurement experiment

Examples and Comparative Examples were manufactured as dumbbell-shaped specimens and performed according to the ASTM D638 test method using a general-purpose tester (Tinius Olsen, H5KT). Table 3 shows the elongation measurement results. Referring to Table 3, it can be seen that in the case of tributyl citrate (TBC), tributyltin (TBT) and oleic acid, the elongation is excellent compared to the comparative example.

classification PVC or internally plasticized PVC content (g) Types of internal plasticizing materials DBA content (g) elongation
(%) Comparison example 1 One doesn't exist 9 400 Example 1 One Tributyl citrate (TBC) 9 455 Example 2 One Polydimethylsiloxane (PDMS) 9 235 Example 3 One Tributyltin (TBT) 9 527 Example 4 One Oleic acid 9 505

light transmittance experiment

Using the lens parts of Examples and Comparative Examples as samples, it was performed using a UV-vis spectrophotometer (HP 8452, HP, USA). Table 4 below shows the results of light transmittance analysis under the condition of 550 nm. Referring to Table 4, it can be seen that except for the case of oleic acid, high light transmittance is exhibited.

classification PVC or internally plasticized PVC content (g) Types of internal plasticizing materials DBA content (g) light transmittance
(%) Comparison example 1 One doesn't exist 9 92 Example 1 One Tributyl citrate (TBC) 9 92 Example 2 One Polydimethylsiloxane (PDMS) 9 92 Example 3 One Tributyltin (TBT) 9 92 Example 4 One Oleic acid 9 78

Relative permittivity experiments

The relative permittivity was measured at a frequency of 1 Hz with a signal amplitude of 2 V at room temperature. Table 5 below shows the relative permittivity analysis results. Referring to Table 5, it can be seen that the relative dielectric constants of tributyl citrate (TBC) and tributyltin (TBT) are very high.

classification PVC or internally plasticized PVC content (g) Types of internal plasticizing materials DBA content (g) Relative permittivity (@ 1 Hz) Comparison example 1 One doesn't exist 9 11505 Example 1 One Tributyl citrate (TBC) 9 15455 Example 2 One Polydimethylsiloxane (PDMS) 9 9705 Example 3 One Tributyltin (TBT) 9 23255 Example 4 One Oleic acid 9 8425

Referring to the above experimental results, it can be seen that tributyl citrate (TBC) and tributyltin (TBT) are particularly suitable as variable focus lens compositions because they have excellent elongation, light transmittance and relative permittivity. In addition, since polydimethylsiloxane (PDMS) has excellent tensile strength and oleic acid has excellent elongation, a suitable variable focus lens can be manufactured by selecting an internally plasticized material according to required physical properties.

The present invention is not limited by the above-described embodiments and accompanying drawings, but is intended to be limited by the appended claims. Therefore, various forms of substitution, modification and change will be possible by those skilled in the art within the scope of the technical spirit of the present invention described in the claims, and this also falls within the scope of the present invention. something to do.

100: variable focus lens, 110: lens unit, 120: upper substrate, 130: lower substrate

Claims (6)

PVC internally plasticized with at least one of tributyl citrate (TBC), polydimethylsiloxane (PDMS) and oleic acid; and
Including; plasticizer;
A composition for varifocal lenses. delete According to claim 1,
When the internally plasticized PVC is internally plasticized by at least one of Polydimethylsiloxane (PDMS) and Oleic acid, the molar ratio between PVC and internally plasticized PDMS or Oleic acid is 1:2,
A composition for varifocal lenses. According to claim 1,
The weight ratio of the internally plasticized PVC and plasticizer is 1:8 to 1:10,
A composition for varifocal lenses. According to claim 1,
The plasticizer is DBA (Dibutyl Adipate),
A composition for varifocal lenses.
Comprising the composition for a variable focus lens of claim 1,
varifocal lens.

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