JPS60249103A - Preparation of light divergent synthetic resin body - Google Patents

Abstract

PURPOSE:To obtain easily a distribution of refractive index exhibiting characteristic of concave lens by swelling a polymer previously prior to a reaction of a low molecular compd. with the polymer body. CONSTITUTION:After swelling a cylindrical transparent polymer body having epoxy groups by dipping the polymer body in a swelling liquid which satisfies formula 1 to cause swelling of the polymer to a predetermined volume, a low molecular compd. having epoxy groups and reactivity generating a reaction product having higher refractive index than the polymer is diffused in the polymer to cause the reaction and then dried. In formula 1, V0 is the volume of the polymer body before it is dipped in the swelling liquid; V is the volume of the polymer body after dipping the polymer body in the swelling liquid until the volume of the swollen polymer body reaches almost a constant value, wherein the value of fluctuation of V/V0 (degree of swelling) per 1hr is within a range of + or -5%, and no boundary face accompanying the diffusion of the liquid is recognized by the visual observation in the swollen polymer body so that the swollen polymer seems apparently to be in an equilibrium swelling.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for producing a light-emitting synthetic resin body.

[Prior art]

As a light focusing lens having a convex lens effect, a glass fiber body in which the refractive index is gradually decreased from the central axis toward the surface has already been proposed in Japanese Patent Publication No. 47-816. However, such a converging light transmitter of glass exhibition,
By interdiffusing ions with a large atomic radius existing in the glass and ions with a small atomic radius existing in the molten salt,
Since it is created by ion exchange, it is difficult to create something that has a concave lens effect.

A light-diverging rond having a concave lens effect has a refractive index distribution approximated by the following equation (1), and only some attempts have been made to create it using synthetic resin.

A: Refractive index distribution constant rt<r>: refractive index at a distance of r from the rod center 71-o
: refractive index at the center of the rod τ: distance from the center of the rod Applied Optics (Appl, Op.
t, ) i Volume 9 P, 1127 (1980), JP-A-58-159506 and JP-A-58-163904
By diffusing and polymerizing a high refractive index monomer from the surface of a semi-cured crosslinked polymer rod, as reported in By devising a polymerization method, we can photocopolymerize two or three monomers with different refractive indexes, as reported in Kogaku Vol. 12, No. 6, P, 470 (1983). A method of continuously forming a refractive index distribution from the surface to the inside by doing so is known.

[Purpose of the invention]

The present invention provides a new manufacturing method that is simpler than these known methods and that can relatively easily obtain a light-emitting synthetic resin body having a desired refractive index distribution.

[Structure of the invention]

The gist of the present invention is to immerse a cylindrical transparent polymer containing an epoxy group in a swelling liquid that satisfies formula (1) to swell it to a predetermined volume, and then swell it to a predetermined volume. A method for producing a light-emitting synthetic resin body, which comprises diffusing and reacting a low-molecular compound having a refractive index higher than that of the polymer into the interior of the polymer, and then drying the polymer. .

1, 1≦−≦3.0 (1) V.

[In the formula, vo is the volume of the polymer before immersion in the swelling liquid, and ■ is the volume of the polymer when it is immersed and swollen in the liquid until the liquid content in the polymer becomes almost constant. show. ]

The volume (V) of the polymer at which the liquid content within the polymer becomes almost constant is the circle after immersion + swelling degree (Nρ) of the columnar polymer within a fluctuation range of 5% per hour. The term refers to the volume of a swollen polymer when visually observed in a state in which there is no boundary surface due to liquid diffusion, resulting in equilibrium swelling.

By pre-swelling the polymer before reacting it with the low-molecular-weight compound as described above, it has become possible to easily create a refractive index distribution that exhibits concave lens characteristics. The swelling degree is closely related to the type of low-molecular compound to be reacted in the next step, especially the molecular size. There is a need to.

If a cylindrical transparent polymer containing an epoxy group is immersed in a swelling liquid, the swelling degree (-7-o) value is 1.
．． If it is smaller than 1, in the next step, when immersed in a dilute solution containing a low-molecular compound that is reactive with epoxy groups and has a lower refractive index than the polymer, the If the diffusion rate of the molecular compound becomes too low, the productivity will drop significantly. It becomes difficult to form a refractive index distribution that changes.

On the other hand, the transparent weight value of a columnar shape containing an epoxy group is 3.
If it is larger than 0, the degree of swelling is too thick (so that when the polymer is dried after forming the refractive index distribution, stretching unevenness may occur due to its own weight).

Surface wrinkles may occur due to shrinkage, and depending on the conditions, the polymer may whiten or crack. Therefore,
When a polymer is swollen by immersing it in a liquid, the degree of swelling is (
1) It is necessary to set the range to satisfy the formula.

Specific examples of the transparent polymer containing an epoxy group used in the present invention include glycidyl acrylate, glycidyl methacrylate, β-methylglycidyl acrylate,
At least one monomer of β-methylglycidyl methacrylate and one other monomer such as methyl methacrylate, ethyl methacrylate, flobyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, styrene, α- Copolymers with methylstyrene/, trifluoroethyl methacrylate, hexafluoroinflovir methacrylate, penta7A/oroflovir methacrylate, ethylene glycol dimethacrylate, pentaerythritol diacrylate, trimethylolpropane triacrylate, or glycidyl methacrylate, β - Homopolymers of methylglycidyl methacrylate. Among these, polymers containing β-methylglycidyl methacrylate as a main component have relatively good thermal stability of the epoxy group, high transparency, and relatively high second-order transition point (approximately 75°C). ), it is the most preferable.

The amount of epoxy groups contained in the polymer is not particularly limited, but is related to the difference in refractive index between the surface and center of the polymer, and is related to light divergence. Therefore, the lens has a small root divergence in which the proportion of the epoxy group-containing monomer contained in the polymer is small.

The cylindrical transparent polymer containing epoxy groups used in the present invention is produced by a bulk polymerization method. The method for shaping into a cylinder is to place a mixture of a monomer or a partially polymerized product and a polymerization initiator in a cylindrical container whose inner diameter is as uniform as possible and whose roundness is maintained. Cut resin plates produced by pouring the resin and polymerizing with heat or heat, or by casting polymerization using two tempered glass plates.
An example is a method of machining into a cylindrical shape. For cylindrical containers, we use polypropylene Vl, a glass tube with good peelability! ! Alternatively, a cylindrical tube made of polyethylene, a cylindrical tube made of polytetrafluoroethylene, etc. are preferable. The inner diameter of the cylindrical tube is approximately 0.5 to 1 (about 1+g), which is suitable for the cylindrical transparent polymer used in the present invention. Nitrile, benzoyl peroxide,
Examples include lauryl peroxide and the like, and photopolymerization initiators such as benzene/alkyl ether. Two or more of these polymerization initiators may be used in combination. In addition, when producing a cylindrical transparent polymer, one way to minimize the number of bubbles generated in the polymer is to use a partially polymerized product and change the polymerization temperature over time under pressure. The polymerization conditions must be appropriately selected depending on the type and size of the cylindrical tube used.

Specific examples of the liquid used for swelling (epoxy group-containing polymer used in the present invention) include methanol, ethanol, furopanol, ethylene glycol, ethylene glycol diethyl ether, propylene glycol dimethyl ether and their solvents, methyl acetate, acetic acid. Examples include, but are not limited to, ethyl, methyl ethyl ketone, menal, aninol, ethylene glycol dimethyl ether, and other mixed solvents with toethyl ether, inflovir ether, butyl ether, and the like.

Specific examples of low-molecular compounds that are reactive with the epoxy group used in the present invention and give a higher refractive index than the polymer before reaction include those of the following chemical formulas IJ, HCCOOH... ■ CJ, CC0OH... ■ Br CH, C0OH== ■ r CH, CHCOOH... ■ 1 0 C(J, CHO (chloral)... @ is As an example, any compound may be used as long as it has addition reactivity with an epoxy group and increases the refractive index of the polymer upon reaction (1, but is not limited to these).

The reaction between the cylindrical transparent polymer containing epoxy groups in a swollen state satisfying the formula (1) and the low molecular compound can be carried out by immersing the swollen polymer in a solution containing the low molecular compound. It is done.

Specific examples of liquids used as solvents for low-molecular compounds at this time include anisole, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, furopyre/glycol dimethyl ether, and mixtures of these with ethyl ether, inflovir ether, butyl ether, etc. are given as preferred examples, but the invention is not limited to these.

After disposing a low-molecular-weight compound that is reactive with epoxy groups with a continuous concentration gradient from the surface of the cylindrical polymer toward the center, when taking the polymer out of the reaction tank and drying it, it is necessary to A preferred method is to carry out two-stage drying in which the polymer is pre-dried at a temperature not exceeding the boiling point of the solvent plus 10°C, and then dried at a temperature in the range of 120 to 150°C until almost no diluent remains in the polymer. The reason for this is that air bubbles may be generated in the polymer due to rapid heating at high temperatures.

If the solvent used in the reaction solution is a mixed solvent system, the rondo may turn white during drying.

In such a case, prior to drying, it is preferable to immerse the polymer rondo in a -supporting low boiling point solvent after reaction, replace the solvent, and then dry. At this time, methanol can be used as an example of a suitable substitution solvent.

The light-emitting synthetic resin body thus formed is cut into various lengths and the cut surfaces are polished before use.

The light-diffusing synthetic resin body according to the present invention can be easily made to exhibit various light-diffusing properties by simply changing its length.
By using it in combination with a Rondo lens that has convex lens performance, it is expected that it will find a wide range of uses as a micro-optic device.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

In addition, the production R of the transparent polymer, the degree of swelling, and the evaluation of light-diffusion performance were performed as follows.

(1) Creation of a cylindrical transparent polymer containing epoxy groups A polymerization stock solution having the composition shown in Table 1 was poured into a polytetrafluoroethylene tube with an inner diameter of 3 fins, a thickness of 1lllls, and a length of 30 cWL. The first stage polymerization was carried out in a constant temperature water bath at 70°C, and the second stage polymerization was carried out in a 120°C air heating furnace under the conditions shown in Table 1.
= b was obtained.

Table 1 (2) Evaluation of degree of swelling of cylindrical transparent polymer The degree of swelling is -
A cylindrical polymer is immersed in a glass container made of polished glass with opposing glass surfaces parallel to each other, and the outer diameter (To) of the polymer before swelling is measured using a cassette meter pointing perpendicular to the polished glass surface. , length 10) and the outer diameter (r) of the polymer after swelling, length 1), and calculated from the following formula.

v r”z vo: Volume of polymer before swelling V6 r6
After (3) Measuring the refractive index distribution The refractive index distribution of the light-diverging synthetic resin body is determined by immersing the created rondo in a liquid that exhibits almost the same refractive index as the rond surface.
Abraibio 1f 42f vol. 19 p. 286 (1980)
The measurement was performed using a measurement method similar to that described in .

〔Example〕

Example 1 Cylindrical transparent polymer a was mixed with ethylene glycol dimethyl ether at 65°C for 50 minutes. parts, and Improvil ether 5
13 hours, 14 hours and 1 part by weight in a swelling solution consisting of 0 parts by weight.
The degree of swelling was measured after 5 hours of immersion and was found to be 1.43.1.
44 and 1.45, which were almost constant. The sample immersed for 15 hours was immediately subjected to a reaction at 65°C consisting of 60 parts by weight of ethylene glycol dimethyl ether, 40 parts by weight of inpropyl ether, and 4 parts by weight of trichloroacetic acid. After being immersed in the solution and reacted for 6 hours, it was placed at room temperature. Transfer to methanol,
Solvent replacement was performed for 1 hour.

This sample was further dried in a vacuum dryer at 75°C for 24 hours [1
It was dried at 20° C. for 24 hours to produce a light-emitting synthetic resin body. As shown in FIG. 1, the refractive index of this sample showed a continuous change that could be approximated by a quadratic curve from the center to the periphery of the rond, and had excellent concave lens performance.

Example 2 A cylindrical transparent polymer was immersed in a swelling liquid consisting of 50 parts by weight of ethylene glycol dimethyl ether and 50 parts by weight of Improvil ether at 65°C for 13 hours, 14 hours, and 15 hours, and the degree of swelling was measured. 1,43.1.44
and remained almost constant at 1.45. Immediately soak the sample for 15 hours in ethylene glycol dimethyl ether 60
parts by weight, 40 parts by weight of Improvil ether, and 10 parts by weight of phthalic anhydride.
After reacting for an hour, the mixture was transferred to methanol at room temperature and the solvent was replaced for 1 hour. This sample was dried in a vacuum dryer at 75°C for 24 hours.
It was further dried at 120° C. for 24 hours to produce a light-emitting synthetic resin body. The refractive index distribution of this sample is shown in FIG. As shown in the figure, there was a continuous change that could be approximated by a quadratic curve from the center to the periphery of the sample, and it had excellent concave lens performance.

Comparative Example 1 Cylindrical transparent polymer a was immersed for 5 hours in a mixed solution at 60° C. consisting of 50 parts by weight of methanol and 50 parts by weight of ethyl acetate. The degree of swelling at this time was 3.5. This swollen Rondo was immersed in a reaction solution consisting of 60 parts of ethylene glycol dimethyl ether, 40 parts of Improvil ether, and 4 parts by weight of trichloroacetic acid at 65°C, reacted for 6 hours, and then transferred to methanol at room temperature. ,1
Time solvent replacement was performed. This sample was dried under reduced pressure at 75°C.
When dried for 12 hours, cracks appeared.

Comparative Example 2 Cylindrical transparent polymer a was immersed in Improvil ether at 50°C for 72 hours. The degree of swelling at this time was 1.04. After soaking, this polymer was mixed with 60 parts by weight of ethylene glycol dimethyl ether, 40 parts by weight of Improvil ether, and 4 parts by weight of trichloroacetic acid at 65°C. The sample was immersed in a reaction solution of iE quantity pro and reacted for 6 hours, then transferred to methanol at room temperature and subjected to solvent replacement for 1 hour. This sample was dried in a vacuum dryer at 75°C for 12 hours and then at 120°C for 24 hours. The refractive index distribution of this sample was so gradual that it could not be measured, and when it was cut into a length of 3 CWL, both end faces were polished to a mirror finish, and the image was observed through the polished surface, no concave/zip performance was observed.

〔Effect of the invention〕

As shown in the Examples, the manufacturing method of the present invention can manufacture a light-diverging synthetic resin body having concave lens performance through a simple process.

[Brief explanation of drawings]

FIGS. 1 and 2 are graphs showing the refractive index distributions of Example 1: F+5 and Example 20-element divergent synthetic resin bodies, respectively. Talent? ] 0 0.5 t, 0 /, 5 2. .

Claims (1)

[Claims] After a cylindrical transparent polymer containing an epoxy group is immersed in a swelling liquid that satisfies formula (1) and swelled to a predetermined volume, the polymer has a reactivity with the epoxy group. , and a method for producing a light-emitting synthetic resin body, which comprises diffusing and reacting a low-molecular compound that reacts to produce a polymer having a higher refractive index than the polymer, and then drying the polymer. . [where vo is the volume of the polymer before immersion in the swelling liquid,
(2) indicates the volume of the polymer when it is immersed in the liquid and swelled until the liquid content in the polymer becomes approximately constant. ]