JPS5898316A - Production of plastic lens material - Google Patents

Abstract

PURPOSE:To improve the yield of gradient index plastic lenses, by detecting angles of rays which pass into one end of a matrix material and pass out of the other end and stopping diffusion of a low-MW organic fluid into the prepolymer. CONSTITUTION:A material is prepared by prepolymerizing diallyl isophthalate as a high-refractive index material in a polypropylene pipe to form a cylinder and finishing the cylinder so as to have parallel ends. The produced prepolymer 3 is placed in a tank 2 in which a methacrylic acid monomer 4 as a low-refractive index material is contained. The incident angle theta1' of laser beams and the light-receiving angle theta2' of a laser beam-receiving device 5 are set so that a predetermined relationship is established between the both. Then, a monomer 4 is poured into the tank 2 and heated. When a refractive index gradient is formed within the prepolymer cylinder and the exiting light coincides with the angle theta2' of the light-receiving device 5, an electrical signal is produced by the light-receiving device 5, a valve 7 is opened by the operation of a controller 9 and the monomer 4 is discharged from the tank 2. Next, the cylindrical prepolymer 3 into which the monomer 4 has been diffused is heated to polymerize it into a plastic lens material.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a refractive index type glass lens.

The gradient index lens material is manufactured by immersing and heating a prepolymer obtained by prepolymerizing a base material into a cylindrical shape in a low molecular weight VR machine mud fluid having a different refractive index from that of the prepolymer. Ru.

More specifically, conditions such as the concentration and temperature of the low-molecular-weight organic fluid are controlled so that the low-molecular-weight organic fluid (in many cases monomers are used) diffuses appropriately into the base material. After the diffusion operation for a predetermined period of time, the base material was taken out, and the mineral mat was fixed in place using a 1.5 inch scale to obtain a refractive index gradient lens material.

In the conventional technology explained above, even if the above-mentioned conditions are controlled, the diffusion rate changes slightly to Kf, so it is difficult and rare to know when the diffusion has finished, resulting in poor product yield and poor performance (refractive index distribution). It had the drawback of varying degrees of variation.

The present invention aims to provide a manufacturing method that eliminates the drawbacks of the prior art described above and improves the manufacturing process of a gradient index plastic lens.

The refractive index distribution obtained by the diffusion method is a parabolic distribution (expressed by equation 11).

n y) -no (1'r!/2)...
...... The path of the ray of light is expressed by equation (2), and the ray of light that enters the skeleton cylinder is located at the 111 K point 8 corner of the end face where it entered, and the ray of light that exits at the other end exits just before the exit. Angle with end face -2
is shown in equation (3).

rg = r&cm (ynZ) + (1/iA)
m elda (y”Z) ・=(21℃m't --
1/A”i gin (JA Z) +tm #1a
s (lA Z ) ·-·=”-(5) θ, the incident angle −;, −2, and the exit angle #; are each related to each other by Snell's law.

In order to achieve the above objective, the position and angle of the incident light beam are determined using the above relationship so that the concentration gradient caused by the diffusion of the low molecular weight organic fluid into the prepolymer becomes a predetermined refractive index distribution. Then, the position and angle of the emitted light were detected, and the diffusion was stopped when the position and angle of the emitted light reached a preset value.

An example of the manufacturing method according to the present invention is shown in the figure.

1 is a laser beam generator, 2 is a cypress that stores a low molecular weight organic fluid (mostly monomer), 5 is a prepolymer, 4 is a low molecular weight organic fluid (mostly monomer), 5 is a laser beam receiver, 6 is a 7 is a discharge valve, 8 is a discharge valve control device, 9 is a drain port, 10 is a heater, 11 is an incident light beam,
12 is an emitted light beam.

Next, the manufacturing process of the gradient index lens material according to the present invention will be explained.

In advance, diallyl inphthalate as a high refractive index material was placed in a polypropylene pipe in a cylindrical shape with a diameter of 4 mm at 80°C.
The prepolymer 5 was prepolymerized for 120 minutes and finished with a length of 100 mm and both ends parallel to each other, and the prepolymer 5 was placed in a cypress 2 containing methyl methacrylate monomer as a low refractive index material.

Isophthalic acid diallylp ν polymer and methyl methacrylate monomer at 80℃ I! Since the refractive index distribution constant A when diffusing at If is required to be 0.2, the laser beam is set at 11- in the radial direction from the central axis of the prepolymer at 0.2. The position of the emitted light when it enters at an angle of t fg is ~
When looking for the relationship, 7621g tMIel knee-
1, therefore, the incident angle e' of the laser beam, the receiving angle θ of the laser beam receiving @ts are set so as to establish this relationship.

Then, inject 4 methyl methacrylate monomers into 2 hinoki cypresses,
Heat to 80°C. After several minutes to 20 minutes have elapsed, when a refractive index distribution occurs within the ruborima cylinder and the emitted light matches the angle θ of the received light @ms, the light receiving device generates an electrical signal and the monomer discharge valve control device @9 is activated. Once activated, the monomer discharge valve 7 is opened and the monomer 4 is discharged to the outside of the tank 2. After that, the cylindrical prepolymer 3 in which the monomer 4 was diffused was heated to 80°C.
A plastic lens material was obtained by heating and polymerizing for 0 hours.

According to the present invention, by closely monitoring the diffusion status of the monomer 4 in the prepolymer 3, it is possible to manufacture a gradient index lens material with good stability.

[Brief explanation of drawings]

The figures are diagrams showing examples of the present invention. 1...Laser beam generator 5... Light receiving device 6...Sealing material 8...Valve operation controller

Claims (1)

[Claims] t A base material having a cylindrical shape of a prepolymer made of a high refractive index material is immersed in a low molecular weight organic fluid liquid having a lower refractive index than the base material, and the low molecular weight organic fluid has a high refractive index. Diffused into the Luborima base material and perpendicular to the axis of the cylinder
A method of manufacturing a graded index plastic lens material that produces a refractive index gradient in a certain direction is based on a method of manufacturing a gradient index plastic lens material that produces a refractive index gradient in a certain direction. A plastic lens characterized in that it detects the angle of a ray of light that enters at one end and exits from the other end with respect to the end face of a base material, and inserts low molecules into a high refractive index prepolymer base material to stop the diffusion of an organic fluid. Method of manufacturing materials.