JPS6363004A - Optical component manufacturing method and equipment - Google Patents

Abstract

PURPOSE:To obtain optical parts having the homogeneous and good quality by understanding a proceeding state of a hardening reaction from a varied state of the intensity of a scattered light, and controlling a reaction condition by executing a feedback, with respect to a format of an optical fiber made of a thermosetting resin. CONSTITUTION:A light beam from an He-Ne laser 1 is divided into two in a prescribed ratio by a beam splitter 2, passes through choppers 3, 3' and lenses 4 and 4' and made incident on light sending fibers 5, 5'. Subsequently, said light beam is condensed by lenses 6, 6', radiated to an optical resin material 8 in a polymerization tube 7, a scattered light from a sample placed at a prescribed angle with a radiated light is made incident on a photodetecting fiber 10 by a lens 9, detected by a photodetector 12, the scattered light intensity is measured by a photon counting method, and the sum and difference of the scattered light intensity from two incident beams are derived by a signal processing system 13, and displayed. In this way, by controlling a flow velocity and a polymerization temperature of the resin, optical parts having the homogeneous and good quality can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides an optical component that controls the reaction by optically measuring the progress of the reaction in the manufacturing process of an optical component made of a thermosetting resin. In particular, it relates to an optical fiber manufacturing method and its apparatus.

[Conventional technology]

Light scattering methods have traditionally been used to measure the turbidity of solutions and the amount of dust in the atmosphere. As an example of application to capturing polymerization reactions, as described in JP-A-56-20001 Kita, light from a light source is guided into a polymerization tank through an optical fiber, and scattered light is received by an optical fiber. The idea was to measure the intensity and detect changes in scattered light from the polymer generated at the start of the polymerization reaction to detect the start of a reaction such as emulsion polymerization.

[Problem that the invention seeks to solve]

The above-mentioned conventional techniques that detect the starting point of the polymerization reaction do not give sufficient consideration to in-tube polymerization. That is, sufficient scattered light intensity cannot be obtained. Further, the above method is for detecting the starting point of the polymerization reaction, and no consideration is given to understanding the progress of the reaction.

The purpose of the present invention is to develop the conventional method as described above, and to control the reaction by measuring the progress of the reaction non-destructively and without contacting the resin in the process of manufacturing optical parts made of thermosetting resin. An object of the present invention is to provide a method for manufacturing optical components and an apparatus therefor.

Means for Solving Problems c] To summarize the present invention, the first invention of the present invention is an invention related to a method for manufacturing an optical component, and in the method for manufacturing an optical component made of a thermosetting resin, It is characterized by obtaining an optical component that is homogeneous and has good properties by understanding the progress of the curing reaction from changes in the intensity of scattered light and controlling the reaction conditions using feedback.

Further, a second invention of the present invention is an invention relating to an optical component manufacturing device, and the device for manufacturing an optical component made of thermosetting resin includes a laser light source, a beam splitter that divides the light beam, and a beam splitter that guides the light beam. Includes the following equipment: a lens and optical fiber system, a polymerization reaction container for resin materials, a light receiving element for scattered light from the container, an electric circuit system for signal processing, and a control system for polymerization reaction conditions based on feedback signals. It is characterized by the fact that

Specifically, the above object can be achieved as follows.

Efficiently illuminate the resin in the polymerization reaction vessel? For irradiation, the light emitted from the light transmission fiber is focused by a lens on one point within the polymerization reaction vessel. Further, the beam is divided into a plurality of beams, for example, two beams, and the beams are made to enter the polymerization reaction vessel from different directions, and the scattered light intensity of each beam and their angular dependence are measured.

In order to understand the state of the polymerization reaction, changes in measured values as the polymerization reaction progresses are measured in advance and correlated with molecular weight, viscosity, etc.

By condensing the incident light with a lens, the light intensity within the container is increased and sufficient scattered light intensity is obtained. Since the angular dependence of scattered light is measured, the influence of scattered light from sources other than optical components can be greatly reduced, making highly reliable measurements possible.

At the beginning of the polymerization reaction, polymer particles appear in the monomer liquid. In the monomer state, there is no angular dependence in scattering from the solution, but as the reaction begins, angular dependence occurs.
Furthermore, the intensity of scattered light increases significantly. Further, as the reaction progresses, the entire resin becomes uniform and the scattered light intensity decreases slightly. By understanding this change, it is possible to understand the progress of the polymerization reaction.

Furthermore, the loss due to light scattering, which is a characteristic of the manufactured optical component, can be estimated from the numerical light intensity after the resin is cured. In an optical fiber, transmission loss consists of absorption loss and scattering loss, of which scattering loss can be estimated. By feeding back this information and controlling the flow rate and polymerization temperature of the resin, it was possible to manufacture a good and homogeneous optical component.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these implementation projects.

Fig. 1 is a schematic diagram of an example of the device of the present invention, and Fig. 2 is a schematic diagram of an example of the device of the present invention.
FIG. 3 is an enlarged cross-sectional view of the measurement portion of the apparatus shown in FIG. 1, and FIG. 3 is a graph showing temporal changes in scattered light intensity during the polymerization process of an optical resin material.

Embodiment 1 One embodiment of the present invention will be described with reference to FIG. This is an example of manufacturing an optical fiber made of thermosetting resin.

In FIG. 1, 1 is a He-No laser, 2 is a beam splitter, 3 and 3' are choppers %4.4',
6.6' and 9 are lenses, 5 and 5' are light transmitting fibers,
7 is a polymer tube, 8 is an optical resin material, 10 is a light receiving fiber,
12 means a light receiving element, and 15 means a signal processing system.

The light from the Ee-Ne laser 1 is split into two at a constant ratio by a beam splitter 2, passes through choppers 3 and 3', lenses 4 and 4', and is sent to light transmission fibers 5 and 5.
′. The light from the light transmission fibers 5 and 5' is focused by lenses 6 and 6', and is irradiated onto the optical resin material 8 in the polymer tube 7. Scattered light from the sample forming a predetermined angle with the irradiated light enters the light receiving fiber 10 through the lens 9. Here, the two incident beams irradiate the resin at different angles with respect to the light receiving fiber 10. Further, the choppers 3 and 3' irradiate the resin with the incident beams alternately. The scattered light passes through the aforementioned light receiving fiber 10 and is detected by the light receiving element 12, and the intensity of the scattered light is measured by a photon counting method. The signal processing system 13 calculates and displays the sum and difference of the scattered light intensities from the two incident beams.

As shown in FIG. 2, the measuring section is covered with a dark box 11, and the aforementioned light transmitting fibers 5 and 5', lenses 6, 6' and 9, polymer tube 7, and light receiving fiber 10 are fixed, and the optical axis is At the same time, the external light kR is cut off to increase the signal-to-noise ratio.

In addition, we measured in advance the changes in the sum and difference of scattered light intensity as the reaction progressed, and determined the molecular weight using various analytical methods.
Correlation with viscosity, etc.? I'll go.

Furthermore, the intensity of scattered light from the resin inside the tube? , normalized to correspond to the measurements described above. Through the above procedure, it was possible to determine the degree of polymerization from the intensity of light scattered by the resin inside the tube.

Time change in measured scattered light intensity? , the angle 1fθ is shown in Figure 3.
1. The relationship between the sum of the scattered light intensities by the two incident beams of θ snow (logarithmically represented, vertical axis, solid line) and the difference between the two (vertical axis, broken line), and time (horizontal axis) is shown as a graph. At the time point (■) in FIG. 3, it becomes semi-gel-like, so it is extruded from the polymerization tube at this time.

By using Figure 3 and normalization constants that represent the attenuation and scattering of light in the polymerization tube, we can grasp the reaction progress inside the tube, feed this back, and control the resin flow rate and polymerization temperature. 9. It is possible to manufacture optical components with homogeneous and good properties.

〔Effect of the invention〕

According to the present invention, it is possible to completely reduce the influence of scattered light from sources other than the optical components, such as dust particles on the circumferential recess of the polymerization reaction vessel, making it possible to perform reliable measurements with high precision.

Furthermore, since the progress of the curing reaction can be measured, monitoring the quality of the optical component during the manufacturing process has the remarkable effect of producing high-quality optical components.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an example of the device of the present invention, Fig. 2 is an enlarged sectional view of the measurement part of the apparatus shown in Fig. 1, and Fig. 3 shows the temporal change in scattered light intensity during the polymerization process of an optical resin material. This is a graph showing.

Claims (1)

[Claims] 1. In a method for manufacturing optical components made of thermosetting resin, the progress of the curing reaction is grasped from the change in the intensity of scattered light, and feedback is provided to control the reaction conditions. A method for producing an optical component, characterized by obtaining an optical component having homogeneous and good properties. 2. The method for manufacturing an optical component according to claim 1, wherein the optical component is an optical fiber. 3. The equipment for manufacturing optical parts made of thermosetting resin includes a laser light source, a beam splitter that separates the light beam, a lens and optical fiber system that guides the light beam, a polymerization reaction container for resin material, and scattered light from the container. 1. An optical component manufacturing apparatus comprising a light receiving element, an electric circuit system for signal processing, and a control system for controlling polymerization reaction conditions based on a feedback signal. 4. Claim 3, wherein the polymerization reaction vessel is a thin tube.
An apparatus for manufacturing optical components as described in Section 1. 5. The device has equipment for dividing an incident laser beam into a plurality of beams, making them incident on the resin material at different angles, and measuring the angular dependence of the scattered light. 4. The optical component manufacturing apparatus according to item 4. 6. The optical component manufacturing apparatus according to claim 5, wherein the incident beam is divided into two beams.