JP3320773B2 - Heat polymerization method for molded composite optical parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heat-polymerizing a molded composite optical component in which a synthetic resin layer made of a thermosetting resin is adhered to a glass substrate.

[0002]

2. Description of the Related Art A composite optical component formed of a glass substrate and a synthetic resin layer, for example, a composite aspherical lens, is obtained by dropping a weighed resin material onto a pre-processed glass substrate. Then, the resin material is stretched by a mold, polymerized, and bonded to a glass substrate.

As a resin material, a thermosetting resin, an ultraviolet curing resin, or the like is used, but the ultraviolet curing resin has the following problems. The composite aspherical lens is obtained by attaching and molding an aspherical synthetic resin layer on a spherical glass. Therefore, if the amount of aspherical surface is increased, the difference in resin thickness between the central portion and the peripheral portion of the lens necessarily increases. However, ultraviolet curable resins are resins that polymerize and cure when irradiated with ultraviolet light, so there is a limit to the thickness due to the problem of absorption of ultraviolet light. The speed is different, and as a result, curing distortion occurs, and the performance as a lens deteriorates. Specifically, the maximum thickness is, for example, about 0.33 mm, the difference in thickness is 0.20 mm maximum
The fact is that it is restricted before and after. For this reason, the effect of using an aspherical lens such as a photographic lens which requires a large aperture and high performance is limited. In addition, the ultraviolet curable resin tends to yellow as a result of absorbing ultraviolet light, and has a problem in color reproducibility as a photographic lens.

[0004] On the other hand, thermosetting resins have attracted attention recently because they do not have the above problems of ultraviolet-curing resins. When this thermosetting resin is polymerized on a glass lens, no optical distortion remains inside, no residual stress occurs inside, high processing accuracy (surface accuracy), curing speed ( (Polymerization rate), that is, good processability, and the like. In particular, the resin material layer of the composite aspherical lens is 1/100 m
Since the thickness is as thin as m to several mm, special heating conditions different from the general heating conditions for thermosetting resins are required.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for heat polymerization of a molded composite optical component formed by polymerizing a thermosetting resin on a glass substrate and providing polymerization conditions satisfying the above requirements. I do.

[0006]

According to the heat polymerization method of the present invention, a thermosetting resin monomer is interposed between a glass substrate and a mold, and the mold is heated to adhere and mold the polymer on the glass substrate. In the heat polymerization method for molded optical parts, the mold is kept at room temperature.
Heating at an initial heating rate of 90 to 110 ° C./5 minutes,
During the initial heating rate to reach 100-110 ° C
The above monomer is preliminarily cured , and then the mold temperature is set to 100 to
It is characterized by maintaining the temperature at 110 ° C. to complete the polymerization of the monomer .

[0007] The present invention provides an initial heating rate of 90 to 110 ° C.
The first characteristic is that the time is set to / 5 minutes. If the initial heating rate exceeds 110 ° C./5 minutes, that is, if the heating rate is higher than the above range, the polymerization reaction runs away, causing problems such as foaming of the resin material, remaining internal strain, and deterioration of surface accuracy. . If the initial heating rate is lower than 90 ° C./5 minutes, the workability is poor. By this initial heating, the monomer is temporarily cured. Temporary curing refers to a state in which the lens and the mold are joined via a resin material, and the two do not separate unless an external force is applied. The resin material in the temporarily cured state has a high viscosity, and the center is already cured.

Next, in the present invention, after the mold reaches 90 to 110 ° C. by the initial heating, the temperature is maintained to complete the polymerization. By this temperature holding step, the resin material temporarily cured in the initial heating step is cured with good shape accuracy without internal distortion.

The thickness of the polymer interposed between the glass substrate and the mold is preferably 1/100 mm to several mm.
The method of the present invention can be applied to optical components other than the composite aspherical lens, but when applied to a composite aspherical lens, the glass base material is a spherical glass lens, and the thickness of the spherical glass lens is A polymer layer consisting of a non-uniform aspherical layer is formed.

As the thermosetting resin, an epoxy resin is preferable. As the epoxy resin, bisphenol A
And epoxy resins such as bisphenol AD type and bisphenol F type. These epoxy resins are cured with acid anhydride, amine or other curing agents.

[0011] The thermosetting resin can provide sufficient adhesion even when formed directly on a glass substrate without interposing a silane coupling agent layer or the like as an intermediate layer.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
The illustrated example shows a process of forming a compound aspherical lens.
A thermosetting resin material 12 weighed in advance according to the amount of aspherical surface is dropped on a glass spherical lens 11 which has been processed into a predetermined spherical surface in advance. Next, the resin material 12 is thinly spread on the glass lens 11 by bringing the mold 14 having the aspheric surface 13 closer to the resin material 12 by a predetermined distance. When the resin material 12 is heated by heating the mold 14 in this state, the polymerization of the monomer proceeds, and the thermosetting resin material 12 having the shape of the aspheric surface 13 transferred thereto is joined on the glass lens 11 to form a composite. An aspheric lens 15 is obtained. A release agent is applied to the surface of the aspherical surface 13 of the mold 14 in advance.

According to the present invention, in the method for heating and polymerizing the composite aspherical lens 15 formed as described above, in order to polymerize and cure the thermosetting resin material 12, as a first step, the mold 14 is heated at an initial heating rate. Temporarily cure by heating at 90 to 110 ° C./5 minutes, and as a second step, mold 14
Is maintained at 100 to 110 ° C. to complete the polymerization.

FIG. 2 is a graph showing a heating rate and a temperature range in the heat polymerization method according to the present invention. The first area A is an initial heating area, and the second area B is a constant temperature holding area. The hatched area is the area according to the present invention. According to the heating rate and temperature conditions in the hatched areas A and B, no optical distortion remains inside the thermosetting resin thermosetting resin material 12 to be polymerized, and no residual stress is generated inside. It was confirmed that high processing accuracy (surface accuracy) was obtained, the curing speed (polymerization speed) was high, and the processability was excellent.

On the other hand, in the region C deviating from the hatched regions A and B on the upper side, the polymerization reaction runs away, causing problems such as foaming of the thermosetting resin material 12, remaining internal strain, and deterioration of surface accuracy. Occurs. On the other hand, in the region deviated to the lower side, the polymerization reaction is slow and the processability is poor.

The thickness of the thermosetting resin material 12 is 1/100 mm
The thickness can be varied depending on the aspherical amount. In the above embodiment, the present invention is applied to a composite aspherical lens. However, the present invention can be similarly applied to other composite optical elements in which a synthetic resin material is formed on a glass substrate.

Next, preferred compounds as the thermosetting resin material 12 of the present invention are shown. A, the following compounds (X) and (Y) as main ingredients, compound (X), bisphenol A type epoxy resin, and molecular structure are shown below.

[Chemical formula 1] Compound (Y) One or more of the following compounds, and mixtures and mixing ratios thereof, are arbitrary. The molecular structure of diglididyl phthalate diglididyl hexahydrophthalate diglididyl tetrahydrophthalate is shown below.

[Chemical formula 2] This compound (X) and (Y) are 10-90: 90-10
The parts are mixed in parts by weight.

B, The following compound (Z) as a curing agent Compound (Z) One or a mixture of two or more of acid anhydride curing agents represented by the following general formulas:

[Chemical formula 3]

C, benzyldimethylamine as a curing accelerator, and molecular structure are shown below.

[Chemical formula 4] D, phosphate compound

The above materials A, B, C, and D are mixed in the following proportions to obtain a resin material 12. A: 40 to 60 parts by weight B: 60 to 40 parts by weight C: 0 to 5 parts by weight D: 0 to 5 parts by weight

Next, the present invention will be described with reference to Examples and Comparative Examples. "Example 1" Glycidyl ether of bisphenol A and glycidyl ether of oxahydrophthalic acid, and the following chemical formula

[Chemical formula 5] An acid anhydride-based curing agent, benzyldimethylamine as an additive, and the following chemical formula

[Chemical formula 6] The phosphoric acid compounds represented by 50: 50: 55: 1:
The mixture was mixed at a composition of 1.5, and the mixture 12 was interposed between the aspherical mold 14 and the spherical glass lens 11 as shown in FIG. At this time, the formed resin layer 12
Was about 0.1 mm at the outer periphery and about 0.3 mm at the center, and the resin amount was about 0.4 g. The curing process was divided into an initial curing and a post-curing to facilitate control of the polymerization reaction. The temperature rise rate of the initial curing had a constant variation reaching 100 ° C. in 5 minutes, and was maintained for 15 minutes after reaching 100 ° C. After this, it is further post-cured to 12
The temperature was raised to 0 ° C. and maintained for 15 minutes to complete the heating. Thereafter, the composite 15 of the lens and the resin was released from the aspherical mold 14 and the resin surface was observed. As a result, no optical defect was observed, and the lens was sufficient as a photographic objective lens. A release agent was applied to the surface 13 of the aspherical mold 14 in advance.

Example 2 The initial polymerization rate of Example 1 was 5
Example 1 was changed to a temperature gradient of 110 ° C.
The same as above. Observing the molded resin surface,
No optical defects were observed, and it was sufficient as a photographic lens.

Example 3 The initial polymerization rate of Example 1 was 5
The temperature was changed to 90 ° C. in minutes, and the holding time was 20 minutes. Others were the same as Example 1. Observation of the molded resin surface showed no optical defects,
It was enough for a photographic lens.

Comparative Example 1 The initial polymerization rate of Example 1 was changed to a temperature gradient of 80 ° C. in 5 minutes, and the holding time was set to 20 minutes. Others are Example 1.
The same as above. The molded lens had not completed the curing reaction of the resin material, and was unsuitable for use as a lens .

Comparative Example 2 The initial polymerization rate of Example 1 was 5
Example 1 was changed to a temperature gradient of 120 ° C.
The same as above. The resin surface of the molded lens had irregularities due to runaway of the curing reaction, and was unsuitable for use as a lens.

[0026]

As described above, in the present invention, a monomer of a thermosetting resin is interposed between a glass substrate and a mold, and the mold is heated to adhere and mold a polymer on the glass substrate. In the heat polymerization method of the molded optical component, the initial heating rate of the mold and the subsequent constant temperature holding temperature are set in a preferable range, so that the resin material to be polymerized and cured, without optical and mechanical distortion, with high accuracy, Moreover, processing can be performed with good productivity.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a procedure for molding a thermosetting resin material on a glass substrate to which the present invention is applied.

FIG. 2 is a graph showing an initial heating rate and a holding constant temperature range of the polymerization method of the present invention.

[Explanation of symbols]

 11 Glass lens 12 Thermosetting resin material 14 Mold A Initial heating area B Constant temperature holding area

Continuation of the front page (56) References JP-A-62-288140 (JP, A) JP-A-56-144129 (JP, A) JP-A-1-192511 (JP, A) JP-A-59-19918 (JP) , A) JP-A-63-264601 (JP, A) Shunji Uchio, Practical Plastic Lens, Nikkan Kogyo Shimbun, Japan, December 25, 1989, P130, P113-115 (58) Fields investigated (Int. Cl. ^7, DB name) B29C 39 / 10,39 / 38 B29D 11/00 C08F 2/00 C08G 85/00 C03B 11/00 G02B 3/00

Claims (3)

(57) [Claims] 1. A method for heating and polymerizing a molded optical component in which a monomer of a thermosetting resin is interposed between a glass substrate and a mold, and the mold is heated to adhere and mold a polymer onto the glass substrate. The mold is heated from room temperature at an initial heating rate of 90 to 110 ° C./5 minutes, and the monomer is temporarily cured while reaching 100 to 110 ° C. at the initial heating rate. Wherein the polymerization of the monomer is completed while maintaining the temperature of the molded composite optical component. 2. The heat polymerization method according to claim 1, wherein
A heat polymerization method wherein the thickness of the polymer is 1/100 mm to several mm. 3. The heat polymerization method according to claim 1, wherein the glass substrate is a spherical lens, and the polymer is an aspherical layer.