JPS5945490B2 - Molding method of photopolymerized resin - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for molding photopolymerized resin.

Polymerization of liquid resin using light energy has been applied to the polymerization of cinnamate esters using ultraviolet rays, and is currently used in resin plate making, curing of printing ink, and painting.

In these applications, which are widely applied to adhesives and the like, the surface irradiated with light is generally in contact with the air, and therefore the surface of the resin is a free interface formed by the surface tension of the liquid phase. In some cases, a glass plate, plastic film, etc. is brought into contact with the surface of the resin to be irradiated, and light is irradiated through these (plate making, glass plate adhesion, etc.); Since it adheres to the resin, it was necessary to apply a mold release agent such as wax or silicone/liquid to the glass plate etc. for purposes that required mold release. The application of such a mold release agent has the drawback of complicating the process because it must be applied every time the resin is molded and polymerized. The object of the present invention is to provide a molding polymerization method, so-called casting or molding method, for photopolymerizable resins that does not have such drawbacks.

In the method of the present invention, when molding and polymerizing a photopolymerizable resin, the mold itself is made of a material that is transparent and has good mold releasability.
This is a photopolymerization method characterized by charging a photopolymerizable resin into the resin, and molding and polymerizing by exposing the resin to light through a mold.

This greatly facilitates the production of molded articles. The necessary conditions for the mold in the present invention include light having the energy necessary for photopolymerization (for example, a wavelength of 9300 to 400 mμ);
High transparency to VC.

Must be able to be easily released from the mold without adhering to the polymerized resin. and have heat resistance sufficient to withstand the heat generated when the resin polymerizes. Mold materials that satisfy these conditions include:
It has been found that fluororesins such as polyvinylidene 75, ethyl 75/16 fluoropropylene copolymer, methylpenote, polyethylene, polypropylene, and silicone/resin are suitable. . For example, 184W/C silicone resin manufactured by Dowconi/G Co., Ltd. with a thickness of 10 nm can transmit over 80% of light with a wavelength of 030077Lμ and over 90% of light with a wavelength of 400μμ, and Asahi Glass (Co., Ltd. % or more and 80% or more, Mitsui Petrochemical (Tokyo TPX Polio V
The same goes for Fuino. Furthermore, all of these have good mold releasability and are well resistant to heat generated during polymerization. Figure 3 shows “184
W/C" silicone resin, "A70N cop" polyvinyuridene heptadide, "TPX" methylpenteno resin manufactured by Mitsui Petrochemicals, and ordinary inorganic glass as a control. Mitsubishi Rayon's "Acrybet" acrylic resin thickness 10
This is a graph obtained by measuring the light transmittance of an 11 m long plate.

As is clear from the figure, the mold material of the present invention is a material suitable for ultraviolet polymerization. Also. There are no particular restrictions on the resin to be molded that can be used in the method of the present invention. Photocrosslinking type (metal ion crosslinking type, photodimerization type...for example, cinnamon), photodegradation type (polymerization starts with radicals generated by decomposition of diazonium compounds, azide compounds, etc.), and photopolymerization type (photopolymerization type) Resins such as vinyl monomers that are directly polymerized by energy (generally in combination with a polymerization initiator) can be used. In addition, the photosensitive wavelength of these resins is 330 to 490 for the photocrosslinkable type.
mμ, photodegradable type: 220-400 mμ. In addition, it is a photopolymerization type that uses a polymerization initiator and has a diameter of 200 to 400 mμ. A fairly wide range of resins can be photopolymerized, depending on their interaction with the mold material. An example of the invention will now be described with reference to the drawings.

Figure 1 shows how small parts such as light emitting diodes are made by casting.
Indicates the column to be sealed. 1 is a mold having a mold cavity 2 of predetermined shape and dimensions.

First, a predetermined amount of photopolymerizable resin liquid 3 is charged into the mold cavity 2. An electronic component 4 to be sealed, such as a light emitting diode, is placed in a mold cavity 2.
Insert into. As a result, the resin liquid 3 flows around the electronic components and completely fills the mold cavity 2. When this is irradiated with light of a predetermined wavelength as shown by the arrow through mold 1, the resin Wt
3 cures within a few minutes. Then, pull the pin of the electronic component to remove it from the mold cavity. FIG. 2 shows an example in which the method of the present invention is applied to fixing a coil of an electromagnet, etc., in which a spiral coil 7 is inserted into an annular recess 6 of a magnetic disk 5 made of sintered ferrite or the like. A predetermined amount of photopolymerizable adhesive 8 is charged onto it. A mold 10 having an annular convex portion 9 is pressed. Next, light is irradiated through the mold 10 as shown by the arrow.

Within a few minutes, the adhesive hardens and holds the mold in place, and the mold is removed. In the above series, molds were made using the silicone resin, polyolefin, and fluorine resin as the mold materials, and the photopolymerizable resin liquid was a polymerization initiator and an ester resin having double bonds (ADEKA TY-2002.
Experiments were conducted using Hitachi Chemical TF-154) and ultraviolet light. In both cases, the expected results were obtained.

The method of the present invention does not require heating and is an extremely short work time, so the rotation efficiency of the mold is good and the amount of equipment is small, and there is no heat generation caused by heat-cured resin or loss of heat transfer time including jigs and tools. .

or. In the example in Figure 2, this is because the convex surface of the magnetic material is held down by the mold. There are no protrusions caused by resin stains and the finish is smooth, eliminating the need for a finishing process.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view showing an example of applying the present invention to the sealing of electric appliance parts. and FIG. 2 is a sectional view showing an example in which the present invention is applied to fixing a coil, and FIG. 3 is a graph showing the relationship between the light transmittance of various mold materials and the wavelength of light. The main parts in the figure are as follows. 1,10...Mold made of releasable and transparent material. 2...Mold cavity. 4, 8...
・Photopolymerizable resin liquid.

Claims (1)

[Claims] 1. In a method of polymerizing a liquid resin using ultraviolet energy, the ultraviolet polymerizable liquid resin is made of polyvinylidene fluoride, ethylene tetrafluoride, etc., which has excellent interfacial releasability with respect to the resin and has good transparency to ultraviolet energy. A mold made of a material selected from the group consisting of propylene hexafluoride copolymer, polymethylpentene, polyethylene, polypropylene, and silicone resin is charged, and light energy is irradiated to the resin through the mold. A method for molding ultraviolet polymerizable resin.