JPS59181328A - Vane made of plastic for optical instrument - Google Patents

Abstract

PURPOSE:To improve light shieldability, antistatic properties and resistance to scratching by using a black polyester film as a blank material, and providing a thermosetting resin coating film contg. a specific amt. of carbon powder and a low mol.wt. PE on both surfaces of the blank material. CONSTITUTION:A black polyester film is used as a blank material 14, and a coating consisting essentially of a thermosetting resin contg. 3-20wt% carbon powder and 0.5-5wt% powder of a low mol.wt. PE is coated at the same thickness on both surfaces of the material 14 and is then subjected to a hardening treatment by heating, by which a coating layer 15 having flatness and a matt surface is formed. The antistatic properties and light shieldability of such film are improved and the reflection of light is prevented by incorporating the carbon powder in the layer 15. The resistance to scratching is also improved by incorporating the low mol.wt. PE. An excellent vane for an optical instrument is thus obtd. and is used for a diaphragm vane 1 and shutter vanes 2, 3 for a camera.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plastic blade for optical machines, and more particularly to a plastic blade made from a blackened polyester film.

For example, optical mechanical blades (shutter blades, diaphragm blades) used in cameras, etc. cover the front surface of the photosensitive material and block light, so they must inherently have light-blocking properties, and the surface must have light-blocking properties. Since the blades must efficiently absorb light without reflecting it, it is preferable that the blades be black and matte. That ball 5
Since the blades work by overlapping each other, they must have good flatness, excellent abrasion resistance (VC), and antistatic ability.

This is particularly important for shutter blades that open and close at high speed.

Therefore, when selecting materials for blades, metal sheets with a culm thickness of 50μ to 100μ were generally used in consideration of this harsh usage environment, but based on recent demands for lighter blades, some metal sheets Instead of sheets, blades made of blackened polyester film are beginning to be provided. It has already been recognized that polyester film is the best plastic material for this type of purpose.

Conventional blades that are made entirely of polyester film generally have a film thickness of r, tiooμ or more, and also have a VC black coating formed on the surface of the soybean, or a metal that has excellent light-shielding properties. Thin film 'Q: It was used as a pestle to obtain light-shielding properties by attaching fJ.

Conventional blades made of black polyester film, which have been affected by this black paint, were undesirable due to the following drawbacks:

First, since it is coated with a general carton, it is easily scratched by the opening and closing operations of the wings 4''M, and its durability has been compromised.

Next, when a thin metal film is applied, especially when treated with Lamio 1, there is a problem that the blades are warped or the paper is distorted due to the difference in expansion coefficient between the polyester film and the metal foil.

Furthermore, in the case of lamination, if the entire surface of the metal foil is treated, it is necessary to apply a black matte treatment, which increases the number of man-hours and is undesirable.On the other hand, if the metal foil is sandwiched inside in a sand-like shape, it becomes difficult to prevent static electricity. Unfavorable from this point of view. This also applies to the case where Anobenium Aek is deposited instead of the metal foil.

On the other hand, looking at the drawbacks of the conventional black polyester film blades mentioned above, which require the attachment of a metal thin film with excellent light-shielding properties, we have seen that black polyester film can provide sufficient light-shielding properties with just the material itself. Research on feathers is progressing, but as mentioned earlier, there are some problems, which I will explain.

First, in 1982, the present applicant developed blades made of various black polyester films that could provide sufficient light-shielding properties depending on the material used.
Why did I already apply for a patent on January 14th, 2015 (Japanese Patent Application No. 56-417?
3) Since this is the case, a brief explanation will be given based on this.

Figure 1 shows the cross-sectional shape of this blade made of black polyester film, and in the figure, 4 is the material of the blade made of biaxially stretched polyester (polyethylene terephthalate) film, and the film thickness is 70 μfi = minimum thickness. And the transmission density (J) is 10 or more at that thickness)
：This film contains black pigment, etc. to the extent that it has excellent light-shielding properties.
If it is up to 0μ, it is possible to obtain a film with good flatness and excellent light-shielding properties without damaging the physical properties of the polyester material itself (dimensional accuracy, mechanical properties, environmental resistance, etc.). It has been found through various experiments that a thickness of 70μ is the limit.

5 is a matte paint coated on the surface of the material 4. Specifically, the paint is made of an acrylic thermosetting resin containing a minimum amount of inorganic compound pigment such as silica, and is coated so that the surface is uneven.

6 is an antistatic film, specifically, immersed in a 1% solution of Statycide (trade name: i5laticide). Then, the antistatic 11N 6 is coated with the above-mentioned matte paint 5 to ensure that all four parts are coated.

Here, the antistatic agent used in this method is one that has an ion-neutralizing layer formed on its surface, which mediates the neutralization effect between ions in the air and static electricity generated on the surface of the object. The surface resistance value is reduced to about 1io' to 1o10ohm.

However, a polyester film with a film thickness of 70μ to 100μ, which is made of a polyester material with a composition such that a transmission density of 10 or more can be obtained when the film thickness is 70μ, pursues light-shielding properties as a blade material. However, there are some problems with VC when using this material as a blade.

For example, this is a problem caused by static electricity generated on the surface of the blade material that opens and closes at high speed, and the antistatic film described above has not been sufficient.

In addition, even if the polyester film has the above composition, if the film thickness is 70 tt or less, m: light shielding property is sufficient.
It may not be possible to obtain it.

Therefore, both an antistatic treatment to prevent the harmful effects of static electricity and a light shielding treatment to supplement light shielding properties are required.

Therefore, the applicant VC further stated that on January 1, 1981,
5 Nikko (Japanese Patent Application No. 56-73772) filed an application regarding a plastic blade that is thought to have excellent light-shielding properties, antistatic properties, scratch resistance, and excellent productivity.

The structure of the blade according to the above-mentioned application is that the material is a polyester film containing a black pigment, and the surface of this material is coated with a paint mainly composed of diallyl phthalate resin mixed with carbon-based powder. However, due to the relationship between its antistatic effect and scratch resistance, there is still a lack of value in its properties, and it has not been possible to fully use it in grooves.

The present invention was made in view of the drawbacks of conventional polyester film blades, and has developed a plastic blade that has excellent light-shielding properties, light-blocking properties, and scratch resistance, and is also excellent in productivity. The purpose is to provide.

The purpose of the present invention is to use a polyester film containing a black pigment as a material, and to
This is achieved by coating the blade with a paint that is entirely made of a thermosetting resin that is completely mixed with carbon powder and low-volume polyethylene (polyethylene wax) powder that has excellent earth protection and scratch resistance.

The present invention will be described below based on the illustrated embodiments. First, FIGS. 2N to 4 are plan views illustrating the shapes and shapes of general aperture blades 1 and shutter blades 2 and 3. FIG. 5 is a side sectional view of these vanes according to the invention.

In the figure, reference numeral 14 indicates a material for the blade made of biaxially stretched polyester (polyethylene terephthalate) film.

A coating layer 15 is made of a paint mainly composed of a thermosetting resin. And in the thermosetting ": 3 to 20% by weight of carbon powder and 0.5 to 5% of low molecular weight polyethylene.
The weight percentage is uniformly dispersed and mixed.

Further, the coating layer 15 is coated on one side of the surface of the blade material 14 to a thickness of 5 to 15 microns using a roll coater or the like, and is sufficiently hardened by baking.

Furthermore, since the coating film is baked and cured without applying appropriate tension, it is also possible to correct distortion and warpage of the film.

This type of blade corrects film distortion and warping! When used as A, it is extremely serious.

The purpose of mixing carbon powder here is to provide antistatic properties, light shielding and prevention of light reflection, and the purpose of mixing low molecular weight polyethylene powder is to provide scratch resistance.

Next, the reason why the mixed amount of carbon powder was set at 3% to 20% and the mixed group of low molecular weight polyethylene powder ('tH0, ranged from 5% to 5%) was explained based on Figures 6 and 7. explain.

FIG. 6 shows the experimental results of the relationship between the surface resistance value and the addition of carbon powder at a coating thickness of 5 μm. When the amount of carbon powder added decreases, the surface resistance value increases and the antistatic effect disappears. If the surface resistance value is 109Ω or less, it has an antistatic effect, so from Figure 6, the amount of carbon powder added is 3.
% or more, it can be seen that the antistatic effect can be fully achieved.

Moreover, FIG. 7 shows the experimental results of the relationship between the amount of carbon powder added, the amount of low molecular weight polyethylene powder Kizome) J [1], and the number of times of sliding when abrasion 5 occurred due to sliding.

When the carbon powder addition fσ7 is more than 20%, the addition of low molecular weight polyethylene powder becomes less effective, and scratches occur even with a small number of sliding movements, and the effect of adding low molecular weight polyethylene cannot be seen. , This 7t is easily scratched because carbon powder 751 is exposed on the surface of the coating film due to the excessive amount of carbon powder attached.

In addition, if the amount of low molecular weight polyethylene added is less than 0.05%,
Since the amount is small, there is no lubrication effect, and therefore scratches occur even after a small number of sliding movements. In addition, if the amount of low molecular weight polyethylene added exceeds 5%, scratches will occur with a small number of sliding movements, but this is because too much low molecular weight polyethylene powder precipitates on the coating surface, causing surface scratches. becomes softer and becomes more susceptible to scratches.

The reason why the thickness of the coating layer 15 is set in the range of 5 to 15μ is that if the thickness is less than 5μ, pinholes will occur, resulting in poor light-shielding properties, and if the thickness is more than 15μ, the coating layer will have poor bending resistance and cracks due to bending. This is because there is an occurrence of

Next, the production process of the polyester film blade according to the present invention will be briefly explained. Polyester chive material mixed with black pigment is coated with thermosetting resin mixed with carbon-based powder and low molecular weight polyethylene powder, baked and hardened, and then continuously punched into the desired blade shape using a press etc. produced by. The reason why continuous production is possible in this way is that the production process according to the present invention continuously coats the biaxially oriented polyester film with paint, and bakes the film at the same time as it hardens. This is because distortion, warpage, etc. can be corrected by applying tension to the material, and continuous processing can be performed using the hoop material.

E1 Polyester film according to the present invention (7) Since the blade is as described in L, it has excellent light-shielding properties, scratch resistance, antistatic properties, and flatness, and is extremely productive and economical. effective.

[Brief explanation of the drawing]

FIG. 1 is an enlarged side sectional view of a conventional blade, FIGS. 2 to 4 are plan views showing the shape of a general blade for reference, and FIG. 5 is an enlarged side sectional view of a blade according to the present invention. 6 and 7 are diagrams showing experimental results. 14. Black polyester film, l&ru feather material 15. Coating layer consisting of a paint mainly composed of a thermosetting resin mixed with carbon powder and low molecular weight polyethylene powder Patent applicant Kobal Tesha Co., Ltd. Amendment ( Method) HmJapanese July 12, 1982 Fl Director General of the Patent Office 1 Punishment 1 Incident Display 1988 Patent W1! No. 56136 2 Name of the invention Optical device] Wearable plastic blades 3 Patent for person making correction Kazuto De 16-2゜〒2-2 Shiri, Itabashi-ku, Tokyo 174 (965
) 1111 (122) Copal Co., Ltd. June 28, 1981

Claims (2)

[Claims] (1) A black polyester film is used as the material, and a paint mainly composed of a thermosetting resin containing 3 to 20% by weight of carbon powder and 05 to 5% by weight of low molecular weight polyethylene powder is applied to the surface of the film. A plastic blade for an optical machine, characterized in that it is coated on both sides with the same thickness to create a matte surface, and is subjected to a heat hardening treatment that also serves as a correction to obtain flatness. (2) A plastic blade for an optical machine according to claim 11, wherein the thickness of the paint is 5 to 15 μ on one side.