JPH03144646A - Film for preventing newton ring - Google Patents

Abstract

PURPOSE:To prevent the generation of Newton rings with the simple method by using specific spherical particles on at least one surface of a plastic film and fixing the spherical particles to a binder resin. CONSTITUTION:The spherical particles with which >=95% of the number of particles is adjusted to a 0.5 to 13mum grain size range are used and 50 to 800 pieces/mm<2> of such spherical particles are fixed by a binder resin onto at least one surface of the plastic film. A biaxially stretched film of polyester in which particularly >=85mol% of the repeating unit is an ethylene terephthalate unit and cellulose triacetate film are preferably used as the plastic film to be used as a base material. The particles which are silicon dioxide particles having good ray transmittability and in which the spherical particle or fine particles aggregate to form a piece of a spherical shape are included as the spherical particles. The transparent film having the two contradicting characteristics that the generation of the Newton rings is suppressed and the drop-out of negative does not arise is obtd. in this way.

Description

Detailed Description of the Invention (Field of Application of Industry 1-) The present invention is used in the field of photoengraving to reduce quality when obtaining color-separated photographs using a color scanner or when performing contact printing with a plate-making camera. This invention relates to a transparent plastic film that makes it possible to prevent Newton's rings.

(Prior art and its disadvantages) For example, when creating color separation negatives using a color scanner, several types of original films are arranged on the surface of the original set drum, and a method is used to fix these original films. , use with an overlay film. However, at this time, gaps are created between the surface of the document set drum and the lower surface of the document film, and between the surface of the document film and the overlay film, and an air layer is formed there. 7E causes Newton's rings.Newton's rings appear on the decomposed film and are carried over until the second stage of printing and appear in the printed image.This phenomenon is unsuitable because it degrades print quality. .

The principle of Newton's ring (interference fringes) generation is described in physics textbooks.

λ 1-・Fringed frame included d=(2 + 1) λ F-minimum fringe d=to- (d: 17 degrees of air layer, λ: wavelength ahead, K=O.

1, 2. 3...) This "l back formation" is clearly observed at 0 and 1F, where the value of K is not very large.In other words, the thickness d of the air layer is close to the wavelength of light (400 to 700 nm) or As the temperature increases, the number of Newton rings emitted/-h increases. Therefore, as a countermeasure to prevent Newton rings +h, it is necessary to leave a certain amount of space between the air layers to prevent contact near the wavelength of light.

Conventionally, in order to increase the thickness of the dry layer, the F method involves spraying starch-based powder, or a liquid made exclusively for liquid paraffin is used instead of an air layer, and the method is used to increase the thickness of the dry layer between the set drum and the original film, or between the original film and the overlay film. In between “i”
Techniques have been taken to prevent the occurrence of Newton's rings by reducing the difference in angle and increasing the thickness of the liquid film.

However, starch-based powder has a wide particle size distribution, so if it is too small, it will not be effective, and if it is too large, powder particle images will appear on the decomposition film, which requires skill.
In particular, when enlarging, it is almost impossible to use because the ripple spreads out and so-called negative omission occurs. Furthermore, in method F, which uses a liquid exclusively for liquid paraffin, it is troublesome to apply the liquid and requires cleaning and removal after color separation is completed, resulting in extremely poor workability.

(Problem to be solved by the invention) [Color scanners have recently become extremely popular in the field of plate making, but when creating color separation negatives, delicate processes such as the dispersion of fine particles are required. It may be possible to eliminate the occurrence of Newton's rings with a simple method, rather than using methods with poor workability such as ! or coating with liquid paraffin 41.
L1 is committed to providing a film for Newton's ring protection that will not cause defects in halftone dots (so-called negative omission) even when magnified from 0 to 300%.
The target is

(Lower stage for solving the problem) The present invention is characterized in that on at least one side of the plastic film, 95% or more of the particles have a particle size in the range of 0.5 to 13.
Il! ! This is a film for preventing Newton's rings, characterized in that it uses well-organized spherical particles r, and the spherical particles r of 50 to 800 pieces/lTl1M are accompanied by a binder resin. When, 1
In order to avoid negative omission due to T even when magnified by 00 to 300%, silicon dioxide particles with good light transmission P1, styrene-based or styrene-benzoguanamine-based ff machine amorphous t+ =, spherical particles - are used. It is coupled by using .

The plastic film that is the base material of the present invention can be a film made of polyester, polyvinyl chloride, polystyrene, polycarbonate, acetate, polypropylene, etc., but it is necessary to have particularly good light transmittance, and it is necessary to repeatedly Biaxially stretched polyester films and cellulose triacetate films in which 85 mol % or more of weight tt't is ethylene terephthalate are more preferably used.

The radiator used in the present invention is a special diaphragm that is contradictory in that it widens the gap between the air layers and prevents the occurrence of Newton's rings, but if the radiator is too large, halftone dots will be missing (negative dropouts) due to the radial layer. It is easy to satisfy the needs, and for negative removal, it is
The light transmittance of r also has an effect. For this purpose, small spherical particles are suitable, and particles in the particle size range of 0.5 to 13 mm can be used.Particles with a particle size of 14μ or more are suitable for use with color scanners. Open the aperture at 200-300% magnification to produce negative omission. Particle size 1IiJ
In the case of n or less, the gap between '/l'; cKiI becomes small and Newton's rings cannot be prevented. side\
Since 1t and amorphous grains R lack monolithicity, the particle size range in which both Newton ring prevention 1hi and negative extraction can be prevented becomes narrow, and it is necessary to adjust the particle size distribution to a very narrow range. Therefore, it is difficult to apply it commercially.

The spherical particles used in the present invention include silicon dioxide-based particles with good light transmittance, and particles in which 111-spherical particles and fine particles aggregate to form a spherical shape.

In addition, (7 non-agglomerated P1 spherical particles include styrene-based particles, 1 benzoguanamine-based particles, 1 melamine-based particles,
Examples include MMA Ladingsen, and these particles can also be used in combination.

It is necessary that at least 95% of the number of these particles is adjusted in advance to have a particle size in the range of 0.5 to 13.
Use methods such as classification and filter precision loca to reduce the particle size distribution. The spherical particles r are fixed to the surface of the plastic film with a binder resin, and the number of the spherical particles is preferably 50 to 800/-. If it is less than 50/-, a sufficient air layer cannot be created and Newton rings will occur. If the number exceeds 800/-, the probability of particles colliding with each other is high and two or more particles may gather together and cause negative omission.

The binder resin for fixing the spherical particles to the surface of the plastic film includes rubber resins such as polybutadiene, poly(styrene-butadiene), poly(acrylonitrile-butadiene); polyvinyl acetate, polyvinyl chloride, polyvinylidene chloride, and their like. Vinyl resins such as copolymers; acrylic resins prepared using acrylic acid, methyl methacrylate, hydroxymethyl acrylate, styrene, glycidyl methacrylate, methyl acrylate, ethyl acrylate, etc.; isophthalic acid, adipic acid, cepatic acid, ethylene There are polyester resins prepared using glycol, diethylene glycol, neopentyl glycol tramethylene glycol, etc.; and polyurethane resins prepared using the above glycols and diisocyanates, as well as polyamide resins, epoxy resins, and polyolefins. It also includes resins such as resins, but is not limited to the above-mentioned resins.

In addition, an antistatic agent may be added to the binder resin for the purpose of imparting antistatic properties, or an antistatic agent may be added to the binder resin in advance.
Electric protection IF-treated plastic films may also be used. Spherical particles are mixed and dispersed in a binder resin and coated on at least one side of a plastic film.
-C If the thickness is less than 0.2 μm, the adhesion rl of the particles is poor and they fall off. When the coating thickness exceeds 2 μm, the particles often become deeply embedded in the resin, making it impossible to create a sufficient air layer. The coating method is not limited to the commonly used reverse coating method, bark coating method, and gravure coating method.

Historically, base films are usually obtained by melting and stretching a thermoplastic outer resin, or by dissolving the resin in a solvent and casting it. After such an unstretched film is uniaxially or biaxially stretched as required, the above-mentioned composition is applied (coated) to the surface thereof by the method described below. A method is applied in which the composition is applied to an unstretched or uniaxially stretched base film, and the composition is further stretched as necessary.

The above resin composition? It is also possible to subject the surface of the base film to corona discharge treatment or ultraviolet irradiation treatment in an air or nitrogen atmosphere before or after lamination using '7T. By performing these treatments, the tightness between the base film and the resin composition layer is further improved.

The method used in history is to wrap a plastic film with spherical particles and a resin mixture on both sides, wrap it around the cylinder of a color scanner, and use the original film on top of the film. (0) When used as an overlay film on one side or both sides of the original m film, or m and (0)
You can use Hao-oh film on both of them to make Newton's ring defense 1.

Explanation will be added below using examples.

In addition, [part] in an example means [Tun 1 Tsuji part].

In addition, 6 special f'l was evaluated by the following method.

1. Newton ring resistance 11.Evaluation of properties and evaluation of negative removal Fluid in the scanning cylinder of a color scanner for photolithography (Large L, manufactured by Hon Screen Co., Ltd. using S G 8 1 8 n J';'I) 1 paraffin? /lishi, part 1
- Set the color Haraaki film on the film, and use the Newton ring prevention film 1 of the present invention as an overlay film on the film.
1-.

Contact the processed side of the film with the color original film optical density (01) 0.05). Color separation negatives were obtained using conventional methods.

(() Newton ring prevention surname evaluation color original film and Newton ring prevention 1' of the present invention
Whether or not Newton's rings were generated between the I- and I-. films was visually determined using a color separation negative.

In lL, there is an inevitable change that the Newton ring is held in two places: between the scanning part cylinder and the original film, and between the original film and the overlay film, but in the judgment method, the part between the running part cylinder and the original film is omitted by using liquid paraffin. , the judgment focused on Newton's rings that occur between the original film and the overlay film. ) (b) Observe a 3-part cyan negative with negative omissions under a 50x magnifying glass, and find that the bright circle with the rule iE L < ・Iff along the front run line has partially collapsed and become irregular. It was determined whether there were any.

Number of solid collapse observed among 200 bright circular parts When evaluation is 0 0 When 1 to 3 pieces △ When 3 or more pieces × 2, Total light transmittance (%) 1 - Split t' Based on a light beam passing measuring device (haze meter).

3. Light transmittance (%) at a specific wavelength The absorbance is determined by /l111 using an ultraviolet/visible spectrophotometer, and the light transmittance (%) at a wavelength of 550 parts ms, 480 parts m, and 1370 parts m is 4.

4. Number of particles (particles/-) In the film of the present invention 1 - The location of the surface 5
Microscopic photo 1: 425x magnification of the area was taken to determine the size and number of γ.

Example I A polyester film (Cosmoshine A2100
! A: A solution of the following composition was filtered and adjusted through a 10μ cloth filter and applied to the non-(j)′ electrotreated surface of Yobo (manufactured by Jun) using a reverse roll coater, and heated at 120°C.
Dry for 1 minute in a drying oven, Newton ring anti-IF,
A film for use was obtained. The solid content of coated 41 mice was 1.2 g/male.

Saturated polyester resin (Vylon 200 manufactured by Toyobo Fiill) 10 parts Spherical silicon dioxide particles ("If') U bead P-700 Catalyst Chemical Industry () Uta manufactured 1, average particle size 4μ) 0.15 parts Toluene 45 parts M.E.K.
45 parts Example 2 In place of the spherical silicon dioxide in Example 1, if
/b The same article as Example 1 except that 0.2 part of benzoguanamine resin particles Y (Eposta-M30 average particle size 3.3μ "manufactured by Shokubai Kagaku Ogyo ■) was used as the spherical particle r.
Newton ring v) 1-I film was used.

Actual HLH Example 3 Instead of the spherical silicon dioxide particles of Example 1, spherical silicon dioxide particles (Microbead P-700/V average particle size 4
0.08 part of μ Catalyst Chemicals (manufactured by L-Gyo 11) and benzoguanamine-based spherical particles (Epostor M30, average particle size 3.3)
A film for preventing Newton's rings was obtained under the same conditions as in Example 1, except that 0.10 part of the mixture (produced by Pr1 Hon Shokubai Kagaku Kogyo Shiki) was used.

Comparative Example 1 A film was obtained in Example 1 except that the spherical silicon dioxide particles were removed.

Comparative Example 2 Instead of the spherical silicon dioxide in Example 1, 0.2 part of benzoguanamine-based resin particles (Epostor Mho, average particle size 5μ, Kuchimoto Catalyst Chemical) was used, and a blended solution was used. I? without filtration with a 10u cloth filter. E
A film was obtained by coating under the same conditions as in Example 1 except that it was used as a liquid.
The second time was a lot (71 tithes).

Comparative Example 3 Instead of the spherical silicon dioxide of Example 1, an amorphous silicon dioxide-based resin (Fine Seal B average particle size 3°5I) was used.
iIn (manufactured by Tokuyama N'/Tsuji 11) 0.2 part was used, and the blended solution was heated to 1.2 parts without filtration with a LOJtR main filter.
．． A Yuo film was obtained under the same conditions as in Practical Example 1 except that i'(& was used.

Comparative Example 4 A coated E film was obtained in the same manner as in Practical Example 1, except that 0.8 parts of spherical silicon dioxide particles were used.

The results are summarized in Table 1.

The following margin table 1 shows that the present invention has a good effect, but on the other hand, when R- was not used at all, the Newton ring prevention was poor (Comparative Example 1), and the number of particles of 13 IU or more was 7 to 7. When the number of particles is 800/miA or more, negative extraction is poor (Comparative Example 2), and when the N-shaped shape used is irregular, both characteristics are poor (Comparative Example 3). It can be seen that in the case of -, negatives are easily removed (Comparative Example 4).

(Effects of the invention) By using spherical particles of the patented particle size, it is possible to suppress the occurrence of Newton's rings, and to obtain a transparent film that has the two contradictory characteristics of not causing negative dropout.
Photo f [I understand that it is extremely useful in the field of plate making.

Patent appearance hole Toyobo Co., Ltd.

Claims (1)

[Claims] (1) On at least one side of the transparent plastic film, 95% or more of the particles are spherical particles adjusted to have a particle size in the range of 0.5 to 13 μm, and 50 to 800 particles/m
m^2 (7) A transparent film for preventing Newton's rings, characterized in that the spherical particles are fixed with a binder resin.