JPS62187302A - Near ir ray absorption plastic protective filter - Google Patents

Abstract

PURPOSE:To obtain a filter having excellent durability with substantially no decrease of near IR absorption performance by kneading and working a specific near IR ray absorbent and UV absorbent. CONSTITUTION:The benzene dithiol metallic complex expressed by the formula and the UV absorbent are added to a transparent thermoplastic resin. Any resin which does not have large light absorption power in a visible region and wavelength region of a near IR part and is a transparent resin formable within about 220 deg.C in terms of high moisture and heat resistance of the near IR ray absorbent is usable as the thermoplastic resin. The benzenedithiol metallic complex has extremely small light absorptivity in the visible part, absorbs the UV part and has a large absorption coefft. of molar ratio of the max. absorption wavelength in the near IR part. This optical filter has a substantial absorption characteristic near 800-1,100nm and has good dispersibility in a plastic material in the stage of kneading and excellent durability.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a plastic protective filter having near-infrared absorption characteristics. <Prior Art> The plastic protective filter is mainly used for eye protection lenses, especially when exposed to strong sunlight outdoors. It is used as sunglasses or welding goggles to protect the eyes from light, arc welding, torch flame, etc. All of these must absorb ultraviolet and near-infrared rays that are harmful to the eyes. Furthermore, these materials need to have high transmittance to visible light, and are also required to have sufficient weather (light) resistance for practical use, and to be durable enough to retain their absorption properties for a long period of time. .

Conventionally, such protective filters are made of glass and are easily available, but protective filters made of plastic have also been proposed to improve the drawbacks of glass.

For example, a method of mixing an infrared absorber into a methyl methacrylate monomer for casting and curing it (Japanese Patent Publication No. 7887/1987), a method of mixing an infrared absorber with a polycarbonate resin,
Infrared absorbing lens obtained by molding (Japanese Patent Application Laid-Open No. 57-4550
Publication No. 9).

<Problems to be Solved by the Invention> However, the above-mentioned conventional methods are not always satisfactory because they are subject to limitations in molding methods and molding material shelves, and some near-infrared absorbers used reduce visible light transmittance. It wasn't something that should have been done.

In addition, various studies have been made on methods of obtaining Kaede infrared absorbers by kneading them into plastic materials. There is still no way to obtain a plastic protective filter that has excellent absorption characteristics, good dispersibility in plastic materials when cross-wired, high visible light transmittance, and so-called durability such as weather (light) resistance. It had not been established.

Means for Solving the Problem> As a result of studies to improve these drawbacks, the present inventors have found that the above object can be achieved by mixing and processing specific near-infrared absorbers and ultraviolet absorbers. This is the heading that led to the present invention.

The present invention provides a transparent thermoplastic resin with a benzenedithiol metal complex represented by the general formula [l] and
This is a near-infrared absorbing plastic protective filter made by adding a palladium or platinum atom, Y is phosphonium, and n is an integer of 1 to 4) and an ultraviolet absorber. Thermoplastic used in the present invention!
As MUj, any transparent resin that can be molded within the visible range and about 220° C. can be used. For example, in addition to polystyrene and polyvinyl chloride, acrylic resins such as polymethyl methacrylate and polymethyl acrylate, or polycarbonate can be used. ξAmong these, the most desirable is a polymer whose main component is methyl methacrylate because of its excellent optical properties and weather resistance! i2# is a pilgrimage. The polymer containing methyl methacrylate as a main component may be a single polymer of methyl methacrylate, but it may also be a copolymer with other acrylic esters such as methyl acrylate, ethyl acrylate, or butyl acrylate, or a copolymer of these. The following polymer compositions are exemplified. Furthermore, due to the ease of molding, the flow characteristics of the polymer are determined by the melt flow index (MF I: J
Load 8.81C#, temperature 28 according to ISK7210
Polymers with a melt flow index of 6 to 4 (1/10 min, more preferably 8 to 259/10 min) (measured at 0°C) can be used. Polymers with flowability lower than this range can be used at high temperatures. This method requires molding and is not necessarily preferable from the viewpoint of heat resistance of the near-infrared absorbent.

The benzenedithiol metal complex used in the present invention has extremely low light absorption in the visible region, absorbs in the ultraviolet region, and has a large molar specific extinction coefficient at the maximum absorption wavelength in the near-infrared region. Not only does it have spectral characteristics close to 4M sensitivity, but its absorption characteristics are relatively stable even after each shelf molding process.

The benzenedithiol metal complex used in the present invention can generally be obtained by reacting benzenedithiol with nickel chloride, palladium chloride or platinum chloride, and then reacting this reaction solution with phosphonium halide. Examples of benzene dithiols include benzene-1゜2-dithiol, toluene-8,4-dithiol, xylene-4,6-dithiol, 8.4゜5.6-tetramethylbenzene-1,2-dithiol, 4- Chloro-benzene-1,2-dithiol, 4,6-cyclobenzene-1,2-dithiol, B, 4,5,6-tetrachlorobenzene-1,2-dithiol and 8.4.5°6-
Tetrabromobenzene-1,2-dithiol and the like are used. As the phosphonium parite, for example, tetraethylphosphonium bromide, tetra n-butylphosphonium bromide, octyltriethylphosphonium bromide, cetyltriethylphosphonium bromide, etc. are used.

Among them, bis(1-methyl-8,4-dithioferrate) elikel(n)tetra-n-butylphosphonium and bis(1-methyl-8゜4-dithioferlate)elikel(II)tetraethylphosphonium are close. It has been found that it has absorption characteristics over a relatively wide range in the infrared region, and has performance suitable for use in plastic protective filters.

The blending ratio of the benzenedithiol metal complex to the resin can be selected according to the thickness of the wooden board when used as a protective filter and the desired luminous intensity of the light film, but it maintains suitable near-infrared absorption performance for a long period of time. 0.
It is desirable to add 01 to 8 in an amount of %. In addition, in order to achieve even better performance, two
It is also possible to obtain absorption performance over a wider near-infrared wavelength range by adding a benzenethiol metal complex of 3 or higher.

Furthermore, a desired infrared absorbing property can be obtained by using an iminium salt represented by the general formula (2) as a near-infrared absorbing agent having absorption performance in a long wavelength range.

In addition, the present inventors have discovered that by using a near-infrared MS absorber together with an ultraviolet absorber, it is possible to suppress coloring of products and improve the long-term weather resistance (dynamics) of the near-infrared absorber. The discovered ultraviolet absorber can be a general-purpose salicylic acid-based, benzophenone-based, or benzotriazole-based UV absorber, but in particular, it is recommended to use a benzotriazole-based UV absorber in an amount of 01 to 0.5 M% in order to absorb near-infrared rays. It is characteristically effective in improving the long-term weather (light) resistance of absorbers.

The benzotriazole-based ultraviolet absorbers used in the present invention include 2(2'-hydroxy-6''-)methylphenyl)benzotriazole, 2(2-hydroxy-8
'-tertbutyl-6'-methylphenyl)5chlorobenzotriazole, 2(2'-hydroxy-8'',6'-ditbutylphenyl)benzotriazole or
'-Hydroxy-8'-t-butyl-6'-methylphenyl) benzotriazole etc. cause less coloring to the product and have a strong effect of improving the weather resistance (light) of the near-infrared absorber. Benzenedithiol gold 84 used for!
In order to improve the weathering (light) resistance of the body and the heat resistance during crosstalk and molding, it is possible to add an antioxidant such as tetrakis [methylene 8 (11,5 di-t-butyl 4-hydroxyphenylpropionate comethane) together. can.

In addition to the above, dyes, lubricants, etc. can be added to the transparent thermoplastic resin used in the present invention in order to improve its physical properties.

There are no particular limitations on the method for making the optical filter, but transparent thermoplastic 4! ! By mixing and melting various additives, an optical filter of a desired shape can be made by compression molding, extrusion molding, or injection molding.

Effect> The optical filter of the present invention has sufficient absorption characteristics in the vicinity of 800 to 1l100n, has good dispersibility in plastic materials at the time of crosstalk, and has high visible light transmittance.
Furthermore, it is an excellent optical filter that has so-called durability such as weather resistance and light resistance.

In addition, the optical filter of the present invention has spectral characteristics close to the visibility of the human eye and can be used as is, but it can be used for general purposes to adjust the amount of transmitted light in the visible light range, adjust the color, or block light depending on the purpose of each l. -11 can exhibit a variety of functions by adding dyes and organic pigments in combination.

The present invention will be explained in detail with reference to Examples below.Example 1 Melt flow index (MF I ) 22.11
Bis (l
-methyl-8,4-dithioferrate)nickel(I
I) Tetra n-butylphosphonium at 0.07'! 1!
1%, ultraviolet absorber Sumisorb■800 (manufactured by Sumitomo Chemical Co., Ltd. 00. Benzotriazole ultraviolet absorber) 0
, 8% by weight, and antioxidant Irganox ■101
0 (manufactured by Ciba Geigy 6.

0.2 parts by weight of tetrakis [methylene 8 (8,5 di-t-butyl-4-hydroxyphenylpropionate comethane) was added, kneaded and granulated at 200°C, and then injection molded.2. A plate molded body having a thickness of .

The transmission spectrum of this product is as shown in Fig. 1, and it sufficiently absorbs ultraviolet and near-infrared rays (universal coverage).A filter suitable for eye protection was obtained.

A 600-hour exposure test was conducted on this product using a sunshine weather meter (88° C. high temperature type manufactured by Suga Test Instruments Co., Ltd.).

The transmission spectrum after the exposure test was as shown in Fig. 1, M2, and there was almost no decrease in near-infrared absorption performance, and the product had excellent durability.

Comparative Example 1 A 2.0-thick plate molded body was obtained in the same manner as in Example 1 except that no ultraviolet absorber and antioxidant were included. The transmission spectrum of this specimen was as shown in Figure 2, M1.9The same test piece was then subjected to a 500-hour exposure test using a sunshine weather meter under the same conditions as in Example 1. The result looked like Todoroki 2 in Figure 2, where the near-infrared absorption performance was greatly reduced and the appearance was also slightly brownish.

Comparative Example 2 Melt flow index (MFI) methacrylic resin Sumipex BRMH (Sumitomo Chemical Co., Ltd.) with a melt flow index (MFI) of 111,710 minutes
Bis(1-methyl-8,4 dithiophelate) nickel(
U) Tetra n-butylphosphonium was added in an amount of 0.07% by weight, and granulation and injection molding were carried out at 280°C, which is the general molding condition for tM- of ξ, to obtain a plate molded body having a thickness of 2.01 mm. The transmission spectrum of this material was as shown in Fig. 8, and sufficient near-infrared absorption performance could not be obtained due to thermal deterioration. Melt flow inde which can be molded at 200℃? riX
In the case of a methacrylic resin with (MF I') of 22.11/10 minutes, the transmission spectrum was that of Todoroki 1 in FIG. 2 of Comparative Example 1, and the difference in melt flow index and molding temperature had a large effect.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 show absorption characteristics of filters of examples of the present invention and comparative examples. Wavelength [nm) Wavelength 1nm]

Claims (3)

[Claims] (1) Benzenedithiol metal complex expressed by the general formula [I] in a transparent thermoplastic resin ▲ Numerical formulas, chemical formulas, tables, etc. are available ▼ [I] (In the formula,
(e represents a nickel, palladium or platinum atom, Y represents a phosphonium, and n represents a number from 1 to 4) and a near-infrared absorbing plastic protective filter. (2) The near-infrared absorbing plastic protective filter according to claim 1, wherein the transparent thermoplastic resin is a polymer containing methyl methacrylate as a main component. (3) Claim 1, characterized in that in the benzenedithiol metal complex represented by the general formula [I], X is a methyl group, n is 1, Me is nickel, and Y is tetraalkylphosphonium. near-infrared absorbing plastic protective filter