JPH0436337A - Near-infrared-absorbing resin composition and its production - Google Patents

Abstract

PURPOSE:To obtain the title composition excellent in near-infrared absorptivity by mixing an acrylic ester monomer with a reaction product of WCl6 with a phosphoric (phosphorous) ester and polymerizing the mixture in the presence of a radical polymerization initiator. CONSTITUTION:A monomer mixture containing an unsaturated monomer (e.g. acrylic acid) based on a (meth)acrylic ester (e.g. methyl acrylate) and which may contain its polymer and/or a (meth)acrylic polyester monomer (e.g. epoxy acrylate) is prepared. 100 pts.wt. this monomer mixture is mixed with a chlorine- free mixture obtained by reacting 0.01-10 pts.wt. tungsten hexachloride with at least 2mol, per mole of the hexachloride, of a phosphoric (phosphorous) ester (e.g. monoethyl phosphate). The obtained mixture is polymerized in the presence of a radical polymerization initiator to obtain a near-infrared-absorbing resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel near-infrared absorbing resin composition that transmits visible light relatively well and has excellent near-infrared absorbing ability, and a method for producing the same.

[Conventional technology]

Conventionally, near-infrared absorbing materials include tungsten hexachloride (WCffi &) and tin chloride (SnCl z・28z
U.S. Pat. No. 3,692,68 discloses that O) can be obtained by dissolving O) in methyl methacrylate and polymerizing it.
It is described in Specification No. 8.

[Problem that the invention seeks to solve]

According to the results of our reexamination of the above US patent, WCjl
! a and 5nCj! A composition prepared by dissolving z・2H20 in methyl methacrylate syrup develops a deep blue color and has the property of absorbing near-infrared rays well, but the mold plate obtained by injecting this into a mold and polymerizing it, that is, a near-infrared absorbing material, The color has faded and the ability to absorb near-infrared rays has decreased significantly, and it is only when exposed to ultraviolet rays or sunlight that it becomes deep blue again and exhibits near-infrared absorption ability, while it is left in a dark place for a long time. The problem was that it exhibited so-called photochromism, which caused the color to fade over time. In the conventional near-infrared absorbing material containing WCj26 and 5nC12.2H20, the large change in spectral characteristics during the polymerization process and the extremely slow progress of photochromism are caused by
This is an undesirable phenomenon in providing industrial products such as optical filters and heat-absorbing glazing with a certain level of quality.

In addition, using methyl methacrylate as a reaction solvent,
T+cI for this! , 6 and SnCl 2 .2HzO, the resin that serves as the base of the filter is limited to polymethyl methacrylate, and the manufacturing method is also limited, making it difficult to use a variety of industrial products in terms of shape, processability, and surface properties. There was also the problem of not being able to meet needs.

Furthermore, Cf6 is unstable and decomposes to generate hydrogen chloride gas, so if unreacted wci, 6 remains in the polymerizable raw material, it has a strong irritating odor and is difficult to handle. However, since it is corrosive to metals, the materials for the preparation container and polymerization equipment are limited. Furthermore, if the polymerizable raw material contains hydrogen chloride and alkyl chloride, which are by-produced by the reaction between -C16 and a phosphoric acid ester and/or a phosphorous acid ester, in addition to the above-mentioned irritation and corrosion problems, polymerization may also occur. There was a problem in that the near-infrared absorbing resin plate obtained by this method suffered from polymerization strain.

Therefore, in order to solve the above-mentioned problems, the present invention provides a near-infrared absorbing resin composition that does not require limited use of methyl methacrylate as a reaction solvent and has excellent near-infrared absorption ability and stability. The purpose is to provide a manufacturing method thereof.

[Means for solving problems]

The present inventors have conducted intensive studies on near-infrared absorbing resin compositions and methods for producing the same, which aim to improve instability during the polymerization process and suppress photochromism. The present invention was completed by discovering that the present invention can be achieved by using a combination of esters and/or phosphite esters.

That is, the gist of the present invention is as follows: (1) 0.01 to 0.01 to tungsten hexachloride to 100 parts by weight of transparent resin;
A near-infrared absorbing material containing a substantially chlorine-free mixture obtained by reacting 10 parts by weight with a phosphoric acid ester and/or a phosphorous acid ester in an amount at least twice as much in mole as that of tungsten hexachloride. a resin composition, and (2) (a) an unsaturated monomer and/or (meth)acrylic acid polyhydric acid which is mainly composed of a (meth)acrylic acid monoester monomer and may contain a polymer thereof; For 100 parts by weight of the ester monomer, (b) 0.01 to 10 parts by weight of tungsten hexachloride, and at least twice the molar amount of phosphoric acid ester and/or tungsten hexachloride.
or a near-infrared absorbing resin composition characterized by adding and mixing a substantially chlorine-free mixture obtained by reacting with a phosphite ester, and then polymerizing the mixture in the presence of a radical polymerization initiator. This is a manufacturing method.

The present invention will be explained in detail below.

The transparent resin in the present invention is not particularly limited as long as it is substantially transparent and does not have large absorption/scattering properties, but specific examples thereof include acrylic resin, allyl diglycol carbonate resin, and styrene resin. resins, vinyl chloride resins, polycarbonate resins, olefin resins, epoxy resins, polyamide resins, etc., and as long as they are substantially transparent, it is not limited to one type of resin, but two or more types of resins can be used. Blends can also be used. Among these transparent resins, thermoplastic or crosslinked (meth)acrylic acid ester resins such as acrylic resins are preferable from the viewpoint of dispersibility of the reaction mixture having near-infrared absorbing performance, and also from the viewpoint of weather resistance. A methacrylic resin containing methyl methacrylate alone or 50% or more of methyl methacrylate units is desirable.

In the present invention, the unsaturated monomer which is mainly composed of a (meth)acrylic acid monoester monomer and may contain a polymer thereof refers to the (meth)acrylic acid monoester monomer alone, or a mixture containing (meth)acrylic acid monoester as the main component and other unsaturated monomers that can be copolymerized with it, or dissolving these polymers in the monomer or monomer mixture. It is a shirub that contains. The proportion of (meth)acrylic acid monoester in the mixture with other unsaturated monomers is 50% by weight or more, preferably 60% by weight.
The content is more preferably 80% by weight or more. (meta)
Specific examples of acrylic acid monoesters include methyl (meth)acrylate (meaning methyl acrylate or methyl methacrylate; the same applies hereinafter), ethyl (meth)acrylate, butyl (meth)acrylate, and (meth)ethyl acrylate. Cyclohexyl acrylate, 2-ethylhexyl (meth)acrylate, methoxyethyl (meth)acrylate, ethoxyethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate,
Tetrahydroxyfurfuryl (meth)acrylate, (
Examples include benzyl meth)acrylate and hydroxyethyl (meth)acrylate, and one or more of these may be used, but methyl methacrylate is preferred in consideration of weather resistance. Examples of other copolymerizable unsaturated monomers include (meth)acrylic acid, (meth)acrylonitrile, (meth)acrylamide, styrene, α-styrene, vinyltoluene, maleic anhydride, etc. . Methods for obtaining partial polymers of (meth)acrylic acid esters include the commonly used method of obtaining partial polymers by bulk prepolymerization, or the method of dissolving polymers in monomers. In consideration of this, it is preferable to adjust the polymer content to 35% by weight or less.

Examples of the (meth)acrylic acid polyester used in the present invention include polyol poly(meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, polyurethane (meth)acrylate, and the like.

Furthermore, specific examples of polyol poly(meth)acrylate include ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate,
Tripropylene glycol di(meth)acrylate, trimethylolethane di(meth)acrylate, neobentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, and polyester(meth)acrylate. ) Specific examples of acrylates include polyhydric alcohols such as ethylene glycol, 1,4-butanediol, diethylene glycol, trimethylolpropane polyethylene glycol, and pentaerythritol, and polybasic acids such as phthalic acid, adipic acid, maleic acid, and itaconic acid. It is a (meth)acrylate of polyester synthesized by reacting , terephthalic acid, etc. Specific examples of epoxy (meth)acrylate include bisphenol A-epichlorohydrin type, phenol novolac-epichlorohydrin type, alicyclic epoxy resin, etc. It is a (meth)acrylate of an epoxy resin, and specific examples of polyurethane (meth)acrylate include (meth)acrylates of isocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate, and one or two of these The above monomers are used.

(a) Unsaturated monomers and/or (meth)acrylic acid polyester monomers that are mainly composed of (meth)acrylic acid monoester monomers and may contain polymers thereof used in the present invention (hereinafter referred to as (meth)acrylic acid ester monomer etc.) refers to an unsaturated monomer mainly composed of the above-mentioned (meth)acrylic acid monoester monomer and which may contain a polymer thereof; The term refers to a (meth)acrylic acid polyester monomer and a mixture thereof, and the composition thereof can be varied over a wide range.

The phosphoric acid ester used in the present invention is represented by the following formula (1)
Phosphate represented by (where n is 1.2 or 3, R is 1 carbon number)
~18 alkyl groups, allyl groups, aryl groups, aralkyl groups, (meth)acryloxyalkyl groups, or derivatives thereof. ), and specific examples include monoethyl phosphate, diethyl phosphate, triethyl phosphate, monobutyl phosphate, dibutyl phosphate, tributyl phosphate, monobutoxyethyl phosphate, and mono(2-ethylhexyl) phosphate. Phate, bis(2-ethylhexyl) phosphate, tris(2-ethylhexyl) phosphate, monophenyl phosphate, diphenyl phosphate, triphenyl phosphate, mono(2-
chloroethyl) phosphate, bis(2-chloroethyl) phosphate, tris(2-chloroethyl) phosphate, mono(2-hydroxyethyl methacrylate) phosphate, bis(2-hydroxyethyl methacrylate) phosphate, tris(2-hydroxyethyl) phosphate methacrylate) phosphate, etc., and among these, diesters, triesters, and mixtures thereof are preferred examples.

The phosphite used in the present invention is expressed by the following formula (2
) (where n is 1, 2 or 3, R is 1 carbon number)
~18 alkyl groups, allyl groups, aryl groups, aralkyl groups, (meth)acryloxyalkyl groups, or derivatives thereof. ), and specific examples include monoethylphosphite, diethylphosphite, triethylphosphite, monobutylphosphite, dibutylphosphite, tributylphosphite, mono(2-ethylhexyl)phosphite, bis(2- ethylhexyl) phosphite, tris(2-ethylhexyl) phosphite, monodecyl phosphite,
didecyl phosphite, tridecyl phosphite,
Monostearylphosphite, distearylphosphite, tristearylphosphite, monophenylphosphite, diphenylphosphite, triphenylphosphite, mono(nonylphenyl)phosphite, bis(nonylphenyl)phosphite, tris(nonylphenyl) Phosphite, mono(2,3-
These include dichloropropyl) phosphite, bis(2,3-dichloropropyl) phosphite, tris(2,3-dichloropropyl) phosphite, and among these, diesters and triesters are preferred examples.

The amount of tungsten hexachloride, phosphate ester, and phosphite used in the present invention can be changed depending on the visible and near-infrared transmittance setting of the target resin composition and the thickness of the resin composition. However, the amount of tungsten hexachloride is 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the transparent resin. If the amount of tungsten hexachloride is less than 0.01 part by weight, the near-infrared absorption ability will not be improved sufficiently (if it exceeds 10 parts by weight, the near-infrared absorption ability will not improve and it will not be dissolved in the polymerization raw material. There is a risk that some parts may remain.

The amount of phosphoric acid ester and/or phosphite ester is at least twice the amount of tungsten hexachloride,
Preferably 2 to 300 times the mole, more preferably 2 to 1
00 times the mole. When tungsten hexachloride is reacted with phosphate ester and/or phosphite, hydrogen chloride and/or alkyl chloride are produced as by-products, but the amount of phosphate and/or phosphite is twice that of tungsten hexachloride. If the amount is less than mol, chlorine may remain in the resulting reaction mixture. This causes inconveniences such as an irritating odor during compounding and polymerization, and limitations on the materials used for instruments and devices, and polymerization distortion occurs in near-infrared absorbing resin plates containing this reaction mixture. Considering these problems, it is desirable to use at least twice the molar amount. On the other hand, if the amount of the phosphoric acid ester and/or the phosphite ester is too large, that is, if the amount exceeds 500 times the mole of large tungsten chloride, the physical properties such as mechanical strength of the resin will decrease significantly, which is not preferable.

The mixture blended into the transparent resin in the present invention is
Tungsten hexachloride and phosphate ester, tungsten hexachloride and phosphite ester, or tungsten hexachloride and phosphate ester and phosphite ester are obtained as starting materials, respectively, and these raw materials are stirred so that they are thoroughly mixed. It is preferable to react while the tungsten hexachloride (WCl &) is reacted from the viewpoint of solubility and reactivity.

At this time, if the phosphate ester and/or phosphite ester is a liquid, 10! The reaction may be carried out by adding 6! or 10! in the solvent. 6 and a phosphoric acid ester and/or a phosphorous acid ester may be added to carry out the reaction. In the case of phosphoric acid esters and/or phosphorous esters that are solid at room temperature, 1016 may be added in the molten state by heating them above their melting point.
Alternatively, the reaction may be carried out after dissolving it in a solvent. The solvent is not particularly limited as long as it dissolves the mixture obtained by the reaction and the boiling point of the solvent is not significantly lower than the reaction temperature, and the amount of the solvent must be at least enough to dissolve the starting materials. Bye. The reaction conditions for obtaining this mixture include carrying out the reaction at room temperature or a temperature slightly higher than room temperature, but at a temperature below which the phosphoric acid ester or phosphite ester, which is one of the starting materials, does not cause severe decomposition. Desirably, specifically 20 to 200
The reaction is carried out at a temperature of preferably 30 to 180°C, more preferably 50 to 150°C, for 30 hours or less, preferably 0.5 to 20 hours, and more preferably 1 to 10 hours.

In terms of product quality and handling, it is preferable that the mixture thus obtained does not contain residual chlorine in the form of by-product hydrogen chloride, alkyl chloride, or other compounds; however, it does not contain substantially chlorine. For example, the amount of tungsten hexachloride in terms of compounds such as hydrogen chloride and alkyl chloride may be 0.1 times the mole or less, preferably 0.05 times the mole or less. Chlorine remaining in the mixture in the form of compounds such as hydrogen chloride and alkyl chloride can be easily removed by blowing inert gas such as nitrogen gas during or after synthesis of the mixture.

In this way, the substantially chlorine-free mixture of the present invention comprises 0.01 to 10 parts by weight of tungsten hexachloride and at least twice the molar amount of the phosphoric acid ester and/or phosphorous ester of the tungsten hexachloride. Water can be added to the reaction system for the purpose of further improving near-infrared absorption performance and stability over time. Water may be added before, during, or after the reaction of tungsten hexachloride with the phosphoric acid ester and/or the phosphorous acid ester. Also, the amount of water added is transparent resin'10
0.01 to 1 part by weight, preferably 0.01 to 1 part by weight.
It is 1 to 0.5 parts by weight.

The resin composition of the present invention contains a mixture obtained by reacting the specific amount of tungsten hexachloride with a phosphoric acid ester and/or a phosphorous acid ester, with respect to 100 parts by weight of the transparent resin. , has excellent near-infrared absorption ability and stability.

The method for producing the near-infrared absorbing resin composition of the present invention includes, for example, a method in which the mixture having near-infrared absorbing ability is mixed and contained in the transparent resin, a constituent monomer of the transparent resin, preferably the (meth) ) A method in which the above mixture is added to a polymerizable raw material such as an acrylic ester and then polymerized, or a method in which large tungsten chloride and a phosphoric ester and/or a phosphorous ester are added and mixed to a polymerizable raw material and polymerized. It will be done.

Examples of methods for mixing and containing the above-mentioned mixture in the transparent resin include extrusion molding, injection molding, press molding, and cast film forming. To obtain the product by extrusion molding or injection molding, a mixture obtained by reacting large tungsten chloride with a phosphoric acid ester and/or a phosphorous acid ester is uniformly mixed with pellets of a transparent thermoplastic resin, and this is melt-molded. Alternatively, the mixed pellets are melted to form pellets of resin containing the reactant and then transported to a melt molding machine for molding. In press molding, it is obtained by molding in a press machine.

The melt molding machine or press machine used in the present invention is a molding machine used for manufacturing ordinary molded products, sheets, and irregularly shaped products. Cast film formation involves dissolving a mixture of transparent resin and near-infrared absorbing material in a solvent to obtain a polymer solution, which is then cast onto a rotating drum, glass plate, metal plate, etc. to remove the solvent. can be obtained.

In addition, in the case of a method in which the mixture is added to a polymerizable raw material such as a constituent monomer of a transparent resin, preferably a (meth)acrylic acid ester, and polymerized, it is carried out in the presence of a radical polymerization initiator. It is desirable to add a radical polymerization initiator in an amount of 0.0001 to 2.0 parts by weight, preferably 0.01 to 1.0 parts by weight, per 100 parts by weight of the polymerizable raw material, and conduct polymerization by heating.

In addition, in the case of a method of adding the above-mentioned mixture to the polymerizable raw material of allyl diglycol carbonate and performing cast polymerization, the process is carried out in the presence of a radical polymerization initiator. It is desirable to add 0.1 to 10 parts by weight, preferably 1.0 to 5.0 parts by weight, and heat polymerize.

Specific examples of azo polymerization initiators used as such radical polymerization initiators include 2,2'-azobisisobutyronitrile, 1,1'-azobis-1-cyclohexanecarbonitrile, and 2,2'-azobisisobutyronitrile. -2,4-dimethylvaleronitrile, 22'azobis-4-methoxy-
Specific examples of peroxide polymerization initiators include 2,4-dimethylvaleronitrile, t-butylperoxyisobutyrate, l,1'-bis-t-butylperoxy-3, Examples include 3,5-trimethylcyclohexane, lauroyl peroxide, benzoyl peroxide, diisopropyl peroxycarbonate, and the like.

The polymerization is carried out in bulk, preferably in cast polymerization. A method for mold polymerization includes a method in which the above-mentioned composition is injected between two sheets of glass facing each other with the periphery sealed with a gasket and heated according to a conventional method. The polymerization temperature varies depending on the type of radical polymerization initiator used, but is generally 40 to 140°C, and the polymerization temperature in the previous stage is usually 40 to 140°C.
It is desirable that the post-90'' C1 polymerization be carried out at 100-140°C.

Further, when the near-infrared absorbing resin composition of the present invention is polymerized in the presence of a photopolymerization initiator, the photopolymerization initiator is added to 0.05 to 20 parts by weight, preferably 0.05 to 20 parts by weight, based on 100 parts by weight of the polymerizable raw material. 0.1 to 10 parts by weight, more preferably 0.2 to 10 parts by weight
It is desirable to add 5 parts by weight.

Specific examples of photopolymerization initiators include acetophenone, 2,2-jetoxyacetophenone, and 2-
Hydroxy-2-methylpropiophenone, benzophenone, 4.4'-bisdimethylaminobenzophenone, 1-hydroxycyclohexylphenylketone, t
-Butylanthraquinone, benzoin, benzoin ethyl ether, etc., and one or more of these may be used. Polymerization is achieved by applying a mixture containing the polymerizable raw material and a photopolymerization initiator as main components, for example, onto a substrate or encapsulating it in a cell, and then curing it with light. The substrates used here include, for example, glass, plastic, and metal. Furthermore, when a cell is used, at least one surface of the cell must transmit the light necessary to initiate photopolymerization, and transparent glass, plastic, etc. are suitable. As a light source for exposure, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an ultraviolet fluorescent lamp, etc. can be used.

Further, in the present invention, by adding water to the polymerization system, the near-infrared absorbing ability of the resin composition can be further improved, and the stability of the near-infrared absorbing ability over time can be further improved. The amount of water added is 0.01 to 1.0 parts by weight, preferably 0.1 to 0 parts by weight, based on 100 parts by weight of the polymerizable raw material.
．． 5 parts by weight is desirable.

In carrying out the present invention, various additives may be added, such as dyes and pigments used for coloring, antioxidants, stabilizers for ultraviolet absorption, flame retardants, desensitizers, polymerization control agents, release agents, etc. Furthermore, when used as a coating composition, such as by applying it on a substrate, an organic solvent can be added to the polymerizable raw material, and the type and amount of these additives can be determined within the range that achieves the purpose of the present invention. Can be selected arbitrarily.

The near-infrared absorbing resin composition produced in this way can be used as an optical filter or heat ray-absorbing glazing that easily imparts near-infrared absorbing ability by taking the form of a resin plate, film, coating film, etc. For example, it is suitable for heat ray absorbing materials, eye protection filters, infrared absorption filters for semiconductor light-receiving elements, and safelight filters for infrared-sensitive photosensitive materials.

〔Example〕

Hereinafter, the present invention will be explained using specific examples, but it is not limited to these examples.

In the examples, parts represent parts by weight, and the transmission spectra of the resin compositions obtained were measured with a spectrophotometer (U-3410 model, manufactured by Hitachi, Ltd.).

Example 1 Tungsten hexachloride (C
l h) Add 60.0 parts and 2 parts of JP-504124 and gradually heat the three-necked flask in an oil bath while stirring with a Teflon stirring rod/impeller to 120°C6.
A time reaction was performed. Hydrogen chloride produced as a by-product at this time was absorbed into an aqueous sodium hydroxide solution, and the amount generated was measured from the temperature change. In addition, nitrogen gas was blown into the three-necked flask to expel the by-produced butyl chloride from the three-necked flask. The amount of hydrogen chloride generated is 4.10 times the mole of tungsten hexachloride,
Butyl chloride was 1.85 times the molar amount.

19.0 parts of the obtained mixture having near-infrared absorption ability was added to 12,000 parts of methyl methacrylate in which 0.3 parts of water had been dissolved in advance, and dissolved in the same manner as in Comparative Example 1. A release agent, an ultraviolet absorber, and a polymerization catalyst were added and polymerization was carried out to obtain a resin plate having a thickness of 3Wl.

The transmission spectrum of the obtained resin plate was measured, and the results are shown in A in Figure 1. The transmission spectrum B of a normal methacrylic resin plate (Kuraray: Paraglass) with a thickness of 3 mm is shown in the same figure. As can be seen from the comparison, this resin plate has relatively good transmission beyond the visible range, but it has excellent absorption ability in the near-infrared range, which is not found in ordinary methacrylic resin plates. Moreover, no polymerization distortion was observed in this resin plate, and the appearance was very good.

Comparative Example 1 Tungsten hexachloride (Kp
&) 60.0 parts, a mixture of monobutyl phosphate and dibutyl phosphate (manufactured by Johoku Kagaku KK: product name J
P-504) 124.2 parts was added, and while stirring with a Teflon stirring rod/impeller, the three-necked flask was gradually heated in an oil bath to conduct a reaction at 120"C for 2 hours. At this time, the chloride produced as a by-product Hydrogen was absorbed into an aqueous sodium hydroxide solution, and the amount generated was measured from the change in concentration.
The mole amount was 4.2 times that of tungsten hexachloride.

19.0 parts of the obtained mixture having near-infrared absorbing ability and containing chlorine was added to 12,000 parts of methyl methacrylate in which 0.3 part of water had been dissolved in advance, and then peeled off. Zelec UN (manufactured by DuPont) as an agent
12.0 parts, Tinuvin 3 as UV absorber
27 (manufactured by Chiha Geigy) and 12.0 parts of 2.2'-azobis-2,4-dimethylvaleronitrile as a polymerization catalyst were added and mixed. This was injected into a mold made by sandwiching a gasket between two pieces of glass according to a conventional method, heated at 60°C for 5 hours, then heated at 120°C for 2 hours to complete polymerization, and then released from the cooled glass. A resin plate having a thickness of 3 mm was obtained by peeling.

Polymerization strain occurred in the area shown in FIG. 2 of the obtained resin plate, and the appearance, which is important for heat ray absorption plates and optical filters, was impaired.

〔Effect of the invention〕

As described above, the present invention provides a transparent resin containing a substantially chlorine-free mixture obtained by reacting tungsten hexachloride with a phosphoric acid ester and/or a phosphorous acid ester. Because it is an infrared absorbing resin composition and its manufacturing method, the resulting resin composition does not have any instability such as fading during the polymerization process, has excellent near-infrared absorbing ability, and has no irritating odor or corrosiveness of tungsten hexachloride. There is no need to take this into consideration, and it has a good appearance, so it is industrially useful as an optical filter, a heat ray absorbing glazing material, etc.

[Brief explanation of drawings]

FIG. 1 is a drawing showing a transmission spectrum, and FIG. 2 is a schematic external view showing the strained state of the resin plate obtained in Comparative Example 1. A; Transmission spectrum of the resin plate obtained in Example 1; B;
Transmission spectrum of normal methacrylic resin layer

Claims (3)

[Claims] (1) Obtained by reacting 0.01 to 10 parts by weight of tungsten hexachloride with phosphoric acid ester and/or phosphorous acid ester in an amount at least twice the mole of tungsten hexachloride with respect to 100 parts by weight of a transparent resin. A near-infrared absorbing resin composition comprising a substantially chlorine-free mixture. (2) The near-infrared absorbing resin composition according to claim 1, wherein the transparent resin is a (meth)acrylic acid ester resin. (3) (a) Unsaturated monomers and/or (meth)acrylic acid polyvalent ester monomers mainly composed of (meth)acrylic acid monoester monomers and which may contain polymers thereof 100 Based on parts by weight, (b) 0 tungsten hexachloride
．． A substantially chlorine-free mixture obtained by reacting 1 to 10 parts by weight of 01 to 10 parts by weight with a phosphoric acid ester and/or a phosphorous acid ester in an amount at least twice the mole of the tungsten hexachloride was added and mixed. A method for producing a near-infrared absorbing resin composition, which comprises subsequently polymerizing in the presence of a radical polymerization initiator.