JPH0645723B2 - Plastic moldings that absorb near infrared rays - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL APPLICABILITY The molded article has the following three main applications.

(1) Control of plant growth It has long been known that light affects the so-called morphogenesis of plant growth and differentiation such as seed germination, stem elongation, leaf development, flower bud and tuber formation. And is being studied as a photomorphogenic effect. In this case, red light around 660 nm and far infrared light around 720 to 730 nm act antagonistically with each other, and by changing the ratio of red light and far infrared light, flowering, heading time or degree of growth, fruit It is known that the yield and other factors change. All such work was done by controlling the light source with a combination of light source lamps and filters, making it impossible to test in large greenhouses or farms. If a plastic film that selectively absorbs light of 700 nm or more can be obtained, it will be possible to apply the above-mentioned principle to actual production situations, and it will bring great progress and benefits to institutional agriculture. For example, by covering a crop with a near-infrared absorbing film at a specific time and blocking the light of 700 nm or more, it is expected to delay the heading time or suppress the growth (Katsumi Inada "Chemical regulation of plants"). Volume 6, First
(See No. 1971) (2) Blocking heat rays Light in the near-infrared and infrared regions of 800 nm or more of the radiant energy of the sun is absorbed by an object and converted into heat energy. Moreover, most of the energy distribution is 800-2.
It is concentrated in the near infrared region of 000 nm. Therefore, the film that selectively absorbs near infrared rays is extremely effective in blocking solar heat, and can suppress an increase in indoor temperature while sufficiently incorporating visible light. It can be applied to horticultural greenhouses as well as homes, offices, shops, automobiles or aircraft windows. Especially in greenhouses, temperature control is very important, and if the temperature rises too much, the crops will be seriously damaged and eventually die. The use of near-infrared absorbing film will facilitate temperature control and enable development of new technologies such as suppressed cultivation in summer.

(3) Blocking near-infrared rays In many cases, near-infrared rays are used to drive or stop electric products such as magnetic tapes, but it is necessary to block near-infrared rays from the outside. In this case, it can also be used for absorption of external near infrared rays.

Conventional technology and problems to be solved by the invention Conventionally, for heat ray shielding, a thin metal layer deposited on the surface of a plastic film, or an inorganic compound such as FeO dispersed in glass is used. However, since these strongly reflect or absorb not only the light in the infrared part but also the light in the visible part, the internal illuminance is lowered, and it is unsuitable especially for agriculture because it causes an absolute shortage of sunshine. Especially for controlling plant growth in (1),
It is necessary to absorb light of 750 nm extremely selectively, and vapor-deposited films and the like are completely unsuitable for this purpose. Therefore, many dyes or pigments having absorption in the near infrared region are known, but none of them are satisfactory as the near infrared absorbing agent having strong absorption in the visible region.

Means for Solving the Problems In order to solve the problems described in the preceding paragraph, the inventors of the present invention have conducted extensive studies, and the following general formula (1) [In the formula (I), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkenyl group. ] The anthraquinone-based compound shown in has an absorption in the near infrared, and has a small absorption in the visible part, and has good compatibility with various resins, it is easy to form a film or the like, The present invention has been completed.

That is, the present invention is a near-infrared absorbing plastic molded article characterized by containing a compound of the general formula (I) as a near-infrared absorbing agent.

In the general formula (I), examples of the substituted or unsubstituted alkyl group represented by R ¹ and R ² include a methyl group, an ethyl group, and n.
-A linear alkyl group such as propyl group, n-hexyl group and n-dodecyl group, iso-propyl group, iso-butyl group,
sec-butyl group, tert-butyl group, branched alkyl group such as 2-ethyl-hexyl group, cycloalkyl group such as cyclohexyl group, methoxyethyl group, ethoxyethyl group, butoxyethyl group, methoxymethyl group, γ-methoxy -Alkoxyalkyl groups such as propyl group and 3-methoxy-pentyl group, aralkyl groups such as benzyl group and phenylethyl group, acyloxyalkyl groups such as acetoxyethyl group, N, N-diethylaminoethyl group, N-
Examples thereof include primary to tertiary amino-alkyl groups such as ethylaminopropyl group and γ-aminopropyl group, and hydroxyalkyl groups such as hydroxyethyl. Examples of the substituted or unsubstituted aryl group include phenyl group and naphthyl group. Base,
N, N-dialkylamino-substituted phenyl group, trifluoromethyl-substituted phenyl group, alkyl group-substituted phenyl group, alkoxy group-substituted phenyl group, halogen-substituted phenyl group,
Examples thereof include a nitro group-substituted phenyl group, an alkoxycarbonyl-substituted phenyl group and a cyano-substituted phenyl group, and examples of the alkenyl group include an allyl group, a methallyl group and a crotyl group.

As the plastic containing and holding the compound of the general formula (I), a thermoplastic plastic film is particularly suitable.

As the film material, all plastics forming a film having excellent transparency and mechanical properties can be used. For example, polyesters represented by polyethylene terephthalate, cellulose esters such as cellulose diacetate, cellulose triacetate, and cellulose acetate butyrate, polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyvinylidene chloride, vinyl chloride, vinyl acetate Examples thereof include polymers and polyvinyl compounds such as polystyrene. Among them, polyethylene and polyvinyl chloride, which are mass-produced and inexpensively available, are suitable.

The absorbent according to the present invention is a high-melting point compound, and as a method of adding and retaining the compound of the general formula (I) to the film material, a method of compounding in a plastic at the time of film production,
That is, the compound of the general formula (I) is blended, and if necessary, a stabilizer, a plasticizer, an antioxidant, an ultraviolet absorber and the like are blended, and the mixture is extruded by a T-die method, an inflation method or a calendar method. A film or sheet is formed into a film by a conventional method such as filming with, and (2) a polymer solution or dispersion containing the compound of the general formula (I) is applied to the surface of the plastic film produced by an appropriate method. There is a method of forming a near-infrared absorption layer by doing. The binder polymer used in the coating solution in the method (2) is selected from those which dissolve the compound of the formula (I) as well as possible and have excellent adhesiveness to the base film. Polymethylmethacrylate, cellulose acetate butyrate and the like are suitable for this purpose. Also in this case, various additives may be added if necessary. Thus, according to the present invention, it is possible to obtain a plastic film which is extremely excellent in the persistence of the infrared absorbing ability in the weather resistance test by using the infrared absorbing agent obtained by the industrially advantageous method.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the part in an Example shows a weight part.

Example 1 1000 parts of polyethylene resin and 1 part of di-tert-butylhydroxytoluene, 1 part of calcium stearate, 1 part of tinuvin P (manufactured by Geigy UV absorber), 1 part of dilauryl thiodipropionate, 2 parts of oleyl amide and 1,4-bis- (n-butylamino) -2,3-di-cyano-5,8-dihydroxyanthraquinone was mixed in 3 parts and molded by a T-die method at a die temperature of 220 ° C.,
A film having a thickness of 0.2 mm was obtained. The obtained film [hereinafter, referred to as film (A)] exhibited a light green color, and when measured using a multi-purpose self-recording spectrophotometer manufactured by Shimadzu Corporation, absorption in the near infrared region of 750 to 900 nm was large.

Example 2 400 parts of polyvinyl chloride resin powder, 160 parts of dioctyl phthalate, 40 parts of dioctyl adipate, 6 parts of calcium stearate, 8 parts of barium stearate and 1,4-bis- (toluidino) -2,3-dicyano-
Add 2.0 parts of 5,8-dihydroxyanthraquinone and add 1
After kneading for 10 minutes between mixing rolls heated at 00 ° C, sandwiched between the felt plates heated at 180 ° C,
A film having a thickness of 0.2 mm was obtained by pressing at a pressure of 100 kg / cm ² for 5 minutes. The obtained film [hereinafter referred to as film (B)] strongly absorbed the near infrared region of 680 to 800 nm (absorption maximum 730 nm).

Example 3 To a mixed solvent of 45 parts of acetone and 45 parts of toluene, 9 parts of polymethylmethacrylate which is a resin as a binder of an infrared absorber and 1 part of cellulose acetate butyrate were added, and 1,4-bis- ( 2 parts of γ-methoxypropylamino) -2,3-dicyano-5,8-dihydroxyanthraquinone were added and dissolved. The solution was applied to the surface of a polyvinyl chloride film having a thickness of 0.2 mm using a small gravure coater so that the dry film thickness was 10 microns, and then dried with hot air at 70 ° C to emit near infrared rays. A polyvinyl chloride film laminated with absorbing polymethylmethacrylate was obtained. The obtained film [hereinafter referred to as film (C)] strongly absorbed the near infrared region of 750 to 850 nm (absorption maximum 800 nm).

Example 4 1000 parts of polystyrene pellets and 0.5 parts of 1,4-bis- (butylamino) -2,3-dicyano-5,8-dihydroxyanthraquinone were added, and the molded product obtained by heat molding strongly received near infrared rays from the outside. Absorbed. In the box made of this molded product, the motor could be driven and stopped by disconnecting the near infrared rays regardless of the external conditions.

Test Example 1 (Resistance Test) The films (A), (B), (C) and the molded products (D) produced in Examples 1 to 4 were subjected to a weather resistance test in a weatherometer using a carbon arc lamp. . The back surface (base film side) was irradiated with light, and the change in the absorbance at each absorption maximum (800 nm) before the light resistance test was determined with the absorbance before the light resistance test being 100. The results are shown in Table 1.

Test Example 2 (Infrared ray blocking effect) 90 cm in length, 120 cm in width, 90 cm in height with a film on the side and top of a wooden frame, and an illuminance meter (TOSHIBA No. 5 illuminance meter), a Gortinsky sunshine meter and an integrated illuminance meter ( Toyo Rika Kogyo, PH-11 type) was installed. Illuminance (unit lu
x), the amount of sunlight (unit cal) and the amount of radiation in the ultraviolet, visible and infrared parts (unit mw.min / cm ² ), and converted to a relative value with the value when not covered (outdoor) as 100. The obtained results are shown in Table 2, and the film (A) of the present invention only reduces the light in the visible portion by 25%, but has the effect of reducing the amount of sunshine to about 1/2 in the infrared portion. .

Claims (1)

[Claims] 1. A near infrared absorbing plastic molded article containing a compound of general formula (I) represented by the following formula as a near infrared absorbing agent: [In the formula (I), R ¹ and R ² each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted alkenyl group. ]