CH486035A - Method of protecting an object against the harmful effects of incident near infrared radiation - Google Patents

Description

  

  <B> Method for protecting an object against the harmful effects of incident radiation </B> <B> in the near infrared </B> The present invention relates to a method for protecting an object against the harmful effects of incident radiation in the near infrared, which is characterized in that a barrier is placed between the object and the source of radiation which contains at least 0.01 g of a compound of the following formula I per 0.0929 m2 surface:

       
EMI0001.0006
    where Y is -NO2, -NHz or -NRR ', where <B> R </B> is allyl or optionally substituted, unbranched or branched alkyl having 1 to 12 carbon atoms and R' is hydrogen or the same as R, m = 0 , 1 or 2, A is either, when m = 0, a group of the formula:
EMI0001.0017
    means, or if m = 1, a group of the formula:
EMI0001.0018
    means or, if m = 2, a group of the formula:

    
EMI0001.0019
    means, where n = 1 or 2, and X represents an anion, it being possible for the benzoid and quinoid rings to be substituted.



  It will be noted that the compounds of Formula I are derivatives of two types of N, N'-substituted diamino compounds; H. of p-phenylene diamines (n = 1) and of benzidines (n = 2). If desired, the phenyl nuclei can be further substituted by groups which are inert during use, e.g. By lower alkyl or alkoxy, halogen, hydroxyl and the like.

    



  The compounds of formula I with m = 0 can be prepared from readily available starting materials by means of the reaction illustrated in the following reaction scheme:
EMI0001.0036
    
EMI0002.0001
  
EMI0002.0002
  
EMI0002.0003
    In the above formula Ia, the various substituents R and R 'can be identical or different. If desired, R or R ', when alkyl, can be further substituted by groups which are inert in use. If desired, the phenyl groups can be substituted in the same way, eg. B.

    by lower alkyl or alkoxy, halogen, hydroxyl and the like.



  The reaction of a p-nitrohalogenobenzene of the formula II with a p-phenylenediamine or benzidine of the formula III can be carried out in a suitable solvent, preferably before dimethylformamide, in the presence of an alkali such as sodium or potassium carbonate, and additionally if desired and preferably in the presence of Copper powder.



  Examples of p-nitrohalobenzenes of the formula II are, for example, p-nitrochlorobenzene, p-nitrobromobenzene, p-nitroiodobenzene, p-nitrofluorobenzene, 3,4-dichloronitrobenzene, 2-chloro-5-nitrotoluene, 2-chloro-5- nitroethyl benzene, 2-nitro-5-bromotoluene, 2-chloro-5-nitroanisole and the like.



  Examples of p-phenylenediamines of the formula III (n = 1) are, for example, p-phenylenediamine, p-toluylenediamine and the like; and examples of benzidines of the formula III (n = 2) are benzidine, 3,3'-dichlorobenzidine, o-tolidine, o-dianisidine, m-tolidine and the like.



  The compounds of the formula V can easily be prepared by reducing compounds of the formula IV. This is expediently achieved by catalytic hydrogenation in a suitable solvent, again preferably dimethylformamide. Standard catalysts for the hydrogenation of aromatic nitro compounds can be used. These include palladium on carbon and Raney nickel. The compound of formula V can be in a suitable solvent such.

   B. aqueous acetone, are reacted with the reactant RZ R'Z, which is an alkyl halide such as methyl chloride, ethyl iodide, propyl bromide, butyl iodide, hexyl bromide, octyl bromide, dodecyl bromide and the like, or an alkyl sulfate such as methyl sulfate, ethyl sulfate and the like , or an alkylarylsulfonate,

   such as methyl p-toluenesulfonate. An allyl halide such as allyl bromide can also be used. An alkali or alkaline salt, such as. B. sodium carbonate or potassium carbonate is normally also used. The reaction amounts and conditions can be chosen so that either one or two groups R per amino group are introduced.



  The conversion of compounds of the formula IA into salts of the formula I can be carried out by oxidizing the former in a solution in an organic solvent with a silver salt of a suitable acid.



       Dimethylformamide is a good solvent to use as a reaction medium. Other solvent, e.g. B. acetone can also be used. A wide variety of silver salts can be used. These include perchlorate (C104-), fluoroborate (BF4-), trichloroacetate (CC13-COO-), trifluoroacetate (CFIC00-), picrate [(NO,) 3C6H.0-],

          Hexafluoroarsenate (AsFr, -), hexafluoroantimonate (SbF6-), benzenesulfonate (Cr, H5SO.j), ethanesulfonate (C2H5S03-), phosphate (P04- -), sulfate (S04--), chloride (Cl-) and the like .



  Various aminium compounds, such as. B. Tris (p-dialkylaminophenyl) aminium salts have been proposed for use in various substrates to reduce the transmittance in the infrared region of the spectrum. Such salts absorb strongly in the near infrared region of the spectrum. However, the most effective protection occurs near 960 millimicrons. Suitable compounds capable of broad absorption at longer wavelengths in the near infrared have been desired, but have not been available in the past.

   It is therefore a primary object of the present invention to provide compounds with such broader absorption bands.



  The compounds of the formula I absorb broadly in the near infrared region of the spectrum at longer wavelengths than the compounds previously accessible. The improved absorption is obtained in the range of longer wavelengths between approx. 1000 and approx. 1800 millimeters. Many of the compounds also have desirable absorption at shorter wavelengths in the near infrared region. These compounds also transmit a useful amount of visible light.



  The radiant energy from the sun is often grouped into 3 areas, the near ultraviolet, the visible and the near infrared. Together these 3 areas cover the range of wavelengths from 0.290 microns to approximately 5.0 microns. Somewhat arbitrarily, one can view the near ultraviolet spectrum as if it covered the 0.300 to 0.400 micron area, the visible spectrum as if it covered the 0.400 to 0.700 micron area, and the near infrared spectrum as if it covered the 0.700 area covered to 5.0 microns.



  The heat from the sun is essentially due to the near infrared radiation energy. At other high-temperature body, such. B. tungsten filaments, fluorescent lamps, carbon arcs, etc., also emit energy in the near infrared region. For practical purposes, this area is often defined as falling between 0.7 and 5.0 microns, which is the area where the common sources of infrared radiation emit substantially all of their infrared energy.

    Over half of the total radiant energy emitted by the sun or electric lamps is in the near infrared region.



  This is shown in the tables below.
EMI0003.0024
  
    <I> Table <SEP> 1 </I>
<tb> Approximate <SEP> distribution <SEP> of the <SEP> radiant energy
<tb> from <SEP> different <SEP> energy sources
<tb> / o <SEP> of the <SEP> total <SEP> emitted
<tb> radiant energy
<tb> about
<tb> 0.3-0.4 <SEP> <I> fl </I> <SEP> 0.4-0.7 <SEP> <I> u </I> <SEP> 0.6-1 , 6 <SEP> p <SEP> 0.7 <SEP> y
<tb> sunlight <SEP> (that
<tb> reached <SEP> earth <SEP>) <SEP> 5 <SEP> 42 <SEP> 54 <SEP> 53
<tb> tungsten lamp, <SEP> 500 <SEP> W <SEP> 0.1 <SEP> 10 <SEP> 53 <SEP> 90
<tb> fluorescent lamp <SEP> 5 <SEP> 35 <SEP> 28 <SEP> 60
<tb> Carbon filament heater <SEP> 0 <SEP> 1 <SEP> 28 <SEP> 99
<tb> <SEP> not lit <SEP> heater <SEP> 0 <SEP> 0 <SEP> 1,3 <SEP> 100 Accordingly, it can be seen

   that a large proportion of the energy sent out by our ordinary light sources does not serve any useful purpose in terms of lighting, but rather contributes to the development of heat in the material receiving the radiation.
EMI0003.0025
  
    <I> Table <SEP> Il </I>
<tb> Approximate <SEP> distribution <SEP> of the <SEP> radiant energy
<tb> of the <SEP> sunlight
<tb> Area <SEP>% <SEP> of the <SEP> entire <SEP> / o <SEP> of the <SEP> infrared
<tb> radiation <SEP> radiation
<tb> 0.3-0.4 <SEP> 5 <SEP> 0.4-0.7 <SEP> 42 <SEP> 0.7-1.0 <SEP> 23 <SEP> 43.5
<tb> 1.0-1.3 <SEP> 12 <SEP> 22.5
<tb> 1.3-1.6 <SEP> 4.5 <SEP> 8.5
<tb> 1.6-1.9 <SEP> 4.5 <SEP> 8.5
<tb> 1.9-2.7 <SEP> 5 <SEP> 9.5
<tb> 2.7-up <SEP> 4 <SEP> 7.5 This table shows

   that within the near infrared area the greater part of the infrared radiation is emitted within the area of approx. 0.7 to approx. 2.0 microns. For example, in normal sunlight, about? / S of the radiation energy at wavelengths of about 0.7 to about 1.3 microns.



  It can also be seen in Table II that about 43 to 44% of the total infrared radiation in sunlight in the area is just above about 0.7 microns. The latter is approximately the upper limit of the visible range, which, as stated above, is usually defined as lying between approximately 0.4 and 0.7 14 microns, hence the designation near infrared.

   Although in the above definition the near infrared area only extends down to about 0.7 microns, for the purposes of this invention the area of particular interest extends from about 0.65 microns to about 1.3 Micron. In the following discussion this area will be referred to as (NIR).



  In many circumstances it is desirable to filter out invisible radiations of the near infrared region without the permeability; of visible radiation. There are many potential uses for materials that transmit a predominant part of the visible radiation, but at the same time for heat-generating infrared radiation, in particular that in the above-mentioned (NIR), is at least semi-opaque. As such possible applications, sun glasses, welding glasses and other filters that protect the eyes, windows, television filters, projection lenses and the like can be mentioned.

   In many, if not most, such uses, the primary objective is to protect the human eye from the deleterious effects of near infrared radiation.



  Experience has shown that, as an illustrative example, sun glasses should be able to transmit at least about 10 0lo of the incident visible light of shorter wavelengths than about 0.65 microns. However, in order to provide adequate protection to the human eye, the permeability should be less than 40.0 at about 0.65 to 0.75 microns and between about 0.75 and about 0.95 Microns not exceeding 10; 'o. Preferably, about 20% or more of the visible light is transmitted.

   In the two other noted areas, the permeability should preferably not exceed 5010 or 1%. Other optical protective filters can vary with regard to the requirements for the visible range. In most cases, however, the near infrared transmission should not exceed the stated limits.

   This applies, for example, not only to other eye protection devices that are so far different, such as welding goggles and window glass, but also to the protection of inanimate material, as in the case of projection lenses. Optimal use of protection therefore usually requires relatively good permeability for radiation below about 0.65 microns, but reduced or minimized permeability above that value. Obviously a complete cutoff is impossible at exactly this or any other wavelength.

   Nonetheless, for the purposes of the present invention, the clipping should be as sharp as possible within a minimum spread of wavelengths at about 0.65 microns.



  Various organic plastic substrates are available which generally have suitable permeability properties in the visible area. Examples include cellulose derivatives, such as. B. cellulose nitrate, cellulose acetate and the like, regenerated cellulose and cellulose ethers, such as. B. ethyl and methyl cellulose, Polystyrol_kunststoffe such. B.

   Polystyrene per se and polymers and copolymers of various styrenes substituted on the ring, such as. B. o-, m- and p-methylstyrene and other styrenes substituted on the ring, and styrenes substituted on the side chain, such as.

   B. a-methyl and -Atliylstyrol, and various other polymerizable and copolymerizable vinyl idene, various vinyl polymers and copolymers, such as.

   B. polyvinyl butyral and other acetals, polyvinyl chloride, polyvinyl acetate and its hydrolysis products, polyvinyl chloride acetate copolymers and the like, ver different acrylic resins, such as. B.

   Polymers and copolymers of 1-methyl acrylate, methyl methacrylate, acrylamide, methylol acrylamide, acrylonitrile and the like, polyolefins, such as. B. polyethylene. Polypropylene and the same, polyester and unLesättiate modified poly ester resins, such as.

   B. those prepared by condensation of polycarboxylic acids with polyhydric phenols or modified by using uncytic carboxylic acids or further modified by reacting the alkyd resin with another ionomer,

    Polymers of allyl diglycol carbonate and various copolymers using an allyl ester of various acids as a crosslinking monomer. Cellulose acetate, methyl methacrylate, polystyrenes and polymers of allyl diglycol carbonates are of particular interest and preferred as substrates here.



  Any such substrate may vary and will usually differ very markedly from the others in its transmittance to radiant energy at various NN lengths. If not modified, none of the above transmission requirements will nonetheless be met. Some additive is required to reduce infrared transmission without adversely affecting transmission in the visible region.



  The heat resistance of the salts of the formula I (m = 1 or 2) can be determined when the aminium salts are dispersed in organic polymeric materials or when they are dissolved in suitable solvents. They are adequately resistant to being exposed to temperatures of up to approx. 200 C. This temperature often occurs when processing organic polymeric materials, e.g. B. those discussed above. Accordingly, the compounds of formula I are suitable for the purpose of use in such cases.



  The compounds of formula 1 have good light and heat stability when they are incorporated into organic plastic substrates. So far, a satisfactory absorption of radiation energy in the Be rich from 1000 to 2000 millimicrons (as it is emitted by the sun or other light sources) through transparent plastics was not possible. This part of the infrared radiation is a considerable part of the total infrared radiation from sunlight, incandescent lamps and other lamps.



  For use, the salts of the formula I (m = 1 or 2) can be incorporated into any suitable plastic or applied to suitable transparent substrates made of plastic or glass. This can be carried out using any known method, for example by pouring from solution or dipping, hot rolling, applying with the polishing steel or dyeing. Organic plastic materials containing the salts can be made into molded articles, e.g. B. foils and plates, are pressed.



  Any practical embodiment can be used to form a protective barrier between an object to be protected and the source of infrared radiation. Protection is generally achieved by combining salt and organic substrate in a relatively thin layer or a relatively thin sheet-like material, which is then used as a protective barrier. Protection of an article can also be achieved by applying the salts in a suitable carrier directly as a coating to substrates such as glass or molded plastic articles, either to protect the substrate or to form a protective barrier for other articles.



  It is not easy to set limits on the amount that is appropriate to use. In general, the upper limit results from economic considerations. The minimum quantity is 0.01 g per 0.0929 m2 surface of the item.



  The compounds of the formula I can be used in many ways because of the valuable combination of infrared absorption capacity and transparency for visible light. The applications can be classified in such a way that they fall into three main areas according to the function of the infrared absorber.



  In the first area of application, these compounds serve to filter out infrared radiation and prevent it from being transmitted through a substrate on or in which these compounds are dispersed. Specific applications in this area are the use in sunglasses. Schiveisser goggles or protective shields, astronaut face plates and face plates in reflective protective suits for firefighters, where permeability for visible light coupled with protection of the eyes from infrared radiation is desired.

   These compounds can also be incorporated into transparent sheet-like plastic materials or transparent plastic films for windows, doors, skylights, etc. in buildings, greenhouses, automobiles, aircraft, ships, etc. in order to filter out infrared radiation and the build-up of heat inside such cones Reduce restrictions to the minimum value while still allowing visible radiation to pass through. In such applications, these compounds can be dispersed in or on a rigid plastic substrate or can be dispersed in a thin plastic film that can be used alone or adhering to an untreated substrate, which can be glass or plastic.

   For example, in automotive safety glass windshields, the plastic intermediate layer between the two glass plates can contain the infrared absorber. Also for commercial, office or residential windows, a plastic film containing these compounds can adhere to the glass or be hung as a window dressing directly inside the window and, when it is not needed, be rolled up.

    For sunglasses, airplane windows and skylights, these compounds can be incorporated into the plastic from which such objects are made, either as a uniform dispersion throughout the object or as a barrier layer adjacent to a surface thereof.



  In the second area of application, these compounds serve to absorb infrared radiation and accumulate it as heat in order to raise the temperature of the materials containing these compounds. These compounds can thus be applied to natural or synthetic fibers used in clothing to make such clothing warmer in cold climates, although such clothing can be a light color.

   Likewise, these compounds can be dissolved in water or incorporated into plastic particles, flakes or strips of plastic that float on water to reduce the evaporation rate of the water (or another liquid) by solar or other infrared radiation for the purpose of generating distilled water or to increase the salt concentration in the remaining liquor or to extract salt from the solution.

   Furthermore, these compounds can be incorporated into materials to improve drying speeds without significantly changing the color of such materials, such as colored inks, paints, enamels, bathing suits, etc. In the same way, the incorporation of these compounds in polymerizable materials can serve to increase the rate of polymerization under infrared radiation by increasing the effectiveness with which such radiation is absorbed.

   Since different colors absorb radiation at different speeds, varying amounts of these compounds can also be incorporated into inks, paints, or enamels of different colors to modify their drying speeds to make them uniform regardless of color, which makes it easy to use. Uniformity and economic efficiency when processing objects coated with it is important.



  Various processes that are currently in technical operation use powdered inks that are applied to paper or other substrates and are melted in place by infrared radiation. In some reproduction and copier systems, the powdered ink mixtures, which contain carbon black (for infrared absorption and optical contrast with the background) and thermoplastic polymer resins, are either electrostatically attracted to the desired location on metal and then transferred to paper or directly onto specially coated paper. Previously, only black inks could be used in such processes.

   The present compounds can provide the necessary infrared absorption while allowing pigments of various colors to be used in such processes. Powdered inks are also used to provide a raised print on greeting cards, matchboxes, business cards, etc. by a process which consists of printing a pattern on paper with a clear adhesive mixture and then covering it with the powdered ink, which only sticks to the surfaces printed with adhesive. This paper is then passed under a source of infrared in order to melt the ink and fix it.

   The incorporation of these compounds into these inks can reduce the heat required from the infrared source, increase the rate at which the inks can be melted, and allow a wider range of colors to be used without the risk of scorching the paper background before the powdered ink has hardened and allow the use of light colored inks on dark colored background paper without scorching the dark paper.



  Some photothermographic systems of photo reproduction, such as. B. the Thermofax system for copying, use a paper that is coated in order to make it more heat-sensitive during the development of the image by irradiation with infrared radiation. The incorporation of these compounds into the surface coating of the paper used for these and similar processes makes the paper even more heat sensitive without loss of contrast between the print and the background, thereby enabling lower working temperatures or faster operation of copiers using such paper .



  Microencapsulation is the process of pulling materials in the form of small spheres or capsules (diameter from approx. 1 to? 00 \ vIikron) with natural or synthetic polymeric materia lien, such as. B. polymethyl methacrylate. The coating holds the contents in a finely divided state in each individual ball until they are released for use by breaking the capsule walls, which is achieved by mechanical means such. B. pressure, or by application of heat such. B. irradiation with radiation energy can happen.

   The incorporation of the compounds according to the invention in the coating makes the wall more sensitive to breakage by exposure to infrared radiation, which means that less irradiation time or infrared radiation with a lower intensity is required to effect the breakage. By using different elements of these compounds in the coatings of different capsules, such capsules can also be made to break when different amounts of radiation are absorbed, whereby a registration of the relative amounts of infrared radiation which impinge on any surface containing mixtures of such capsules is produced.

        In addition, these connections can serve to increase the effects of infrared radiation falling on sensing elements, if such elements are coated with such connections, which the amplification circuits for converting signals from such elements into usable currents or voltages simplified. Accordingly, sensing elements for the fire detection devices can be treated to make them more sensitive to the presence of flames.

   Sensing elements can also be treated in data processing machines to make them more sensitive to the effects of heat, where they are used to drive electrical circuits.



  In the third area of application, these compounds work through a mixed selection of mechanisms. This category includes such uses as the incorporation of these compounds in colored inks for use in ballpoint pens or other pens so that such inks can be produced by those processes such as e.g. B. Thermofax, which rely on the infrared absorption by the ink on the document being copied, can be reproduced. Currently, carbon black must be used, which limits the inks to black inks for this purpose.

   The incorporation of such compounds in face creams and dyes for clothing and other fabrics can also serve to make the wearer invisible to infrared detection devices, such as B. for the Sniperscope or Snooperscope, which by Re flexion of infrared radiation from the object, z. B. soldiers, tents, nets over cannons, etc., should be discovered back after a detector. Next, the incorporation of such compounds in the colors used to cover non-luminous radiation surfaces such. B.

   Steam or hot water radiators, radiant heating wall, floor or ceiling panels are used to increase the effectiveness of the radiation of thermal energy from such bodies into the environment, even if the colors are light in color or have metallic pigments contain.

      Since the growth rate of plants is sensitive to the wavelengths of incident light, the interposition of a film or sheet material containing these compounds between such plants and the radiation energy source can serve to modify this speed. For example, the germination of latich seeds and the like is most promoted at around 650 millimicrons and most inhibited at around 730 millimicrons.

   By appropriate selection of these compounds and the concentration in such a film or sheet material, virtually all radiation at 730 millimicrons can be absorbed while a large proportion of the radiation at 650 millimicrons can be transmitted to these plants to maximize the germination rate bring.



  The foregoing indicates only a few of the numerous uses for these compounds. From this list and the properties of these compounds discussed elsewhere in this specification, many other uses for these compounds can be immediately apparent. The invention is further illustrated in connection with the following examples. Unless otherwise noted, all parts and percentages are given by weight and all temperatures are given in degrees Celsius.



  <I> Example 1 </I> N, N, N ', N'-Tetrakis- (p-nitrophenyl) -p-phenylenediamine
EMI0006.0035
    A mixture of 10.8 parts (0.1 mol) of p-phenylenediamine, 94.5 parts (0.6 mol) of p-nitrochlorobenzene, 31.7 parts (0.23 mol) of potassium carbonate and 2 parts of copper powder is used Stirred in 150 parts of dimethylformamide for 48 hours and heated to reflux.

   The mixture is then filtered and the solid substance is washed well with dimethylformamide, water and acetone and then dried. About 37 parts (59%) of a red-brown solid substance with a melting point of 387 to 390 ° C. are obtained.

   An 8-fold approach gave a yield of 76% of product which melts at 390.degree. After recrystallization from nitrobenzene, a sample had a melting point of 390 to 392 C and the following analysis:

    
EMI0006.0069
  
    Ber. <SEP> for <SEP> C90HQ0Ne08: <SEP> C <SEP> 60.8; <SEP> H <SEP> 3.4; <SEP> N <SEP> 14.2
<tb> Found: <SEP> C <SEP> 60.7; <SEP> H <SEP> 3.5; <SEP> N <SEP> 13.9 <I> Example 2 </I> N, N, N ', N'-Tetrakis- (p-nitrophenyl) -p-benzidine
EMI0006.0071
    A mixture of 9.2 parts (0.05 mol) benzidine, 47.3 parts (0.3 mol) p-nitrochlorobenzene, 16.6 parts (0.12 Mo () anhydrous potassium carbonate, 1.0 part of copper powder and 75 parts of dimethylformamide is stirred and refluxed for 4 days.

   The mixture is then filtered, washed well with dimethylformamide, water and acetone and dried. Approx. 24.0 parts of an orange powder are obtained (71% yield). Melting point 370 to 374 C.



  <I> Examples 3 to II </I> The p-nitrochlorobenzene and p-phenylenediamine or benzidine [of the formulas (II) or (11I) 1 are replaced by various materials in the process of Examples 1 or 2. The starting materials and products are shown in Table III below.

        <I> Table 1l1 </I> <I> Starting materials </I>
EMI0007.0001
  
    Example <SEP> of the <SEP> formula <SEP> (II) <SEP> of the <SEP> formula <SEP> (III)
<tb> No.
<tb> 3 <SEP> p-nitrobromobenzene <SEP> p-phenylenediamine
<tb> 4 <SEP> p-nitroiodobenzene <SEP> p-tolylenediamine
<tb> 5 <SEP> 3,4-dichloronitrobenzene <SEP> chloro-p-phenylenediamine
<tb> 6 <SEP> 3,4-dichloronitrobenzene <SEP> benzidine
<tb> 7 <SEP> 2-chloro-5-nitrotoluene <SEP> o-tolidine
<tb> 8 <SEP> 2-chloro-5-nitroethyl- <SEP> o-dianisidine
<tb> benzene
<tb> 9 <SEP> p-nitrochlorobenzene <SEP> m-tolidine
<tb> 10 <SEP> p-nitrochlorobenzene <SEP> 3,3'-dichlorobenzidine
<tb> 11 <SEP> 2-chloro-5-nitroanisole <SEP> p-phenylenediamine <I> products of the formula (IV) </I>
EMI0007.0002
  
    example
<tb> No.
<tb> 3 <SEP> Product <SEP> from <SEP> Example <SEP> 1
<tb> 4 <SEP> N, N, N ', N'-Tetrakis- (p-nitrophenyl)

  -p-toluene diamine
<tb> 5 <SEP> N, N, N ', N'-Tetrakis- (o-chloro-p-nitrophenyl) chloro-p-phenylenediamine
<tb> 6 <SEP> N, N, N ', N'-Tetrakis- (o-chloro-p-nitrophenyl) benzidine
<tb> 7 <SEP> N, N, N ', N'-Tetrakis- (o-methyl-p-nitrophenyl) o-tolidine
<tb> 8 <SEP> N, N, N ', N'-tetrakis- (o-ethyl-p-nitrophenyl) -o dianisidine
<tb> 9 <SEP> N, N, N ', N'-Tetrakis- (p-nitrophenyl) -m-tolidine
<tb> 10 <SEP> N, N, N ', N'-Tetrakis- (p-nitrophenyl) -3,3'-dichlorobenzidine
<tb> 11 <SEP> N, N, N ', N'-Tetrakis- (o-methoxy-p-nitrophenyl) p-phenylenediamine <I> Example 12 </I> N, N, N', N'- Tetrakis (p-aminophenyl) -p-phenylenediamine
EMI0007.0004
    A mixture of 29.6 parts (0.05 moles of N, N, N ', N'-tetrakis- (p-nitrophenyl)

  -p-phenylenediamine (from example 1), one part of 10% palladium-on-carbon catalyst and 100 parts of dimethylformamide is hydrogenated at 90 ° C. in a hydrogenation autoclave until the theoretical pressure drop is obtained. The mixture is filtered and the filtrate poured into 300 parts of water.

   The solid substance that separates out is recrystallized from a mixture of ethanol and dimethylformamide, giving approx. 15 parts (64%) of the purified product which melts above 300 ° C and has the following analysis:

    
EMI0007.0029
  
    Ber. <SEP> for <SEP> CsoHQ8Ne: <SEP> C <SEP> 76.2; <SEP> H <SEP> 5.97; <SEP> N <SEP> 17.8
<tb> Found: <SEP> C <SEP> 76.1; <SEP> H <SEP> 5.97; <SEP> N <SEP> 17.8 <I> Example 13 </I> N, N, N ', N'-Tetrakis- (p-aminophenyl) -benzidine
EMI0007.0031
    A mixture of 24.0 parts (0.035 mol) of N, N, N ', N'-tetrakis- (p-nitrophenyl) -benzidine (from Example 2),

   1 part of 10% palladium-on-carbon catalyst and 100 parts of dimethylformamide is hydrogenated in a hydrogenation autoclave at 80 ° C. until the theoretical pressure drop is observed. The mixture is filtered and the filtrate is diluted with 300 parts of water. The solid substance, which is switched off, is recrystallized from a mixture of dimethylformamide and ethanol, giving about 11.2 parts (55.0, '0 yield) of the product, which melts at 313-316C.

    
EMI0007.0046
  
    Ber. <SEP> for <SEP> Ca0H3: N0: <SEP> C <SEP> 78.8; <SEP> H <SEP> 5.84; <SEP> N <SEP> 15.3
<tb> Found: <SEP> C <SEP> 77.9; <SEP> H <SEP> 5.90; <SEP> N <SEP> 16.7 <I> Examples 14-21 </I> In the procedure of Example 12 or 13, the products of Examples 3-11 are used in place of the p-phenylenediamine or benzidine compound of that example . The products are shown in the following table IV.



  <I> Table IV </I>
EMI0007.0051
  
    Output connection
<tb> Example <SEP> from <SEP> For No. <SEP> play <SEP> No. <SEP> Product <SEP> of the <SEP> formula
<tb> 14 <SEP> 4 <SEP> N, N, N ', N'-tetrakis- (p-amino phenyl) -p-tolylenediamine
<tb> 15 <SEP> 5 <SEP> N, N, N ', N'-Tetrakis- (o-chloro-p-aminophenyl) -chlor-p-phenylenediamine
<tb> 16 <SEP> 6 <SEP> N, N, N ', N'-Tetrakis- (o-chloro-p aminophenyl) -benzidine
<tb> 17 <SEP> 7 <SEP> N, N, N ', N'-Tetrakis- (o-methyl-p aminophenyl) -o-tolidine
<tb> 18 <SEP> 8 <SEP> N, N, N ', N'-tetrakis- (o-ethyl-p aminophenyl) -o-dianisidine
<tb> 19 <SEP> 9 <SEP> N, N, N ', N'-tetrakis- (p-amino phenyl) -m-tolidine
<tb> 20 <SEP> 10 <SEP> N, N, N ', N'-tetrakis- (p-amino phenyl) -3,3'-dichlorobenzidine
<tb> 21 <SEP> 11 <SEP> N, N, N ', N'-Tetrakis- (o-methoxy-p aminophenyl) -p-phenylenediamine The compounds of the formula (V) are as in the following reaction scheme (C )

   shown converted into appropriately substituted N, N, N ', N'-derivatives.
EMI0008.0002
    where R is allyl or an alkyl having 1 to 12 carbon atoms, R1 is hydrogen or R and n is 1 or 2 and RZ is an alkyl ester of an inorganic acid.



  The amino compound of formula (V) is dissolved in a suitable solvent such as e.g. B. aqueous acetone, reacted with the reactant RZ, which is an alkyl halide, such as. B. methyl chloride, ethyl iodide, propyl bromide, butyl iodide, heryl bromide, octyl bromide, dodecyl bromide and the like, or an alkyl sulfate, such as.

   B. methyl sulfate, ethyl sulfate and the like, or an alkylarylsulfonate, such as. B. methyl p-toluenesulfonate may be. It can also be an allyl halogen such as e.g. B. allyl bromide can be used. An alkali or alkali cal salt, such as. Such as sodium carbonate or potassium carbonate is usually also used.

   The reaction menoen and conditions are chosen so that either 1 or 2 groups R per amino group <I> Example 24 </I> N, N, N ', N'-tetrakis- (p-di-n-propylaminophenyl) - p-phenylenediamine
EMI0008.0030
    The procedure of Example 22 is followed using an equivalent amount of - n-propyl iodide in place of the ethyl iodide. The product melts at 157 to 158 C. The analysis follows. be introduced. A typical illustration is shown in the following examples.



  <I> Example 22 </I> N, N, N ', N'-Tetrakis- (p-diethylaminophenyl) -p-phenylenediamine
EMI0008.0039
    A mixture of 14.2 parts (0.03 mol) of N, N, N ', N'-tetrakis- (p-aminophenyl) -p-phenylenediamine (from Example 12), 56.2 parts (0.36 mol ) Ethyl iodide and 33.1 parts (0.24 mol) of potassium carbonate are stirred in 200 parts of 80% aqueous acetone for 4 hours and heated to reflux. The mixture is then cooled and filtered.

   The collected solid substance is washed with water, dried and then recrystallized from a mixture of dimethylformamide and ethanol. The product is obtained as a yellow-green solid substance with a melting point of 214 to 215.degree. His analysis follows:
EMI0008.0050
  
    Ber. <SEP> for <SEP> C "H" Ne: <SEP> C <SEP> 79.3; <SEP> H <SEP> 8.7; <SEP> N <SEP> 12.1
<tb> Found: <SEP> C <SEP> 79.2; <SEP> H <SEP> 8.7; <SEP> N <SEP> 12.0 <I> Example 23 </I> N, N, N ', N'-tetrakis- (p-dimethylaminophenyl) -p-phenylenediamine
EMI0008.0053
    The procedure of Example 22 is followed using an equivalent amount of methyl iodide in place of the ethyl iodide.

   The product melts at 271 to 273 C. Analysis follows.
EMI0008.0057
  
    Ber. <SEP> for <SEP> C "H, oNo: <SEP> C <SEP> 78.0; <SEP> H <SEP> 7.5; <SEP> N <SEP> 14.4
<tb> Found: <SEP> C <SEP> 77.2; <SEP> H <SEP> 7.7; <SEP> N <SEP> 14.5
EMI0008.0058
  
    Ber. <SEP> for <SEP> C "H, 2No: <SEP> C <SEP> 80.2; <SEP> H <SEP> 9.5; <SEP> N <SEP> 10.4
<tb> Found: <SEP> C <SEP> 80.0; <SEP> H <SEP> 9.7; <SEP> N <SEP> 10.9 <I> Example 25 </I> N, N, N ', N'-tetrakis- (p-di-n-butylaminophenyl) -p-phenylenedianmin
EMI0009.0002
    The procedure of Example 22 is followed using an equivalent amount of n-butyl iodide in place of the ethyl iodide.

   The product melts at 92 to 94 C. Analysis follows.
EMI0009.0007
  
    Ber. <SEP> for <SEP> C82Ho2No: <SEP> C <SEP> 80.8; <SEP> H <SEP> 10.1; <SEP> N <SEP> 9.1
<tb> Found: <SEP> C <SEP> 81.1; <SEP> H <SEP> 9.6;

   <SEP> N <SEP> 9.3 <I> Example 26 </I> N, N, N ', N'-Tetrakis- (p-diethylaminophenyl) -benzidine
EMI0009.0009
    A mixture of 11.0 parts (0.02 mol) of N, N, N ', N'-tetrakis (p-aminophenyl) benzidine (from Example 13), 37.4 parts (0.24 mol) of ethyl iodide, 22.1 parts (0.16 mol) of anhydrous potassium carbonate and 160 parts of 80% aqueous acetone is stirred and refluxed for 5 hours.

   The mixture is cooled and filtered, and the solid is washed well with water and then with acetone and dried. The product is recrystallized from hot dimethylformamide, giving a solid, approx. 9.5 parts (62% yield) with a melting point of 213 to 214.5 ° C.
EMI0009.0030
  
    Ber. <SEP> for <SEP> C "H" N8: <SEP> C <SEP> 80.83; <SEP> H <SEP> 8.29; <SEP> N <SEP> 10.88
<tb> Found: <SEP> C <SEP> 78.21; <SEP> H <SEP> 8.13;

   <SEP> N <SEP> 11.49 Compounds of the formula (VI) are then oxidized to the protective aminium or dimonium salts desired as the end product by oxidation of the amino compounds. This is carried out in a solution in an organic solvent by reacting the p-phenylenediamine or benzidine compound (V1) with a silver salt of a suitable acid.



       Dimethylformamide is a good solvent to use as a reaction medium. Other solvents, such as. B. acetone, who used the. A wide variety of silver salts can be used.

   These include perchlorate (CIOä), fluoborate (BF ;-), trichloroacetate (CC13C00-), trifluoroacetate (CF'COO-), picrate (N02) sC, H20-, hexafluoroarsenate (AsFe), hexafluoroantimonate ( SbFe), benzenesulfonate (C, H, S03),

       Ethanesulfonate (C_H, SOS-), phosphate (PO, =), sulfate <B> (SO, -), </B> chloride (Cl-) and the like.



  Oxidation of an amino group of compounds of the formula (VI) produces aminium compounds of the following formula (VII):
EMI0009.0067
    and of two amino groups the diimonium compounds of the following formula (VIII):
EMI0009.0072
    wherein, as above, R is allyl or alkyl having 1 to 12 carbon atoms, R, hydrogen or R, n is an integer of 1 or 2 and X is an anion.



  This is shown in the following examples, which are typical of the general procedure. <I> Example 27 </I> Bis- (p-diethylaminophenyl) - [N, N-bis- (p-diethylaminophenyl) -p-aminophenyl] -aminium hexafluoroarsenate
EMI0010.0002
    To a solution of 3.49 parts (0.005 mol) of N, N, N ', N'-tetrakis- (p-diethylaminophenyl) -p-phenylenediamine (product of Example 22) in 25 parts of hot dimethylformamide, 1.49 Parts (0.005 mol) of silver hexafluoroarsenate are added to 25 parts of dimethylformamide.

   After stirring for half an hour, the mixture is filtered and the filtrate is diluted with 350 parts of ether. The product separates out on cooling in a mixture of dry ice and acetone. About 3.5 parts of a green solid substance with a melting point of 184 to 185 ° C. are obtained.

      <I> Example 28 </I> Bis- (p-diethylaminophenyl) - [N, N-bis- (p-diethylaminophenyl) -4'-aminobiphenylyl] -aminium hexafluoroarsenate
EMI0010.0014
    To a solution of 0.77 parts (0.001 mol) of N, N, N ', N' -Tetrakis- (p-diethylaminophenyl) -benzidine (product of Example 23) in 40 parts of acetone, a solution of 0, Added 30 parts (0.001 mol) of silver hexafluoroarsenate in 5 parts of acetone. After stirring for about 5 minutes, the mixture is filtered and the filtrate is diluted with 200 parts of ethyl ether.

   On cooling in dry ice and acetone, a green solid separates out, 0.71 part of product. <I> Example 29 </I> N, N, N ', N'-Tetrakis- (p-diethylaminophenyl) -p-benzoquinone-bis- (imonium hexafluoroantimonate)
EMI0010.0023
    1.38 parts are added to a stirred mixture of 1.39 parts (0.002 mol) of N, N, N ', N'-tetrakis (p-diethylaminophenyl) - p-phenylenediamine (product of Example 22) in 20 parts of acetone (0.004 mol) of silver hexafluoroantimonate was added.

   After stirring for half an hour, the dark blue solution is filtered and the filtrate is diluted with 100 parts of ether. The mixture is cooled and the solid that separates out is collected, washed with ether and petroleum ether and dried. 2.1 parts of product are obtained which melts at 216 ° C. with decomposition. Compounds of formula (VII) and (VIII) absorb broadly in the near infrared region of the spectrum at longer wavelengths than those obtained with previously available compounds. Improved absorption is achieved in the area of longer wavelengths between approx.

      1000 and 18,000 millimicrons obtained. Many of the compounds also have desirable absorption at shorter wavelengths in the near infrared region. These compounds also transmit a useful amount of visible light. Example <I> 30 </I> N, N, N ', N'-Tetrakis- (p-dioctylaminophenyl) -p-phenylenediamine
EMI0011.0009
    The procedure of Example 29 is followed using an equivalent amount of octyl iodide in place of the ethyl iodide.



       Example <I> 31 </I> N, N, N ', N'-Tetrakis- (p-didodecylaminophenyl) -p-phenylenediamine
EMI0011.0015
    The procedure of Example 29 is followed using an equivalent amount of dodecyl bromide in place of the ethyl iodide.



  <I> Example 32 </I> N, N, N ', N'-Tetrakis- (p-ethylaminophenyl) -p-phenylenediamine
EMI0011.0019
    The procedure of Example 29 is followed using 18.7 parts (0.12 moles) of ethyl iodide and 16.6 parts (0.12 moles) of potassium carbonate in place of the amounts used therein.



  <I> Example 33 </I>
EMI0011.0024
    A series of aminium compounds of the formula above are prepared using the general procedure of Example 27 using the appropriate N, N, N ', N'-tetrakis (p-dialkylaminophenyl) p-phenylenediamine and silver salt.

    
EMI0011.0030
  
    <B> R </B> <SEP> X <SEP> Melting point <SEP> (C)
<tb> a <SEP> CH, <SEP> AsFe <SEP> 180-182
<tb> b <SEP> CH, <SEP> SbF, <SEP> 184-185
<tb> c <SEP> C, H, <SEP> SbF, <SEP> 186-187
<tb> d <SEP> C, H, <SEP> BF4 <SEP> 170-172
<tb> e <SEP> n-C, H, 1 <SEP> AsF, <SEP> 214-216
<tb> f <SEP> n-C, H, I <SEP> SbFe <SEP> 215-216
<tb> g <SEP> n-CQH, <SEP> AsFe <SEP> 170 =
<tb> h <SEP> n-C, H, <SEP> SbF, <SEP> 175 =
<tb> i <SEP> C8H1, <SEP> SbFe
<tb> j <SEP> C1pH = 5 <SEP> SbFe <SEP> 3
<tb> <B> '</B> The <SEP> filtrate <SEP> is <SEP> diluted with <SEP> an <SEP> equal <SEP> volume <SEP> ethanol <SEP>
<tb> $ <SEP> Approximately
<tb> <B> 3 </B> <SEP> Not <SEP> determined <I> Example 34 </I> Bis- (p-ethylaminophenyl) - [N, N-bis- (p-ethylaminophenyl)

  -p-aminophenyl] -aminium hexafluoroarsenate
EMI0012.0002
    The procedure of Example 39 is repeated, using an equivalent amount of N, N, N ', N'-tetrakis- (p-ethylaminophenyl) -p-phenylenediamine (product of Example 32) in place of the N, N, N', N '-Tetrakis- (p-diethyl-aminophenyl) -p-phenylenediamines used. <I> Example 35 </I>
EMI0012.0007
    Two aminium compounds of the above formula were prepared using the procedure of Example 28 using an equivalent amount of the appropriate silver salt in place of the silver hexafluoroarsenate as shown below.

    
EMI0012.0010
  
    Connection <SEP> X
<tb> a <SEP> C10,
<tb> b <SEP> SbFe The spectral absorption curves of solutions in organic solvents of the salts according to the invention were determined in the visible and near infrared regions at 0.35 to 2.00 microns. For this purpose, a registration spectrophotometer provided with a near infrared device and a tungsten light source is used.

   The wave length of the maximum absorption (@ ma @.) Is determined from the curve. The absorbance at the wavelength of maximum absorption, which is referred to as (a. ".,.), Is an expression of the absorbance. It is calculated using the following relationship.

    
EMI0012.0021
    wherein
EMI0012.0022
  
    a <SEP> = <SEP> absorption capacity,
<tb> b <SEP> = <SEP> thickness <SEP> of <SEP> cell <SEP> (spectrophotometer) <SEP> in <SEP> cm,
<tb> c <SEP> = <SEP> concentration <SEP> in <SEP> g <SEP> per <SEP> liter,
<tb> T <SEP> = <SEP> permeability <SEP> for <SEP> light, <SEP> the <SEP> the <SEP> solution
<tb> happens
<tb> To = <SEP> permeability <SEP> of <SEP> light, <SEP> that <SEP> through <SEP> that
<tb> Solvent <SEP> in <SEP> of the <SEP> same <SEP> cell <SEP> happens. The molar absorption capacity at the wavelength of maximum absorption (ema =) is an expression for the degree of absorption.

   It is calculated using the following relationship:
EMI0012.0026
         wherein
EMI0012.0028
  
    e <SEP> = <SEP> molar <SEP> absorption capacity,
<tb> M <SEP> = <SEP> Molecular weight <SEP> of the <SEP> dissolved <SEP> substance. Hence, e ", @ x. Is the absorption power based on a molar concentration of 1 gramol compound per liter of solution, or it can serve as a measure for the absorption of each gramol of compound. The larger the value of, the larger the absorption.



  <I> Example 36 </I> In accordance with the discussion above, spectral absorption curves of the solutions of aminium salts of Examples 27 and 28 in acetone are determined in the visible and near infrared region at 0.35 to 2.00 microns. Illustrative results are shown below. It will be noted that there are two absorption peaks in the near infrared for the phenylenediamine derivatives of Examples 13 and 14.

    
EMI0012.0042
  
    Maximum <SEP> absorption
<tb> Product <SEP> from <SEP> Example <SEP>, i <SEP> (-p) <SEP> a <SEP> e
<tb> 27 <SEP> 1450 <SEP> 20.9 <SEP> 18,500
<tb> 930 <SEP> 23.5 <SEP> 20,800
<tb> 414 <SEP> 22.2 <SEP> 19,700
<tb> 33a <SEP> 1325 <SEP> 19.2 <SEP> 14,900
<tb> 930 <SEP> 18.9 <SEP> 14,600
<tb> 410 <SEP> 19.5 <SEP> 15,100
EMI0013.0001
  
    Maximum <SEP> absorption
<tb> Product <SEP> by <SEP> Example <SEP> <I> @, <SEP> (my) <SEP> a <SEP> E </I>
<tb> 33b <SEP> 1310 <SEP> 15.6 <SEP> <B> 1 </B> 2,800
<tb> 970 <SEP> 16.0 <SEP> 13,100
<tb> 410 <SEP> 16.4 <SEP> 13,500
<tb> 33c <SEP> 1450 <SEP> 18.7 <SEP> 17,400
<tb> 930 <SEP> 21.3 <SEP> 19,900
<tb> 414 <SEP> 19.3 <SEP> 18,000
<tb> 33d <SEP> 1440 <SEP> 20.7 <SEP> 16.200
<tb> 950 <SEP> 24.1 <SEP> 18,900
<tb> 415 <SEP> 21.7 <SEP> 17,000
<tb> 33e <SEP> 1460 <SEP> 18,

  4 <SEP> 18,400
<tb> 950 <SEP> 20.5 <SEP> 20,500
<tb> 415 <SEP> 18.6 <SEP> 18,600
<tb> 33f <SEP> 1460 <SEP> 17.1 <SEP> 17,900
<tb> 950 <SEP> 19.4 <SEP> 20,300
<tb> 415 <SEP> 17.7 <SEP> 18,500
<tb> 33g <SEP> 1460 <SEP> 14,1 <SEP> 15,700
<tb> 980 <SEP> 26.0 <SEP> 28,900
<tb> 410 <SEP> 16.4 <SEP> 18.200
<tb> 33h <SEP> 1420 <SEP> 13.8 <SEP> 16,000
<tb> 980 <SEP> 23.1 <SEP> 26,700
<tb> 415 <SEP> 16.4 <SEP> 19,000
<tb> 28 <SEP> 1050 <SEP> 31.9 <SEP> 30,700
<tb> 610 (1 <B>) </B> <SEP> 3,3 <SEP> 3,200
<tb> 400 <SEP> 24.8 <SEP> 23,800
<tb> 35a <SEP> 1050 <SEP> 21.0 <SEP> 18,300
<tb> 610 <SEP> 2.6 <SEP> 2,300
<tb> 365 <SEP> 35.0 <SEP> 30,500
<tb> 35b <SEP> 1055 <SEP> 24.1 <SEP> 24,300
<tb> 600 <SEP> 2.6 <SEP> 2,600
<tb> 365 <SEP> 31,

  6 <SEP> 31.900
<tb> (1> <SEP> = <SEP> not <SEP> A <SEP> max <I> Example 37 </I> Spectral absorption curves of solutions of the product from Example 27 in three solvents are obtained.



  solvent
EMI0013.0003
  
    Acetone <SEP> <B> # </B> <SEP> max <SEP> 1470 <SEP> m, u <SEP> 940 <SEP> m, u <SEP> 414 <SEP> m, u
<tb> a <SEP> max <SEP> 21.5 <SEP> 23.9 <SEP> 22.7
<tb> Methanol <SEP> A <SEP> max <SEP> 1450 <SEP> mu <SEP> 950 <SEP> my <SEP> 414 <SEP> m, ec
<tb> a <SEP> max <SEP> 20.9 <SEP> 23.5 <SEP> 22.2
<tb> methyl salicylate <SEP> 7. <SEP> max <SEP> 1550 <SEP> my <SEP> 910 <SEP> m /. <SEP> 420 <SEP> m, u
<tb> a <SEP> max <SEP> 26.8 <SEP> 22.2 <SEP> 21.5 <I> Example 38 </I> The product of Example 27 is made by pouring an acetone solution of the plastic and the additive incorporated into a cellulose acetate film on mirror glass.

   These thin films show strong absorption in the near infrared with peaks at 1450 and 950 millimicrons. The light resistance of the additive during exposure in an Atlas Fade-Ometer is measured spectrally. Curves are taken before and after each exposure period. The remaining percentage of additive is calculated from the formula% remaining = AVA0 x too, where A,) is the absorption capacity at 950 millimicrons before exposure and AT is the absorption capacity at 950 millimicrons after T hours of exposure.

    
EMI0013.0016
  
    Fade-meter exposure <SEP>% <SEP> remaining <SEP> additive
<tb> (hours)
<tb> 5 <SEP> 99
<tb> 15 <SEP> 93
<tb> 20 <SEP> 86
<tb> 30 <SEP> 79
<tb> 40 <SEP> 73
<tb> 50 <SEP> 69 <I> Example 39 </I> The product from Example 27 is incorporated into poly (methyl methacrylate) films in the manner described in Example 38 for cellulose acetate. These films show intense absorption in the near infrared with peaks at 1450 and 950 millimicrons. The light stability of the additive is measured.

    
EMI0013.0022
  
    Hours <SEP> fade-meter exposure <SEP> / o <SEP> remaining <SEP> additive
<tb> 5 <SEP> 95
<tb> 15 <SEP> 33
<tb> 20 <SEP> 20 <I> Example 40 </I> The product from Example 27 is made at a concentration of 0.10% (based on the weight of the plastic) in poly (methyl methacrylate) press powder by plasticizing incorporated on steam-heated roller mills. Schnitzel with a thickness of 1.88 mm are compression molded. A transmission curve of the chips shows that the additive acts as a very effective barrier in the near infrared, while allowing a significant amount of visible light to pass through.

    
EMI0013.0025
  
    Wavelength <SEP> (millimicron) <SEP> / o <SEP> transmittance
<tb> 2000 <SEP> 20
<tb> 1700 <SEP> 0
<tb> 1000 <SEP> 0
<tb> 825 <SEP> 0
<tb> 800 <SEP> 1
<tb> 700 <SEP> 21
<tb> 530 <SEP> 57
<tb> 445 <SEP> 0
<tb> 400 <SEP> 0 <I> Example 41 </I> The stability of the product from Example 27 when it is exposed to high temperatures for a long time is measured using methyl salicylate as the high-boiling solvent. Dilute solutions of the additive are heated to different temperatures in an oil bath. The remaining percentages of additive are measured spectrally.

    
EMI0014.0002
  
    Temperature <SEP> = <SEP> 200 <SEP> C <SEP> Temperature <SEP> = <SEP> 210 <SEP> C
<tb> Heating- <SEP>,! o <SEP> Heating- <SEP> / o
<tb> duration <SEP> remaining <SEP> duration <SEP> remaining
<tb> (min.) <SEP> additive <SEP> (min.) <SEP> additive
<tb> 5 <SEP> 96 <SEP> 5 <SEP> 81
<tb> 8 <SEP> 94 <SEP> 8 <SEP> 59 <I> Example 42 </I> The heat stability of the product from Example 27 in a poly (methyl methacrylate) is measured as follows. Films containing 0.32% additive, based on the weight of the plastic, are poured onto mirror glass from an acetone solution of the polymer and the additive.

   The films are dried for several hours at 70 ° C. in order to remove the solvent. It will hold a curve of the cast film. It is believed that no decomposition occurs during this heat treatment. Sections of the cast film are compression molded between electrically heated plates at different temperatures. The curves of the compression molded chips are compared to the cast film to determine the percentage of additive lost on heating.

    
EMI0014.0008
  
    Press temperature <SEP> Per <SEP> minute <SEP> lost <SEP> lost <SEP> additive
<tb> (Average <SEP> percentage)
<tb> 160 <SEP> C <SEP> little <SEP> or <SEP> none
<tb> 170 <SEP> C <SEP> 5
<tb> 180 <SEP> C <SEP> 10
<tb> 190 <SEP> C <SEP> 15
<tb> 200 <SEP> C <SEP> 20
<tb> 210 <SEP> C <SEP> 25
<tb> 220 <SEP> C <SEP> 28
<tb> 230 <SEP> C <SEP> 35 <I> Example 43 </I> N, N, N ', N'-tetrakis- (p-diethylaminophenyl) -p-benzoquinone-bis- (imonium hexafluoroarsenate) The procedure of Example 29 is followed using an equivalent amount of silver hexafluoroarsenate in place of the silver hexafluoroantimonate. The product melts with decomposition at 170 C.

           Example <I> 44 </I>
EMI0014.0014
    A series of p-benzoquinone demonium salts of the above formula are prepared using the general procedure of Example 29 using the appropriate N, N, N ', N'-tetrakis (p-dialkylaminophenyl) p-phenylenediamine and silver salt .

   The substituents are given in the following list:
EMI0014.0025
  
    Compound <SEP> alkyl. <SEP> .X.
<tb> a <SEP> CH, <SEP> AsFe
<tb> b <SEP> CH, <SEP> SbFe
<tb> c <SEP> n-C, H, <SEP> BF,
<tb> d <SEP> n-C, H, <SEP> SbFe
<tb> e <SEP> n-C, H, <SEP> AsF,
<tb> f <SEP> C8HI, <SEP> SbFe
<tb> g <SEP> C, xH: s <SEP> AsFe

 

Claims (1)

PATENT CLAIM A method for protecting an object against the harmful effects of incident radiation in the near infrared, characterized in that a barrier is placed between the object and the source of the radiation, which is at least 0.01 g per 0.0929 m $ surface a compound of the following formula I contains: EMI0014.0028 wherein Y is -NO, -NH = or -NRR ', where R is allyl or optionally substituted, unbranched or branched alkyl having 1 to 12 carbon atoms and R' is hydrogen or the same as R, m = 0, 1 or 2 is , A either, if m = 0, a group of the formula: EMI0014.0036 means, or if m = 1, a group of the formula: \ N I @ v means N / n or, if m = 2, a group of the formula: EMI0015.0003 means, where n = 1 or 2, and X represents an anion, it being possible for the benzoid and quinoid rings to be substituted. SUBClaims 1. The method according to claim, characterized in that the compound of formula I is a bis (p-diethylaminophenyl) - [N, N-bis- (p-diethylaminophenyl) -p-aminophenyl] aminium salt. 2. The method according to claim, characterized in that an organic polymeric material containing the compound of formula 1 is used as the barrier. 3. Method according to dependent claim 2, characterized in that the polymeric material is able to transmit visible light. 4. The method according to claim, characterized in that the compound of formula I is practically uniformly spread through the entire barrier. <I> Note from the </I> Federal <I> Office for Intellectual Property: </I> If parts of the description do not comply with the definition of the invention given in the patent claim, it should be remembered that according to Art 51 of the Patent Act, the patent claim is decisive for the material scope of the patent.