FR2488899A1 - PROCESS FOR MANUFACTURING A MODIFIED SYNTHETIC BODY IN ITS OPTICAL PROPERTIES - Google Patents

Abstract

PROCESS FOR MANUFACTURING A BODY IN SYNTHETIC PRODUCT MODIFIED IN ITS OPTICAL PROPERTIES. THE PROCESS ACCORDING TO THE INVENTION IS CHARACTERIZED IN THAT ONE INCORPORATES IN A SOLUTION OF THE POLYMER OR AT LEAST ONE OF THE SOLUTIONS OF THE POLYADDITION COMPONENTS AT LEAST ONE SOLID MODIFIER DISSOLVED IN A COMMON SOLVENT, AT AN INSUFFICIENT CONCENTRATION TO REACH THE SATURATION IN THE POLYMER, AND IN WHAT THIS SOLVENT IS AGAIN REMOVED AFTER PHYSICAL DRYING OR AFTER SYNTHESIS OF THE POLYMER.

Description

The present invention relates to a method of manufacturing a body

in modified synthetic product

in its optical properties.

  In what follows, it is necessary to understand under the term "body" certain particular pieces, but

  also layers and dandruff.

  We know that many synthetic products

  work more easily than

  inorganic properties. However, for many

  applications, the refractive index of the syn-

  thetic, limited by the very nature of the material, is a disadvantage. That's why we went

  strives to improve these properties of syn-

  theories with additives. The German patent application No. 22 18 782 thus describes, according to the concept set forth in claim 1, a method whereby transparent polymer parts are modified to deflect the optical radiation by means of low weight organic liquids.

  molecular diffusion by diffusion at lower temperatures

  to the glass transition point so that a continuous refractive index gradient is formed in the polymeric material, substantially perpendicular to

the optical axis of the body.

  It is known that softening liquids dissolved in synthetic products tend to diffuse outward and migrate into the environment,

  particular in natural and synthetic polymers

  similar or different types that enter into

  contact with these synthetic products.

  The invention therefore responds to the need to create a

  synthetic synthetic products manufacturing process

  modified, in which the refractive index does not change in time or place -2- and have a higher refractive index

  extending evenly throughout the body.

  In particular, this process must create layers of

  which are likely to receive

  see a print and that apply by adhering strongly to a backing material, such as cardboard or

  a sheet of a synthetic product of semi-

  blable or different. Finally, it is also necessary to be able to cast films and sheets on a support

  provisionally and then remove them again.

  The invention is characterized in the

  dications. The bodies and layers of synthetic product created according to this process have an improved brightness, they keep without other additives their transparency and, when mixed with dyes and pigments, a pronounced shine and others

  desirable optical effects. As a result, we can get

  create more reflective surfaces in different

  parts, for example in so-called eyes

  de-chat, lenses with a smaller radius of curvature or other dimensions that are weak and combinations of low-achromatic lenses as well as thin colored layers and therefore

  more economical and easier to work.

  The following examples specify the invention.

  Examples 1 and 2 describe a manufacturing process

  parts with improved brightness and layers with greater strength, and Examples 3 to 6 a method of manufacturing layers susceptible to printing for certain particular applications. Under the term "parts", it is necessary to understand

  each time, in the following examples,

weightings.

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EXAMPLE 1

  35 parts of an epoxy resin are intimately mixed with an epoxy equivalent of 500 with portions of an aliphatic, aromatic or cycloaliphatic diamine hardener. 95 parts of this mixture, according to the desired viscosity, are mixed homogeneously with 30 parts of a solvent, preferably a glycol and / or a polyhydric alcohol, preferably ethylene glycol, or

  mixture of this glycol with butylene glycol, 15 parts

  finely divided thionalide, previously converted to a paste and dissolved in a weighed amount of the foregoing components at 70 to 80 C. The thionalide is alpha-mercapto-N-2-naphthylacetamide whose molecular weight is 217.29 and the point of

melting 109-111tC.

- NH-C-CH-SH

  The unmodified epoxy resin of the foregoing components has a refractive index

n20 of about 1.57.

  Instead of thionalide, other organic compounds can be used as the modifying agent

  solid, compatible with the high-concentration polymer

  tration. These can have compounds with the photochemical transitions n -> - * - and - y - q *, in particular those of general formula

(H) (H)

(C) (C) - (H)

  (H) -N, N - = (C), (C) --- N - (C), (C) === S or (C) (c) --- C -4- o the symbols enclosed in parentheses may be one or more constituent elements, present in a chain or at least one nucleus, designated by the symbol considered. The mixture can be processed by known methods. The solidification and the formation of the synthetic body from the components take place at the

  at room temperature or faster at a

  ture, the solvent may also be a component. You can also cast films on

  a temporary support and later separate them.

  The modifying agent is dissolved in the body

  in solid form, the body remaining intact

  transparent. Naturally, its concentration must not reach the saturation point in the polymer. Parts made from resin

  modified epoxy have, when using di-

  aromatic amines as curing, an index of refraction n20 of 1.61 to 1.64; when using an aliphatic hardening nD 2,6, a refractive index n20 of 1.59 to 1.61. These parts can be used for highly refractive decorative parts with reflective reflective surface for reflectors, etc. The optical efficiency of the modifying agent depends on the one hand on its concentration in the body of synthetic material and on the other hand on its own refractive index. This in turn depends on the chemical composition of the modifying agent. You have to choose the percentage of it so that the

  molar refraction of the modifying agent with the

  The molar fraction of the polymer additively gives the desired refractive index of the body to synthetic product. When adding to the mixture of 95 parts of epoxy resin components + 20 to 40 parts of methylene glycol + 15 parts of finely divided thionalide, another 30 parts of titanium dioxide, in particular rutile modification, and pigments are added.

  colored or transparent dyes and 2

  silicic acid in submicroscopic dispersion and homogenized in a mill with three cylinders, can be prepared printing colors for intaglio or screen printing with excellent hiding power and at the same time excellent gloss, these dyes possessing

  pot life of about 10 hours. These printer colors

  are particularly suitable for printing documents because of their adhesiveness and

abrasion resistance.

EXAMPLE 2

  The procedure is as in Example 1, but the polymer-forming components, the modifying agent

  and the percentages used are different.

  The synthetic product components consist of 50 parts of a hydroxy-functional acrylic resin and 10 parts of a polyisocyanate

  low viscosity, the mixture being adjusted to the equiva-

  OH groups of the acrylic resin and isocyanate groups of the polyisocyanate. Parts of ethylene glycol and, depending on the desired viscosity, polyalcohols and 10 to 15 parts

  4: 2 mixture of pyrene and thionalide.

  Crude formula: C16H10 Pyrene: Molecular weight: 202.26 Melting point: 145 to 1480C -6-

  The mixture has a pot life of about

  10 o'clock and is so fluid that it can be used

  to varnish. While the unmodified lacquer

  lide has a refractive index n2 of 1.538, the modified lacquer layer has a refractive index of

  from 1.56 to 1.59 and therefore has a significant

  tively larger. It is somewhat thermo

  Plastically deformable, so that it can also be used as the layers of the following examples for fully transparent printable layers or for printing colors that can be used for printing, when adding dyes or pigments. It is also suitable for high-gloss, abrasion-resistant coatings on paper or protective layers on printed sheets or synthetic parts and for

metal coatings.

  The conditions mentioned in Example 1 for the modifying agent and its concentration are also applicable.

  for this example and all who follow.

EXAMPLE 3

  In 10 parts of an 8% solution of a pure polyvinyl chloride powder with a K of at least 70 in tetrahydrofuran, alone or mixed with methyl ethyl ketone 1: 1, dissolved 0, 0.5

  or 1.0 part finely divided thionalide.

  The concentration of the modifying agent is

  also in this case below the saturation point

  in the solidified polymer. Lacquer

  from this solution is cast into a film

  the, which after dissipation of the solvent has the following refractive index 2: without modifying agent: 1.540; with 0.5 part of modifying agent: 1.605;

  with 1.0 part modifying agent: 1.630.

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  The film is, without other additives, transparent

  rent and printable and is therefore well suited for

  cation described in Swiss Pat. No. 594,936 as an intermediate layer for an information carrier that can be used automatically in two dimensions, readable by a machine, with optical markings in the form of holograms or diffraction gratings, information carrier which on one side is applied to a support made of cardboard or a sheet of synthetic product and which on the other side is provided with a transparent protective layer having a different refractive index. It is thus possible to print the support and / or to color with a transparent dye the intermediate optical layer presenting the printed information. We can thus mark or hide according to the

  desires the printed location for automatic reading

information.

  For the application mentioned above, it is important to use a hard and elastic polymer at room temperature which has a softening point between 60 and 1200C and a melting point of at least 1500C, which is further suitable to the

  manufacture of synthetic and printed products

  mable. These fully thermoplastic polymers are in a refractive index range of 1.49 to 1.57 when they are not modified. Another

  condition is that they are essentially transparent

  colorless and colorless. In addition to polyvinyl chloride, these conditions also meet the thermoplastic polymer mentioned in another example, as well as a polymer consisting of two components and cited above.

in the previous example.

  By increasing the difference in refraction between the cover layer and the support layer by means of the modifying agent in the support layer, the readability of the light-modified, relief-structured, printed optical markings is facilitated and clearly improved. This allows on the other hand a refinement of optical markings and the application of known and new printing techniques. The

  markings of this kind with a protective lacquer pre-

  feeling an index of refraction n20 of less than 1.5 are no longer visible to the eye and increase the

  security against falsification and destruction.

  They allow an improved automatic reading of the structures in relief, acting by reflection or optical refraction, thanks to which for example one can

  save metallization with a layer of

thin metal xion.

EXAMPLE 4

  Layers usable for the same purpose as in the previous example are prepared from a mixture of 10 parts of an 8% solution in the

  tetrahydrofuran of a polyvinyl chloride

  pure vinyl with a refractive index n20 of 1.53 and 2 parts of a 33% solution of acridine in tetrahydrofuran.

  Acridine: Crude formula C13H9Nt Molecular weight

  179.22, m.p. 107 to 1091 ° C.

  Dry film has a refractive index

  fraction nD of 1,611, is printable and can be applied to printed or unprinted

  to be covered by layers DrotecteurSen pro-

transparent synthetic fats.

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EXAMPLE 5

  A film consisting of 10 parts of an 8% solution of the polyvinylchloride of the preceding example in cyclohexanone and 2 parts of a 30% solution of pyrene in the same solvent is prepared and processed. same way in the same goal as in the previous example. The refractive index n20 is 1.638,

EXAMPLE 6

  To prepare a film, 10 parts of an 18% solution of a polymethyl methacrylate with a refractive index are mixed in this example.

  n 2 of 1.4925 in dimethylformamide with 1.8 parts

  of a 50% solution of N-phenylthiourea in the

same solvent.

  N-phenylthiourea: - - C - NH2 Molecular weight: 152.15 Melting point: 145 to 150 ° C. The dried film of the modified synthetic product has a refractive index n20 of nD 1.549. She can find the same use as

that according to example 3.

-10-

Claims (6)

A process for preparing a body of synthetic material modified in its optical properties, in which a body of synthetic product having a higher refractive index compared to the unmodified state is obtained by adding colorless and transparent modifying agents, such as glass, which do not cause crystallisation, characterized in that at least one solution of the polymer or at least one of the solutions of the polyaddition components is incorporated with at least one solid disintegrating agent. in a common solvent, at a concentration insufficient to achieve saturation in the polymer, and in that this solvent is removed again after physical drying or after synthesis of the polymer. Process according to claim 1, characterized in that a fully thermoplastic polymer is used as the polymer. A process according to claim 1, characterized in that the modifying agent fraction is selected so that its molar refraction additively gives the desired refractive index of the body to the synthetic polymer by adding to the molar refraction of the polymer.   40) Process according to claims 1 and 3,   characterized in that the modifying agent is a compound   solid organic layer compatible with the polymer at high concentrations, which remains, after formation of the layer with the polymer, dissolved therewith in solid form, and which forms a fully transparent body. Process according to claim 4, characterized in that as a modifying agent compounds with photochemical transitions are used n> Born * and M --- l *.   6. Process according to claim 4, characterized in that the modifier used is a solid compound of the general formula: 1 /. (H) (H) > C - (C), - C--, (H) N, (H) (CC) N (H)   / (c) (H) N, N- (C), (C) N - (C), (C) -S or (C) - Ci the symbols in parentheses may be one or more chemical constituent elements present in a chain or at least in a nucleus,   designated by the symbols considered.   7. Process according to claim 4, characterized   rised by the use of thionalide, acridine,   pyrene or N-phenylthiourea as a modifying agent trusting.   8) Process according to claim 2, characterized   rised in that one uses to prepare a strat-   printable product a synthetic product made of a   polymerization product and having a refractive index   fraction of 1.49 to 1.57, a softening point of 60 to 120 ° C and a melting point of at least 150 ° C.   9) Process according to claims 2 and 8,   characterized in that the solvent used is   tetrahydrofuran, methyl ethyl ketone, cyclo- hexanone or dimethylformamide.    Method according to claims 1,2 and   8, characterized in that a solution of the synthetic product and modifying agent is applied to a solid support made of cardboard or a sheet of   synthetic product, and in that one does volati- remove the solvent.   Method according to claim 3, characterized in that, to prepare printing colors, the solution is   components before treatment of transparent dyes   and / or overlapping pigments.   12) Method according to claim 10,   characterized in that a protective layer is applied   transparent trice on the layer or foil   solidified, modified and printed synthesis duit.