DE1098197B - Use of polymerization inhibitors in molding and coating compositions that crosslink when exposed to light - Google Patents

Description

GERMAN

The invention relates to the use of oxygen-containing compounds of the general formulas

OH

OH

Use of polymerization inhibitors in exposure to light cross-linking molding and coating compounds

- R

- R

HO '

in which R is a hydrogen atom, an alkyl radical or an alkoxy radical having 1 to 5 carbon atoms or Aralkyloxy radical with 6 to 11 carbon atoms is used as a polymerization inhibitor when exposed to light crosslinking molding and coating compounds based on light-sensitive polyamides.

The masses, e.g. B. powder, according to the invention can be used with advantage for the production shaped printing plates and also for other purposes.

According to the invention, photosensitive polyamide resin molding materials are used or coating compositions created in which the photosensitive component as a photopolymerizable Compound is present that is bound to the polyamide resin molecule and incorporated into the resin and which can also be incorporated directly into the polyamide molecule; the thermal polymerization of the photopolymerizable Component is switched off or held up and delayed.

Examples of preferred polymerization inhibitors are pyrogallol, quinone, hydroquinone, tert-butylbenzcatechol, Hydroquinone monobenzyl ether, methylhydroquinone, amylquinone, amyloxyhydroquinone, n-butylphenol, Phenol and hydroquinone monopropyl ether.

In a preferred embodiment, blends of photosensitive polyamides are formed by exposure of light-polymerizable unsaturated monomeric compounds or their reaction products, Photopolymerization catalysts and the inhibitors implemented under the action of light.

The unsaturated compounds here are advantageously those of the general formula

= C-CONH-X-NHCO-C =

R R '

in which X is a straight or branched alkylene group having 1 to 10 carbon atoms, with 1 to 6 carbon atoms lie in a straight chain connecting the nitrogen atoms of the amido groups, while any remaining carbon atoms attached to the chain belong to alkyl radicals, and in which R and R ' Denote hydrogen atoms or an alkyl group of 1 to 5 carbon atoms can be used.

Applicant:

Time, Incorporated,

New York, N.Y. (V. St. A.)

Representative:

Dr. phil. Dr. rer. pole. Kv Köhler, patent attorney, Munich 2, Amalienstr. 15th

Claimed priority: V. S, t. v. America April 22, 1957

Robert M. Leekley, Westport, Conn. (V. St. Α.), Has been named as the inventor

According to a further preferred embodiment, residues of optionally substituted stilbene dicarboxylic acids are used containing polyamide in the presence of the inhibitors under the action of Light implemented. In this case, those containing the inhibitor already from the polycondensation are advantageous Polyamide-containing masses implemented under the action of light.

According to a preferred embodiment of the invention, the implementation is only at predetermined points made of sheet-like structures of the photosensitive compositions optionally applied to supports. The amount of the polymerization inhibitor is relatively arbitrary. The crowd should be so large that the Polymerization of the polyamide composition is inhibited during molding. It can have a some polymerization may be desirable to increase the strength of the molded body, but it should capture only a small amount of the polymerizable components. Preferably, heat polymerization is used completely prevented. Usually 0.001 to 1 percent by weight of the inhibitor, based on the mass, sufficient.

Advantageously, a photoinitiator that is stable to heat and the photopolymerization reaction after Bringing formation in motion at the desired time, used.

The polyamide resins and mixed polyamide resins used for the compositions according to the invention are according to

109 507/526

known processes. Reference is made to the USA patents 2 071250, 2 071253, 2130523, 2320088, 2430860 and 2441057 and on J. Polymer Sci., 2 (1947), pp. 306 to 313 and 412 to 419, and 3 (1948), pp. 85 to 95.

The photosensitive units can be incorporated into the polyamide resin molecule to be built in.

Examples of these units are stilbene units

-CH = CH-

attached to the polyamide molecule through the carbonyl carbon of the carboxylic acid group to form Amide units of the chain, or via the amino substance of a methyleneamino group:

CH = CH

CH = CH

-NHCH

CH = CH

CH = CH

-CH = CH

CH = CH

1! c

C O

CH ₂ NH-

CH ₂ NH-CH ₂ NH-

CH ₂ NH-

If both bound units are on the same ring, they should preferably not be in the o-position to one another stand.

The polymers according to the invention should have a weight ratio of stilbene compound to the others in order to produce the optimum photosensitivity Use reagents in the range of 1:99 to 25:75, preferably 5:95 to 15:85.

A particularly preferred polymer is through

Copolymerization of hexamethylene diammonium adipate, hexamethylene diamine, 4,4'-stilbene dicarboxylic acid or esters and ε-caprolactam or α-aminocaproic acid copolymer obtained.

Small amounts of an unsaturated compound are incorporated into the polyamides according to the invention the photosensitivity of the polyamide is significantly increased. Such compounds can also be added ίο if the polyamide is highly sensitive units, e.g. B. Stilbene units in the molecule, because then the photosensitivity of such photosensitive polyamide resins is increased. These unsaturated compounds should be at least one

CH ₂ = C. grouping

contain. Acrylic residues are more reactive than allyl residues. The compound should have a boiling point of at least

ao 10O ⁰ C and preferably boiling at at least as high a temperature as the N-allyl acrylamide in order to avoid excessive evaporation under the conditions of the process.

Unsaturated compound found to be useful

z5 of this type may be mentioned N-allylacrylamide, hexahydro-1,3,5-triacryl-S-triazine, Hexahydro-1, 3,5-trimethacryl-S-triazine, Ethylene glycol bisalryl maleate, diallyhn aleate, Ν, Ν-diallylacrylamide, ethylene diacrylate, triallyl cyanurate, Ν, Ν'-Methylenebismethacrylamid, N, N'-Methylenbismethacrylamid, N.N'-Hexamethylenbismethacrylamid, N.N'-hexamethylene bisacrylamide, N, N'-pentamethylene bisacrylamide, N, N'-trimethylene bisbutyl acrylamide, NjN'-dimethylene bisamyl acrylamide, N, N'-tetramethylene propyl acrylamide, N, N'-neopentylenebisacrylamide, 5-acrylylammo-N-auylcaproamide, acrylylamino-N-allylacetamide and 2-acrylylamino-N, N'-diallylglutaramide.

Experiments have shown that with increasing molecular weight, the photosensitivity and reactivity decreases, so that compounds of lower molecular weight are generally more suitable than Higher molecular weight compounds; such connections are capable of cross-linking or cross-linking to enter into with the polyamide resins, so that it is inclined to believe that the effectiveness of these Compounds in the process of the invention rely on the formation of such crosslinks is based. However, this is only a hypothesis, and in fact it is not known whether such cross-links actually occur are formed.

The relative amounts of the polyamide and the unsaturated compound can vary as required be changed. When using the unsaturated compound, such an amount should be present that an effect occurs. The amounts generally range from about 99 to about 75, preferably 85 to 95% polyamide resin and about 1 to about 25, preferably 5 to 15% of the unsaturated compound.

The photopolymerization of the unsaturated compound

and the polyamide can by simply irradiating the mixture of the two components, either by Light or combination of light and heat radiation take place. In the case of stilbene polyamides, there is a photoinitiator Usually not necessary as these substances are quite sensitive to light. The sensitivity to light however, the unsaturated compounds are insufficient and require a catalytic amount of a photosensitive Photoinitiators.

Thermally stable catalysts are known to initiate similar polymerization reactions under the action of light. Among these known

i uyö iy /

5 6

th catalysts that are photosensitive will have. You can just mix and match the components a row dry grind the configuration together. That way it gets

However, it is difficult to obtain a homogeneous mixture, so that

jj this type of procedure is not recommended. Preferential

5 wise, all components are in a usual way

Solvent dissolved.

If the polyamide resin is soluble in alcohol, then in which the phenyl radical substituents, e.g. B. a lower alkanol, e.g. B. methyl alcohol or ethyl hydroxyl or carboxyl groups. This alcohol, be used. The solution can be spray substances are particularly suitable. Examples of such light- io dried or poured onto a base sensitive catalysts, a number of which are removed with solvent, after which the film Have the above configuration, are benzil, benzoin, peeled off and crushed or cut to Benzaldehyde, benzophenone, substituted benzophenones, formation of a powder of the desired particle size, z. B. p-aminobenzophenone, p-chlorobenzophenone, p-ben- The molding powder or molding powder can also be produced zoylbenzoic acid, ρ, ρ'-dimethylaminobenzophenone, p-Hy- 15 are made from a homogeneous melt of the mixture and droxybenzophenon, ρ, ρ'-dihydroxybenzophenone, p, p'-di- extrusion or forming a layer, which is then zerchlorbenzophenon and p-methoxybenzophenone, benzoin- is reduced and converted into powder form. There a acetate, benzilic acid, acetophenone and similar compounds are present. the use of these substances is preferred. treatment can be carried out. It is also possible to use other keto compounds such as butane ao die molding powder or molding powder according to the invention dione can be used and also benzoyl peroxide. can through to objects of the desired shape

A photoinitiator will be processed to speed up hot forming or extrusion. the Reaction used, the concentration is more common - obtained objects retain their thermoplastic wise low and is preferably in the range of properties for a desired period of time, provided about 0.01% to about 10% photoinitiator based on the fact that the article is not exposed to radiation the weight of the mass. Usually 1 to 5% will, which is the photopolymerization of the polyamide in used. The amount depends on the amount that can be set. It follows that the objects are made up wanted absorption. Since the photosensitive photod the molding powder according to the invention absorbs light after the molding initiator, it affects the input can be processed or as constituents penetrate the mass of light. The amount of photo 30 can be used by larger objects initiators must therefore be chosen in such a way that they are ones that are difficult to shape in one piece. In this way desired speed of photopolymerization at can large and complicated objects from one the surface results. To the mass up to the desired number of separately molded units are produced Depth to photopolymerize e.g. B. when the crowd becomes. The entire object can then be exposed Forming a printing plate is used, the amount should be 35 photopolymerization so that the polyan Photoinitiator the penetration of sufficient merization of the polyamide and / or the amount of photopolymerized light To a depth allow a subordinate connection to be brought to an end; then that is cut of the image components during the development of the object is no longer thermoplastic, as a poly prevents it will. A reasonably high concentration merization with crosslinking of the polyamide resin molecules of the photoinitiator is involved in absorbing the 4.0 that has taken place.

small, in bulk laterally in the areas that are not There are other ways of using the

should stop at a larger angle than to the molding powder or molding powder of the invention, as this Increasing shoulder size is desirable, can be easily shaped in the heat while being distracted Light. This deflected light is thus prevented, it does not polymerize, but is later caused by undesirable effects Cause polymerisation in the parts, 45 allow light to polymerise out, that are not parts of the image. The photopolymerization reaction is preferred

The photosensitive molding powder according to the Er- carried out by irradiating the mixture by means of Finding can also fillers, as they are in such form - a light source. Ultraviolet light is common powders are commonly used. The more photosensitive, the more effective than ordinary. The for one by exposure the molding powders are according to the invention, the more time it takes to start the reaction changes if the photopolymerization through the whole should be considerable, depending on the amount of photo-powder used should go, the fillers used transparent initiator, the reactivity of the mixture, the or be light deflecting. If only a surface desired depth, z. B. the thickness of the exposed counter-photopolymerization is desired, any level, and reaction conditions, however, will common filler material for molding powder can be used. usually an exposure time of 1 to 30 minutes Usable clear or light reflective fill up to several hours may be required. Small stuff are glass fibers, polyamide resins with a longer clearing times result in a shallow depth of the photo-melting point than that for the formation of the powder polymerisation.

used resin, polyethylene resins, silicates, clays and If no photoinitiator is used, the

Clays. 60 reaction can also be brought about by exposure to light,

The amount of filler can, within certain limits, however, naturally be longer exposure times be chosen because the filler may need a time. The insolubility is then common Is part of the mass, but can also be absent. Not as big as when working with a photoinitiator preferred range is between 5 and 60%; one will.

Amounts above 80 ° / ₀ should not be used, because then it is important that the photosensitive mass obtained impair the cohesion of the molded body so that it is so translucent or transparent that it is too much diluted as a binder for sufficient amount of light for polymerization up to the polyamide resin used as the filler. desired depth can be effected. A very high one

The photosensitive polyamide powder according to the degree of transparency is not required as the Invention can be produced in various ways 70 polymerization usually not through the whole

7 8

Object must go through. A cloudiness from falling light depends on the light reflecting about 0.01 to about 0.5 to 0.00254 mm gives satisfactory properties of the photosensitive polyamide and producing results. can, if desired, be controlled by reflective surfaces

The invention is of particular advantage in that.

Formation of printing plates and films made entirely from 5 When indirect light or obliquely incident light the photosensitive mass exist. These items are used for exposure, so must for good are then photosensitive through and through. The contact of the negative and the photosensitive plate Driving the invention also allows the formation of worries. This is essential when making any printing plates from coatings on any basis, broadening of the picture elements should be avoided. the by applying films or coatings from the emulsion side of the negative should be directly on the plate without light-sensitive polyamide mass on the base. an intermediate layer can be placed. A liner

Typical documents are metal plates or sheets, but can be used if the picture plates or layers of synthetic resins and cellulose elements are widened or the contours are blurred derivatives, fabrics, paper and leather. Which should be completely out of the way. A vacuum frame is used to great advantage photosensitive polyamide composition of the invention or 15 holding the negative and the plate together, with a coating therefrom existing plates are used to further illustrate the invention

useful in photomechanical reproductions- the following examples, the preferred execution methods, lithography and intaglio printing. In particular, represent shapes.

the invention is suitable for the production of plates and the solubility information (soluble, insoluble or by

Intermediate plates for offset printing, made insoluble for silk exposure to light) relate to screen printing, of block plates or, in the case of the block method, the solubility properties of the polyamide in the process of covering stencils for the production of winding fluid. All parts and percentages are numerous transfers, lithographic parts by weight and percentages by weight.
Plates, relief plates and engraved plates. The expression
Printing plate includes all of these types of plates and 25
Intermediate plates. example 1

A particularly preferred application of the invention

is part of the typical process of making a following fabrics are lined in a glass

Printing plate illustrated. A stainless steel autoclave plate is filled:
formed from the photosensitive polyamide or 30

its mixture with a light-sensitive polymerizing. ■ ",, - .. ·" ·, ·, 1-, ·, 1, ^^^^ ·,

free monomeric compound by a molding process, ⁴ > ⁴ -stübendicarbonsauredunethylester 100 parts

z. B. by an extrusion process, converting into 1,6-hexamethylenediamine 39.1 parts

Plate shape or by working in a hydrau- ε-caprolactam 1700 parts

lish press. The surface of the plate is then given 0.5 parts of pyrogallol

Light through an applied, made of transparent and water 4300 parts

opaque areas on a negative

Exposed through film or glass. The light brings them

Photopolymerization reaction in progress, which places the air in the autoclave is replaced by nitrogen

insoluble replaced 40 by the transparent parts of the image and the autoclave was heated to 250 to 260 ⁰ C. After doing, during the places under the opaque 2 hours - the pressure rose to 21 kg / cm ² - the parts of the image that were shielded from the light pressure gradually increased to atmospheric pressure during the

were to remain soluble. the next hour by slowly releasing the gases

The soluble spots on the surface are lowered to one. During the next hour the pressure was removed to a sufficient depth by a developer 45 slowly lowered to 2 mm of mercury and then in such a way that the raised, remaining, insoluble parts on 2 mm of mercury can be used as a relief printing plate for a further hour. That kept. At the end of the heating, the autoclave mass according to the invention can, however, be cooled to others under vacuum. The product was easy to use. It can be a thin film of colored, tough or solid stilbene polyamide. It has been used to form a permanent image on a metal 50 crushed into small particles to form a mold base or other base. After powder, which can then be developed in a hydraulic press, the base with chemical flat layer was formed. This layer was etched by etching agents, for example acid or ferric chloride, or by means of a blower exposed to the light of a carbon arc through a negative to form a relief and then etched for 15 minutes in a solution of 90 g on the substrate. In a corresponding manner, 55 calcium chloride can be dissolved in 100 ml methyl alcohol, a two-layer offset consisting of two metals; a clear relief image was formed. With plate could be produced using the mass of this plate as with a printing plate for the according to the invention as a template. Another type of lettuce print can be printed.
Offset plates can be made by mounting

the composition according to the invention on a hydrophilic 60 Example 2

Document. The polyamide image obtained by developing

absorbs ink or paint, while the moist carrier produces the polyamide used as the starting material

Repels paint or ink. A polyamide resin made of four components was produced

When exposing the photosensitive polyamide composition made from a mixture of 45 parts of adipic acid it is desirable to have some light on the plate with 65 hexamethylenediamine, 40 parts sebacic acid hexahigh Angle of incidence. This is the case with methylenediamine, 13 parts of caprolactam and 85 parts Turning a large light source, e.g. a lamp - water. The mixture was lined up in one with a glass or a tubular lamp or pull-through lined autoclave, the air was through of the plates under a tubular light source. The nitrogen replaced and the autoclave closed. the The optimal amount of indirect light or an oblique reaction was carried out as follows:

9 temperature Time pressure 250 to 260 ° C 1V ₂ hours 7 to 21 kg / cm ² 250 to 260 ° C IV ₄ hours Pressure reduction
on atmospheres
pressure through long
same distillation
of water 250 to 26O ⁰ C IV ₄ hours Pressure slowly
2 mm lowered 250 to 26O ⁰ C IV ₂ hours Pressure 2 mm

At the end of the heating the autoclave was closed. The polymer was cooled under vacuum. It was a slightly colored, tough or firm product and could easily be drawn in the cold. The softening point was 160 ^° C. Protection is not claimed for this.

This mixed polymer was brought into finely divided form by dissolving 1 part in 10 parts of formic acid at 25 ° C. 14 parts of absolute methyl alcohol and then 21 parts of diethyl ether were added with stirring and the polymer precipitated as small particles. The powder was filtered off, washed thoroughly by slurrying three times with ether, dried in the air and then dried IV in an oven at 105 ^° C. for _{2 hours.}

The photosensitive polyamide composition was prepared according to the invention by slurrying the polymer in a solution of 970 parts of absolute methyl alcohol, 5 parts of Ν, Ν'-methylenebisacrylamide, 5 parts of benzophenone and 0.07 part of methylene blue. The alcohol was then evaporated and the mass dried over anhydrous calcium chloride for 20 hours. The molding powder was molded into a plate at about 175 ° C. and a pressure of 352 kg / cm ² .

The plate was exposed through a type negative in a vacuum frame for 6 minutes at a distance of 10.16 cm using a water-jacketed UV lamp. The exposed plate was developed for 5 minutes at 250 ^° C. in a spray developer device in a solution of absolute methyl alcohol with a content of 90 g of anhydrous calcium chloride per liter of methyl alcohol. The developed plate showed the characters in relief, corresponding to the transparent areas of the negative, and represented a printing plate for letter printing.

Example 3

In a heated stainless steel mixer, an impregnating solution was made up of the following Components manufactured:

184 parts of absolute methyl alcohol,
16 parts of an alcohol-soluble polyamide copolymer,

0.8 parts Ν, Ν'-methylenebisacrylamide,
0.8 parts benzophenone,
0.0112 parts methylene blue.

The solution was divided into two equal parts, 100 parts of chopped cotton fiber became 1 part of the Solution added and the moist mass kneaded until most of the solution is absorbed by the cotton was. The impregnated cotton fiber was dried in a hot air oven for 20 hours and then into one Fiber body using a conventional steel die heated to 177 ° C under a pressure of 2268 kg shaped. The layer filled with polyamide was rigid and hard, namely harder than a layer made of the photosensitive Resin alone. After the laminated body had been exposed to light using a mercury lamp, it was practically insoluble in boiling methanol, while the non-light-cured plate rapidly dissolves dissolved.

Example 4

Two tightly woven cloths made from threads of polyhexamethylene adipamide were coated by dipping in the impregnation solution of Example 3 and on air dried for 24 hours. These layers were placed in a conventional mold and at a Pressure of 2268 kg at 177 ° C pressed into a plate of uniform structure. The fabric-containing polyamide layer was rigid and strong, stronger than a corresponding plate made of the photosensitive resin alone.

A simple embossing kit was made by placing a copper stencil against the surface of the Polyamide layer and hardening of the part of the layer not covered by the die. The unexposed Spots were loosened to a depth of 6.4 mm by spraying with a solution of 150 g calcium chloride in 11 methyl alcohol at 38 ° C. The wells were clean and sharp as the developer solution was also free Loosened lying fibers of the polyhexamethylene adipamide.

The copper stencil and the corresponding hollow form from the photosensitive, layered plate was made used as a pressure body for imprinting the shape in paper.

Example 5

A coarse-meshed cloth made of glass fibers was treated with the impregnation solution from Example 3. To When the laminated body was formed, it was rigid and firm. It was insoluble in boiling methanol after Exposure by means of a mercury lamp.

Example 6

The following parts were used to produce a photosensitive molding powder:

A. 10 parts of a copolymer of 40 parts of hexamethylene adipamide, 30 parts of hexamethylene sebacamide and 40 parts of caprolactam, softening point 144 ° C .;

B. 1 part Ν, Ν'-methylenebisacrylamide;

C. 0.5 part benzophenone;
D. 0.05 parts hydroquinone.

The copolymer and the Ν, Ν'-methylenebisacrylamide were with until they passed through a sieve 0.25 mm mesh size ground.

The components B, C, D were first mixed together with a small amount of ether and then up stirred to dryness. The product was then mixed with component A to form the photosensitive Molding powder. The powder was divided into two parts. To one part of the powder became a the same amount of finely chopped cotton fiber is mixed in and the mixture is entered in a conventional printing form. At a mold temperature of 177 ° C and one A plate was made under pressure of 2268 kg. The plate was stronger and more rigid than a plate that came out of the photosensitive powder was pressed without filler.

Example 7

100 parts of the impregnation solution of Example 3 were poured onto glass plates and air-dried a layer practically free of methyl alcohol. the

109 507/526

1 098191

The layer was then crushed using a conventional plastic crushing device into a molding powder which passed through a sieve with a mesh size of 0.5 mm.

An equal amount by weight of crushed asbestos fiber was added to 8 parts of the dry photosensitive powder admitted; the two ingredients were mixed by kneading. Using a usual A highly sensitive plate, which contained asbestos as a filler, was made at 177 ° C. under a pressure of ta kg formed. The plate was more rigid and stronger than the plate made from the highly sensitive powder without asbestos.

Claims (6)

PATENT CLAIMS: 1. Use of oxygen-containing compounds of the general formulas: OH OH HO - R - R in which R represents a hydrogen atom, an alkyl radical or an alkoxy radical having 1 to 5 carbon atoms or a Aralkyloxy radical with 6 to 11 carbon atoms is, as a polymerization inhibitor in upon exposure to Light-crosslinking molding and coating compounds based on kitchen-sensitive polyamides. 2. Embodiment according to claim 1, characterized in that mixtures of high-sensitivity Polyamides, unsaturated monomeric compounds polymerizable by the action of light 3 or their reaction products, photopolymerization catalysts and the inhibitors under the action implemented by light. 3. Embodiment according to claim 2, characterized in that the unsaturated compounds those of the general formula: = C-CONH-X-NHCO-C = R ' in which X is a straight or branched alkylene group having 1 to 10 carbon atoms, with 1 to 6 carbon atoms in a straight chain connecting the nitrogen atoms of the amido groups, while any remaining carbon atoms attached to the chain belong to alkyl radicals, and in the R and R 'represent hydrogen atoms or an alkyl group of 1 to 5 carbon atoms is used will. 4. Embodiment according to claim 1 to 3, characterized characterized in that residues of optionally substituted stilbene dicarboxylic acids containing polyamide containing compositions are reacted in the presence of the inhibitors under the action of light. 5. Embodiment according to claim 4, characterized in that already from the polycondensation forth the inhibitor-containing polyamide containing masses are reacted under the action of light. 6. Embodiment according to claims 1 to 5, characterized in that the implementation is only on predetermined locations of the photosensitive sheet-like structures optionally applied to supports Masses is made. Considered publications:
German Patent Nos. 954 3Q8, 954127;
U.S. Patent No. 2,657,195. © 109 507/526 1.61