CH630950A5 - Compositions suitable for use as filling primers, spray putties (mastics) and paint coatings - Google Patents

Description

The invention further relates to a process for the preparation of the above compositions, in which chemically crosslinkable plastic binders are dissolved in solvents, mineral fillers and / or pigments are dispersed in this solution and, if appropriate, further binders are added to the dispersion obtained. In the process according to the invention, a synthetic resin or synthetic resin mixture which gives a film with 35-65% pendulum hardness according to Persoz is used as the film-forming binder, and a solvent mixture which consists of 20-96% by weight solvents) with an evaporation number smaller is used as the solvent than 32 and a surface tension below 29 dyn.cm, 4-20% by weight of solvent (s) with an evaporation number greater than 40 and 0-76% by weight of other solvents.

Epoxy resins crosslinked with polyamides are particularly suitable as binders for primers, spray putties and middle coats, since their curing is a polyaddition reaction, i.e. without the formation of by-products, which enables application even in thick layers. However, a disadvantage of these epoxy resins is that they produce a very hard film that is difficult to grind. It has now been found that modified epoxy resins which are easy to grind and are therefore excellently suitable as binders of the compositions according to the invention can be produced if epoxy resins with a molecular weight of 320-4200 and a hydroxyl number of 0.06-0.45 with polyisocyanates with a viscosity of 6000- 90,000 cP and the NCO content of 1.6-28 wt .-% implemented; at least 3% by weight, preferably 10-30% by weight, of polyisocyanate are expediently used. The coatings produced with these modified epoxy resins are easy to sand. According to a preferred embodiment of the process according to the invention, a plastic binder is obtained by reacting epoxy resins of molecular weight 320-4200 and hydroxyl number 0.06-0.45 with polyisocyanates having a viscosity of 6000-90,000 cP and an NCO content of 1.6-28 % By weight obtained modified epoxy resin used.

Of the binders customary in the paint industry, plastic binders are primarily epoxy resins, amine resins, modified alkyd resins, vinyl resins or their various combinations plasticized with polyisocyanates. The crosslinking agent necessary when using epoxy resins is generally mixed into the dispersion before the composition is applied.

If a mixture of alkyd resin and amine resin is used as the binder, the desired hardness can be set by the quantitative ratio of the two synthetic resins to one another.

Mineral fillers whose grinding resistance, measured according to Rosiwal, is less than 30 are preferably used as fillers. Such fillers are primarily sulfates, for example barite or gypsum, carbonates, for example chalk, easily cleavable silicates, for example talc and feldspar, and clay minerals, for example kaolins.

When selecting the pigments, the lowest possible abrasion hardness is first of all taken into account, then the desired color and opacity, and in the case of filling primers the corrosion-inhibiting effect is also taken into account. Pigments which can preferably be used are titanium dioxide (anatase), the lithopones, the zinc sulfide and the zinc chromate.

630 950

The Persoz pendulum hardness is measured according to the Hungarian standard MSZ 9640 / 4-71.

The evaporation number is determined according to the Hungarian standard MSZ 1636-66, point 2.08.

The relative grinding hardness is measured by grinding a piece of the mineral to be examined with a surface area of 4 cm 2 under defined conditions (Koch and Sztrókay: Âsvânytan, Volume I, page 261, Tankönyvkiado, Budapest 1976) and measuring the weight or volume loss that the Hardness are inversely proportional; the grinding hardness measured on the surface of the quartz is 100.

The table below shows the surface tensions and evaporation numbers of some solvents.

Table 1

Solvent surface evaporation voltage dyn.cm number

Toluene 30.8 6.1

Xylene 30.7 13.5

n-butanol 26.2 33

Isobutanol 25.6 27.0

Ethyl acetate 26.9 2.8

Butyl acetate 26.5 12.1

Acetone 26.2 2.1

Ethyl glycol 29.4 43

Tetralin 39.8 190 methyl isobutyl ketone 26.2 6.7 ethyl glycol acetate 29.0 41

In addition to solvent (s) with an evaporation number below 32 and a surface tension of less than 29 dyn.cm and solvent (s) with an evaporation number of over 40, the solvent mixture of the combination according to the invention can contain as a further component any solvent that is miscible with the first two solvents is. Aliphatic and aromatic hydrocarbons, glycol ethers, ether acetates, ethers, esters and terpene derivatives are primarily considered as such a further component.

The main advantages of the composition according to the invention can be summarized as follows:

a) The composition applied by spraying results in a smooth and even coating without flowing, even on vertical surfaces.

b) The cover made from the composition is easy to sand and therefore requires little sanding work. The grinding resistance of the coating can be adjusted well by a suitable choice of fillers.

c) A finer emery paper can be used to sand the coating produced with the composition according to the invention; this results in an essentially scratch-free surface on which the top coat gives a nicer coating.

d) Applying the composition requires less expertise.

e) Rejects due to flowing down (ripple) can be completely avoided.

f) Since the work required for grinding is less, productivity is significantly increased or the cycle time is shortened.

The invention is explained in more detail below on the basis of exemplary embodiments.

example 1

22 parts by weight are dissolved in the solution of 12.5 parts by weight of a polyisocyanate-modified epoxy resin in a mixture of 6.25 parts by weight of xylene and 6.25 parts by weight of isobutanol.

3rd

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

630 950 4

Parts of lithopone, 17 parts by weight of talc, 9.5 parts by weight of zinc. The chromate obtained in this way, suitable for medium coats, and 8.5 parts by weight of titanium dioxide dispersed. The dis color is mixed with 64 parts by weight of xylene, 31 parts by weight.

persion is mixed with a mixture of 8 parts by weight of isobutanol, len isobutanol and 5 parts by weight of ethyl glycol.

Dilute 8 parts by weight of xylene and 2 parts by weight of tetralin. Diluted solvent mixture to a flow time of 18-22 seconds (measured in a DIN cup with a 4 mm nozzle).

Before use, the dispersion is mixed with 5.2% by weight. The coating applied by spraying does not flow

Parts of fatty acid polyamide crosslinker mixed and reduced by shrinking and after 20 minutes of baking at 90 ° C thin with a mixture of 47 parts by weight of xylene, 47 parts by weight gives an easily sandable surface. The deck color applied to it

Parts of isobutanol and 6 parts by weight of tetralin on a spout form a smooth, pleasing surface.

time (measured according to Hungarian standard MSZ 9650 / 3-73 io in a DIN cup with a 4 mm nozzle) of 18-22 seconds - Example 3

represents - 24 parts by weight of the 50% solution prepared with xylene

The filling primer obtained gives a smooth surface when applied with a spray gun containing 26% by weight of fatty acid and 30% by weight of vinyl monomer, and the alkyd resin, which has been modified after drying, becomes an easily sandable, corrosion-protective coating with 4 parts by weight of ethyl glycol or baking 15 acetate diluted. 13 coatings are formed in the alkyd resin solution obtained. Parts by weight of titanium dioxide (anatase), 15 parts by weight of barium sulfate. Characteristic of the grindability is the result of the dispersed 12 parts by weight of talc. To the pig obtained according to the Hungarian standard MSZ 9640/7-T with the The abrasion test carried out with butanol be-abrasion apparatus is carried out with constant stirring those with methyl isobutyl ketone were rubbed with a grinding wheel CS 17 at 300 wheel-modified 10% solution of a vinyl chloride-vinyl acetate solution 0.1498 g material, while given under the sliding polymer, which contains free hydroxyl groups.

The conditions of abrasion of the film are similar to one another. After homogenization, 0.5 part by weight of a 6th

mixed fill primer, the epoxy resin binder containing wt.% cobalt-containing cobalt naphthenate solution and 9

but was not modified with polyisocyanate, only 0.0951 g of 25 parts by weight of butyl acetate were added. To apply with the amount. In the filling primer spray gun produced according to the invention, the dispersion is mixed with a mixture of 45

weight loss was 58% higher. Parts by weight of methyl isobutyl ketone, 28 parts by weight of xylene, 20

The modified epoxy resin parts by weight of butyl acetate and 7 parts by weight of ethyl glycol acetate used as the starting material is produced in the following way: on an outlet (measured in a DIN cup with a 4 mm nozzle)

70 parts by weight of epoxy resin (molecular weight: 900; hydroxyl number: 30 diluted for 18-22 seconds.

0.25) are melted and then heated to 90-100 0 C. The spray kit layer applied by spraying is

With constant stirring, 30 parts by weight of polyisocyanate become smooth and uniform and can be baked after 30 minutes

(NCO content: 2.4% by weight, viscosity: 80,000 cP) was added. be lightly sanded at 80 ° C.

The temperature is raised to 140-160 ° C. A sample is taken every 30 minutes with continued stirring. This 35 example 4 is dissolved in a ratio of 1: 1 in a mixture of 50 parts by weight, 14 parts by weight of one containing 26% by weight of fatty acid and 30 xylene and 50 parts by weight of isobutanol, and the run-out time is% by weight. Vinyl monomer modified alkyd resin is measured in the solution in a DIN cup with a 4 mm nozzle. When 14 parts by weight of butyl acetate are dissolved. The solution is diluted with 7 the flow time of the solution a value of 80-90 seconds by weight of ethyl glycol acetate. In the Al obtained, the reaction is interrupted by cooling. 40 kydharzlösung 13 parts by weight of titanium dioxide (anatase), 15 The product obtained is dissolved in a mixture of 50 parts by weight of barium sulfate and 12 parts by weight of talc disper parts of xylene and 50 parts by weight of isobutanol . yaws. The pigment paste is added with constant stirring

18 parts by weight of methyl isobutyl ketone prepared solution of 2

Example 2 parts by weight of vinyl chloride-vinyl acetate copolymer.

19.5 parts by weight of the 70% solution prepared with xylene 45 After homogenization, 1 part by weight of a 6 parts by weight

of a cobalt naphthenate solution containing 70-80% by weight of phthalate and containing rizine fat% of cobalt and 4% by weight of

Acid or synthetic fatty acid modified alkyd resin parts of butyl acetate added. Before application with the 11.5 parts by weight of the 55 spray gun prepared with butanol, the dispersion obtained is coated with an 84

% By weight solution of an etherified amine resin mixed. Parts by weight of butyl acetate and 16 parts by weight of ethyl glycol acetate

The solution obtained is mixed with a mixture of 8% by weight of an existing mixture onto a (in a DIN cup with a 4 mm nozzle

Parts of isobutanol, 5.3 parts by weight of xylene and 1.2 parts by weight of measured) diluted in 18-22 seconds.

Diluted ethyl glycol. 14 parts by weight of Ti are dissolved in the solution

tandioxide (anatase), 17.5 parts by weight of Lithopone, 12 parts by weight of stoving at 80 ° C for one minute

Talc and 11 parts by weight of chalk dispersed. Coating.

C.

Claims (5)

630 950 L PATENT REQUIREMENTS The primers, spray putty and middle coats 1. A smooth surface and little sanding work hold comparatively little binder and a lot of pigment requiring as filler primers, spray putty and mineral filler. After application of medium-layer usable compositions, which are dispersed in, they have to be sanded smooth with fine emery paper, the solution of che- prepared with organic solvents so that the glossy top coat layer applied later does not show any mix-crosslinkable plastic binders with mineral fill unevenness. The grinding is a very labor-intensive substance and / or pigment, characterized, ger process. That is why the grinding work is extraordinary - that as an organic solvent solvent mixtures it was an important quality factor. In many cases, for example in the case of those containing 20-96% by weight of solvent (s) with an evaporation number on the conveyor belt, which is bound to cycle times, is less than 32 and a surface tension polishing of vehicles becomes usable of less than 29 dyn. cm, 4-20% by weight of solvents) with filler primers, spray putty and medium coats, which means that the evaporation rate is greater than 40 and 0-76% by weight, otherwise it is decided whether their surface is within the available solvents. standing time may or may not be sanded. The 2. A process for the production of the compositions according to the effort and time required for smooth grinding. Claim 1, in which the chemically crosslinkable 15 depends in part on the smoothness of the plastic binders formed on spraying, dissolved in solvents, in this soldered surface, ie The flowability of the mineral fillers and / or pigments dispersed in the solution, on the other hand the grinding resistance of the substance, characterized in that one removes as a film-forming coating. Binder is a synthetic resin or synthetic resin mixture that is used to improve the sandability Film with 35-65% pendulum hardness according to Persoz results, and is usually used as a “20” soft filler. The formation of smooth surface agents uses a solvent mixture which, when sprayed on - as in the paint industry for% by weight of solvents) with a evaporation number smaller than 20-96% when achieving better flow - by An-than 32 and a surface tension below 29 dyn.cm, 4-20 using slowly evaporating solvents, which% by weight solvent (s) with an evaporation number greater than keep the applied coating longer and than 40 and 0-76% by weight other solvents. 25 enable the sprayed drops to coexist 3. The method according to claim 2, characterized in that flow away. The softest, in terms of grindability, that a filler, for example talc, which is most suitable as a result of the reaction of epoxy resin, for example, talc, the molecular weight 320 ^ 4-200 and the hydroxyl number, however, poor the flowability. In the highly filled 0.06-0.45 with polyisocyanates with a viscosity of 6000-90,000 cP primers, spray putties and medium coats and the NCO content 1.6-28% by weight is modified to achieve a better flowability of the proportion tes epoxy resin mixed with crosslinkers. of solvents of lower tension, i.e. the proportion of less volatile solvents increased. Especially on vertical ones However, a smooth coating cannot be formed on surfaces in this way, because the applied layer begins to flow. The invention relates to a smooth surface that results in 35 and thus becomes wavy. The elimination of this ripple requires little sanding work, as filler primer, spray putty requires a lot of sanding work. and compositions that can be used as layers of paint, easy-to-sand and also well-flowing filler The dispersions in the preparations, spray putties and middle coats prepared with organic solvents have so far not been known to dissolve chemically crosslinkable plastic binders. contain mineral fillers and / or pigments. The inventions 4 "The aim of the invention, while avoiding the disadvantages of the manure, furthermore relates to a process for the production of these known materials, the elaboration of a compound which can be used as a filling primer position, spray putty and paint layer. It is known that on the surface of the painting position, which results in a smooth surface when sprayed on, metal, wood and other objects that require less grinding work. and major recesses and consequently one <»5 The invention is based on the knowledge that the above aesthetically satisfactory coating can only be achieved completely in the way that the objective can be achieved if one can become that one uses the uneven solvent mixture which fills from a larger one before the top coating and creates a smooth surface by grinding. Amount of rapidly evaporating, i.e. If this is neglected, the solvent that is applied in a thin layer and a much smaller amount of opaque paint do not give a pleasing, i.e. smooth and shiny so slowly evaporating, i.e. have a low tension Coating. gender solvent is compiled and at least To fill the larger recesses, so-called Spach 20% by weight consists of components, the surface span material of which is less than 29 dyn.cm with the smoothing knife. It was found that syste-about 500-1000 (am applied and then to obtain a me containing such a solvent mixture, on smooth surface with coarse emery paper (by hand or spraying 55 form so tiny paint droplets that even on machine) In order to remove the surfaces perpendicular to the grinding wheel without tiling, a uniform surface and the smaller unevenness will then result in the entire coating. This finding is surprising, since according to Provide the surface with a liquid that can be applied by spraying the previous views when applying by spraying so-called spray putty or middle coat, which can only achieve a layer - a smooth surface if it has a thickness of 60-100 [im. Spray putty and medium coat 60 applied coating due to a content of heavy volatile are usually applied to a base coat. The central solvents remain liquid for some time, i.e. if telan painting is often also pigmented and contains a little more binary. means than the spray putty, in which the color plays no role. The invention accordingly relates to a smooth upper, in some cases primer and middle coat are surface-requiring and require little sanding, and a single layer is applied as filler; For this purpose, 65 primers, spray putties and layers of paint are so-called. Filling primers Use, which also contain corrosion-resistant compositions, which are dispersed in the pigments containing organic mende and which are applied directly to the metal surface of the solution of chemically cross-linkable solvents. Plastic binders, mineral fillers and / or pigments elements included. According to the invention, the compositions contain, as organic solvent, solvent mixtures which consist of 20-96% by weight solvent (s) with an evaporation number less than 32 and a surface tension below 29 dyn.cm, 4-20% by weight solvent (s) with a Evaporation number greater than 40 and 0-76 wt .-% other solvents exist.