FR2461736A1 - MIXTURES OF CURABLE EPOXY RESINS AND USE THEREOF - Google Patents

Abstract

MIXTURES OF HARDENABLE EPOXID RESINS. THEY MAY INCLUDE DIFFERENT EPOXIDE RESINS AND AS HARDENERS, IN PARTICULAR NOVOLAQUES WITH THE ONLY FUNCTIONAL GROUPS 3 PHENOLIC HYDROXYLES, OR REACTION PRODUCTS OF GLYOXAL OR ACROLEIN WITH PHENOL. APPLICATION TO ANTI-CORROSION COATING OF STEEL SHEETS.

Description

The present invention relates to

  curable resins of epoxy resins, which are particularly suitable for anticorrosive coating of steel sheets. Epoxy resin-hardener combinations have long been known for protection against corrosion. In this regard, reference is made, for example, to US Pat. No. 3,019,202 and German Patent Application No. 2,505,278. The curable mixtures according to US Pat. No. 3,019,202 contain, as epoxide resins, diepoxy sulfones, and as hardeners, they may contain inter alia monomeric polyphenols, such as bis- (4-hydroxyphenyl) -2,2-propane, pyrogallol and resorcinol. Curable mixtures of this state

  of the art, however, have important disadvantages

  healthy. In particular, they require cooking times

  or very long hardening. It is not possible to ob-

  maintain a satisfactory hardening at

  less than 1601C. It is desirable, however,

  given the cost of energy, to have cooking times

  reduced and low cooking temperatures.

  The layer thicknesses that can be obtained

  The process according to this state of the art is so low that the coating has to be repeated 3-7 times to obtain a layer thickness of about 100 microns. However this minimum layer thickness is necessary in any case with these known systems if one

  wants to get effective protection against corrosion.

  These multiple coatings associated with final thicknesses of relatively thick layers are uneconomical both from the point of view of time and from the point of view of

the matter.

  German Patent Application No. 2,505,278

  steel sheets coated with synthetic resins

  c. The coating systems described therein are mixtures of epoxy resins which contain as

246 1736

  hardeners of phenolic resins hardening on

  their. These phenolic resins, for example the resols, already have considerable molecular weight and contain, in addition to phenolic OH groups, other functional groups such as methylol groups.

  Synthetic resin systems de-

  German Patent Application No. 2,505,278 has substantially the same disadvantages as the systems described in the aforementioned U.S. Patent. The two known systems also lead to coatings

  which are not sufficiently resistant to

  aggressive liquids, such as acetic acid solutions at concentrations of 50% or more, concentrated hydrochloric acid, nitric acid

ammonia.

  The invention relates to the preparation of suitable curable epoxy resin mixtures

  for the preparation of coatings resistant to corrosion

  on steel plates or other substrates, and

  which do not have the disadvantages described in the

  known problems. For their hardening, we must be able to

  use shorter cooking times and

  lower cooking zones. During the first

  of the steel sheets, sufficiently large layer thicknesses must already be obtained, which are even greater by their anticorrosion action to the known systems more

  thick, with multiple layers.

  The invention relates to hardened mixtures

  epoxy resin sand containing: a) one or more epoxy resins based on bisphenol A and / or bisphenol F having an epoxide content of 0.3 to 2.0 Val / kg, and / or b) one or more epoxy resins based on bisphenol

  A and / or bisphenol F and / or phenol- or alkyl-

  phenol-novolak having an epoxide content of 2.0 to 6.0 Val / kg, and / or c) one or more glycidyl ethers of hydrogenated bisphenol A and / or hydantoin-epoxide resins and / or polyglycidyl esters having a content of epoxide of 4.0 to 8.0 Val / g, d) 10 to 100% by weight, based on the sum of the resins

  epoxides indicated in (a) to (c), one or more

  type of polyphenols and / or oligophenols containing at least 3 OH phenol groups and, outside thereof, no other functional group, and e) from 0.2 to 3.0% by weight, based on sum of

  epoxy resins specified in (a) to (c), of one or more

  curing accelerators, and additionally containing, where appropriate: (f) ordinary additives and additives for lacquers and / or

g) organic solvents.

  Curable mixtures of epoxy resins containing a) one or more epoxy resins based on bisphenol A and / or bisphenol F having an epoxide content of 0.3 to 2.0 Val / kg, and / or b) are preferred. or more epoxy resins based on bisphenol

  A and / or bisphenol F and / or phenol- or alkyl-

  phenol-novolak having an epoxide content of 2.0 to 6.0 val / kg, and / or c) one or more glycidyl ethers of hydrogenated bisphenol A and / or hydantoin-epoxide resins and / or polyglycidyl esters having a content of epoxide of 4.0 to 8.0 Val / g, d) 10 to 40% by weight, based on the sum of the resins

  epoxides specified in (a) to (c), of one or more

  type of polyphenols and / or oligophenols containing at least 3 phenolic OH groups, and not containing any functional groups other than these and e) 0.2 to 3.0% by weight, based on the sum of the resins epoxides indicated in a) to c), one or more curing accelerators, and further containing if necessary f) usual additives and lacquer additives, and / or

g) organic solvents.

  As hardeners of the type of polyphenols and / or oligo-phenols d) containing at least 3 OH groups

  phenolic and not containing other functional groups.

  such as these, the mixtures of the invention

  preferably those from the phenol group.

  novolaks, cresol-novolacs, bisphenol-2-novolacs, bisphenol-F-novolacs, reaction products of 1 mole of glyoxal with 4 moles of phenol and reaction products of 1 mole of acrolein with 3 moles of phenol. As hardening accelerators (e), the mixtures preferably contain those of the group of organotin compounds, imidazole derivatives,

and 4-dialkylaminopyridines.

  A preferred form of the invention is represented by the mixtures consisting of a) 30 to 50 parts by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having an epoxide content of 0.5 to 2.0 Val / g, b) 50 to 70 parts by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F and / or phenol or alkylphenol novolac having an epoxide content from 2.0 to 4.0 Val / kg, c) 25 to 35% by weight, based on the sum of the epoxy resins indicated in a) and b), of a cresolnovolac corresponding to the approximate formula I:

9H 9H

  vH3 v \ / CH3 _ CH 3 I * - f * * - CH ô + i! (I), "o?.] 2

  (d) 0.2 to 1.0% by weight, based on the sum of the residues

  epoxides indicated in (a) and (b), of one or more

  accelerators of the imidazole group, 4-

  dimethylaminopyridine and tin octoate, and additionally, where appropriate, e) 0.5 to 2% by weight, based on epoxy resins and hardeners, leveling agents and f) solvents in the group of ethylglycol acetate,

  methyl isobutyl ketone and xylene.

  Another preferred form of the invention is also represented by mixtures which contain as an epoxidized compound a bisphenol A epoxy resin half solid to solid, and as a hardener (d) simply a cresol novolac of the formula I, weight ratio being chosen such that there is 1 (+ 30%) epoxide group for 1 phenolic OH group. A particular embodiment of the invention is represented by the mixtures consisting of: a) 10 to 100 parts by weight; weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having an epoxide content of 0.3 to 6.0 Val / kg, b) 0 to 100 parts by weight of one or more resins

  epoxides based on phenol- or alkylphenol-novola-

  with an epoxide content of 3.0 to 6.0 Val / kg, c) 0 to 100 parts by weight of one or more hydantoin-epoxide resins and / or polyglycidyl esters having an epoxide content of 4, 0 to 8.0 Val / Kg,

  d) 10 to 100% by weight, based on the sum of the residues

  epoxides indicated in (a) to (c), of one or more

  hardeners of the type of polyphenols and / or oligomers

  phenols containing at least 3 phenolic OH groups

  and no other functional group apart from those

ci, and

  o10 e) 0.2 to 3.0% by weight, based on the sum of the

  epoxy compounds indicated in a) to c), one or more curing accelerators, and, where appropriate, f) conventional additives and lacquer additives, in the form of powders, the particles

  individual particles being homogeneous particles of the

  total, and which do not contain any resin

  among the epoxy resins specified in (a), (b) and (c) and no solvent or only a quantity of liquid epoxy resin and / or a quantity of solvent

  such that the powder is non-tacky and fluent.

  Mixed powder mixtures are preferred

  of: (a) 10 to 100 parts by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having an epoxide content of 0.3 to 6.0 Val / kg, b) O to 100 parts by weight of one or more resins

  epoxides based on phenol or alkylphenol-novola-

  with an epoxide content of 3.0 to 6.0 Val / kg, c) 0 to 100 parts by weight of one or more hydantoin-epoxide resins and / or polyglycidyl esters having an epoxide content of 4, 0 to 8.0 Val / g, d) 10 to 40% by weight relative to the sum of the resins

  epoxides indicated in (a) to (c), one or more

  type of polyphenols and / or oligophenols containing at least 3 phenolic OH groups and

  containing no other functional groups than those

ci, and

  e) 0.2 to 3.0% by weight, based on the sum of the

  epoxy compounds indicated in (a) to (c), one or more curing accelerators and, where appropriate, f) ordinary lacquer additives and additives;

  powders, the various

  cules being homogeneous particles of the total mixture and which contain no liquid resin among the epoxy resins indicated in a), b) and c), and no solvent or an amount of liquid epoxy resin and / or solvent sufficiently low that the powder

is non-sticky and fluent.

  A preferred form of these blends in

  Special products are mixtures consisting of: (a) 10 to 100 parts by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having an epoxide content of 0.3 to 6.0 Val / kg, b) 0 to 100 parts by weight of one or more epoxy resins based on phenol or alkylphenol novolac with an epoxide content of 3.0 to 6.0 Val / g, c) 15 to 30 % by weight, based on the sum of the epoxy resins indicated in (a) and (b), of one or more

  hardeners of the polyphenol and / or oligophenic type

  Nols containing at least 3 phenolic OH groups and no other functional groups outside thereof, and

  d) 0.2 to 3.0% by weight, based on the sum of the

  epoxide groups indicated in (a) and (b), of one or more

  curing accelerators and, where appropriate, e) additives and additives for ordinary lacquers,

  powders, the various

  cules being homogeneous particles of the total mixture, and which do not contain any liquid resin among the resins indicated in a) and b), and no solvent, or

  a quantity of liquid epoxy resin and / or

  sufficiently weak for the powder to be

non-sticky and fluent.

  The pulverulent mixtures of the invention can also be suspended in water or in a

  organic solvent which does not dissolve the mixture, the concentration

  solid substances being from 15 to 5% by weight per

compared to the total suspension.

  The mixtures of the invention may

  hold one or more of the epoxy resins specified in (a),

  (b) and (c), in whole or in part, and one or more of

  solvents listed in d), wholly or partly in the form of preaddition products (reaction products of the epoxy resin and the hardener). The table below shows the addition products that are fundamentally

  possible (he makes it heard here by a), b), c) etc ...

  The products mentioned in these letters in the above blends). (a) and (b) adduct with (d) (a) (b) (a) and (c) (c). b) and c) a) and b) and c) The epoxy resins contained in the mixtures of the invention have been known for a long time and have been repeatedly described in the literature,

  so that it will be superfluous to describe them further

  floor. This also applies to hardeners containing

  at least 3 phenolic OH groups and not containing

  out of these no other functional groups, such as novolaks and products of the reaction of glyoxal and acrolein with phenol. These products are obtained by condensation in an acid medium. With regard to these hardeners, we will refer to the literature on chemistry

modern phenolic resins.

  Adjuvants and additives which may be present in the mixtures of the invention include, in particular, fillers, pigments, colorants, modifiers, softeners, plasticizers and leveling agents. Known leveling agents are, for example, polyvinyl butyral, ester resins

  carbamic acid and particular polyacrylates.

  These adjuvants are also described in detail in the literature (for example in the "handbook of epoxy resins"

  H.Lee and K.Neville, Mc.Graw-Hill Book Camp. (1967)).

  This also applies, for the rest, to organic solvents

  substances contained in the mixtures of

  and possibly for hardening accelerators.

ment.

  Another object of the invention is the use

  mixtures of the invention for the manufacture of coatings on metals, in particular on steel sheets,

  stable acids, alkalis and ammonia. The inventors

  tion is usable inter alia for the anti-

  acid, for the application of the primer in construction

  automotive and for the internal lacquering of packaging, fats, containers including cans for

food and drinks.

  If a liquid mixture according to the invention (lacquer solution) is used for the production of such a corrosion-resistant coating, the application of this coating is first carried out on the steel sheet. for example by immersion processes, with a brush or

246-1 736

  roll, but preferably by means of a spray gun.

  riser for ordinary lacquer. Then come the drying

  age and hardening at lower temperatures or

equal to 130 ° C.

  Solvent-free mixtures or

  solvents of the invention are used in accordance with

  according to the invention either in dry form or in

  powder coatings, or under

  form of suspensions in water or in solvents

  different. In the first case, the application of the

  dre is carried out by known powder coating processes such as fluidized bed powder coating, flame spraying or dispersion by means of

  electrostatic spraying system

  ders. When using a powder suspension, the most

  simple is to carry out the application by means of a pistol

  let sprayer lacquer. In both cases, the operation

  This is followed again by a hardening at 1301C at

  less with, if necessary, prior drying.

  The following nonlimiting examples are given by way of illustration of the invention. Except

  contrary indications, the parts are by weight.

EXAMPLE 1

  (Epoxy resin lacquer systems /

crésolnovolaque).

  65 g of a polyglycidyl ether are mixed

  as a semi-solid at room temperature, prepared by condensing bisphenol A with epichlorohydrin in the presence of an alkali, having an epoxide content of 4.0 Val / kg with 35 g of a solid polyglycidyl ether at room temperature, prepared by condensation of

  bisphenol A with epichlorohydrin in the presence of a

  cali. having an epoxide content of 0.5 Val / kg, and

  dissolves at 80-1000C in a mixture of ethyl acetate and

  glycol / xylene 1: 1 to give a 50% solution. 34 g of a cresolnovolac with an OH content of 8.25 Val / kg are then added to the epoxy resin solution cooled to room temperature (cresol: formaldehyde molar ratio in the preparation = 1: 0.7). which was dissolved at 60-80 ° C in 22 g of methyl isobutyl ketone and then cooled to room temperature. As a reaction accelerator, 0.8 g of a mixture of

  0.4 g of tin octoate and 0.4 g of dimethylaminopyridine.

  The lacquer thus obtained is adjusted to

  a viscosity of about 150 mPa s / 25 C with methyl-

  isobutyl ketone, and applied with a spray gun

  on a steel substrate. The dry film thickness after firing the lacquer (20 min.,

   C at 20 °, 60 ° C) is about 50 microns. The properties

  of the film thus obtained are collected in

Table I.

EXAMPLE 2

  (Lacquer systems epoxy resin / poly-

phenol).

  76 g of a bisphenol ether-A-

  semi-solid glycidyl at room temperature (prepa-

  as described in Example 1) having an epoxide content of 2.5 Val / kg with 24 g of a solid bisphenol-A-glycidyl ether at room temperature (prepared as described in US Pat. Example 1) having an epoxide content of 0.5 Val / kg and dissolved in a mixture

  Ethylglycol acetate: xylene 1: 1. to give a solution

  50%. To the cooled epoxy resin solution

  at room temperature, 22 g of a poly-

  phenol prepared by reaction of 3 moles of phenol with 1 mole of acrolein, having a hydroxyl content of 9.35

  Val / kg, which was dissolved at 60-80 C in 15 g of methyl

  isobutyl ketone and then cooled to room temperature.

  As a reaction accelerator, 0.6 g of a

  mixture of 0.3 g of tin octoate and 0.3 g of dimethyl

  aminopyridine. The lacquer thus prepared is adjusted with methyl isobutyl ketone at a viscosity of about 150 mPa s / 25 C and applied to a steel substrate with a

  conventional spray apparatus. The thickness of the film

  dry after cooking the lacquer (20 minutes at 130-

   C) is about 50 microns. The properties of the pel-

  lacquer are also indicated in Table I.

  INDICATIONS ON TEST METHODS (SUBSTRATE: TOLE

STEEL).

  P: pendulum hardness according to Persoz, measured on a film 40-50 microns thick at 20 C and 65% relative humidity (RH) * (French standard AFNOR NFT 30.016) Apparatus type 300 from Erichsen

(FRG).

  E Deep drawing ability according to

  Erichsen, DIN 53156 measured on film

  cells 40 to 50 microns thick,

  at 20 C and 65% RH. Expressed in mm.

  J Impact test, the test is carried out on the

  film, with a thickness of 40 to 50 microns.

  Weight of the test sheep 1 kg, diameter of

  the half-sphere of percussion: 2 cm.

Test temperature 20 C, 65% RH.

  RJ Reverse impact test, the impact is on the substrate (steel sheet). Thickness of film 40-50 microns, weight of

  test sheep 1 kg, diameter of half

  2 cm percussion sphere. Temperature

test temperature 20 C, 65% RH.

  * The hardness is expressed in seconds.

  D: 8mm pin bend test at 20C and 65% RH, film thickness 40-50

microns (DIN 53 152).

  AC: Acetone friction test. We do

  kills 20 alternating passages each time with a cotton wool impregnated with acetone on the hardened film. Film thickness: -50 microns. Test temperature: 201C,% RH. Assessment in accordance with

DIN 53.230.

  KW: boiling water test, 6 h at 960C on

  films of 40 to 50 microns thick

  sor. Assessment in accordance with

DIN 53 230.

  Gt: Network incision test, DIN 53 151 with cutting device A. Film thickness: 40-50 microns. Temperature

201C-65% RH test.

  Ch Chemical resistance test

  on films with a thickness of about 100 microns (application in 2 layers), hardening 2 x 20 'at 130C

  or 2 x 20 'to 1600C. Immersion temperature

20-220C.

  Resistance is appreciated visually.

  There are three possibilities here: +: The film is resistant to the test environment and is

  unchanged at the end of the test (1 month).

  A: The film has limited strength

  in the middle of the test, that is to say that it does not

  only a short time. After one month of

  Sure, there is slight damage such as swelling or softening. The protection of

  substrate (steel sheet) is ensured.

  Z: The film is destroyed, that is to say that the protection of the substrate is no longer ensured by the coating material the test medium is in

contact with the suwstram.

TA B L E A U I

  Example N 1 | 2 types of resin / epoxy resin. epoxy resin / novolak resin-polyphenol curing conditions 20 '130 C 20' 160 C 20 '130 C 120 C 160 _ _ _ _ _ (P) hardness seloi Persoz (sec.) 390 380 395 365 (E) test! Erichsen (mm) 7.5 7.0 8.5 8.0 (J) shock test (cmkg) 90 90 90 90

(RJ) Reverse-Im-

  pact (cmkg) 90 90 90 90 (D) bend test around 81 boauon (4) 1 180 180 180 (Ac) friction test at 0 I 1 1 acetone 0 1 (KW) boiling e test 0 0 0 0 (Gt) lattice co pe test 1 1 2 1 Resistance to water deionized + + to ammonia + + + + to 25% to acid + + + acetic acid to 50% to 70% + sulfur + + A + furic acid + + + + hydrochloric acid

36% + + + +

with nitric acid

  than at 20% + + + + to methanol Z A Z Z I toluene + Z +

EXAMPLES 3 to 20:

  The procedure is as in Example 1, but using the following epoxy resins and hardeners: epoxy resin-type 1-epoxy resin-type 2 epoxy resin-type 3 epoxy resin-type 4 epoxy resin-type 5 epoxy resin-type 6 Epoxy resin - type 7 Polyphenol I: Semi-solid bisphenol A epoxy resin having an epoxide content of 3.6 to 4.0 Val / kg,

  Bisphenol A epoxy resin

lide having an epoxide content

of 2.3-2.6 Val / kg.

  Bisphenol F epoxy resin

which has a viscosity of 5000 to 8000 mPa s / 25 C and a

epoxide 5.6 to 6.0 Val / kg.

  Cresolnovolac-epoxy resin having an epoxide content

4.8 to 5.2 Val / kg.

  Bisphenol H Epoxy Resin (i.e.

Bisphenol A completely hydro-

gene) having a viscosity of

2000 to 3000 mPa s / 25 C and a range of

  epoxide neur from 4.2 to 4.6 Val / kgo Liquid hydantoin-epoxide resin with a viscosity of 1500-2000

mPa s / 25 C and a content of

xyd from 7 to 7.5 Val / kg.

  Diglycidyl ester of liquid tetrahydrophthalic acid having a viscosity of 400 to 700 mPa s / 25 C and an epoxide content

from 6.1 to 6.6 Val / kg.

(the same as in example 2). Pro-

the reaction of the mole of

  crolein and 3 moles of phenol Polyphenol II: cresolnovolac with a hydroxyl content of

9.35 Val / kg.

  Product of reaction of glyoxal and 4 moles of phenol with a content

in hydroxyl of 10.05 Val / kg.

  III: (As in example 1) having a content

in hydroxyls of 8.25 Val / kg.

  The lacquers prepared are adjusted to a viscosity of about 150 mPa s / 25 C by the method described in Example 1, using methyl isobutyl ketone, and applied to a steel substrate with an ordinary spray apparatus. The thickness of the dry film after lacquer cooking (20 minutes at 130-160 ° C) is

about 50 microns.

  Experimental values of coatings

  The resulting films are summarized in Table II.

table II next page

T A B L E A U II

  Ex. G of r-type gde p g of -decr-, g of ac- Condi- P E J RJ Ac KWct Io n o T! Deficiencies N mepolated Ilyplenol0Y-sol noncellated hardened. nnmm cmkg cmkg 10 oepde _ (20 from

  No 3iyd 'sne e ohenol hardeners

  poxide, -Ynol.I am I HI (20 rd) o 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1000C CCCCCCCCCC 1600C 7 4.0 4.5 , 5 7, 0 3.0 4.0 4.5 3.0 7.0 6.5 7.0, 7.5 7.5 7.0, 0 8.0, 0 7.5 oooooooooooooooooo OOOOOOOOOO ii ii -4 or 0% - at I -4 o0

EXAMPLE 21

(Powder coating method)

  87 parts of a bisphenol A epoxy resin having an epoxide content of 1.3 Val / kg are mixed with 12.5 parts of the reaction product of 1 mole of acrylonitrile.

  3 mol of phenol, 25 parts of TiO 2, 25 parts of

  BaSO4, as feedstock, 0.25 parts of imidazole and

  0.7 part of a leveling agent of the polyvinyl butyral type

  (Modaflow of the Monsanto Company), they are homogenous

  in a Ko-Knetter (from the Buss Company) at tempe-

  between 30 and 1000 ° C and cooled to room temperature. The product obtained is milled to a grain fineness less than or equal to 100 microns

  and it is applied in a known manner by means of a

  electrostatic spraying of powders on

  various sample sheets. After a hardening

  complete 20 minutes at 1500C, we obtain homogeneous films, free of pores, with good spreading

  and a high mechanical and chemical resistance.

EXAMPLE 22

  (Use of a powder suspension).

  Mixed as in Example 21, 50

  parts of a bisphenol A epoxy resin having a

  epoxide of 1.3 Val / kg, it parts of a bisphenol-F novolak with an epoxide content of 120 Val / g, relative to phenolic OH groups, having a melting point of 85-901C, 31 parts of TiO2, 0.6 part of imidazole and 0.9 part of the leveling agent used in Example 21, homogenized and transformed

  into a powder having an average particle size of

less than or equal to 100 microns.

  35 parts of this powder are suspended in 65 parts of water and ground in a bead mill to a particle size of about 10 microns. The suspension thus obtained is applied by means of a spray gun for ordinary lacquers

  samples and cooked for 20 minutes.

  at 150 ° C. Homogeneous films, exemplary of pores, having good spreading and good chemical and mechanical properties are formed.

EXAMPLES 23 to 30:

  We proceed as in example 1. We use

  the epoxy resins and hardeners

  epoxy resin type 8: Bisphenol A epoxy resin having

  an epoxide content of 0.5 Val / kg; horn-

  corresponds to the solid resin mentioned in

Examples 1 and 2.

  bisphenol F-novolac: condensation product of phenol and formaldehyde corresponding to the formula HO-- '.-CH- .- H (semisolid)

\ .5 z .._.

hydroxyl content: 10.0 Val / kg.

  Phenolnovolac: Condensation product of phenol and formaldehyde, but of a higher molecular weight than bisphenol F. The majority is trifunctional, as in the case of cresolnovolac. Solid product having a hydroxyl content of

9.9 Val / kg.

  Bisphenol-A-novolac: a condensation product of bisphenol

  nol A and formaldehyde (solid). Content

in hydroxyls 8.25 Val / kg.

  Prepared lacquers are adjusted to

  150 mPa s / 25 C as described in Example 1,

  using methyl isobutyl / ketone at a viscosity of

  150 mPa s / 25 C and applied to a substrate of

  with an ordinary spray apparatus. The thick-

  dry film after firing lacquer

  (20 minutes at 130-1601C) is about 50 microns.

  The compositions of the mixtures of

  ples 23 to 30 and the curing conditions thereof are shown in Table III, and the experimental values of the film coatings obtained in FIG.

Table IV.

  See tables III and IV following pages

T A B L E A U III

  Example Per 100 g of Crésolnovola-Bisphenol-F Phenol-BisphenolImidazol Hardening

  novolak novolac novolak (accelerating epoxy resin (g) mixture) to g (g) (g) (g)

23 40 2 32 1 130 C

8

6,160 C

24 70 8 28 1 130 C

7

 C

70 2 47 1 1300C

6

 C

26 70 2 44 1 1300C

7

1600C

27 40 8 38 1 1300C

4

 C

28 65 1 29 1 1300C

8

   C t '., -A N 4N 0% -.4 Lw 0% T A B LE AU III (end)

  Example For 100 g of Crésolnovola-Bisphenol-F Phenol-Bisphenol-A Imidazol Hardening

  NO melanic acid (g) novolak ovola novolac accel- eration e xe. (g) ue (g) (g) ters) 20 g Typ (g)

29 65 1 29 1 1300C

8

o c

65 J. 34 1 130 C

8

oc Ni t 'a%> -4. LN o4.

TABLE IV

  Example P E J RJ D Ae KW Gt Curing N sec. mm cmkg cmrkg 4O 20 min. have.._......__.

23 290 6.5 90 90 180 1 4 2 130 C

290 7.5 90 90 180 0 4 1 160 C

24,330 8.5 90 90 180 3 4 1 130 C

330 9.0 90 90 180 2 4 1 160 C

320 5.0 90 90 180 0 4 2 130 C

320 6.5 90 90 180 0 4 5 1600C

26,320 7.5 90 40 180 0 4 5 130 C

290 7.0 90 90 180 0 4 1 160 C

27,310 7.0 90 40 180 0 0 3 1300C

310 5.0 90 50 180 0 0 3 160 C

28 230 9.5 70 60 90 3 0 2 130 C

270 9.5 90 90 180 3 0 2 160 C

29,300 9.0 90 90 180 2 0 1 130 C

310 9.0 90 90 180 2 0 1 160 C

310 8.0 90 70 180 1 0 2 130 C

300 8.0 90 90 180 0 0 4 160 C

f.J w ru 0% 0%

EXAMPLE 31

  (Preparation of the preaddition product I).

  290 g of the cresolnovolac are dissolved in a sulphonation flask in 290 g of methyl isobutyl ketone under slight reflux. To the clear solution, then

  240 g of the 50% solution / prepared separately

  reforming the type 1 solid epoxy resin in methyl isobutyl ketone,

  and boil under slight reflux -

  until the epoxide content of the solution is less than 0.005 Val / kg. To accelerate the reaction, 0.5% by weight of imidazole, based on the total mixture, is added. The solution has a viscosity of about

  2000 mPa s / 25 C and one hydroxyl equivalent of 2.4 Val / kg.

EXAMPLE 32

  (Preparation of the preaddition product II).

  290 g of the cresolnovolac were dissolved in a sulphonation flask in 590 g of methyl isobutyl ketone under slight reflux. To the clear solution is then added 300 g of the type 8 solid epoxy resin and boiled under slight reflux until the epoxide content of the solution is less than 0.005 Val / kg. To speed up the reaction, add 0.5%

  by weight of imidazole, based on the total mixture. The

  The solution has a viscosity of about 2000 mPa s / 25 C and a

  hydroxyl equivalent of 1.9 Val / kg.

  Mixes prepared using the

  pre-additions I and II and the experimental values of the film coatings obtained are summarized in

Table V.

BOARD

  Example N 31 32 Type X epoxy resin (g) 60 100 Type 8 epoxy resin 40 Preadd product. (112 (at 50%) (g) Preadd.II 212 product (at 50%) (g) Imidazole (wt%) 0.5 0.5 Solvent (g) 236 168 Viscosity (mPa s) 110 110 Tinner of material 35% by weight (% by weight) Curing 20 min at 130 C 160 C 130 C 160 C (P) Hardness according to 330 360 400 390 Persoz (sec) (E) Erichsen test (mm) 7.5 5 , 5 8.0 7.5 (J) Impact test 90 90 90 90 (cmkg) (RJ) Shock on the sub 90 60 50 90 Reverse impact (cmk) (D) Test folding () 180 180 180 180 on oroche (Ac) Acetone Friction Test (KW) Boiling Water Test (Gt) Network Incision 1 1 1 1 Table VI gives the chemical resistance of the formulas of Table V after immersion during

  6 months at 20-22 ° C (curing time: 20 minutes at 160 ° C).

24617'36

TABLE VI

  Example No. 31 32 Resistant Deionized Water Resistant

Synonymous seawater

  Thirsty sodium hydroxide solution at 30% Ammonia at 250 resistant 5 months resistant 1 month -Acid acetic at 50% resistant Acid sulfurir sm at 70% "resistant 4 months

Hydrochloric acid

  20% RHD "resistant Horyr acid due to a036% orhyd resistant 4 months Nitric acid 20% resistant Resistant Toluene 2 months softens Non resistant methanol resistant

Claims (12)

  1.- Mixtures of hardened epoxy resins   sands, containing a) one or more epoxy resins based on bisphenol A and / or bisphenol F, having an epoxide content of 0.3 to 2.0 Val / kg, and / or b) one or more epoxy resins with Bisphenol A base   and / or bisphenol F and / or phenol- or alkylphenol-   novolak having an epoxide content of 2.0 to 6.0 Val / kg, and / or c) one or more glycidyl ethers of hydrogenated bisphenol A and / or hydantofne epoxide resins and / or polyglycidyl esters having a content of epoxide of 4.0 to 8.0 Val / kg, d) 10 to 100% by weight, based on the sum of the resins   epoxides indicated in (a) to (c), of one or more   polyphenols and / or oligophenols containing at least 3 phenolic OH groups and no other functional group than these and e) 0.2 to 3.0% by weight, based on the sum of the resins   epoxides indicated in (a) to (c) of one or more accelerations   curing agents, and additionally containing, where appropriate, f) conventional additives and lacquer additives, and / or g) organic solvents.   2.- Mixtures of hardened epoxy resins   bles containing a) one or more bisphenol A and / or bisphenol F epoxy resins having an epoxide content of 0.3 to 2.0 Val / kg, and / or b) one or more epoxy resins containing bisphenol base   A and / or bisphenol F and / or phenol- or alkylphenol-   novolac having an epoxide content of 2.0 to 6.0 Val / kg, and / or c) one or more glycidyl ethers of hydrogenated bisphenol A and / or hydantoin-epoxide resins and / or polyglycidyl esters having a content of epoxide of 4.0 to 8.0 Val / kg.   d) 10 to 40% by weight, based on the sum of the resins   epoxides indicated in (a) to (c), of one or more   polyphenol and / or oligophenol type containing at least 3 phenolic OH groups and no other functional group than these, and e) 0.2 to 3.0% by weight, based on the sum of the resins.   epoxides indicated in (a) to (c), of one or more accelerations   curing agents, and additionally containing, where appropriate, f) conventional additives and additives for lacquers and / or g) organic solvents.   3.- Mixtures according to claim 1, characterized in that they contain as hardeners of the type of polyphenols and / or oligophenols (d) containing at least   minus 3 phenolic OH groups and no other functional groups   that hardeners from the phenol group   novolacs, cresolnovolacs, bisphenol-A-   novolaks, bisphenol-F-novolacs, reaction products of 1 mole of glyoxal with 4 moles of phenol and reaction products of 1 mole of acrolein with 3 moles of phenol.   4. Mixtures according to claim 1, characterized in that they contain as accelerators   hardening (e) accelerators group   Organic Sn coatings, imidazole derivatives and 4-dialkylaminopyridines. 5. Mixtures according to claim 1, characterized in that they contain one or more resins of the epoxy resins indicated in a), b) and c),   totally or partially, and one or more of the dura-   compounds listed in d), totally or partially, in the form of preaddition products (reaction products   epoxy resin and hardener).   6. Mixtures according to claim 1,   characterized in that they are composed of a) 30 to 50 parts   by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having an epoxide content of 0.5 to 2.0 Val / g, b) 50 to 70 parts by weight of one or several epoxy resins based on bisphenol A and / or bisphenol F and / or phenol or alkylphenol novolac with an epoxide content of 2.0 to 4.0 Val / kg, c) 25 to 35% by weight, in relation to the sum of the epoxy resins indicated in (a) and (b), a cresolnovolac corresponding to the approximate formula I: CHH CH q3 ! 1 <* --- CH2! <2 *! I   d) 0.2 to 1.0% by weight, based on the sum of the resins   epoxides indicated in (a) and (b), of one or more accelerations   of the imidazole group, 4-dimethylamino-   pyridine and tin octoate, and additionally, where appropriate, e) 0.5 to 2% by weight, based on epoxy resins and hardeners, leveling agents and f) solvents in the group of ethylglycol acetate,   methyl isobutyl ketone and xylene.   7. Mixtures according to claim 6, characterized in that they simply contain as epoxy a bisphenol A epoxy resin semi-solid to   solid, and as hardener (d) simply a cresolnovo   lacquer of formula I, the weight ratio being   chosen so that we have for an OH group nolic 1 (+ 30%) epoxide group.   8.- Mixtures according to claim 1, characterized in that they consist of a) 10 to 100 parts by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having a content of epoxide of 0.3 to 6.0 Val / kg, b) 0 to 100 parts by weight of one or more phenol- or alkylphenol-novolac-based epoxy resins having an epoxide content of 3.0 to 6.0 Val / kg, c) 0 to 100 parts by weight of one or more hydantoin-epoxide resins and / or polyglycidyl esters having an epoxide content of 4.0 to 8.0 Val / kg, d) 10 to 100 % by weight, based on the sum of the resins   epoxides indicated in (a) to (c), of one or more   of the type of polyphenols and / or oligophenols   holding at least 3 phenolic OH groups and no other functional groups outside thereof, and   e) 0.2 to 3.0% by weight, based on the sum of the residues   epoxides indicated in (a) to (c), of one or more   hardeners, and, where appropriate, f) conventional additives and additives for lacquers,   and in that they are in the form of powders, the particles   the individual being homogeneous particles of the   total, and which contain no liquid resin among the epoxy resins indicated in a), b) and c) and no solvent, or only a quantity of liquid epoxy resin and / or a quantity of solvent such as   the powder is non-tacky and fluent.   9.- Mixtures according to claim 8, characterized in that they consist of a) 10 to 100 parts by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having a content of epoxide of 0.3 to 6.0 Val / kg, b) 0 to 100 parts by weight of one or more resins 246 1,736   phenol- or alkylphenol-novolac epoxides having an epoxide content of 3.0 to 6.0 Val / kg, c) 0 to 100 parts by weight of one or more hydantol-epoxide resins and / or or polyglycidyl esters having an epoxide content of 4.0 to 8.0 Val / g, d) 10 to 40% by weight based on the sum of the epoxy resins indicated in a), & c), one or more hardeners of type of polyphenols and / or oligophenols containing at least   at least 3 phenolic OH groups and not containing   very functional groups such as these, and e) 0.2 to 3.0% by weight, based on the sum of the resins   epoxides indicated in (a) to (c), of one or more accelerations   curing agents, and in addition, on the sample, f) additives and additives for ordinary lacquers,   in that they are in the form of powders, the di-   particles being homogeneous particles of the   total and which contain no liquid resin among the epoxy resins indicated in a), b) and c), and no solvent or an amount of liquid epoxy resin and / or solvent sufficiently low for the powder is non-sticky and fluent.   10. Mixtures according to claim 8, characterized in that they consist of a) 10 to 100 parts by weight of one or more epoxy resins based on bisphenol A and / or bisphenol F having a content of epoxide of 0.3 to 6.0 Val / kg, b) 0 to 100 parts by weight of one or more phenol- or alkylphenol-novolac-based epoxy resins having an epoxide content of 3.0 to 6.0 Val / g, c) 15 to 30% by weight relative to the sum of the resins   epoxides in (a) and (b), of one or more   polyphenols and / or oligophenols   at least 3 phenolic OH groups and no other functional group outside thereof, and d) 0.2 to 3.0% by weight, based on the sum of the resins. 246 1736   epoxides indicated in (a) and (b), of one or more   hardeners, and where appropriate e) additives and additives for ordinary lacquers, in the form of powders,   particles being homogeneous particles of the   total age, and which do not contain any liquid resin   the resins indicated in a) and b) and no solvent,   or a quantity of liquid epoxy resin and / or   sufficiently weak for the powder to be sticky and fluent.   11. Mixtures according to claim 8, characterized in that they are suspended in water or in an organic solvent which does not dissolve the mixture.   or in a mixture of these, the concentration of   from 15 to 50% by weight of the total suspension.   12.- Use of the following mixtures   any of the preceding claims for the   formation of protective coatings resistant to acids, alkalis and ammonia on metals   and other substrates, in particular on steel sheets.