DE1669222A1 - Coating compound - Google Patents

Description

M 2060

U 4

Minnesota Mining and Manufacturing Company,
Saint Paul, Minnesota 55101, V.St.A.

Coating compound

This invention relates to protective coating compositions, particularly solid, powdered, meltable and thermosetting coatings which are used in suspensions or as sprays
can be. In detail concerns! the invention powdered
Coating compositions based on superior combinations of epoxy resins. Hardening agents and catalysts are based.

In the heat hardening, powder-coated © Har-se w@röe.n in such a way in Suspensioßsübersjisgs-process applied © .fe.i öas-s msm ®tn ^ Piiitsfees- Merksfeüok la ä £ © 'S «®p © Bs £ oE ä © ^ ^ tlQtmwi © teüGB @ life ₅ oils ösaa aaffaags

• - 2 - M 2060

first to be softened by the heat for a while and on it hardened. These resins must be storable, i.e. they may even with longer storage or slightly higher temperatures, possibly up to 50 or 60 ° C, do not gel prematurely or harden. When melting, the powders should have a fairly smooth, well bonded, fairly uniform and uninterrupted layer on the surfaces of the workpiece including any Create bumps or sharp corners. Especially for objects that are used outdoors or in the ground, the cover must be solid, strong and infusible and resistant to heat and chemicals.

In addition, the desired coatings should be supple and flexible be. The coating process can then be carried out using a suspension also use for objects to achieve a protective coating, which are bent or undergo a constant change in shape or twist during their use. For example, unterirdife see pipes that are an essential object for this coating process, often uses that require that they are bent just before installation.

A fast continuous process is in the practice of the ■

Suspension coating of objects is very desirable, e.g. that.

• Coating in a fluidized bed or the ice-free spraying process of the electrostatic process, so we are looking for resins,

- which produce a ".cover- isifc & @ ji i3 © sefeteöen®a llgenseliaft ^ n * - / ·

• 'ate s @ hjj @ ll -gelieren waä seiaiell-'affii © inen'

BADOR) GINAL

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harden the tough coating after placing it on the hot workpiece melted. Resins that gell within a few minutes and are post-hardened, in practice the suspension trains very preferred.

The Üuerzugswassen of the present invention are, as far as the Applicant known that the first sufficiently protective of their kind, based on a large selection of commercially available diglycide ethers from polyhydric phenols that cure quickly as well are pliable enough that the coated objects are continuous in lh. he shape can be changed without damaging the coating will. In preferred embodiments, the new ones cure Masses within 60 or 90 seconds or even faster. To the Illustration of their flexural properties were unsupported films of the new coating compositions in preferred embodiments 8 - 10 $, in some preferred cases even more, before they tore. The new masses also produce coatings with increased shock resistance, and on the other hand have excellent mechanical and electrical properties

The powdered coating compositions of the present invention based on synthetic resin generally comprise mutually reacting proportions of an epoxy resin which is solid at room temperature and has on average more than one 1,2-epoxy group per molecule, a hardening agent which is solid at room temperature, can be activated by heat and reacts with spoxy groups, consisting of an aromatic polyamine, which is added to the aromatic ring with

0 0 9 8 3 3/2 C 0 3 BAD ORSGJNAL

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nigfibens two primary or secondary nitrogen atoms directly connected, which in turn eats at least three active hydrogen atoms wear, and a heat activatable catalytic accelerator to increase the rate of the curing reaction, consisting of a combination of (a) a tin, zinc, iron, cobalt, manganese or lead salt of a carboxylic acid and (b) either a .carboxylic acid or its anhydride. .

A wide variety of compounds with 1,2-epoxy groups have been made applied in the coating compositions of the present invention. These Epoxy compounds should be solid substances at room temperature, which melt at temperatures above about 60 or even 75 ° C and in the uncured state even without the presence of other components are sufficiently brittle to be pulverized. You need on average more than one, preferably almost two or have more 1,2-epoxy groups per molecule for crosslinking. The various commercially available diglycidyl ethers of polyhydric phenols, which are solid at room temperature, were preferably used. especially the diglycide ether of bisphenol A is used. However, were also synthesized inner complex compounds, the 1,2-epoxy groups contained, used and thereby the properties of the hardened Product further varies. For example, they produce powdered ones Synthetic resin coating compounds based on polyesters and polyamides, that contain terminal epoxy groups, coatings that still show greater flexibility than those obtained with the help of ordinary

'J

chen epoxy resins can be achieved.

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The curing agents used in the fast-curing, flexible coating composition of the present invention are aromatic polyamines which are solid at room temperature and which can be activated by heat. Examples for these compounds the m-, o- and p-phenylenediamines, ^4,4-f ~ methylene dianiline, diamino-diphenyl-aulfon, 1,4-naphthalene diamine, 3,4-diamine-Taluyl and Oxyddianilin. To ensure rapid gelling and hardening of the coating masses, one gram equivalent of epoxy from the epoxy compounds should account for at least about 0.85 gram equivalents of active hydrogen from the aromatic amines. On the other hand, the aromatic amine component should not contain more than about 1.5 gram equivalents of active hydrogen per gram equivalent of epoxy group in order to obtain compositions which give coatings of the desired flexibility. Even better results are obtained when the ratio of aromatic amine to epoxy compound, expressed as the ratio of the granular equivalents of active hydrogen to dehefj of the epoxides, is between 0.95 and 1.3, at best around 1.2 »

I - "" i ■■ - ■ "■

I ■ "■ ■ - ■ -

The third essential component of the coating compositions of this invention is a heat-activated cocatalyst mixture of a metal salt, such as tin, zinc, iron, carbon, manganese or lead salt of an organic carboxylic acid with either an oarboneatrektev an earboneMureanid, Presentation * Examples

1689222

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Phthalic acid and the anhydrides of phthalic acid, the tetrahydro- * phthalic acid, succinic acid, 1,4,5,6,7,7-HeXaChIOrO- ' bicyolo- / ~ 2,2,17-5-heptane-2,3i * dicarboxylic acid (Chlörendio acid) and polyazoleic acid. It is theS ^ etically believed that all of these connections accelerate the hardening process. Without the bending » to impair the homopolymerization of the Do not catalyze epoxy resin. For this reason, catalysts that catalyze Hearing polymerisation, in general ". undesirable in the present hatred

Although acids and anhydrides are normally used as crosslinking agents for spoxy resins, the Aninelean believes that their function in the present mass only of a catalytic nature Jst.

The proportion of metal salts is normally between 0.2 and 5 wt .- ^ and the proportion of acid or anhydride between 0 * 1 and,> wt .- #, each weighted on the epoxy resin. However, should an oram equivalent? Epoxy aas the fpf ^ not averbinäüngen »ore than 0.2 gram equivalents of acid or anhydride omitted · liquid compounds with boiling point einem'niedrigen are less preferred because something would evaporate during melting of the particles on the heated workpiece; but it can anyway

a small amount of liquid substance is present without the

I 1

desired Bige ^ aoiutffeen de? small-part Mä »b® of the modified

Resin materials are affected *;

ff

009 * 83/2003

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The following table shows representative fermentation times of the Coating compositions of the present invention compiled and the improvements in the Gellerungszelt dui'ch the presence of carboxylic acids or carboxylic acid anhydrides and metal salts. The tabulated results were obtained from three different ones Basic mixes »which are mixed homogeneously when dry were sampled and various metal salts were added to each. “Each of the three basic mixes contained 625 g di glycidyl ether. Of bisphenol A with an epoxy equivalent weight from 550 - 7GQ and a melting point of 75 - 85 ° C (Epon 1002) and 60 g ^ "- methylenedianiline, the first mixture contained no other ingredients »The second mixture contained the above Ingredients in the given proportions and 7 g of adipic acid. The third mixture contained 7 g of tetrahydrophthalic acid instead of adipic acid. A small sample of the homogeneous mixture was placed on a 205 ° C hot plate, and a catalytic one Amount of the respective metal salt added and the time until Gelling measured. At 205 ° C they were those given in the table Times required for gelation.

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BATH

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Tabel Metal salt I. with acid with Anhy
drid GeIungszeit at no 60 - - 65 Tin (II) octoate 205 ° C in seconds 4th 3 Zinc octoate without acid
or anhyarid β 3 Tin (II) -s tearat 120 ίο J> Zinc naphthenate 20th 12th 6th Zinc stearate 28 8th 10 Zinc acetate 30th 6th 10 Lead acetate 30th 14th 10 Iron oetoate 35 12th 12th Lead naphthenate 22nd 22nd 16 Iron naphthenate 45 16 18th Cobalt octoate 65 25th 20th Manganese naphthenate 90 ² 5 30th Iron acetate 60 18th 30th Cobalt acetate 58 25th 35 90 75 80

Except for the epoxy resin, the aromatic amine and the Go catalyst mixture can use the coating composition described in the application Flue regulating agents and also pigments and fillers are added. But if the greatest flexibility is required, will preferably no fillers are used, although the fillers enhance the mechanical properties, such as impact resistance, to enhance.

00 98 83/20 0 3

The ingredients of the compositions of this invention are preferred mixed and fused thoroughly and homogeneously in such a way that they are left on in rubber mills or internal mixers for a sufficiently long time elevated temperatures, around 70 ° C. During mixing, you can choose between the epoxy resin and the aromatic amine reaction occurs to a small extent, but essentially no reaction takes place in the mixture, so that on the the heated workpiece can then melt and harden. After mixing, the mass is quickly cooled until it is solid and then pulverized into a small-sized mass, whose individual particles' have a size that can be put through a sieve 0.420 mm clear mesh size passes through. You can also do that Mix the individual components dry homogeneously without melting, but this method is not preferred.

The following examples demonstrate the unique properties exhibited by the fabrics of this invention. In Examples 1 * 8, the epoxy resin used was diglycidyl ether of bisphenol A with an average epoxy equivalent weight of 625 and a melting point of 85-95 °. G (Araldite 7072) was used. In Example 9, a terminally-terminated polyester containing epoxy groups and having an acid number of 0.15 and an epoxy equivalent weight of 1600 was used. This polyester is the friction product of a carboxyl equivalent of the terminal acid groups-containing adipinic acid-li ^ -btttandlol-ester, which has the acid number 53 * 6 and the hydroxyl number 2, with 4 epoxy equivalent weight diglycidyl ethers of Büphenol A, which has an average epoxy equivalent

009883/2003

BATH ORIGINAL

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of 950 and a melting point of 95 - 105 ° C (Epon 1004). Ethyl acrylate was used as wetting agent in the examples polymerized long-chain hydrocarbons (Modaflow).

The components of the various examples took about 20 minutes in a two-roll Kautsehukmühlei in which a malt was heated to 45 ° C by steam. The mixture then becomes too Sheets less than 1 cm thick rolled out. After cooling down in the air bath, the plates become a sieve size of 0.149 mm clear mesh size or smaller · The shredded parts are placed on a clean tube of 2.54 cm in diameter and are, unless otherwise noted, preheated to 250 ° C. According to the examples given The tubes were quenched to room temperature with cold water.

When the masses of the examples were tested for impact resistance, a 0.02-0.025 thick layer of the masses was initially used; applied by melting onto a 0.318 µm thick steel plate. The samples were then placed in a Gardener Impact Tester, where a 0.9 kg weight with a bent end 1.59 cm in diameter fell onto the coated surface from various heights. In all examples the coating showed neither Cracks still breaks or other visible defects after being hit!

■ '' ■ - "" - ■ '"■" ·, I from awhr as 1,849 leg' »(16O inehpounde) were exposed. The>

Flexibility of the coatings was demonstrated in the various examples by bending a coated drill 'of 2.54 on the Burehawaaer';

■ BAD ORlSTNAL

M 20β0

Ό ° tested with the help of a cable bending device. In none of the examples, the coating had peeled off the pipe and he showed no break either before or after it was bent

/ the one hole.

example 1

Araldite 7072 hA '-Hethylene dianiline * tetrahydrophthalic anhydride tin ctioate (T ~ 9) wetting agent

W eights 623

The coating was gelled on the tube after 10 seconds and was quenched on the dent tube after a total of 00 seconds. In addition, there was a thin film of the above product 0.127 mm thick generated by a melt coating on a release agent surface. This film showed a tensile strength of 612.5 kg / cm and one Definition at the fraction of 8.5 #. Dielectric properties, in particular the dissipation factor and dielectric constant were measured on this film at the frequency of 100 revolutions per second eaten at the following temperatures:

23 ° c 60 ° c 90 ° C. 12c 1 ⁰ C 150 ° c 180 ° C Dielectric
constant 3, 14th 3 , 11 3, 09 3. 18th "3 .48. 4.07 Loss factor 0, 002 0 , 00 ^ 0, 003 0, 019 0 , 061 0.565

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BATH

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Example 2 Parts by weight

Aralaite 7072 625

4,4 ^I -methylene dianiline 60

Tin (II) Octoate (T-9) '. 7th

Phthalic anhydride. 7th

Wetting agent 4

The coating was gelled on the tube after 5 seconds and was quenched after 30 seconds.

Example 3 Parts by weight

Araldtte 7072 625

^, Ji'-methylenedianiline - ■ 60

Tin (II) octoate (T-9) 6

Succinic anhydride 6

Wetting agent 4

The coating gelled in J seconds and was quenched in 60 seconds.

Example 4

Parts by weight Araldite 7072
4,4 * -methylene dianiline
TinCllJ-octcat (T-9)

0 0-9 6ö3 / 2003

625 60 7th SAD

- I? - M 2θ6θ

Example 4 (port setting)

Parts by weight

Adipic acid '7

Wetting agent 4

The coating was gelled in 7 seconds and gelled in 90 seconds deterred.

Example 5 Parts by weight

Araldite 7072 625

4,4'-methylenedianiline 60

Benzoic acid 14.

Tin (II) Octoate (T-9) 7

Wetting agent 4

The coating was gelled in 5 seconds and gelled in 40 seconds deterred.

Example 6 Parts by weight

Araldite 7072 625

4,4'-methylenedianiline 60

Zinc stearate 14

Tetrahydrophthalic anhydride 7

Wetting agent '3

009833/2003

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The coating was gelled in 10 seconds and gelled in 40 seconds deterred.

Example 7 Parts by weight

Araldite 7072 625

4,4'-methylenedianiline 60

Tin (ll) stearate 14

Tetrahydrophthalic anhyaride 7

Wetting agent 3

The coating was gelled in 7 seconds and gelled in 40 seconds deterred.

Example 8 Parts by weight

Araldite 7072 625

m-phenylenediamine 48

Tin (II) oetoate (T-9) 6

Tetrahydrophthalic anhydride 6

Wetting agent 3

The coating was gelled in 4 seconds and gelled in 90 seconds deterred.

009883/2003

M 2060

Example 9

Terminal polyester containing terminal hydroxide groups 4,4'-methylene-ilaniline tin (II) -: ictoate (T-9) total hydrophthalic anhydride wetting agent

Parts by weight

800 , 5 37 7th 7th , 5 1

Has tube was preheated to 200 ° C and the time for gelation was 11 seconds and until quenching was 40 seconds. Unsupported·? Fil ::. E 0.127 mm thick from this example also by enamel coating on a release agent surface manufactured. They showed a tensile strength of 405 kg / cm * "and were stretched by h ~; \ - before they broke. The loss factor and the dielectric constant of the samples was at 100 revolutions / Second measured at different temperatures. The results are as follows:

60 ° C 90 ° C 105 ° C 120 ⁰ C 4.26 5.10 5.03

1J55 ° C

Loss factor 0.00c 0.013 0.015 0.026 0.1} 4 0.477 Dielei: trizitiits-

5.00 5.92

In typical applications of the particulate masses of this invention is .ie one, Ir. which preheats a metallic workpiece and is brought into a fluidized bed of the particles or with these particles res:;: T / .t will. According to a different procedure, we are on ele.rtrc-

00 3 8

_BATH

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static way, a layer of the particles is distributed on the workpiece and then heated. It is on I5O ⁰ C or higher preferably heated> to achieve rapid curing.

Compounds of this invention are used as molding compounds, in particular for encasing electrical components; for these purposes it is sometimes desirable to add surfactants (release agents), pigments, fillers or the like.

- patent claims -

009883/2003

Claims (5)

- 17 - M 2060 patent claims: 1. Small-part, normally solid and brittle, storable coating mass, which is a mixture in mutually reacting proportions of a 1,2-epoxy resin solid at room temperature with an average of more than one 1,2-epoxy group per molecule, one solid at room temperature, through heat contains activatable hardening agent which reacts with epoxides and a catalytic accelerator which can be activated by heat to increase the rate of the hardening reaction, characterized in that the mass, as hardening agent which is solid at room temperature and which can be activated by heat and reacts with epoxides, contains an aromatic polyamine., which contains at least two groups, The primary or secondary nitrogen atoms are bound directly to an aromatic ring, with these nitrogen atoms bearing a total of at least three active hydrogen atoms, and as a catalytic accelerator that can be activated by heat, a co-catalyst combination of (a) a salt that contains a tin ring Zinc, iron, cobalt, manganese or lead as a carboxylic acid, and (b) a carboxylic acid compound which can be a carboxylic acid or a carboxylic acid anhydride ;. 0Ü9883 / 2003 - 18 - M, -06O 2. Coating composition according to claim 1, further characterized in that the hardening agent content is between 0.85 and 1.5 gram equivalents of active hydrogen per gram equivalent of Ep- ^ y u the epoxy compounds moved that the proportion of the metal salts ^ between 0.2 and 5 wt .-. "J, based on the epoxy resin, moves, that the carboxylic acid or the anhydride is between 0.1 and 3 wt .- ;; based on the epoxy resin, and that dio Gram equivalents of acid and anhydride are not greater than 0.2 of the number of gram equivalents of the epoxy groups. J5. Coating compound according to Claim 1, characterized in that the proportion of hardener varies between 0.95 and 1.J gram equivalents of active hydrogen per gram equivalent of epoxy from the epoxy compounds. 4. Coating composition according to claim 1, characterized in that the carboxy compound is a carboxylic acid anhydride. 5. Coating composition according to claim 1, characterized in that the metal salt is a tin or zinc salt of a carboxylic acid. 009883/2003 bathroom