DE1249427B - Silicone varnishes - Google Patents

Description

GERMAN

PATENT OFFICE

EDITORIAL

C 090 183 /

German class: 22h-3

Zl

Number: 1249 427

File number: T 25835IV c / 22 h

Filing date: March 17, 1964

Opened on: September 7, 1967

The invention relates to silicone varnishes that are used at low Temperatures can be dried.

In order to give silicone coatings, in addition to their superior property of heat resistance sufficient mechanical and electrical properties, it has been required that coatings for a longer period of time and at a relatively higher temperature (ie, at 200 to 25O ⁰ C) compared to conventional organic coatings to harden in the heat. This is one of the most important problems when using silicone varnishes on electrical machines and devices as insulating material.

According to a known solution to this problem, the composition of the silicone varnishes was chosen so that they contained more trifunctional radicals. According to another known method, strongly basic substances were used as drying accelerators to improve the drying properties, including the salts of lead, zinc, iron, cobalt, nickel, tin and other organic acids, or amines such as buthylamine, triethanolamine and others, or hydroxides such as tetraalkylammonium hydroxide and tetraalkyl phosphonium hydroxide. If it is also possible to dry the silicone coatings former at a relatively low temperature ranging from room temperature to 150 ⁰ C, the dried lacquer orders are very fragile and not very flexible, they also develop adhesive properties when heated to higher temperatures so that they can no longer be used in practical use. If silicone varnishes contain metal salts of organic acids, not only is the surface stability of the varnish impaired, but these additives also accelerate the deterioration of the dried varnish films to a high degree - depending on the type of metal used. If amines are contained in the silicone varnishes, good results can only be achieved with large amounts, which also affects the surface stability and the heat resistance of the varnish. The inclusion of strongly basic materials also results in a reduction in surface stability and a deterioration in the paint films. These tendencies are particularly pronounced when inorganic basic materials are used. It is also known to add an organic acid, such as acetic acid, to an organic basic material or to use this in the form of a neutralized salt in order to improve the stability of the paints. According to this. Method, varnishes can be obtained that are silicone varnishes at a relatively low temperature

Applicant:

Tokyo Shibaura Electric Co., Ltd.,
Kawasaki (Japan)

Representative:

Dr. H. Maeckler, lawyer,
Düsseldorf, Bleichstr. 14th

Named as inventor:

Tamotsu Wada, Tokyo;

Mitsuo Ishizaka, Yokohama (Japan)

Claimed priority:

Japan March 18, 1963 (12 667)

can be dried between room temperature and 150 ⁰ C without impairing the heat resistance properties of the applied paint films, but the drying accelerator can remain undecomposed due to its high decomposition temperature, whereby the electrical, in particular the dielectric properties of the applied films are impaired at elevated temperatures.

It is also known to accelerate the curing of silicone resins with metal complex compounds to use, the reaction of cobalt naphthenate with Dioxiäthyl-n-buthylamine in the Silicone resin solutions are generated. The hardening acceleration achieved with these complex compounds the silicone resin is larger than when using cobalt naphthenate alone, but remains far behind the hardening acceleration caused by lead compounds.

Water-soluble chelate compounds of tin or zirconia can also act as hardening accelerators can be used for aqueous silicone resin emulsions. The mode of action of these chelate compounds is based on the fact that they are initially only in the aqueous phase are dissolved and only act on the silicone resins forming the filling phase when the aqueous phase is off the emulsion is removed. For spreads that do not contain water, these are hardening accelerators therefore not suitable.

709 640 / 54S

3 4

Also with combinations of titanic acid esters and [Col {(OH2) Co (en) ₂ } ₃ ] Cl _e ,

Metal naphthenates or octoates or complex [CoIYOH) Co (NH) I ICl

organic metal compounds can be: * * L ^ ' ^{3 e>}

certain acceleration of the drying of silicone [(en) ₃ Co (OH ₂ ) Co (en) ₂ JCl ₄ and

lacquers are effected. These hardener combinations 5 [(en) ₂ Cr (OH) ₂ ] Cr (en) ₂ Cl _4J
but also undesirably increase the

tion tendency and thereby reduce the storage and silver oxide or silver acetate are produced

ability of silicone varnishes in an undesirable manner on or by a reaction between a sulfate, such as only a few days.

One of the objects of the invention is to provide io [(NH ₃ ) SCo (OH) ₃ Co (OH ₃ ) CO (NH ₃ ) ,,] ^!); ,,
Silicone varnishes, which can be treated in a short time by treatment [(NH ₃ J ₄ Cr (OH ₂ ) Cr (NH ₃ ) ₄ ] (SO ₄ ) _a and
these paints at a relatively low temperature tnstr \ u \ n ~ f * ~ \ \ before »\
between room temperature and about 15O ⁰ C getrock- [Cr {(OH) ₂ Cr (s) _{8} a]} (SO _{4) 3,}
can be net, forming films with excellent electrical properties. 15 as well as barium hydroxide or barium acetate. The poly-

It is also an object of the invention to provide novel nuclear complex compounds represented by

To create silicone varnishes that, after being painted on, can use the general formula (MaXoYc) Z * for themselves

by brief heating to relatively low levels alone or in combination with other polynuclear

Temperatures can be used to film excellent flexi-complex compounds. The arrival

bility and heat resistance are transferred ao number of the entire suffixes a, b, c and d are determined

can. depending on the types and the number of

It is another object of the invention to provide silicone lacquers with central atoms and ligands. When using

to create that. a good. Have stability and polynuclear complex compounds with a hy-

this property over a long period of time during droxyd it is advantageous to use a monobasic organ-

of the warehouse. * add niche acid, such as B. acetic acid. if

According to this invention, these and others - based on the resin component - can be less than

Objectives are achieved by including an appropriate 0.1 percent by weight of the polynuclear polynuclear

Neten amount of polynuclear complex compound complex compound in the polysiloxane resin solution

in a solution of an organic polysiloxane resin. is included, the resulting

The invention relates to silicone varnishes, which result from an improvement in drying behavior that is quite small,

Solution of organopolysiloxanes in general, whereas when using the complex compounds

Formula in amounts greater than 3.0 percent by weight

'KnSiO. ( ₄ - _ft ) the same drying behavior as with an additive

—§— from 0.1 to 3.0 percent by weight gives the cost

35 needlessly increased. It can also be the

in which R is a methyl or a phenyl group and η is the above-mentioned drying accelerator Ji in addition to

means a number between · 1 · and 2, in organic a conventional drying accelerator, e.g. B.

Solvents exist and metal compounds as an organic salt of the said metal, ver

Hardening accelerator included. It is characteristic to find a turn.

for these silicone varnishes that they act as hardening accelerators. Even polysiloxane resin solutions that normally

Metal compounds with a general drying period of more than one hour

Formula high temperatures between 200 to 25O ⁰ C required

γμ γ ν 1 fru rr>r> \ ^{tigen> can at a} lower temperature

| M "X", Y _C J (CH ₃ CUU ^, between room temperature and 150 ° C and within

45 a shorter time to be dried if them

in which M is the central atom chromium or cobalt, X is the poly

Ligands ammonia, ethylenediamine or water, nuclear complex compounds are added.

Y the bridging agents hydroxy, amino or ace- accordingly, the coatings made of silicone

toxy groups, α a number from 2 to 4 and b, c and d the lacquer by simple heating means, such as infrared

Number of ligands or bridging agents or 50 lamps, are lightly dried, whereby the drying

Acctoxy groups mean, in amounts of 0.1 to the process is greatly simplified.

3.0 percent by weight - based on the weight of the In addition, one is able to easily

dissolved organopolysiloxanes - contain. the silicone varnish of this invention for electrical equipment

To be used as a solvent for the organopolysiloxanes, which consist of a material that

serve benzenes, toluenes, xylenes, propyl alcohol, 55 z. B. a temperature of over 200 ⁰ C does not tolerate.

Butyl alcohol, methyl isobutyl carbinol and diacetone- The silicone varnishes according to the invention produce

alcohol. th spreads show no tendency to stick,

The polynuclear compounds that are used to entrap when exposed to high temperatures of for example

in the polysiloxane resin solution corresponding to this 250 ⁰ C after it, as above

Invention suitable can be described by reaction 60, dried at low temperature

a chlorine-containing compound, such as. B. have been. Since the aforementioned polynuclear

Complex compounds easily at the low dry

[(HN ₃ ) _B Co (NH ₈ ) Co (NH ₃ ) ₆ ] CI ₆ , decompose temperatures, spreads are obtained.

[(NH _a ) _i Co (NH, XOH) Co (NH ₁ ) ₁ ] Cl ₄ , L ^e . ⁿ 'the superior electrical and heat resistant

fNH Ϊ CofNH vom CoHSJHι 1Π ⁶⁵ properties. The Sihconlacke dveser

L (NH ₃ J ₃ CO (NH ₂ XOHJ ₂ Co (NH ₃ J ₃ JCI ₃ , invention have excellent drying properties

[(NH ₃ J ₄ Co (OH) ₂ Co (NH ₃ ) ₄ ] C1 ₄ , strength and stability.

[(en) _a Co (OH) ₂ Co (en) o (H ₂ 0) _a ] CI ₄ , these properties are played by the invention

compared to conventional silicone varnishes.

example 1

To carry out the following experiments, the 50% solution of a silicone resin was used as xylene which contains the following components:

12 mole percent (CH ₃ ) SiOL ₅ ,
28 mole percent (C ₆ H ₈ ) SiOL ₅ ,
41 mole percent (CH ₃ ) ₂ Si0,
19 mole percent (C ₆ H ₅ ) SiO.

These solutions are those mentioned in the table below and known as curing catalysts Metal acetylacetonate (Ac) and, as an example of a compound to be used according to the invention, a Metal compound of the formula

X ₂ Co (OH) ₂ CoX ₂ (CH ₃ COO) ₄

(X stands for ethylenediamine) added in the specified amounts. The in the table below specified drying characteristics (drying temperature and time) were determined by the dried specimen with an asbestos paper

ίο (0.3 X 25.4 X 100 mm) and this was covered with a steel sheet (25 X 25 X 25 mm, 125 g) and kept at a temperature of 200 ^° C. for 15 minutes. The conditions were met when the hot asbestos then fell off the specimen

iS could.

The thermal resistance was measured as the time after which a lacquer layer was bent over cracks occurred with a 3 mm thick mandrel.

Art

Amount in percent by weight, based on the amount of resin Drying characteristics Drying time in minutes

250 ⁰ C 200 ⁰ C 150 ⁰ C

Thermal resistance

of

Spreads

at 25 ⁰ C

in hours

Shelf life

of the paint

at normal

Temperatures

in days

No

Ni (Ac) ₂

Cr (Ac) ₃

2 "(Ac) ₂

M _n (Ac) ₂

CoIi (Ac) ₂

Coin (Ac) _s

FeHi (Ac) ₃

Al (Ac) ₃

PC ₂ Co (OH) ₂ CoX ₂ ] (CH ₃ COO) ₄

0.75

1.0

0.75

0.75

0.75

1.0

1.0

1.0

1.0 30

75
75
75
75
75
45
15th
15th
15th

1000

210
60
60
60

500

40

1000

100

100

100

34 100 100

45 100 100

Example 2

became. A polynuclear complex compound

A mixed solvent consisting of xylene'50 [(NHs) ₄ Co (OH ₂ ) Co (NHa) ₄ ] (CH ₃ COO) ₄

and butanol (1: 1), three types of polysiloxane

resins added, each of which can be compounded by adding an equivalent amount of Acetic acid settles into a polynuclear complex hydroxide

that was built up by the

A. - =
Si

B. - =

Si

CH ₃ C ₆ H ₅

CH ₃

= 1.50, reaction of

[(NH ₃ ) ₄ Co (OH) ₂ Co (NH ₃ ) ₄ ] (SO ₄ ) _!!

C.

₌ ι 37 and barium hydroxide, each of those was mentioned

C ₆ H ₅ '' 6o solutions added as a drying accelerator and

thus obtained three types of silicone varnishes.
Ppi Table 1 below shows the test results

- = 1.27, the drying, the heat resistance and the

C ₆ H ₅ electrical properties of these three silicone varnishes

as well as a silicone varnish that does not have any drying

(wherein R a CH ₃ group and a C ₆ H ₅ group accelerator was added, the test being defaced), and the resin solutions diluted to 60 percent by weight according to JIS (Japanese Industrial Standards) of the resin component in each case C 2122 were carried out became.

Si

Tabel Test samples

Paint sample B

Amount of added
Drying accelerator, ° / ₀ *)

Drying property ...

Heat adhesion property **)

Heat loss (25O ⁰ C,
" 72 hours), %

Bending property (250 ⁰ C,
3 mm diameter) ..,

Isolating voltage safety (kV, 0.1 mm)

normal

after immersion in
Water for
24 hours

Specific resistance,
cm

normal

after immersion in
Water for
24 hours

Dielectric constant

25 ⁰ C

18O ⁰ C

Dielectricity tangent,%

25 ⁰ C

18O ⁰ C

stability

25O ⁰ C over 6 hours

250 ⁰ C for 6 hours

5.8

over 1000 hours

8.3 7.7

over 10.16

over 10.16

3.2 2.7

0.5 1.3

1.0

200 ⁰ C above

3 hours

200 ⁰ C

4 hours

5.5

over 1000 hours

8.0 7.7

over 10.16

over 10.16

3.2 2.6

0.7 2.5

200 ⁰ C above
hour

200 ⁰ C
hours

7.2

above
hours

8.02
8.3

above
10.16

above
10.16

3.0
2.5

0.3
1.0

0.5

15O ⁰ C for 30 minutes

150 ⁰ C 1 hour

6.3

over 300 hours

8.1 7.8

over 10.16

over 10.16

3.1 2.1

0.5 0.7

150 ^° C. for 10 minutes

15O ⁰ C over 6 hours

8.5

over 50 hours

7.8 7.5

over 10.16

over 10.16

3.0 2.6

0.4 0.9

0.5

100 ⁰ C for 20 minutes

150 ⁰ C 1 hour

6.5

over 50 hours

7.5 7.7

over 10.16

over 10.16

3.0 2.6

0.6

2.1

does not shrink after standing at room temperature for 6 months

*) Weight percent based on the resin component of the paint.

* ♦) A drying condition in which an asbestos paper of 0.3 X 25.4x100 mm is applied to a dry test piece and an iron piece (125 g) of 25 χ 25 X 25 mm is applied to the asbestos paper and the hot asbestos precipitates freely can after heating at 200 ⁰ C for 15 minutes.

As can be clearly seen from this example, the invention makes it possible to reduce the drying temperature by about 50 ° C. and also to reduce the drying time. These dried films not only show adhesion at a high temperature between 200 and 25O ⁰ C, but they also at low heat loss without affecting the properties of heat resistance and electrical properties and stability.

60 Example 3

0.5% by weight based on the resin compound of the solution of a drying accelerator

[(Cn) ₂ Co (OH) ₂ Co (OH) ₂ Co (Cn) ₂ (H ₂ O) ₂ ] (CH ₃ COO) ₄ which was composed of

[(Cn) ₂ Co (OH) ₂ (CoOH ₂ ) Co (Cn) ₂ (H ₂ O) ₂ ] Cl ₄ and silver acetate were added to the polysiloxane resin solution (B) of Example 1 and the same test method as in Example 1 was subjected. It turned out here that the film was dried in 15 minutes at 15O ⁰ C and the bending property (3 mm diameter) was 500 hours at 250 ⁰ C.

Example 4 [Co {(OH) ₂ Co (en) ₂ } ₃ ] Cl _e

was built up from cobalt chloride and ethylenediamine, wherein the polynuclear complex chloride reacted with silver acetate, creating a drying accelerator

[Co {(OH) ₂ Co (en) ₂ } ₃ ] (CH ₃ COO) _e

was obtained. This drying accelerator was added to the polysiloxane resin solution B of Example 1,

d. H. in an amount of 0.3, 0.5, 1.0 and 2.0 percent by weight, based on the resin component of the solution mentioned. Table 2 below shows the

Test results of the drying properties of the various paints using the same test method as described in example 1.

Tabel Drying property

0.3%

Amount of added drying accelerator

0.5 · /. I 1.0%

2.0 · /.

Drying time for a
Temperature from

; 90 ° C

LlO ⁰ C. '

13O ⁰ C

150 ⁰ C

5 hours

2 hours

1 hour

40 minutes 3 hours
1.5 hours
40 minutes
20 minutes

2 hours

1 hour

30 minutes

15 minutes

1.5 hours
50 minutes
20 minutes
10 mins

The bending properties of these coatings was about 500 hours at 250 ⁰ C (3 mm diameter), and their isolation voltage safety and their resistivity were also excellent.

Example 5
[CrKOHkCrtenkUSO ^

was built up from chrome alum and ethylenediamine, with the polynuclear complex sulfate with Barium acetate has been reacted to be a drying accelerator

[Cr {(OH) ₂ Cr (en) ₂ } ₃ ] (CH ₃ COO) ₆

to obtain. Thereafter, the drying accelerator was added to the polysiloxane resin solution C of Example 1 in an amount of 0.5 percent by weight, based on the resin component of the aforementioned resin solution, and subjected to a test by the same method as in Example 1. The film was dry ^{at 100 ° C. within 30 minutes.} A dried for 2 hours at 100 ⁰ C film showed no Wärmeadhäsionseigenschaften at 200 ° C. The heat loss after heating at 250 ⁰ C for 72 hours was 6.0% · The bending property was 50 hours at 250 ⁰ C (3 mm diameter) . This product is therefore equivalent to the films that did not contain any drying accelerators. The electrical property and the stability of the product according to the invention were also excellent.

Example 6

[(Cn) ₂ Co (OH) ₈ Co (Cn) ₂ ] (CH ₃ COO) ₄
was built from

[(en) ₂ Co (OH) ₂ Co (en) ₂ ] CI ₄

and silver acetate, the complex compound of the polysiloxane resin solution B of Example 1 being added to said resin solution in an amount of 1.0 percent by weight, based on the resin component, and tested in accordance with the method used in Example 1. The film was dry within 10 minutes at 150 ⁰ C and 30 minutes at 130 ⁰ C. The bending property was over 300 hours at 25O ⁰ C (3 mm diameter). This varnish did not gel after standing for 3 months at room temperature.

Example 7

[(NH ₃ ) ₄ Cr (OH) ₂ Cr (NH ₃ ) ₄ ] (CH ₃ COO) ₄ ,
built from

[(NH ₃ ) ₄ Cr (OH) ₂ Cr (NH ₃ ) ₄ ] (SO ₄ ) ₂

and barium acetate, was added to the polysiloxane resin solution B of Example 1 in an amount of 0.5 percent by weight, based on the resin component of the solution mentioned, and tested according to the method of Example 1. It turned out that the film was dry within 20 minutes at 15O ⁰ C and that the film was dried at 15O ⁰ C for 1 hour, showed no Wärmeadhäsionseigenschaft at 200 ° C. The electrical and heat resistant property were excellent.

Example 8

[(NHa) ₄ Co (NH ₃ ) (OH) Co (NH ₃ ) J (CH ₃ COO) ₄ ,
built from

[(NHa) ₄ Co (NH ₃ ) (OH) Co (NH ₃ ) JCl ₄

and silver acetate, was added to the polysiloxane resin solution B of Example 1 in an amount of 0.5 percent by weight, based on the resin component of said resin solution, and tested by the same method as in Example 1. It turned out that the film was dry within 10 minutes at 150 ⁰ C, and that the bending property of a dried at 130 ⁰ C for 30 minutes, the film was (3 mm diameter) 400 hours at 25O ⁰ C.

Example 9
[(NH ₃ ) ₃ Co (OH) ₂ (CH ₃ COO) Co (NH ₃ ) ₃ ] (CH ₃ COO) ₃ ,

built from
[(NH ₃ ) ₃ Co (OH) ₂ (CH ₂ COO) Co (NH ₃ ) ₃ ] Cl ₃

and silver acetate, was added to the polysiloxane resin solution C of Example 1 in an amount of 0.5 percent by weight, based on the resin component of said solution, and tested by the same method as in Example 1. The film was dry within 30 minutes and at 100 ^° C. and had good electrical properties and stability.

709 640/548

Claims (1)

Claim: Silicone varnishes made from a solution of organopolysiloxane of the general formula (4-H) J.
"2" in which R is a methyl or a phenyl group and ti cine number between 1 and 2 means consist in organic solvents and contain metal compounds as curing accelerators ,, characterized in that they contain as härtiingsbcschlcunigende metal compounds those of the general formula [M _n X ₆ Yc] (CH ₃ COO) ₀ , in which M the central atoms chromium or cobalt, X the ligands ammonia, ethylenediamine or water, Y the bridging agents hydroxyamino or acetoxy groups, α a number from 2 to 4 and b, c and d the number of ligands or bridging agents or acetoxy groups , in amounts of 0.1 to 3.0 percent by weight - based on the weight of the dissolved organopolysiloxanes. Tn considered publications:
German Auslegeschriften No. 1 035 293, 037 045, 058 254;
"Deutsche Farbenzeitschrift", 1956, booklet, p. 4. 709 640/548 p. 67 Q Bundesdruckerei Berlin