DE1570961C3 - Process for the production of an electrical insulating material based on reaction products of glydyl ethers - Google Patents

Description

45 about it can be used and at the same time

Electrically insulating casting resins should have good electrical insulating properties, Have sufficiently low viscosity, so that the subject matter of the invention is a method for

Pouring into a mold that contains an electrical component or production of a flexible, heat-resistant, electrical device, all spaces between the component tric insulating material from a solvent-free, or device. The resin should initially be a liquid mixture at room temperature ^W »^ 5 *? w ^ ΐ * ^S T ^de - ^{free & e6e} u ^{d lead} ^ ⁿ ' (A) ^a polyglycidyl ether of a polyvalent Phes should, however, with moderate warming, quickly reach a _nok ^ _{a viscosity of a few} ^ 3 *, _{m cP}

sufficiently tough, adhesive state hard enough to be able to withstand ^ i 24 ° C and at least 1.5 oxirane groups per thermal and mechanical shock effects average molecular weight to which the cured product 55 _{(B) mcinmö} i _and / or a liquid condensate are exposed during its use can, and _from r ^, ^ ,, «. _{and a} polyhydric aliphagleichzeitig good electrical insulation properties under _{üschen Mkohol} ^ _{a JodaW VOQ} l _uade * may have _aa nachteihgen conditions. ^ ^ _WOBD total amount 40 to 110 weight-Haize that these requirements "erfuUen since _{teüe per 100 parts} by weight _{of the} poi _y gi _ycidyl ether, many years commercially obtainable. So far, however, 60 _and ^{JfcV J 6} ^ has not been able to develop a resin which would be suitable for _{(Q a oda menreren} dicarboxylic acid anhydrides permanent use at temperatures of 155 ° C _{from the G} maleic anhydride or ad- or above, although already since _{products made from} maleic anhydride and Olefin, which long efforts made in this direction _{raise a} s ^^^ _of ^ _{cht above} ^ ⁰ C. 65 point,

From a report by Armed Services Technical Information Agency with the designation »Develop- possibly known hardening accelerators and

ment of Flexible Polymers as Thermal Insulation in possibly pigments, thixotropic agents or

The fillers and hardeners of the poured liquid olefin are hexahydrophthalic anhydride

Mixture by heating, in which the loading (melting point 36 ° C) and the alkenylsuccinic acid

constituents (A) to (C) used in such proportions, anhydrides, such as. B. the liquid tetrapropenyl amber

that 1 to 1.5 oxirane groups of the polyglycidyl ether stinic anhydride, which can be prepared by

in each by reaction between the composite s equimolar amounts of maleic anhydride and one

component (B) and the anhydride produced carboxyl group olefin material, which mainly consists of the tetra-

and there is unreacted amers of propylene in each anhydride group, are heated together

hydrids are included and at least 20% more den.

Anhydride groups are present than to fully- The same anhydrides are for the anhydride final carboxylation of component (B) is necessary, which are in excess compared to the complete. constant carboxylation of component (B)

The invention achieves that a required amount is used. A particularly useful method for producing an insulating material available for this purpose is the tetrapropenyl amber insert which, in the absence of a filler, has acid anhydride, since it provides a free-flowing liquid with a viscosity of 15 before hardening. Hexahydrophthalic anhydride is room temperature, to a tough, pliable also a particularly good means for reducing the hardening state and in the hardened state an un- viscosity. Maleic anhydride is a comfortably good electrical insulating material for this purpose, which is less preferred because it tends to volatilize, particularly in such applications, and poses toxicity problems. It will be used in areas where the electrical insulating material 20 is generally anhydride in amounts not exceeding one at high temperatures, such as e.g. B. ISS ⁰ C, is exposed. group of maleic anhydride per hydroxyl group When used for the three essential components of castor oil.

According to one embodiment of the invention, the proposed method of the invention parts are not adhered to, the electrical component (B) is practically completely covered with the insulating material not the desired combination of 35 hydride esterified before it with the polyglycidyl ether Properties on. is mixed.

The initially free-flowing at room temperature to carry out the esterification, the liquid mixture can may conveniently be conducted in 2 parts: i, ingredients several hours to 121.1 ⁰ C heated ie in the form of component (A) and the constituents are. The reaction is brought to market by a Veresteteile (B) and (C), the 30 nmgskatalysator, such. B. tin (II) octoate or by itself under normal storage conditions on tin (H) fluoride or a tertiary amine, can be stored for a very indefinite period. In accelerates. At lower temperatures, the absence of fillers or thixotropic agents results in the same product with longer reaction times, mixtures of components (A) to (C) at and even at normal room temperature with room temperature for hours in a free carboxylation of component (B ) to be kept flowing liquid state after 2 months, so that in the presence of an esterification catalyst it is almost normally possible to complete one in the morning.

One working day is enough for the whole working day - If component B does not contain the anhydride

the stock of the mixture is esterified by mixing it before it is mixed with the polyglycidyl ether

Constituents (A) to (C) to produce. 40 is mixed, with the incorporation of an

Dicarboxylic anhydrides that can be used as a compost esterification catalyst according to the genente (C) include male- nal timespan required for packaging, storage, shipping and distribution of the acid anhydride and adducts of maleic anhydride, and olefin with a melting point ^{not higher than 40 °} C. before the mixtures are used. Normally, suitable adducts of maleic acid-45 should be almost complete. But even anhydride with olefins includes methylenedomethyl - if this is not the case, mixtures provide lentetrahydrophthalic anhydride, a light yellow, semi-polyglycidyl ether and partially carboxy-viscous liquid with a viscosity of 138.4 cP lated component (B) plus the excess des at 25 ° C. Another suitable anhydride is the low-melting anhydride hardened products, adduct of myrcene and maleic anhydride, the 50% of those products in which the compound can be made: 15.6 kg male component (B) beforehand was completely converted, acid anhydride is placed in a reaction vessel and it is practically indistinguishable. Tat and heated to 62.8 C ^0. The mixtures can slowly be added to the vessel in the form of 28.8 kg of myrcene, and the temperature can be brought to the point where one part of the reactant is below 65.6 ° C. only the unreacted Hold component (B) until all of the myrcene has been added. After the polyglycidyl addition of the myrcene has ended during the other part, the reaction ether of the polyhydric phenol and the entire vessel are heated to 93.3 ° C. for 2 hours. It will then contain an amount of the anhydride as long as only one portion is allowed to cool to 65.6 ° C. When this esterification catalyst is present at a verifying temperature, the pressure within the reaction between component (B) and the vessel is slowly reduced to 20 to 30 mm Hg to ensure the anhydride when the two then raise the temperature to 148, 9 ° C is increased. Parts are mixed together. This packaging If the entire distillate is removed in this way, but is generally less prevalent, the reaction vessel is added to 79.4 ° C, cooled because of the lower shelf life, and the low-melting reaction there is a tendency to there is a reaction between the product, the myrcene-maleic anhydride adduct, polyglycidyl ether and the anhydride. It is then withdrawn into a storage container. Others use at least part of the anhydride preferred anhydride adducts of maleic anhydride and incorporated into component (B) in order to achieve the

To make the volume of the two parts the same for ease of measurement.

The components (A) to (C) should, as indicated above, be used in such proportions, that 1 to 1.5 oxirane groups of the polyglycidyl ether for each carboxyl group in component (B) is included, and account for each anhydride group of the unreacted anhydride. If on every carboxyl and anhydride groups contain far more than 1.5 oxirane groups, there is a considerable risk that not the entire amount of the polyglycidyl ether is converted. In this case, the hardened Product subject to undesirable degradation when exposed to adverse conditions. If there is less than one oxirane group in each carboxyl and anhydride group, it is the hardened one Product less resistant to high temperatures, both in terms of electrical Insulation properties as well as in terms of resistance to degradation. At current market prices However, the polyglycidyl ether is much more expensive than component (B) and the low-melting anhydrides, so that for applications where the best properties are not important, the total number of carboxyl and anhydride groups slightly exceed the number of oxirane groups can.

If less than about 40 parts by weight of component (B) are used, the cured Product have less toughness and flexibility than desired. Is the one of it on the other hand, if the amount used is well above 110 parts by weight, the hardened tends to be Product to be somewhat weak and the high temperature electrical insulation properties that are included in primary objects of the invention are not to have.

As indicated above, some or all of the castor oil can be replaced by liquid condensates of ricinoleic acid and polyhydric aliphatic alcohols, such as. B. glycerine, dipropylene glycol, Pentserythritol and trimethylolpropane. Such condensates have the following properties:

Molecular weight about 350 to 1100,
Hydroxyl number about 100 to 350,
Functionality about 2 to 5,
Viscosity at 24 ° C = 3000 to 400OcP.

CH ₂ CH - CH ₂ - O

The diglycidyl ether of resorcinol is also useful.

To give mixtures (A) to (Q a lower viscosity and the hardened insulating material a to give greater flexibility - although a certain deterioration in toughness is accepted must be taken - monoepoxides can be used in amounts of up to about 20 percent by weight of the polyglycidyl ether be incorporated. However, the amount of these monoepoxides may only be so large that still a slight hardening to a tough one, to simplify the terminology here is the The term "castor oil" - except in the examples - is used in a comprehensive and general sense, in order to also record these ricinoleic acid condensates.

The castor oil should be purified and cannot be used non-hydrogenated or partially hydrogenated. However, the WIJS iodine number is preferably greater than 50. In the case of iodine numbers above 50, the component is (B) sufficiently free-flowing so that the initial viscosity of the compositions according to the invention is well below of 30 00OcP at 24 ° C, while it is when using more hydrogenated castor oil preparations It can be difficult to stay below this viscosity value.

In the mixtures of (A) to (C) there should be at least about 20% more anhydride groups of the low-melting point Dicarboxylic anhydride adducts may be included as is required to have an anhydride group for each

ao hydroxyl group originally present in component (B) to be made available. If such an excess of low-melting unreacted anhydride is not present, the cured product tends to be used for general electrical

Trical embedding purposes somewhat weak and inferior to be.

In the mixtures of (A) to (Q are preferably catalysts of the type as used for accelerating the curing acid-curable epoxy resin compositions containing in an amount such that the mixtures are virtually cured within 16 hours at 150 ⁰ C. To Suitable catalysts include tertiary amines such as dimethylbenzylamine and its salts; Lewis acids such as tin (IV) chloride or boron trifluoride, usually in the form of an amine complex; and metallic soaps such as tin (II) -octoate.

As polyglycidyl ethers are particularly useful liquid condensation products of epichlorohydrin and bisphenol A. Typical of such condensation products is one which has a softening point according to Durrans of about 10 ⁰ C and an epoxy equivalent of about 190th (This polyglycidyl ether is hereinafter referred to as “polyglycidyl ether 1”.) Another suitable polyglycidyl ether is one with a viscosity at 25 ° C of 10,000 to 20,000 ocP, an epoxy equivalent weight of 180 to 200 and the following structure:

p-CH ₂ -CH CH ₂

practically infusible, insoluble state is reached. Typical monoepoxies that can be used are Dodecene oxide, octylene oxide, dipentene monoxide, pinene oxide, styrene oxide, phenylglycidyl ether, vinylcyclohexene monoxide and epoxidized long chain olefins such as. B. having 16 to 18 carbon atoms.

₆ , reaction product of castor oil and maleic acid. anhydride

This reaction product was prepared using castor oil, which has a WIJS iodine number of

Q-CH ₂ -CH CH ₂

86, a hydroxyl number of 154 (1 mol of hydroxyl at 24 ^° C. The aqueous titration showed an acid group per 365 g) and a viscosity of 660 cP equivalent of 2.15 meq / g.
at 25 ^° C. It was based on the following approach “. ·, · ,, ·,
assumed: Example I to 3

Parts by weight of ⁵ ^ as ° ^ ^en described reaction product from

Castor oil 365 Castor oil and maleic anhydride were

Maleic anhydride ". '.'. '.'. '.'. '.'. '.'. '.'. 98 different proportions with tetrapropenyl

TinflD octoate 0 46 succinic anhydride and Tns- (2,4,6-dimethylamine

'nomethyl) phenol to form stable mixtures

The castor oil and the tin (II) octoate were mixed with-io, which then with a liquid polyglycidyl

mixed with each other and in a glass flask on ether of bisphenol A (»polyglycidyl ether 1«) to mi

Heated at 121.1 ° C. The maleic anhydride was mixed with the following composition

added with stirring while the mixture was up: 93.3 ° C was allowed to cool, after which the whole

Mass with frequent stirring for 2 hours at 15

121.1 ° C was heated to boiling. The reaction * ² _ ^

product was a clear liquid, which at 24 ° C was a

Had a viscosity of 4300 cP. It possessed a ver "polyglycidyl ether 1" 100 100 100

soap equivalent weight of 147, resulting in Carboxylated castor oil 80 80 80

it was possible to calculate that 1 mol of ester groups per 225 g of pre-20 (reaction product of

lay. This means that all hydroxyl groups castor oil and maleic

were esterified with the maleic anhydride. The acid anhydride)

Non-aqueous titration delivered one acid equivalent of tetrapropenyl amber 90 82 70

of 2.35 meq / g, while the aqueous titration is a stinic anhydride

Acid equivalent of 2.52 meq / g. The difference 25 “. , ~ _{A £ A} - _tU , _Λ « _1n ·, ~ _c

between the Tns- (2,4,6-dimethyl-1.35 1.0 1.25

Value and that of the non-aqueous titration aminomethyl) phenol

obtained value means that something in the product

free maleic anhydride was included. From the The ratio of the oxirane groups of the polyglycidyl

The results of the infrared analysis showed that this was also 30 more ethereal than the sum of the carboxyl groups

remove. The product was with the “polyglycidyl castor oil maleic anhydride reaction product

ether 1 «at room temperature in all quantity and anhydride groups of the tetrapropenyl amber

conditions compatible. stinic anhydride was as follows:

Example 1 = 1.02; Example 2 = 1.09; Example 3

Reaction product of castor oil and hexahydro- _{35 =} i ₅ 20.

phthalic anhydride The initial viscosities of these mixtures were included

Parts by weight 24 ° C in the range from 4000 to 5000 cP. Castings out

Castor oil. 365 of these mixtures gelled within 20 minutes

Hexahydrophthalic anhydride ... 154 at 130 ° C and showed after dissolving hardening

Tin (II) octoate at 0.5 * ° at this temperature has the following properties.

The water absorption test runs were carried out by

The hexahydrophthalic anhydride was carried out by immersing castings, the removal

Melted 65.6 ° C and with the castor oil and the measurements of 76.2 X 25.4 X 3.175 mm.

Tin (II) octoate mixed in a glass flask. The heat resistance was determined by

Mass was heated to 121.1 ° C and under frequent 45 castings with dimensions of 50.8 X 50.8 X

Stirring held at this value for 2 hours. The 12.7 mm in an air circulation oven at 155 ° C

Reaction product had a viscosity of 55,000 cP.

Hardness, Shore D.

Water absorption:

Weight gain after 1 week of immersion at room temperature. Weight gain after 1 week Immersion at 100 ° C Shore D hardness after immersion at 100 ° C

Heat resistance:

Weight loss after 1 week in the oven at 155 ° C
Shore D hardness after the test

65

0.4% 0.5% 0.4% 809649/19 4.7% 2.2% 2.5% 50 30th 30th 1.4% 0.8% 0.7% 80 80 82

continuation

Mechanical shock resistance
(US Mil. Spec. Mil-II-16923 D):

Specimen resistance ball size

Dielectric dissipation factor
at 109 volts and 100 Hz

at 23 ⁰ C
105 ⁰ C
155 ° C
180 ° C

Dielectric constant at 109 volts and 100 Hz

at 23 ° C

105 ° C

155 ⁰ C

18O ⁰ C

Specific resistance at 500 volts direct current (ohm-cm) at 23 ° C

105 ° C

155 ° C

180 ° C

*) Value! Ag outside the scale of the measuring device used.

95.25mm 95.25mm 95.25mm

0.02 10 " 0.03 10 " 0.02 10 ¹⁴ 0.16 10 ¹⁰ 0.04 ΙΟ ¹⁰ 0.02 10 " + 10 » 1.51 10 » 0.37 10 ¹⁰ 10 » + 10 » 0.45 10 ¹⁰ 3.3 3.5 3.5 5.0 4.9 5.0 + 11.9 4.7 + 4.5 2.3- 8.9- 2.2- 4.3 9.9 2.5- 4.4 · 2.5 · 1.9 3.7 2.1 · 1.4

The above data show that the cured insulating materials of Example 3 performed exceptionally good toughness, degradation resistance and electrical insulating properties are characterized and im A very significant advance compared to the previously known flexible type resin products in relation to these properties. The products of Examples 1 and 2 are also better than the known products, but do not quite reach the values of the product of example 3.

Example 4

The castor oil-maleic anhydride reaction product was also used to produce the following Recipe used:

Parts by weight

"Polyglycidyl ether 1" 100

Castor oil maleic anhydride

Reaction product 90

Powdered Talc 155

Hexahydrophthalic anhydride ... 43 Dimethylbenzylamine 1.16

The ratio of the oxirane groups to the sum of the carboxyl groups of the castor oil reaction product and the unreacted anhydride groups in the mixture was about 1.09.

Castings made from this mixture gel within 15 to 20 minutes at 120 ° C. After 16 hours Curing at this temperature was - with the same measurement as in Examples 1 to 3 - the following Properties of the insulating material measured:

Hardness (Shore D) 75

Water absorption:
Weight gain after

1 week at room temperature 0.29%

Weight gain after

1 week at 100 ^° C 6.4%

Shore D hardness after testing

at 100 ° C 57

Heat resistance:
Weight loss after 1 week

in the oven at 155 ° C 0.18%

Barcol hardness after the test .. 24

Mechanical shock resistance:

Test specimen resistance ball size 82.55 mm

C. Dielectric Dielectric More specific C. Loss factor constant resistance At 23 ° C. 0.036 4.63 8.7 x 10 " 105 ° C. 0.059 6.56 2.0 x 10 " 155 ° 0.284 5.89 3.6 · 10 ¹⁰ 180 ° 0.301 5.80 2.4 · 10 ¹⁰

11 12

Example 5 aminomethyl) phenol was used here both as a

Parts by weight esterification catalyst as well as to accelerate the

»Polyglycidyl ether 1« 100 hardening with the polyglycidyl ether used.

Castor oil hexahydrophthalic acid _n . .

anhydride reaction product 90 5 B e ι s ρ ι e 1 7

Tetrapropenylsuccinic acid- To 170 parts of the same anhydride-polyglycidyl-

anhydride 72 ether mixture were 60 parts of an adduct of

Tris (2,4,6-dimethylaminomethyl) ricinoleic acid and a polyvalent aliphatic

phenol 1,3 alcohol, which has an approximate functionality of 2.2,

to a hydroxyl number of 254, a specific gravity of 0.969 at 25 ° C and a viscosity of 380 at

The ratio of the oxirane groups of the polyglycidyl- 25 ° C. 1.15 parts were added to this mixture

ether added to the sum of the carboxyl groups of the tris-2,4,6- (dimethylaminomethyl) phenol.

Castor oil reaction product and the anhydride The mass was clear and had a viscosity of

groups of tetrapropenylsuccinic anhydride 15 115OcP at 24 ° C.

was about 1.20. The initial viscosity of the mixture during heating to 120 ⁰ C, the mixture gelled in at 24 ° C was 800OcP. 15 to 20 minutes and was, after 1 hour to a On heating to 120 ⁰ C, the mixture gelled in clear, hard, tough casting (50.8 X 50.8 χ 12.7 mm) for about 15 minutes and was after 2 hours at this hardened, which hardened at 24 ° C a Shore D hardness of temperature to a tough casting, ao 50 showed. The hardened insulating material was tested according to the US test method with a Shore D hardness of 66 at room temperature. Mil. Spec. Mil-I-16923 D (which had the casting. The casting, the dimensions of the ling, however, had different dimensions than there) was 50.8 × 50.8 × 12.7 mm, showed a good test for mechanical impact resistance, being impact resistance because it withstood the test specimen of the 95.25 mm ball when repeatedly hard. Posing on the floor didn't broke. as toughness This value shows that all the components of the mixture _... ,, participated in the curing reaction ^Bei P ^{iel 6} have.

70 parts of hexahydrophthalic anhydride were b; i In the mixtures of (A) to (C) can be given-

Melted at 65.6 ° C and with 100 parts »Polyglycidyl - if the most varied pigments, thixotropic agents

ether 1 «mixed. Then 63 parts of castor oil 30 or fillers (grains or fibers) were incorporated

and 1.2 parts of tris-2,4,6- (dimethylaminomethyl) phenol. For example, mica, talc,

mixed in, with a thick, incompatible, but calcium carbonate and silica as well usable

free-flowing liquid mass (viscosity at 24 ° C has been shown to be hardened products that have a large

less than 30,000), the percentage of these materials in powder form when heated

to 67 ⁰ C became clear and contained a very low viscosity 35, excellent strength, toughness and

exhibited. showed electrical insulating properties.

This mass gelled in 15 minutes at 120 ⁰ C Since the mixtures to achieve a larger

and was launched after 2 hours to a clear, hard, persistence in two parts

tough castings (50.8 X 50.8 X 12.7 mm) are hardened, it is usually desirable to

which had a Shore D hardness of 72 at 24 ° C. 40 different colors to be easily identified

The casting did not break if it can be pressed hard against whether complete mixing is achieved

Was thrown on the floor. The Tris-2,4,6- (dimethyl- has been.

Claims (2)

Solid-Propellant Rocket Motors «of October 13, claims: 1961, flexible polymers are known for thermal insulation. However, there is nothing in this report 1. A process for the production of a flexible, electrical insulating material from a 5 lierstoffe via a process for the production of electrical iso-heat-resistant, electrical insulating material. solvent-free, initially at room temperature In US Patent 29 99 824 are polyepoxide Liquid mixture of products described in which no additional (A) a polyglycidyl ether of a polyvalent anhydride group is present. According to the local phenol with a viscosity of less than ^B _f ^e . ^is f ^el _t ^e ? ^{6th and} , ⁹ ™ f *. ¹ W ^ ¹ athylaminkomplex gehartet ^{by Di} "30,000 cP at 24 ° C and at least 1.5 oxirane ^lo aftyentnamm or depending average molecular Borfluondmonogruppen by emen. chtT German Auslegeschrift 10 57 783 concerns a (B) castor oil and / or a liquid condensate process for hardening glycidyl polyethers made from ricinoleic acid and a polyvalent J ™ glycidyl polyether, a higher aliphatic one aliphatic alcohol with an iodine number of «monocarboxylic acid and an anhydride of at least 50, the total amount of 40 being converted to basic carboxylic acid. The higher 110 parts by weight per 100 parts of the polygly-asian monocarboxylic acid can be of dehydrated cidvläthers, and be derived from castor oil. In no example will (C) one or more dicarboxylic anhy- ^ cmvsol or dehydrated castor oil is used. It hydrides from the group maleic anhydride ^ao "J ^{there AUC} ^ ^mcht indicated that the higher AH or adducts of maleic anhydride and monocarboxylic acids plushing hydroxyl ent-olefin, the transmitter has a melting point of not ^na f ^ ^{n mus} above 40 ° C have ^{ese Ausie} S ^eschnft not further mediates the 'Doctrine that the proportions of the individual components If necessary, known hardening accelerators 25 must be carefully adjusted in order to obtain products and possibly pigments, thixotropic agents with special insulating properties. The or fillers and hardening of the hardened glycidyl polyether liquid mixture described there by heating, which should be flexible and tough, but nothing is indicated that the constituents of their electrical properties and counter parts (A) to (C) in such proportions used, 30 resistance to high temperatures andaß given 1.1 to 1.5 oxirane groups of the polyglycidyl. äthers in each by implementation between the The invention is based on the object a Component (B) and the anhydride produced process for the production of a resinous, tough, Carboxyl group and in each anhydride group flexible, heat-resistant, at high temperatures unreacted anhydride are contained and 35 advantageous electrical insulating material under Herm at least 20% more anhydride groups in front of a solvent-free, at room temperatures are initially free-flowing liquid mixture for complete carboxylation of component (B) are necessary. to make available, after which the initially 2. The method according to claim 1, characterized in that a free flowing liquid mixture is sufficient draws that component (B) has a fully low viscosity for more than an hour constantly esterified with the anhydride before it remains free-flowing, increases rapidly with moderate heating mixed with your polyglycidyl ether. hardens to a sufficiently tough state and then thermal and mechanical shock effects can withstand, especially at 155 ° C or