HK1192267A - Reactive resins for cable sealing compounds - Google Patents

Description

Reactive resin for cable potting compound

Technical Field

The invention relates to compositions, in particular for cable potting compounds, comprising (meth) acrylated polyether polyols and/or polyester polyols and/or (meth) acrylated hydroxy-functional triglycerides, having a controlled pot life, in particular as two-component systems.

Background

Commercially available cable casting compounds are currently based on two-component polyurethane resins (PUR resins) or epoxy systems.

A significant disadvantage of the PUR systems used is that isocyanates have to be used as curing agent components. Isocyanates, especially MDI (diphenylmethane diisocyanate), are suspected to have carcinogenic effects.

EP1070730 describes methacrylate-based cable casting compounds in which the crosslinking is carried out via polyethylene glycol dimethacrylate. WO2011/012918 describes cable potting compounds comprising urethane acrylate oligomers and epoxy acrylate oligomers as crosslinker components. The disadvantage here is the use of monomers having a high vapor pressure.

Disclosure of Invention

Problem(s)

The problem to be solved by the present invention is to provide systems which cure at room temperature and whose curing properties can be influenced in a simple manner. More specifically, the pot life should be adjustable within wide limits and the composition nevertheless still cures rapidly at a defined point in time without energy supply, for example within 100min, preferably within less than 50 min.

In addition, it should be possible to adjust and vary the mechanical properties of the cured resin in a simple manner, for example by changing the resin components, to the desired application conditions.

Another problem to be solved according to the invention is to minimize shrinkage during curing, as well as the odor load caused by the ingredients used.

The following disadvantages of the polyurethane systems known from the prior art are to be avoided: when used as a potting compound, the adhesion between the mould shell and the potting compound is so high that the mould shell hitherto remains in place as a lining component around the potting compound, i.e. can no longer be removed. A composition should be provided that only slightly adhesively bonds or does not adhesively bond to the shell mold and that cures rapidly without a high exotherm so that the shell mold can be used again as a mold.

Furthermore, the use of isocyanate-containing compounds should be avoided.

Solution scheme

These objects, as well as others not explicitly stated but which can be easily deduced or inferred from the context discussed at the time of introduction herein, are achieved by a composition having all the features of claim 1.

Suitable modifications of the composition according to the invention, for example as a design of the composition in the form of a two-component system or the use of said composition, are claimed in the dependent claims which refer back to claim 1.

It has surprisingly been found that with the compositions according to the invention it is possible to dispense with the use of cyanate esters without the processability, for example the pot life, of the compositions being deteriorated.

It has also been found that the compositions exhibit particularly low water absorption, especially when used as cable potting compounds.

It has also been found that the high molecular weight of the components used results in compositions having a low vapor pressure. Two-component systems known from the prior art, which contain methacrylates, are classified as irritating, since the exposure is increased during processing due to the higher vapor pressure of the monomers.

Furthermore, it has been found that the inventive mixtures have a lower shrinkage after polymerization than the methacrylate systems on the market.

The pot life can be varied within wide limits via the amounts of initiator and activator used. Depending on the ambient temperature and the stabilization of the components, the pot life can be optimized via the amount of initiator and/or activator. For this purpose, in particular, the polymerization time measurement (PT measurement) described in the figures gives the user a simple screening method with which, by means of a small number of test series, the optimum choice can be found for their end use in terms of processing time (pot life) and curing speed of the components mixed. More specifically, the temperature evolution and the maximum temperature during the polymerization of the composition can be estimated and adjusted in a targeted manner. The values determined in the PT measurements in the preliminary tests correlate very well with the curing parameters of mixtures of the corresponding composition under the conditions of use.

The (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy functional triglycerides used in the scope of the present invention are prepared by reacting a suitable (meth) acrylic compound with a polyether polyol, a polyester polyol or a hydroxy functional triglyceride. This can be done, for example, by acid-catalyzed esterification of these compounds with (meth) acrylic acid or by transesterification. For the transesterification of polyols with (meth) acrylates, transesterification catalysts known to the person skilled in the art can be used. Particularly suitable are the systems described in DE3423443, EP1924547, EP2162423, EP2294048 and DE 1020100009485.

Herein, the expression "(meth) acrylate" refers both to methacrylate, such as methyl methacrylate, ethyl methacrylate, etc., and to acrylate, such as methyl acrylate, ethyl acrylate, etc., and to mixtures of these two monomers.

Polyether polyols are generally the polymerization products of epoxides, such as Ethylene Oxide (EO), Propylene Oxide (PO), butylene oxide, styrene oxide or epichlorohydrin, with themselves or with these epoxides, optionally in the form of mixtures or in succession, added to starter components containing active hydrogen atoms, such as water, alcohols, ammonia or amines. Such starter molecules here generally have a functionality of from 1 to 8. Examples of such starting compounds are di-to octafunctional hydroxyl compounds, such as polyols, in particular diols such as ethylene glycol, 1, 2-propanediol, 1, 3-propanediol, diethylene glycol, dipropylene glycol, 1, 4-butanediol and 1, 6-hexanediol, triols such as glycerol and trimethylolpropane, tetrols such as pentaerythritol, hexaols such as sorbitol and octaols such as sucrose. Depending on the process control, these polyether polyols may be homopolymers, block copolymers or statistically distributed copolymers.

Conventional polyester polyols in this connection are those which are composed entirely or predominantly of polycarboxylic acids or derivatives thereof which contain at least 2 and up to 6, preferably 4, carboxyl groups and a total of 4 to 12 carbon atoms, i.e. for example adipic acid, glutaric acid, succinic acid, phthalic acid, etc., and are prepared at temperatures of > 180 ℃ with dissociation of water or low molecular weight, usually monofunctional alcohols. Typical catalysts are, for example, tin compounds or titanium compounds. The preparation and properties of polyester polyols, for example for polyurethanes, are described inIn numerous patents and literature publications. Mention may be made, for example, of the Kunstst of fhandbuch (handbook of plastics)]Volume VII, Polyurethane, Carl-Hanser-Verlag, munich black, first edition 1966, editors dr.r.vieweg and dr.a.And second edition 1983 and third edition 1993, the editor is dr.

The hydroxy-functional triglycerides used may be naturally occurring hydroxy-functional triglycerides or semi-synthetic hydroxy-functional triglycerides.

Examples of naturally occurring raw materials are castor oil, lesquerella oil, polyhydroxy fatty acids, ricinoleic acid, hydroxyl-modified oils, such as grape seed oil, black grass oil, pumpkin seed oil, borage seed oil, soybean oil, wheat germ oil, rapeseed oil, sunflower oil, peanut oil, almond oil, pistachio nut oil, almond oil, olive oil, macadamia nut oil, avocado oil, sea buckthorn oil, sesame oil, hemp seed oil, hazelnut oil, evening primrose oil, rose oil, safflower oil, walnut oil, hydroxyl-modified fatty acids and fatty acid esters based on myristoleic acid, palmitoleic acid, oleic acid, vaccenic acid, petroselinic acid, gadoleic acid, erucic acid, nervonic acid, linoleic acid, linolenic acid, cis 6, 9, 12, 15-stearidonic acid, arachidonic acid, eicosapentaenoic acid, 4, 7, 11-docosatriene-18-alkynoic acid, docosahexaenoic acid.

Particularly preferred is castor oil, which is present in the seeds of castor oil, which is cultivated in large quantities in many parts of the world, such as india, brazil and china. Castor oil is unique among seed oils because it is composed primarily of unsaturated C containing one hydroxyl group₁₈Fatty acids (so-called ricinoleic acid).

Natural castor oil has a functionality of about 2.7 OH groups/mol and an OH number of at least 160mg KOH/g. The acid content of natural castor oil is a maximum of 2mg KOH/g. The average molecular weight of the castor oil is in the range of more than 800g/mol, particularly 800-2000g/mol, preferably 820-1500g/mol, more preferably 850-1200 g/mol. Castor oil may be composed of a mixture of glycerides of fatty acids such as ricinoleic acid, oleic acid, linoleic acid, stearic acid or dihydroxystearic acid. Depending on the origin of the castor oil, it may also be advantageous to use partially hydrogenated castor oil for the subsequent (meth) acrylation. Particular preference is given to using castor oil which contains at least 85% by weight, preferably at least 90% by weight, of ricinoleic acid glyceride.

Hydroxyl-functional triglycerides can also be obtained, for example, by epoxidation and subsequent hydrolysis of unsaturated triglycerides.

The mechanical properties of the potting compound can be adjusted by using individual compounds of the (meth) acrylated polyols or by using suitable mixtures of the above-mentioned (meth) acrylated different polyols. Polyols with high molecular weight and low hydroxyl number lead to lower cross-linking densities due to the long molecular domains between the branch points, and the resulting perfusates are formed softer. Polyols with lower molecular weights and high hydroxyl numbers lead to stiffer pours due to higher crosslink density and shorter molecular length between the individual branch points. Depending on the requirements (hardness, desired curing speed) of the potting compound, the potting compound can be adjusted accordingly with regard to the proportion and mixing ratio of the polyol components, optionally including the measurement of the polymerization time. In a particular embodiment, the potting compound is formed from several (meth) acrylated polyols, preferably from a mixture of at least two different (meth) acrylated compounds of component a). For example, such a mixture may consist of two different representatives of different compound classes, for example a mixture of in each case one (meth) acrylated polyether/polyester, polyether/hydroxy functional triglyceride or polyester/hydroxy functional triglyceride. However, likewise, two or more structurally different representatives of a single compound class can also be used in the form of mixtures, for example two or more polyethers each having a different molecular weight and/or hydroxyl number, two or more polyesters each having a different molecular weight and/or hydroxyl number, or two or more hydroxy-functionalized triglycerides each having a different molecular weight and/or hydroxyl number. In particular embodiments, two or more different representatives of different compound classes and two or more structurally different representatives of a single compound class may also be used in admixture.

Advantageous mixtures comprise, for example, polyether polyols which, prior to (meth) acrylation, generally have an average molecular weight of 230-650g/mol and an average hydroxyl value of 220-500mg KOH/g, preferably an average molecular weight of 300-500g/mol and an average hydroxyl value of 300-450mg KOH/g, in particular an average molecular weight of 400-500g/mol and an average hydroxyl value of 340-420mg KOH/g. Whereas the second polyether polyol generally has, prior to (meth) acrylation, an average molecular weight of 1000-.

If the (meth) acrylated polyester polyols are used in the form of a mixture, they generally have an average molecular weight of 500-2000g/mol and an average hydroxyl value of 40-250mgKOH/g, preferably an average molecular weight of 600-1500g/mol and an average hydroxyl value of 100-220mgKOH/g, in particular an average molecular weight of 800-1100g/mol and an average hydroxyl value of 110-140mgKOH/g, before (meth) acrylation.

If (meth) acrylated hydroxy functional triglycerides are used in the preparation of the mixture, they preferably have an average molecular weight of > 800g/mol, in particular 800-. Particularly preferred as (meth) acrylated hydroxy functional triglyceride is (meth) acrylated castor oil.

The composition may also optionally comprise other mono-or polyfunctional monomers if, for example, specific properties of the composition are to be achieved. For this purpose, it is possible to use all ethylenically unsaturated compounds which can be copolymerized with the monomers a) according to the invention. Non-limiting examples thereof are methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, phenethyl (meth) acrylate, 3, 5-trimethylcyclohexyl (meth) acrylate, hydroxyalkyl (meth) acrylates such as 3-hydroxypropyl methacrylate, 3, 4-dihydroxybutyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2, 5-dimethyl-1, 6-hexanediol (meth) acrylate, 1, 10-decanediol (meth) acrylate.

Diol dimethacrylates such as 1, 4-butanediol methacrylate, 2-butoxyethyl methacrylate, 2-ethoxyethoxymethyl methacrylate, 2-ethoxyethyl methacrylate;

methacrylates of ether alcohols, for example tetrahydrofurfuryl methacrylate, vinyloxyethoxyethyl methacrylate, methoxyethoxyethyl methacrylate, 1-butoxypropyl methacrylate, 1-methyl- (2-vinyloxy) ethyl methacrylate, cyclohexyloxymethyl methacrylate, methoxymethoxyethyl methacrylate, benzyloxymethyl methacrylate, furfuryl methacrylate, 2-butoxyethyl methacrylate, 2-ethoxyethoxymethyl methacrylate, 2-ethoxyethyl methacrylate, allyloxymethyl methacrylate, 1-ethoxybutyl methacrylate, methoxymethyl methacrylate, 1-ethoxyethyl methacrylate, n-butoxyethyl methacrylate, n-ethoxyethyl methacrylate, n-butoxyethyl, Ethoxymethyl methacrylate and ethoxylated (meth) acrylates preferably containing 1 to 20, in particular 2 to 8, ethoxy groups;

styrene, substituted styrenes having alkyl substituents in the side chain, such as α -methylstyrene and α -ethylstyrene, substituted styrenes having alkyl substituents in the ring, such as vinyltoluene and p-methylstyrene, halogenated styrenes, such as monochlorostyrene, dichlorostyrene, tribromostyrene and tetrabromostyrene.

When these compounds are used, they are used only in small amounts, due to their higher vapor pressure relative to the (meth) acrylated compound a). These compounds may be present in the composition in a total amount of from 0 to 25% by weight, preferably from 0 to 20% by weight, more preferably from 0 to 10% by weight, where these percentages are based on the weight of the total composition and the sum of all ingredients, i.e. compounds a) to d) and optionally other ingredients, must always total 100% by weight.

In the art, curing is considered sufficient when a dimensional stability of greater than 10 shore D is achieved, preferably a shore D hardness of greater than 20 after full cure. This is achieved only after approximately 30 minutes with polyurethane systems according to the prior art, wherein the adhesion between the mold shell and the potting compound has also been found to be high, so that the mold shell has hitherto remained as a lining component around the potting compound, i.e. it has not been removed at all.

In contrast, the compositions according to the invention have the advantage that, when used as potting compounds, they do not form any adhesive bond at all with the shell mold, cure rapidly without an excessively high exotherm, so that the shell mold can be used again as a mold.

The compositions based on (meth) acrylated polyols according to the invention enable curing times of 20-30min with moderate reaction temperatures of 30-95 ℃, preferably 40-85 ℃, especially preferably 50-75 ℃, which far reach the maximum allowable thermal stress of the cable insulation of less than about 100 ℃. More specifically, the curing temperature of the composition should not exceed 95 ℃, preferably 85 ℃, more preferably 75 ℃.

The stabilizers or inhibitors used may be phenolic or amine-containing inhibitors known from the prior art, preferably HQME, Tempol or phenothiazine. If the (meth) acrylated compound a) should be stabilized, a stabilizer is generally added to said (meth) acrylated compound a) in an amount of 1 to 1000 ppm. In mixtures of different (meth) acrylated compounds a), which may consist both of unstabilized compounds and of compounds having in each case different stabilizer contents, the stabilizer content may be between 1 and 1000ppm, wherein the data are based on the total amount of compound a) present in the mixture.

The initiators are used in the usual amounts, for example in amounts of from 0.01 to 10% by weight, preferably from 0.05 to 5% by weight, in particular from 0.1 to 1.0% by weight, based on the weight of the total composition. When the initiator is used in diluted form (so-called phlegmatized form), the individual percentage content of the initiator therein must be taken into account in the initial weighing, whereby the above-mentioned amounts of effective initiator are also actually used. The initiators used may be all compounds which decompose into free radicals under the polymerization conditions, such as peroxides, hydroperoxides, hydrogen peroxide, persulfates, azo compounds and the so-called redox initiators. In some cases, it is advantageous to use mixtures of different initiators, for example mixtures of hydrogen peroxide and sodium peroxodisulfate or potassium peroxodisulfate. Mixtures of hydrogen peroxide and sodium peroxodisulfate can be used in any desired ratio. Suitable organic peroxides are, for example, acetylacetone peroxide, methyl ethyl ketone peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert-amyl perpivalate, tert-butyl perneohexanoate, tert-butyl perisobutyrate, tert-butyl per-2-ethylhexanoate, tert-butyl perisononanoate, tert-butyl permaleate, tert-butyl perbenzoate, di (2-ethylhexyl) peroxydicarbonate, dicyclohexyl peroxydicarbonate, di (4-tert-butylcyclohexyl) peroxydicarbonate, dimyristyl peroxydicarbonate, diacetyl peroxydicarbonate, allyl peresters, cumyl peroxyneodecanoate, tert-butyl per-3, 5, 5-trimethylhexanoate, acetylcyclohexylsulfonyl peroxide, dilauryl peroxide, dibenzoyl peroxide and tert-amyl perneodecanoate. Other initiators are azo compounds, such as 2, 2 ' -azobisisobutyronitrile, 2, 2 ' -azobis (2, 4-dimethylvaleronitrile) and 2, 2 ' -azobis (4-methoxy-2, 4-dimethylvaleronitrile). Preferred initiators are redox initiator systems. They contain at least one of the abovementioned peroxy compounds as oxidizing component and contain, for example, ascorbic acid, glucose, sorbose, ammonium or alkali metal bisulfite, ammonium or alkali metal sulfite, ammonium or alkali metal thiosulfate, ammonium or alkali metal dithionite, ammonium or alkali metal pyrosulfite, ammonium or alkali metal sulfide or sodium hydroxymethylsulfoxylate as reducing component.

For fast curing, amines other than peroxides may be used as accelerators (activators) in redox initiator systems, such as dimethyl or diethyl aniline, p-toluidine or their adducts with ethylene oxide (BISOMER PTE, International specialty chemicals). The accelerator component is typically added to the initiator-free potting component or directly to the initiator-containing potting component prior to use in solid, liquid or dissolved form. In addition to such peroxide/amine redox systems, a peroxide/cobalt accelerator combination may also be used.

Based on the amount of monomers used for the polymerization, for example, 1X 10^-5To 1 mol% of the reducing component of the redox catalyst.

In a particular embodiment, the composition of the invention is used as a two-component system. In this case, component a may comprise only the initiator, or both the initiator and the filler. Component A here comprises from 0.01 to 10% by weight of initiator and from 0 to 90% by weight of filler, where the percentage data are based on the weight of the total composition composed of the two components A and B (i.e.compounds a) to d) and optionally further ingredients). In the case where component A consists only of the initiator, it constitutes 100% by weight of component A, but, as stated above, it constitutes 0.01 to 10% by weight, based on the weight of the total composition. Component B in this embodiment comprises from 9.98 to 99.98% by weight of one or more compounds from the group of (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy-functional triglycerides, and from 0.01 to 10% by weight of activators, where these percentages are based on the weight of the total composition and the sum of all the constituents of components A and B, i.e. compounds a) to d) and optionally other constituents, must always sum to 100% by weight.

In another embodiment, component a may comprise 9.98 to 99.98 wt.% of one or more compounds selected from (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy functional triglycerides, 0.01 to 10 wt.% of an initiator and optionally 0 to 90 wt.% of a filler, and component B may comprise 9.98 to 99.98 wt.% of one or more compounds selected from (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy functional triglycerides and 0.01 to 10 wt.% of an activator. In contrast to the above-described embodiments, the mixture of (meth) acrylated polyols is here present both in component a and in component B. The above-mentioned percentage data are based on the weight of the total composition, i.e. the sum of all the constituents of components A and B, i.e. compounds a) to d) and optionally further constituents, and the sum of all individual values must always total 100% by weight.

In a particularly preferred variant of this embodiment, this two-component system with controlled pot life comprises as component a): 89.90-99.99% by weight of a (meth) acrylated polyether polyol or a (meth) acrylated polyester polyol or a mixture of both, 0.01-10% by weight of an initiator and 1-1000ppm of a stabilizer, wherein the sum of components A must always amount to 100% by weight, and comprising as component B): 89.90 to 99.99% by weight of a (meth) acrylated polyether polyol or a (meth) acrylated polyester polyol or a mixture of the two, 0.01 to 10% by weight of an activator and 1 to 1000ppm of a stabilizer, wherein the sum of components B must always sum to 100% by weight and comprise 0 to 90% by weight of a filler.

However, both embodiments comprising compound a) in both component a and component B are generally not suitable for longer term storage.

In another embodiment, the initiator is dissolved in component a of the mixture comprising the (meth) acrylated polyol. In that case, component B consists only of the activator. In this embodiment, component a may comprise from 9.98 to 99.98% by weight of one or more compounds selected from (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy functional triglycerides, from 0.01 to 10% by weight of initiator and optionally from 0 to 90% by weight of filler, and component B may comprise from 0.01 to 10% by weight of activator. The above-mentioned percentage data are based on the weight of the total composition, i.e. the sum of all the constituents of components A and B, i.e. compounds a) to d) and optionally further constituents, and the sum of all individual values must always total 100% by weight.

In a particular embodiment, a two-component system is used which comprises from 50 to 85% of component A and from 15 to 50% of component B, preferably from 55 to 75% of component A and from 25 to 45% of component B, more preferably from 60 to 70% of component A and from 30 to 40% of component B, and components A and B may consist of the above-described compositions.

The fillers used may be all inorganic fillers known from the prior art, preferably quartz powder, dolomite, sand, chalk, oxides, hydroxides, basic carbonates and alkaline earth metal carbonates may be used. The one-or two-component systems of the present invention can be used without filler or at high loadings of up to 90 wt.%; the fillers can preferably be used in amounts of from 10 to 90% by weight, preferably from 30 to 80% by weight, more preferably from 60 to 70% by weight. These above percentage values are based on the total weight of the composition upon completion of mixing.

The compositions according to the invention are preferably used for the preparation of compositions for waterproofing against electrical breakdown in cavities, in particular potting compounds for sealing cables in cable connection sleeves, or as potting compounds for electronic components.

Typically, the potting compound is used as a two-component system. The method of providing a potting compound preferably comprises the steps of:

a) providing component A in a suitable container (box, bag, bucket, etc.)

b) Component B is provided in a suitable container (box, bag, bucket, etc.)

c) Mixing the two components before use and filling the cavity to be filled with this mixture, followed by curing

d) Optionally removing the cavity liner forming the cavity.

Containers useful for components a and B are well known to those skilled in the art. In addition to boxes, bags and tubs made of any material, bags made of polymeric materials may be used in particular. They are also sometimes referred to as hose bags or split bags.

In an advantageous form of application, the containers for the components a and B consist of a single bag made of polymeric material containing the two components in separate chambers. This can be achieved via a suitably introduced weld or, for example, with a small clamp or an isolating clamp. After mechanical removal of the area separating the two components, for example by tearing or breaking a separation weld, undoing a small clamp or separation clamp or the like, it is possible to mix the two components in the bag, for example by vigorous kneading, and the cavity to be filled can be filled with this mixture.

The mould shell to be used is known to the person skilled in the art and all types of mould shells known from the prior art can be used within the scope of the invention.

Detailed Description

Example (b):

1.1. synthesis of methacrylated principal component

The polyols used were:

castor oil (Roth corporation)

Polyether polyol ISO-Pol T35(Isoelektra Co.)

Mw 4800g/mol OHN 35mg KOH/g (from the manufacturer)

Polyether polyol ISO-Pol T400(Isoelektra Co.)

Mw 450g/mol, OHN 400mg KOH/g (from manufacturer)

Polyester polyol P-1010(Kuraray Co., Ltd.)

Mw 1000g/mol, OHN 112mg KOH/g (from manufacturer)

The polyol is transesterified with methyl methacrylate according to DE3423443, in which the OH groups are almost completely methacrylated. Depending on the mixture, the OH number after the reaction is between 1.6 and 5.6mg KOH/g (see Table 1).

Example (b):

synthesis of methacrylated polyether polyols

A mixture of 430.0g of ISO-POLT35 polyether polyol, 450.0g of methyl methacrylate, 0.09g of hydroquinone monomethyl ether, 0.009g of a mixture of 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-1-oxyl and, as catalyst, 0.88g of calcium oxide and 0.18g of lithium hydroxide is initially charged into a 2 l four-neck round-bottomed flask with a knife stirrer, an inlet tube for compressed air, a 30cm column with random packing, an automatic column head, a bottom or top thermometer and a heating mantle. The reaction mixture was heated to boiling with the introduction of air. At a top temperature of about 85 ℃, at a temperature of 50: a reflux ratio of 1 separates the methyl methacrylate/MeOH azeotrope. During the reaction, the top temperature rose slowly; the reaction was terminated when a top temperature of 100 ℃ was reached. During the reaction, by measuring the refractive index (n)_D ²⁰) The conversion was measured.

After the end of the reaction, excess methyl methacrylate was removed by reducing the pressure up to 20 mbar at a bottom temperature of up to 115 ℃. The mixture was cooled to room temperature and filtered. A clear yellowish product was obtained.

Similar to the examples, the conversion of the other polyols was carried out under conditions adapted to the catalyst and the reaction conditions.

Determination of OH number (hydroxyl number, OHN)

By titration with acetic anhydride according to DIN 53240-2.

1.3. Preparation of reactive resins

Monomer (b):

methacrylated castor oil (Roth Co., Ltd.)

Methacrylated polyether polyols (ISO-Pol T35 and ISO-Pol T400, Isoelektra, Inc.)

Methacrylated polyester polyol (P-1010, Kuraray Co., Ltd.)

Initiator: 1-3% by weight of 50% benzoyl peroxide (BP-50FT, Fluka Corp.)

Activating agent: 0.4-1% by weight of N-ethoxylated p-toluidine (PT25E/2, Saltigo Co.)

And (3) stabilizing: HQME of 450ppm

For the different samples, the main components (composition: see Table 1) were weighed in and the mixture was homogenized on a roller bed for 3 hours.

1.4. Bulk polymerization and determination of polymerization time (PT measurement)

The monomer tempering treatment to a suitable measured temperature (T ═ 23 ℃) is maintained in a water bath or in a climate controlled chamber for at least 2 h. The initiator (BP-50-FT, amount data based on 50% initial weight supplied) and the activator (PT25E/2) were dissolved separately in each half of the monomer or monomer mixture in separate beakers. The two mixtures were combined, homogenized for 2min on a magnetic stirrer and transferred to test tubes(18X 180mm), and then the polymerization time was measured. With the aid of a temperature sensor, the temperature profile of the reaction is recorded. This temperature sensor is in a second smaller tube filled with diethylene glycol as a carrier fluid, which is fixed in the middle of the tube so that it is immersed sufficiently low into the sample liquid to enable an accurate measurement of the sample temperature. Suitably considered as the start of the measurement is the point in time at which the redox components are combined. Maximum reaction temperature T_maxCorresponds to the polymerization time.

1.5. Swelling study in Water

Disks were cut out of the polymer obtained from the polymerization time measurement, so that cylindrical test pieces (d 15mm, h 5mm) were obtained. They were weighed on an analytical balance in a Petri dish as weighing aid. Storage in 400ml of distilled water in a beaker (wide format) at room temperature is then carried out. The test piece is removed at a regular distance, patted dry with cellulose and weighed again.

After a total storage time of 7 days, the samples were dried again overnight (about 14h) in a drying cabinet at 80 ℃ and weighed again.

The values obtained were used to calculate solvent absorption (solv. absorption), weight loss and true swelling as follows.

Or

Wherein

m₁Empty Petri dish (as a weighing aid) weight

m₂Weight of Petri dish containing sample before Water storage

m₃Weight of Petri dishes containing samples after storage in water (7 days)

m₄Weight of Petri dishes containing samples after drying at 80 deg.C

1.6. Evaluation of hardness of Polymer

1.6.1. Visual evaluation

All polymers from PT measurements were removed from the glass of the test tube and evaluated for hardness and consistency.

1.6.2. Shore hardness

For this purpose, the sheet polymerization was carried out in a cell consisting of a glass plate with a round cord of 5 mm. The reaction mixture was prepared as described in 1.4, and then filled into the prepared cell. Where they were allowed to cure at room temperature for about 2 h. The shore hardness is subsequently measured according to ISO 868.

Table 2: effect of activator/initiator concentration on polymerization time

Table 3: comparison of mechanical Properties of sample 2 as unfilled and filled System

The examples show that the mechanical properties of the cured resins can be adapted and modified by changing the resin composition, i.e. by using different methacrylated polyol components (polyester polyols, polyether polyols or natural polyols, such as castor oil). Long chain polyether polyols, such as methacryloylated (meth.) Iso-pol T35 resulted in a resin with a low Shore hardness (sample 7). Short-chain polyether polyols, such as methacrylated Iso-pol T400, resulted in a resin with a high shore hardness due to the higher crosslink density (sample 8). The combination with methacrylated castor oil thus makes it possible to prepare infusions having different shore hardnesses. Sample 2 showed a decrease in shore hardness compared to a resin consisting of pure methacrylated castor oil (sample 1) by using methacrylated Iso-Pol T35. Sample 3 shows an increase in shore hardness by using methacrylated Iso-Pol T400 compared to a resin consisting of pure methacrylated castor oil (sample 1).

As shown in table 2, the polymerization time of the resin can be adjusted via adaptive adjustment of initiator and activator concentrations (samples 3 and 6, graphs 1 and 2). If the activator or initiator concentration is reduced, the polymerization time is prolonged. This enables the preparation of resins with variable processing times depending on the end use.

The system can be used both in unfilled form and in filled form. The mechanical properties can additionally be influenced by the addition of suitable fillers (table 3).

Claims (16)

1. A composition having a controlled pot life comprising

a)9.98 to 99.98 wt.% of one or more compounds selected from (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy-functionalized triglycerides

b)0.01 to 10 wt.% of an initiator

c)0.01 to 10% by weight of an activator and

d)0 to 90 wt% of a filler

Wherein the sum of components a) to d) must always add up to 100% by weight and the percentage data are based on the weight of the total composition.

2. Composition according to claim 1, characterized in that component a) is formed from a mixture of at least two different (meth) acrylated compounds of component a).

3. Composition according to claim 1 or 2, characterized in that it is formed by a two-component system consisting of component A) and component B),

said component A) comprises

b)0.01 to 10% by weight of an initiator,

d)0 to 90% by weight of a filler,

said component B) comprises

a)9.98 to 99.98% by weight of one or more compounds selected from (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy-functional triglycerides,

c)0.01 to 10% by weight of an activator,

wherein the sum of components a) to d) must always add up to 100% by weight and the percentage data are based on the weight of the total composition.

4. Composition according to claim 1 or 2, characterized in that it is formed by a two-component system consisting of component A) and component B),

said component A) comprising a)9.98 to 99.98 wt.% of one or more compounds selected from (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy-functionalized triglycerides,

b)0.01 to 10% by weight of an initiator,

d)0 to 90% by weight of a filler,

said component B) comprises

a)9.98 to 99.98% by weight of one or more compounds selected from (meth) acrylated polyether polyols, (meth) acrylated polyester polyols or (meth) acrylated hydroxy-functional triglycerides,

c)0.01 to 10% by weight of an activator,

wherein the sum of components a) to d) must always add up to 100% by weight and the percentage data are based on the weight of the total composition.

5. Composition according to any one of claims 1 to 4, characterized in that the compounds a) each contain 1 to 1000ppm of stabilizer, based on the total content of compounds a) present.

6. Composition according to claim 3, 4 or 5, characterized in that it comprises

50-85% of component A and

15-50% of component B.

7. Composition according to any one of the preceding claims, comprising a (meth) acrylated polyether polyol obtainable via transesterification of a polyether polyol having an average molecular weight of 230-8000g/mol and a hydroxyl value of 10-500mg KOH/g with a (meth) acrylate.

8. Composition according to any one of the preceding claims, comprising a first (meth) acrylated polyether polyol obtainable by transesterification of a polyether polyol having an average molecular weight of 230-650g/mol and a hydroxyl value of 220-500mg KOH/g with (meth) acrylate and a second (meth) acrylated polyether polyol obtainable by transesterification of a polyether polyol having an average molecular weight of 1000-8000g/mol and a hydroxyl value of 10-180mg KOH/g with (meth) acrylate.

9. Composition according to any one of the preceding claims, comprising a (meth) acrylated polyester polyol obtainable via transesterification of a polyester polyol having an average molecular weight of 500-2000g/mol and a hydroxyl value of 40-250mg KOH/g with a (meth) acrylate.

10. Composition according to any one of the preceding claims, comprising (meth) acrylated hydroxy-functionalized triglycerides obtainable by transesterification of hydroxy-functionalized triglycerides having an average molecular weight of 800-2000g/mol and a hydroxyl value of 120-250mg KOH/g with (meth) acrylates.

11. Composition according to any one of the preceding claims, characterized in that the (meth) acrylated hydroxy functional triglyceride is (meth) acrylated castor oil.

12. Use of a composition according to any of the preceding claims for the preparation of a waterproof electrical breakdown-resistant composition in a cavity.

13. Use of a composition according to any one of claims 1 to 11 as a potting compound for sealing an electrical cable.

14. A method of providing a potting compound for sealing a cable, comprising the steps of:

a) providing component A in a suitable container

b) Providing component B in a suitable container

c) Mixing the two components before use and filling the cavity to be filled with this mixture, followed by curing

d) Optionally removing the cavity liner forming the cavity.

15. A method according to claim 14, characterized in that the container for components a and B is constituted by a bag made of a polymer material.

16. Method according to claim 15, characterized in that the containers of the components a and B are constituted by a single bag made of polymeric material containing said two components in separate chambers and enabling the mixing of said two components in the bag after the mechanical removal of the zone separating said two components.