Polyisocyanurate plastics with rubber-like properties

Abstract

In the present invention, the total amount of plastic is a) a cured polymer, based on the total amount of polymer: at least 75% by weight of polyether chains, 1 to 5.2% by weight of urethane groups, and 0.7 to 7% by weight of isocyanurate groups a cured polymer comprising: b) at least 20% by weight of at least one filler Polyisocyanurate plastics containing Polyisocyanurate plastics exhibit remarkable rubber-like properties, including low modulus, low glass transition temperature, and surprisingly high dimensional stability with high elastic recovery after compression, without any tendency to become embrittled over time. They are readily available and are particularly suitable for applications such as shock absorbers, sealants, adhesives, or gap fillers, especially gap fillers with high thermal conductivity, and are particularly suitable for contacts with electronic elements or devices, such as batteries in electric vehicles.

Description

[Technical Field]

[0001] The present invention relates to polyisocyanurate plastics and their use as elastomers with rubber-like properties. [Background technology]

[0002] Natural and synthetic rubbers are obtained by vulcanization, resulting in durable elastomers. Rubbers have low glass transition temperatures and good dimensional stability with high elastic recovery after compression. Among other uses, rubber is particularly suitable for elastic seals or damping materials, for example as components of shock absorbers in vehicle structures. However, over time, rubber becomes embrittled due to oxidation by air and loses its elasticity, meaning that it must be replaced periodically. Therefore, there is a need for elastomeric plastics with rubber-like properties that do not tend to embrittle during use.

[0003] Polyurethanes are elastomeric plastics widely used in industry. They have good elasticity and adjustable hardness, ranging from soft to hard (i.e., low or high modulus). Polyurethanes are typically cured by the reaction of isocyanate groups with polyols and / or moisture to form urethane and urea bonds (in the case of moisture). However, the use of polyurethane plastics presents many challenges. In one-component systems, the water required for curing must be obtained from the outside in the form of atmospheric moisture, and there is always a risk of blister formation. This limits the application of such systems in thick layers and between moist, tight substrates. A problem with two-component systems containing a polyol component and an isocyanate component is that the components must be mixed in very precise amounts to achieve the correct stoichiometry for the curing reaction to yield the desired material properties. In addition, the isocyanate groups can react not only with the hydroxyl groups of the polyol but also with any water present. This can lead to the formation of bubbles and incomplete polymerization, resulting in reduced strength and elasticity, especially in high-humidity environments. Another drawback of polyurethane elastomers is that their dimensional stability after compression is significantly lower than that of rubber, meaning that they exhibit high compression set and significant irreversible plastic deformation when compressed, especially at high temperatures. Therefore, polyurethane plastics cannot be used in applications such as shock absorbers, which have high requirements for long-term dimensional stability after repeated compression and relaxation.

[0004] Plastics crosslinked by isocyanurate groups are also known. Isocyanurate groups are formed by trimerization of isocyanate groups. Such curing is achieved by the addition of special alkaline catalysts. Trimerization curing does not require moisture, and the system is highly tolerant to mixing errors related to the trimerization catalyst dosage. However, known polyisocyanurate plastics are primarily hard, high-strength materials with high glass transition temperatures. They are typically used as adhesives, composite resins, and durable varnish-like coatings.

[0005] US Patent Application Publication No. 2022 / 0145149 describes anhydrous-curing polyisocyanate adhesives that cure by trimerization and have a high content of isocyanate groups, which allows for the desired high adhesive strength.

[0006] EP 2,137,224 describes polyisocyanate-based adhesives suitable for laminating packaging films. These adhesives are cured by the reaction of a polyisocyanate with a substoichiometric amount of a polyol in the presence of a trimerization catalyst. To achieve high adhesion, a balanced amount of polyol is required, but not too much.

[0007] US Pat. No. 5,102,918 describes compositions that are cured by the reaction of a polyisocyanate with a substoichiometric amount of a polyol in the presence of a trimerization catalyst to yield a rigid material.

[0008] U.S. Patent No. 3,697,485 describes electrical potting compounds obtained by curing a mixture of an isocyanate-functional polymer and a polyisocyanate by trimerization of the isocyanate groups. The resulting cured plastic is not soft enough to exhibit rubber-like properties. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to provide an elastic plastic having rubber-like properties, in particular high dimensional stability and a compression set comparable to that of rubber, which overcomes the drawbacks of plastics in the prior art, in particular with regard to the loss of elasticity over time. [Means for solving the problem]

[0010] Surprisingly, this object is achieved by the polyisocyanurate plastics described in claim 1. The plastics of the present invention contain a cured polymer having a very high content of polyether chains and a low content of urethane and isocyanurate groups. The plastics of the present invention further contain at least 20% by weight of at least one filler and a catalyst for the trimerization of isocyanate groups, where the trimerization catalyst is present during the curing reaction and can disappear after curing, for example, by evaporation and / or decomposition.

[0011] The polyisocyanurate plastics of the present invention exhibit surprisingly high dimensional stability under repeated compressive stress, significantly higher than that of corresponding conventional polyurethane plastics substantially free of isocyanurate groups. The polyisocyanurate plastics of the present invention exhibit remarkable rubber-like properties, including very low compression set, and do not tend to lose their elasticity over time. They have high dimensional stability accompanied by a very low glass transition temperature, a low modulus, and a low compression set, especially after compression at high temperatures such as 70°C. The polyisocyanurate plastics are soft and elastic without embrittlement at low temperatures such as -20°C. They are highly stable against heat and humidity, and exhibit good mechanical strength and toughness with good elasticity. The included fillers further provide beneficial properties, as, surprisingly, trimerization cure is not adversely affected by the fillers. The high amount of carbon black filler provides particularly high toughness along with excellent dimensional stability. The high amount of thermally conductive filler makes the plastic particularly suitable for contacting electronic components or devices that generate large amounts of heat under high loads, particularly electric vehicle batteries.

[0012] The polyisocyanurate plastics of the present invention are particularly easily obtainable by curing compositions containing suitable isocyanate-functional polymers with a trimerization catalyst. The tolerance to mixing errors when adding the trimerization catalyst is high, no water is required for curing, and no substances are released during curing, allowing applications at large layer thicknesses and in substantially enclosed environments, such as filling gaps or voids.

[0013] These unique properties make the polyisocyanurate plastics of the present invention perfectly suited for applications requiring soft elasticity and vibration damping properties, as well as high dimensional stability, especially associated with low compression set, for elastic materials. The polyisocyanurate plastics of the present invention are particularly suitable as thermally conductive gap fillers for contacts with electronic components or devices, particularly electric vehicle batteries, where the plastics are able to accommodate the thermal expansion and contraction of the battery components during the charge and discharge cycle, known as battery breathing. They are even more particularly preferred for use as impact-absorbing plastics, particularly for housing steel springs in vehicle shock absorbers.

[0014] Further aspects of the invention are set out in the other independent claims. Preferred aspects of the invention are set out in the dependent claims.

[0015] The subject of the present invention is a) a cured polymer, based on the total amount of polymer: at least 75% by weight of polyether chains, 1 to 5.2% by weight of urethane groups, and 0.7 to 7% by weight of isocyanurate groups, a cured polymer comprising b) at least 20% by weight of at least one filler, based on the total weight of the plastic It is a polyisocyanurate plastic containing

[0016] In this document, the term "isocyanurate group" refers to a group of the formula [ka] which is available by trimerization of isocyanate groups.

[0017] In this document, the term "isocyanate group" refers to a functional group of formula ---N=C=O.

[0018] In this document, the term "urethane group" refers to a group of the formula [ka] which is available from the reaction of an isocyanate group with a hydroxyl group.

[0019] In this document, dashed lines in formulae represent the bond between a substituent and the associated remainder of the molecule.

[0020] In this document, the content of polyether chains in the cured polymer is calculated from the content of polyether polyols in the cured polymer. All polyether polyols used in the synthesis of the isocyanate-functional polymers cured in polyisocyanurate plastics correspond to the content of polyether chains in the cured polymer with a reasonable degree of accuracy. In other words, the mass of these polyols corresponds to the mass of polyether chains in the cured polymer, thus allowing the calculation of the mass fraction of polyether chains in this cured polymer.

[0021] In this document, the content of urethane groups in the cured polymer is calculated from the content of hydroxyl groups that react with isocyanate groups to form urethane groups in the cured polymer, which gives a molecular weight of 59 g / mol (-NH-CO-O-). The molar content of urethane groups in the cured polymer therefore corresponds exactly to the molar content of hydroxyl groups of the polyol used in the synthesis of the isocyanate-functional polymer that is cured in the polyisocyanurate plastic, from which it is possible to calculate the mass fraction of urethane groups in this cured polymer.

[0022] In this document, the content of isocyanurate groups in a cured polymer is calculated from the content of isocyanate groups in the uncured polymer before curing, where it is assumed that all isocyanate groups are converted to isocyanurate groups by trimerization. The content of isocyanurate groups in a cured polymer (expressed as a mass fraction relative to the cured polymer) therefore corresponds exactly to the content of isocyanate groups in the uncured polymer (expressed as a mass fraction relative to the uncured polymer).

[0023] The content of isocyanate groups in the uncured polymer is calculated, or preferably measured, by reaction with a molar excess of dibutylamine and back-titration of the remaining dibutylamine with aqueous hydrochloric acid, where the molecular weight of the isocyanate groups is 42 g / mol (-NCO).

[0024] In this document, the term "NCO content" refers to the content of isocyanate groups in weight percent of a molecule, polymer or composition.

[0025] In this document, a material name beginning with "poly", such as polyol or polyisocyanate, refers to a material that contains two or more of the functional groups that appear in the name.

[0026] In this document, the term "plastic" refers to a synthetic or semi-synthetic material that is based on crosslinked polymers and is solid at room temperature. The term "polyisocyanurate plastic" refers to a plastic based on polymers crosslinked by isocyanurate groups.

[0027] In this document, the term "filler" refers to a powdered or granular solid material, preferably having a particle size of less than 2 mm, preferably less than 0.5 mm, more preferably less than 0.2 mm, especially less than 0.1 mm.

[0028] In this document, the term "shelf-life stability" refers to the ability of a composition to be stored at room temperature in a suitable container, with the exclusion of moisture, for a period of time, particularly several months, without significant changes in application or end-use properties.

[0029] In this document, the term "working life" refers to the period of time during which a multi-component composition can be applied without failure after the components have been mixed.

[0030] In this document, the term "molecular weight" refers to the molar mass (g / mol) of a molecule. The term "average molecular weight" refers to the number average molecular weight (M n ) It is measured by gel permeation chromatography (GPC) against polystyrene as a standard, specifically using tetrahydrofuran as the mobile phase and a refractive index detector.

[0031] In this document, the term "wt. %" or "% by weight" refers to the mass fraction of a component of a composition based on the total composition, unless otherwise specified. The terms "weight" and "mass" are used interchangeably in this document.

[0032] In this document, "room temperature" refers to a temperature of 23°C.

[0033] All industry standards and regulations referred to in this document refer to the editions in effect at the time of original filing unless otherwise specified.

[0034] The content of the polyether chain relative to the total amount of the polymer is preferably 75 to 97% by weight, particularly preferably 80 to 94% by weight.

[0035] Preferably, the polyether chains consist of repeating units selected from oxyethylene, oxy-1,2-propylene, oxy-1,3-propylene, oxy-1,4-butylene, oxy-1,2-butylene and mixtures thereof, and the content of oxyethylene units is less than 20% by weight, preferably less than 10% by weight, in particular less than 5% by weight, based on the total amount of the polyether chains.

[0036] Oxyethylene, oxy-1,2-propylene, oxy-1,3-propylene or oxy-1,4-butylene units are preferred.

[0037] Particularly preferred are polyether chains consisting of oxy-1,2-propylene units end-capped with a certain amount of oxyethylene units, or poly(oxy-1,2-propylene) chains. Such materials are readily available and provide polyisocyanurate plastics with high hydrophobicity, dimensional stability, and hydrolytic stability.

[0038] Preferably, the polyether chain does not contain any oxyethylene units.

[0039] Most preferably, the polyether chain consists of oxy-1,2-propylene units.

[0040] The content of urethane groups relative to the total amount of the polymer is preferably 1.5 to 4% by weight, particularly preferably 1.8 to 3.5% by weight.

[0041] The content of isocyanurate groups relative to the total amount of the polymer is preferably 1 to 6% by weight, more preferably 1.2 to 5% by weight, more preferably 1.4 to 4% by weight, and particularly preferably 1.5 to 3% by weight.

[0042] Preferably, the cured polymer is selected from the group consisting of isomeric diphenylmethane diisocyanates (MDI), isomeric toluene diisocyanates (TDI), naphthalene-1,5-diisocyanate (NDI), 1,5-pentane diisocyanate (PDI), 1,6-hexane diisocyanate (HDI), isophorone diisocyanate (IPDI), isomeric dicyclohexylmethane diisocyanates (HDI), 12 MDI) and mixtures thereof, and the portion after removal of two isocyanate groups.

[0043] These moieties are specifically attached to the urethane and isocyanurate groups of the cured polymer.

[0044] Particularly preferred are MDI, IPDI, HDI or mixtures thereof, especially MDI or IPDI moieties.

[0045] The portion of MDI after removal of the two isocyanate groups is most preferred.

[0046] The MDI is preferably 4,4'-diphenylmethane diisocyanate, which optionally contains a certain amount of 2,4'-diphenylmethane diisocyanate and / or 2,2'-diphenylmethane diisocyanate.

[0047] Preferred cured polymers provide polyisocyanurate plastics with particularly high thermal and hydrolytic stability, particularly low glass transition temperatures, low modulus with high strength and toughness, and / or particularly high dimensional stability associated with low compression set.

[0048] The polyisocyanurate plastic of the present invention preferably contains 2 to 80% by weight of the cured polymer described above, based on the total weight of the plastic.

[0049] The polyisocyanurate plastics of the present invention further contain at least 20% by weight, preferably 20 to 95% by weight, and in particular 30 to 90% by weight, of at least one filler, based on the total weight of the plastic. A filler content of at least 30% by weight is preferred. Such plastics exhibit high damping properties, especially with respect to vibrations and / or noise, and high dimensional stability, especially with high elastic recovery after compression at high temperatures.

[0050] Suitable fillers are, in particular, ground or precipitated calcium carbonate (chalk), optionally surface-coated with a fatty acid such as stearic acid, barium sulfate (baryte), slate, silicates (quartz), magnesium silicate (talc), aluminum silicate (clay, kaolin), dolomite, mica, glass microspheres, silicic acid, in particular highly dispersed silicic acid derived from pyrogenic processes (fumed silica), carbon black, graphite, microspheres, pigments, in particular titanium dioxide or iron oxide, calcium oxide, calcium hydroxide, aluminum oxide, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, magnesium hydroxide, zinc oxide, antimony trioxide, antimony pentoxide, boric acid, zinc borate, zinc phosphate, melamine borate, melamine cyanurate, ethylenediamine phosphate, ammonium polyphosphate, dimelamine orthophosphate, dimelamine pyrophosphate, hexabromocyclododecane, decabromodiphenyl oxide or tris(bromoneopentyl)phosphate.

[0051] The filler is preferably selected from the group consisting of calcium carbonate, barium sulfate, slate, silicate, magnesium silicate, aluminum silicate, dolomite, mica, fumed silica, carbon black, graphite, titanium dioxide, calcium oxide, calcium hydroxide, aluminum oxide, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, magnesium hydroxide, zinc oxide, and mixtures of any of these fillers.

[0052] The polyisocyanurate plastics may contain further compounding ingredients, in particular: plasticizers, in particular phthalates, in particular diisononyl phthalate (DINP) or diisodecyl phthalate (DIDP), hydrogenated phthalates, in particular hydrogenated DINP (which is diisononyl-1,2-cyclohexanedicarboxylate (DINCH)), terephthalates, in particular bis(2-ethylhexyl) terephthalate (DEHT) or diisononyl terephthalate (DINT), hydrogenated terephthalates, in particular bis(2-ethylhexyl)-1,4-cyclohexanedicarboxylate, trimellitates, adipates, in particular dioctyl adipate (DOA), a gelates, sebacates, citrates, benzoates, glycol ethers, glycol esters such as triethylene glycol bis(2-ethylhexanoate), polyether mono- or polyols whose hydroxyl groups are blocked, in particular in the form of acetate groups, organic sulfonates or phosphates, in particular diphenylcresyl phosphate (DPK) or tris(2-ethylhexyl)phosphate (TOP), polybutenes, polyisobutenes or plasticizers obtainable from natural fats and oils, such as epoxidized soybean oil or linseed oil; fibres, in particular glass fibres, carbon fibres, metal fibres, ceramic fibres, plastic fibres, in particular polyamide fibres or polyethylene fibres, or natural fibres such as wool, cellulose, hemp or sisal; nanofillers such as graphene or carbon nanotubes; -pigments and / or dyes; UV or heat stabilizers or antioxidants.

[0053] Preferred plasticizers are glycol esters such as triethylene glycol bis(2-ethylhexanoate), phosphates such as diphenyl cresyl phosphate or tris(2-ethylhexyl) phosphate, or conventional plasticizers for polyurethanes such as DINP, DIDP, DINCH, DEHT, DINT or DOA.

[0054] In a preferred embodiment of the present invention, the amount of filler relative to the total amount of plastic is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, and in particular at least 80% by weight, where the polyisocyanurate plastic optionally further contains at least one plasticizer. Preferred fillers for such high loadings are inorganic fillers with an average particle size of more than 1 μm.

[0055] The average particle size of the filler is preferably determined by laser diffraction analysis according to ISO 13320:2009, for example measured on a CILAS 920 particle size analyzer (Cilas) or a Malvern Mastersizer 3000 (Malvern).

[0056] Particularly preferred such highly loaded polyisocyanurate plastics contain at least one filler selected from graphite, aluminum oxide, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, magnesium hydroxide, zinc oxide, and mixtures of any of these fillers, with aluminum oxide, aluminum hydroxide, or magnesium dihydroxide being preferred.

[0057] Such polyisocyanurate plastics have particularly high thermal conductivity, making them particularly suitable for use as gap fillers and / or sealants with high thermal conductivity that come into contact with electronic components or devices, particularly batteries in electric vehicles. These polyisocyanurate plastics can be used, in particular, to directly cover, seal, or bond batteries, or to fill gaps therein. The rubber-like properties, along with good dimensional stability associated with low compression set, provide the durability of the plastic with vibration damping properties, protecting the battery and dissipating heat generated by the battery during charging or high loads. This improves the functionality and service life of the battery.

[0058] Particularly preferred polyisocyanate plastics contain, based on the total amount of plastics: 2 to 10% by weight, preferably 2.5 to 5% by weight, of a curing polymer, 70 to 95% by weight of fillers selected from graphite, aluminum oxide, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, magnesium hydroxide and zinc oxide, and 0 to 30% by weight, preferably 5 to 20% by weight, of plasticizers Contains:

[0059] Such plastics have particularly high thermal conductivity.

[0060] In a further preferred embodiment of the present invention, the polyisocyanurate plastic contains at least 10% by weight of fillers with an average particle size of less than 1 μm, based on the total weight of the plastic. Such fillers with small particle sizes have a large surface area, and therefore require a large amount of fluid to wet the fillers. This means that a small loading by weight corresponds to a fairly high loading by volume. Preferred fillers with such small particle sizes are carbon black or fumed silica.

[0061] Particularly preferred are polyisocyanurate plastics containing at least 20% by weight, preferably at least 30% by weight, of carbon black, based on the total weight of the plastic. Such plastics are particularly suitable for use as impact-absorbing plastics. They have particularly high strength and toughness and are particularly suitable for housing steel springs in vehicle shock absorbers. This provides durable impact-absorbing properties and high dimensional stability after compression over a wide temperature range.

[0062] Further particularly preferred polyisocyanate plastics contain, based on the total amount of plastics: 40 to 80% by weight, preferably 50 to 70% by weight, of a cured polymer, 20 to 50% by weight, preferably 30 to 50% by weight, of carbon black, and 0 to 40% by weight, preferably 0 to 20% by weight, of plasticizers Contains:

[0063] Such polyisocyanate plastics have particularly high impact-absorbing properties.

[0064] The polyisocyanate plastics of the present invention are solid materials with elastic, rubber-like properties. They may be coatings, adhesives, sealants, or moldings that contain or consist of the polyisocyanate plastics of the present invention. They are preferably used in large layer thicknesses.

[0065] Preferably, the layer thickness of the polyisocyanate plastic of the present invention is at least 1 mm, preferably at least 2 mm, more preferably at least 4 mm, in particular at least 5 mm, where "layer thickness" means the smallest dimensions of length, width and height of the polyisocyanurate plastic.

[0066] Such plastics have high dimensional stability associated with low compression set and are capable of effectively damping vibrations and other mechanical deformations.

[0067] The polyisocyanate plastics of the present invention have particularly high dimensional stability with low compression set, preferably with a deformation after compression at 70°C of less than 50%, preferably less than 40%, in particular less than 30%, as measured for cylindrical samples 13 mm in diameter and 6 mm in height by compressing the sample by 25% to a height of 4.5 mm at 70°C for 94 hours, followed by cooling the compressed sample to room temperature, releasing the pressure, and measuring the loss in height in % based on a compression height of 1.5 mm.

[0068] The polyisocyanurate plastics of the present invention further have particularly low glass transition temperatures, preferably below -40°C, in particular below -45°C, measured by DMTA on elongated samples (2.5 mm wide, 8.5 mm long, 2 mm thick) in shear mode at an excitation frequency of 1 Hz and a heating rate of 5 K / min, where the glass transition temperature corresponds to the temperature at which the loss modulus is maximum.

[0069] A further subject of the present invention is a process for obtaining the polyisocyanurate plastics of the invention, comprising: i) a composition comprising: at least one isocyanate-functional polymer containing at least 75% by weight of polyether chains, 1 to 5.2% by weight of urethane groups and 0.7 to 4% by weight of isocyanate groups, based on the total weight of the polymer; and at least 20% by weight, relative to the total weight of the composition, of at least one filler; providing a composition comprising: ii) adding at least one catalyst for the trimerization of isocyanate groups; iii) curing the composition by trimerization of the isocyanate groups, preferably at a temperature of from 5 to 100°C, more preferably from 10 to 90°C, especially from 15 to 80°C. It is a process including:

[0070] The composition provided in step i) contains at least one isocyanate-functional polymer having at least 75% by weight of polyether chains, 1 to 5.2% by weight of urethane groups and 0.7 to 4% by weight of isocyanate groups.

[0071] The isocyanate-functional polymer is preferably liquid at room temperature. It preferably has a low viscosity, preferably 1 to 200 Pa·s, preferably 1 to 100 Pa·s, more preferably 2 to 50 Pa·s, especially 3 to 25 Pa·s, which can be measured at 20°C using a cone-plate rheometer with a 25 mm cone diameter, a 1° cone angle, a 0.05 mm cone-plate distance, and a 10 s-1 It is measured at a shear rate of .

[0072] The content and nature of the polyether chains of the isocyanate-functional polymer preferably correspond to those described and preferred for the cured polymers contained in the polyisocyanurate plastics of the present invention.

[0073] The content and nature of urethane groups of the isocyanate-functional polymer preferably corresponds to that described and preferred for the cured polymers contained in the polyisocyanurate plastics of the present invention.

[0074] The content of isocyanate groups in the isocyanate-functional polymer relative to the total amount of polymer is preferably 1 to 3.5% by weight, particularly 1.5 to 3% by weight.

[0075] The isocyanate-functional polymer preferably has an average molecular weight M of 2,000 to 15,000 g / mol, in particular 3,000 to 10,000 g / mol. n It has.

[0076] The isocyanate-functional polymer preferably results from the reaction of at least one monomeric diisocyanate and at least one polyether polyol.

[0077] Suitable monomeric diisocyanates are, in particular, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, naphthalene-1,5-diisocyanate, 3,3'-dimethyl-4,4'-diisocyanatodiphenyl, 1,4-butane diisocyanate, 1,5-pentane diisocyanate, 2-methyl-1,5-pentane diisocyanate, 1,6-hexane diisocyanate, 2,2(4),4-trimethyl-1,6-hexane diisocyanate, 1 ,10-decane diisocyanate, 1,12-dodecane diisocyanate, cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1-methyl-2,4-diisocyanatocyclohexane, 1-methyl-2,6-diisocyanatocyclohexane, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, m-xylylene diisocyanate, p-xylylene diisocyanate or 3,6-bis-(9-isocyanatononyl)-4,5-di(1-heptenyl)cyclohexene (dimeryl diisocyanate).

[0078] Isomers of diphenylmethane diisocyanates (MDI), isomers of toluene diisocyanates (TDI), naphthalene-1,5-diisocyanate (NDI), 1,5-pentane diisocyanate (PDI), 1,6-hexane diisocyanate (HDI), isophorone diisocyanate (IPDI) or isomers of dicyclohexylmethane diisocyanates (H 12 MDI) and mixtures thereof are preferred, with MDI, HDI or IPDI being particularly preferred, and MDI or IPDI being particularly preferred.

[0079] MDI is most preferred, preferably 4,4'-diphenylmethane diisocyanate, optionally containing some 2,4'-diphenylmethane diisocyanate and / or 2,2'-diphenylmethane diisocyanate.

[0080] Suitable polyether polyols are in particular polyether polyols having repeating units selected from oxyethylene, oxy-1,2-propylene, oxy-1,3-propylene, oxy-1,4-butylene, oxy-1,2-butylene and mixtures thereof, in which the content of oxyethylene units is less than 20% by weight, preferably less than 10% by weight, in particular less than 5% by weight, based on the total amount of polyol.

[0081] Poly(oxy-1,2-propylene) diol or poly(oxy-1,2-propylene) triol initiated with trimethylolpropane or glycerin (which are optionally end-capped with some ethylene oxide) is particularly preferred. Poly(oxy-1,2-propylene) diol or triol without oxyethylene units is preferred. Poly(oxy-1,2-propylene) diol is particularly preferred.

[0082] Preferably, the OH value of the polyether polyol is within the range of 10 to 60 mg KOH / g.

[0083] Polyether polyols having an unsaturation content of less than 0.02 meq / g, preferably less than 0.01 meq / g, are preferred.

[0084] Average molecular weight M of 1,800 to 12,000 g / mol, preferably 2,000 to 8,000 g / mol n or a polyether diol having an average molecular weight M of 3,000 to 10,000 g / mol, preferably 4,000 to 8,000 g / mol. n Particularly preferred are polyether triols having the formula: Polyether diols are most preferred.

[0085] The isocyanate-functional polymer is preferably prepared by combining at least one monomeric diisocyanate and at least one polyether polyol in the absence of moisture, at a temperature in the range of 20 to 160°C, preferably 40 to 140°C, optionally in the presence of a suitable catalyst, in an NCO / OH molar ratio of at least 1.3, preferably at least 1.5, more preferably at least 1.8.

[0086] Particularly preferred isocyanate-functional polymers have a monomeric diisocyanate content of less than 0.5 wt.%, preferably less than 0.3 wt.%, more preferably less than 0.2 wt.%, and most preferably less than 0.1 wt.%, based on the total weight of the polymer. Such low monomeric isocyanate-functional polymers provide curable compositions that have a monomeric diisocyanate content of less than 0.1 wt.%, can be used safely without special protective measures, and do not require hazardous material labeling.

[0087] For such polymers, the reaction is preferably carried out at an NCO / OH molar ratio of at least 3 / 1, preferably from 3 / 1 to 10 / 1, in particular from 3 / 1 to 8 / 1, followed by removal of most of the remaining monomeric diisocyanate by a distillation process, preferably thin film distillation or short path distillation under reduced pressure.

[0088] Another possible way to obtain isocyanate-functional polymers with a low content of monomeric diisocyanates is to chemically reduce the content of monomeric diisocyanates, for example by adding small amounts of water, preferably in combination with a surfactant.

[0089] The composition provided in step i) further contains at least 20 wt.% of at least one filler, the nature of the filler preferably corresponding to that described and preferred for the polyisocyanurate plastics of the present invention. Since some additional filler can be added together with the catalyst in step ii), the amount of filler in the composition provided in step i) can be less than the amount in the polyisocyanurate plastics of the present invention.

[0090] In addition to the already mentioned further formulation ingredients optionally contained in the polyisocyanurate plastics of the present invention, the composition of step i) may preferably further contain small amounts of: oligomeric polyisocyanates, such as biurets or isocyanurates or uretdiones or iminooxadiazinediones or allophanates of HDI, isocyanurates of IPDI, isocyanurates of PDI or mixed isocyanurates based on TDI and HDI, preferably isocyanurates of HDI; desiccants, in particular molecular sieves, calcium oxide, highly reactive isocyanates such as p-tosylisocyanate, mono-oxazolidines such as Incozol® 2 (Incorez), or orthoformates (calcium oxide is particularly preferred here); adhesion promoters, in particular 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (meth)acrylosilanes, anhydrosilanes, carbamatosilanes, organic alkoxysilanes such as alkylsilanes or iminosilanes, or oligomers thereof, or titanates; thickeners such as bentonite, castor oil derivatives, hydrogenated castor oil, polyamides, polyamide waxes, polyurethanes, urea compounds, fumed silica, cellulose ethers or hydrophobically modified polyoxyethylene; - organic solvents; Additives such as wetting agents, flow aids, leveling agents, defoamers, antifoaming agents or biocides.

[0091] Preferably, the composition contains at least one desiccant, in particular calcium oxide, which reacts with water to form calcium hydroxide, thereby preventing the reaction of isocyanate groups with water that may be contained in the filler during storage of the composition.

[0092] The composition provided in step i) is prepared by mixing all ingredients under moisture-exclusion conditions to obtain a macroscopically homogeneous fluid or paste, and stored in a moisture-tight container at ambient temperature. Suitable moisture-tight containers are preferably buckets, barrels, pails, bags, sausage packs, cartridges, cans, bottles or tubes. With suitable packaging and storage, the composition exhibits good shelf-life stability.

[0093] In step ii) at least one catalyst for the trimerization of isocyanate groups is added to the composition.

[0094] Suitable trimerization catalysts are typically basic materials that catalyze the trimerization of isocyanate groups at room temperature.

[0095] Suitable catalysts are, in particular, tertiary amines such as triethylamine, tributylamine, N,N-dimethylpiperazine, or 1,4-diazabicyclo[2.2.2]octane (DABCO), or hydroxyamines such as triethanolamine or dimethylethanolamine. Further suitable catalysts are, in particular, amidines such as 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), or guanidines such as 1,1,3,3-tetramethylguanidine or 1-hexyl-2,3-diisopropylguanidine. Further suitable catalysts are, in particular, phenols containing tertiary amine groups, such as 2,4,6-tris(dimethylaminomethyl)phenol or disodium 2,6-bis(N-methyl-N-carboxymethyl-aminomethyl)-4-nonylphenol. Further suitable catalysts are, in particular, tetraalkylammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, or trimethylhydroxypropylammonium hydroxide. Further suitable catalysts are, in particular, ammonium salts of carboxylates, such as trimethylhydroxypropylammonium formate, trimethylammonium pivalate, or tetraethylammonium acetate. Further suitable catalysts are, in particular, metal salts of carboxylates, such as potassium acetate, potassium 2-ethylhexanoate, potassium neodecanoate, stannous octoate, or sodium benzoate. Further suitable catalysts are, in particular, alkali metal phenolates, such as sodium or potassium phenolate, or alkali metal alcoholates. Further suitable catalysts are, in particular, metal complex compounds of crown ethers, ethers, or carboxylates, such as zirconium tetra-n-butylate or zirconium tetra-2-ethylhexanoate. Further suitable catalysts are, in particular, phosphorus-containing substances, such as trioctylphosphine or tetrabutylphosphonium fluoride.

[0096] Particularly preferred trimerization catalysts are tetraethylammonium hydroxide, trimethyl-2-hydroxypropylammonium formate, trimethylammonium pivalate, potassium 2-ethylhexanoate, potassium neodecanoate, disodium 2,6-bis(N-methyl-N-carboxymethyl-aminomethyl)-4-nonylphenol or tin octoate.

[0097] Catalysts that are solid at room temperature are preferably used as a solution in a suitable liquid, preferably glycol or diethylene glycol, and / or in a plasticizer.

[0098] Suitable trimerization catalysts are commercially available, in particular as DABCO® TMR-2, DABCO® TMR-7, DABCO® TMR-12 or DABCO® TMR-31 (all from Evonik).

[0099] The amount of the trimerization catalyst added relative to the total amount of the obtained polyisocyanurate plastic is preferably 0.01 to 5% by weight, more preferably 0.02 to 3% by weight, and particularly preferably 0.05 to 1% by weight.

[0100] The catalyst can be added in pure form or in a concentrated solution containing 20 to 80% by weight of catalyst. However, due to the low amount of catalyst relative to the composition provided in step i), it is preferred to add the catalyst in highly diluted form to achieve a mixture ratio in parts by weight between the composition and the diluted catalyst in the range of 10:1 to 1:1. Such highly diluted catalyst preferably contains a plasticizer and, optionally, a filler.

[0101] In a preferred embodiment of the process, the composition in step i) is called the "isocyanate component" and the catalyst added in step ii) is added in diluted form as the so-called "catalyst component".

[0102] Preferred catalyst components contain a plasticizer and, optionally, a filler, where the same fillers and plasticizers that are part of the isocyanate component are preferred.

[0103] Preferably, the isocyanate component and catalyst component are packaged separately, each stored in a moisture-tight container with good shelf-life stability, and then mixed together in step ii) of the process.

[0104] The catalyst in step ii) can be added by any possible mixing technique.

[0105] Preferably, the addition of the catalyst in step ii) is carried out by static or dynamic mixing. Preferably, the catalyst is added in diluted form, in particular as part of a catalyst component which further contains a plasticizer and optionally a filler.

[0106] Step ii) is preferably carried out at ambient temperature, preferably between 5 and 40°C, more preferably between 10 and 35°C, especially between 15 and 30°C.

[0107] Upon mixing, the trimerization catalyst contacts the isocyanate-functional polymer, thereby initiating curing by trimerization of the isocyanate groups in step iii).

[0108] The curing in step iii) can be carried out at ambient temperature or at elevated temperatures, preferably at temperatures of from 5 to 100°C, more preferably from 10 to 90°C, especially from 15 to 80°C.

[0109] During the curing step iii), the composition mixed with the catalyst is preferably contacted with one or more substrates, preferably moisture-tight substrates, which cover substantially the entire surface of the mixed material, meaning that the surface of the mixed material is preferably not exposed to atmospheric moisture during curing, or is only exposed to a minimal extent.

[0110] During curing, the reaction of the isocyanate groups with water leads to the formation of, for example, urea groups and the release of carbon dioxide, or to the formation of iminooxadiazinedione groups, of the formula [ka] Some side reactions may occur, such as the formation of asymmetric trimers with functional groups.

[0111] The use of a suitable catalyst in a suitable amount and a hydrophobic isocyanate-functional polymer with a low or no content of ethyleneoxy units in the polyether chain ensures the formation of predominantly isocyanurate groups upon curing. Preferably, at least 90% of the isocyanate groups present in the composition of step i) are converted to isocyanurate groups upon curing.

[0112] Another subject of the present invention is the use of the polyisocyanurate plastics described above as gap fillers, especially gap fillers with high thermal conductivity, or as shock absorbers, vibration or noise damping materials, coatings, adhesives, or sealing materials. For these uses, the elastic, rubber-like properties and high dimensional stability associated with low compression set of the polyisocyanurate plastics of the present invention are of great advantage, as are their easy application, high tolerance to mixing errors, and the fact that they do not require moisture for curing and do not release substances such as carbon dioxide, ethanol, or methanol during curing.

[0113] For these uses, the mixed composition from step ii) of the process described above is preferably brought into the desired location and shape where it is intended to harden while still workable, i.e., within the working life of the mixed composition. This process is called application.

[0114] The mixed composition is preferably applied by injection into a mold, or into a space or gap in the case of a gap filler, or by placing it on a substrate or between two or more substrates in the case of a coating, sealant or adhesive.

[0115] Particularly preferred application is from a cartridge, preferably a dual cartridge, via a static mixer, or from a combined mixing and pumping device incorporating a static or dynamic mixer.

[0116] Another particularly preferred application is by simply pouring the mixed composition into a mold or cavity and allowing it to fill the voids to the desired extent.

[0117] A particularly preferred use is as a gap filler and / or sealant with high thermal conductivity that contacts electronic components or devices, particularly batteries in electric vehicles. Such polyisocyanurate plastics can directly cover, seal, or bond batteries, or fill gaps therein. The rubber-like properties, along with high dimensional stability associated with low compression set, provide the durability of the plastic with vibration damping properties, protecting the battery and allowing the dissipation of heat generated by the battery during charging or high load. This improves the function and service life of the battery.

[0118] A further preferred use of some embodiments of the plastics of the present invention in this regard is as an elastic adhesive, particularly in bonding battery boxes, such as for bonding battery box lids, where the unique properties of the polyisocyanurate plastics of the present invention, including elastic recovery and thermal and oxidative stability, provide useful technical advantages.

[0119] A particularly preferred use is as an impact-absorbing plastic, particularly for housing steel springs in vehicle shock absorbers, which provides durable impact-absorbing properties without embrittlement due to oxidation in air, and high dimensional stability with high elastic recovery after compression over a wide temperature range. [Brief explanation of the drawings]

[0120] [Figure 1] FIG. 1 shows the storage and loss modulus versus temperature curves for Example 2 as measured by the DMTA measurements previously described. DETAILED DESCRIPTION OF THE INVENTION

[0121] The following examples illustrate the invention without limiting it.

[0122] "Standard climatic conditions" means a temperature of 23±1°C and an atmospheric relative humidity of 50±5%, abbreviated as "SCC".

[0123] Chemicals not otherwise specified were from Sigma-Aldrich Chemie GmbH and were used as received.

[0124] Preparation of isocyanate-functional polymers The NCO content was determined by reaction with a molar excess of dibutylamine and back-titration of the remaining dibutylamine with aqueous hydrochloric acid.

[0125] The viscosity was measured using a thermostatic cone-plate viscometer Rheotec RC30 (cone diameter 50 mm, cone angle 1°, cone-plate distance 0.05 mm, shear rate 10 s -1 ) was measured.

[0126] The content of monomeric diisocyanates was determined by HPLC (light-emitting diode array detection; 0.04 M sodium acetate / acetonitrile mobile phase) after derivatization with N-propyl-4-nitrobenzylamine.

[0127] Substances used Desmophen® 5031 BT ethylene oxide-endcapped polyoxypropylene triol, OH value 28 mg KOH / g (Covestro) Acclaim® 4200 polyoxypropylene diol, OH value 28 mg KOH / g (manufactured by Covestro) Voranol® CP 4755 ethylene oxide-endcapped polyoxypropylene triol, OH value 35.0 mg KOH / g (Dow) Voranol® 1010 L polyoxypropylene diol, OH value 112 mg KOH / g (Dow) MDI 4,4'-diphenylmethane diisocyanate (Desmodur® 44 MC L, manufactured by Covestro) IPDI isophorone diisocyanate (Vestanat® IPDI, manufactured by Evonik)

[0128] Polymer P1 725.0 g of Desmophen® 5031 BT and 275 g of MDI were reacted at 80°C according to known procedures to form a mixture with an NCO content of 7.6 wt. %. The majority of the volatile constituents, especially the monomeric MDI, were then removed from the mixture by distillation in a short-path evaporator (jacket temperature 180°C, 0.1-0.005 mbar), resulting in a polymer with an NCO content of 1.7 wt. %, a viscosity of 19 Pa·s at 20°C, and a content of monomeric MDI of 0.04 wt. %.

[0129] Polymer P2 1,300 g of Acclaim® 4200, 2,600 g of Voranol® CP 4755, 600 g of MDI, and 500 g of diisodecyl phthalate (plasticizer) were reacted at 80°C according to known procedures to obtain a polymer with an NCO content of 2.1% by weight, a viscosity of 57 Pa·s at 20°C, and a content of monomeric MDI of approximately 2.2% by weight.

[0130] Polymer P3 727 g of Acclaim® 4200 and 273 g of MDI were reacted at 80°C according to known procedures to form a mixture with an NCO content of 7.6 wt. %. The majority of the volatile constituents, especially the monomeric MDI, were then removed from the mixture by distillation in a short-path evaporator (jacket temperature 180°C, 0.1-0.005 mbar), resulting in a polymer with an NCO content of 1.7 wt. %, a viscosity of 15 Pa·s at 20°C, and a content of monomeric MDI of 0.08 wt. %.

[0131] Polymer P4 400 g of Acclaim® 4200 and 52 g of MDI were reacted at 80°C according to known procedures, resulting in a polymer with an NCO content of 1.8 wt. %, a viscosity of 32 Pa·s at 20°C, and a content of monomeric MDI of approximately 2.3 wt. %.

[0132] Polymer P5 780 g of Desmophen® 5031 BT and 303 g of IPDI were reacted at 80°C according to known procedures to form a mixture with an NCO content of 9.1 wt. %. The majority of the volatile constituents, especially the monomeric IPDI, were then removed from the mixture by distillation in a short-path evaporator (jacket temperature 160°C, 0.1-0.005 mbar), resulting in a polymer with an NCO content of 1.8 wt. %, a viscosity of 8.2 Pa·s at 20°C, and a content of monomeric IPDI of 0.02 wt. %.

[0133] Polymer P6 590 g of Acclaim® 4200, 1180 g of Voranol® CP 4755 and 230 g of IPDI were reacted at 80°C according to known procedures, resulting in a polymer with an NCO content of 2.1% by weight, a viscosity of 22 Pa·s at 20°C and a content of monomeric IPDI of about 1.8% by weight.

[0134] Polymer P7 600 g of Voranol® 1010 L and 533.3 g of IPDI were reacted at 80°C according to known procedures to form a mixture with an NCO content of 15.6 wt. %. The majority of the volatile constituents, especially the monomeric IPDI, were then removed from the mixture by distillation in a short-path evaporator (jacket temperature 160°C, 0.1-0.005 mbar), resulting in a polymer with an NCO content of 5.2 wt. %, a viscosity of 21.8 Pa·s at 20°C, and a content of monomeric IPDI of 0.03 wt. %.

[0135] [Table 1]

[0136] Preparation of cured polymers crosslinked with isocyanurate groups Catalyst used TMR-2 DABCO® TMR-2 (Evonik) containing trimethyl-2-hydroxypropylammonium formate TMR-7 DABCO® TMR-7 (Evonik) containing trimethylammonium pivalate TMR-12 DABCO® TMR-12 (Evonik) containing potassium 2-ethylhexanoate and trimethylammonium pivalate TMR-31 DABCO® TMR-31 (Evonik) containing disodium 2,6-bis(N-methyl-N-carboxymethyl-aminomethyl)-4-nonylphenol TOP Trioctylphosphine 97% (Sigma Aldrich)

[0137] Compositions C-1~C-10 For each composition, 100 parts by weight of the isocyanate-functional polymer shown in Tables 2-4 was mixed with the catalyst shown in Tables 2-4 in the given amounts (parts by weight) using a centrifugal mixer (SpeedMixer™ DAC 150, FlackTek Inc.) under reduced pressure and moisture exclusion, and then the mixed composition was applied for the tests shown below. For composition C-5 (reference), the isocyanate-functional polymer and HDI-isocyanurate were premixed in the given amounts using a centrifugal mixer, and then the catalyst was added as shown.

[0138] To measure mechanical properties, the compositions were poured into PTFE-coated molds to obtain films with a layer thickness of approximately 2 mm, which were immediately covered with a PTFE-coated metal plate and stored in a standard atmosphere for 7 days. The films were then removed from the molds, and dumbbell-shaped samples with a length of 75 mm, a bridge length of 30 mm, and a bridge width of 4 mm were subsequently punched out of the cured films. The tensile strength, elongation at break, and 5% modulus (modulus of elasticity between 0.5 and 5% elongation) of the thus prepared samples were measured at a crosshead speed of 200 mm / min according to DIN EN 53504. These results are designated "covered cure (RT)." For some compositions, equivalent films were prepared but were not covered with a PTFE-coated metal plate and cured with the surface open for 7 days in a standard atmosphere. These results are designated "open cure (SCC)."

[0139] The Tg values ​​(glass transition temperatures) were measured by DMTA measurements as described in Example 1.

[0140] The cured films of all of these examples were clear, homogeneous, and bubble-free.

[0141] The test results are shown in Tables 2 to 4.

[0142] The reference composition is labeled "(Reference)".

[0143] [Table 2]

[0144] [Table 3]

[0145] [Table 4]

[0146] Compositions of Table 5 For each composition, 10 g of the isocyanate-functional polymer shown in Table 5 was mixed with the catalyst shown in Table 5 in the given amount (% by weight based on the total amount of polymer) using a centrifugal mixer under reduced pressure and with the exclusion of moisture, and then the tack-free time (TFT) was measured.

[0147] For the measurement of TFT release (SCC), the freshly mixed material was applied in a standard atmosphere onto a cardboard sheet in a layer thickness of approximately 5 mm, after which an LDPE pipette was gently touched to the surface from time to time until no polymer residue was left on the pipette upon contact.

[0148] The test results are shown in Table 5.

[0149] [Table 5]

[0150] Examples 1 and 2 (suitable for use as impact absorbing plastics) For each composition, the isocyanate component was prepared by mixing the ingredients shown in Table 6 in the given amounts (parts by weight) using a planetary mixer under reduced pressure and with the exclusion of moisture, and then stored in a moisture-tight container.

[0151] At the time of use, the catalyst components shown in Table 6 were added to the isocyanate component in the given amounts (parts by weight) and mixed under moisture exclusion conditions using a centrifugal mixer (SpeedMixer™ DAC 150, FlackTek Inc.), after which the mixed compositions were applied for the tests shown below.

[0152] After 60 seconds of mixing, the viscosity was measured in a rotation test with a Rheometer MCR 101 from Anton Paar, using plate PP25, with a gap width of 0.2 mm and a speed of 2 rpm at 25°C.

[0153] To measure mechanical properties, the composition was applied between two PTFE-coated foils and compressed by two metal plates into a film approximately 2 mm thick. The film covered with the two metal plates was then cured in an oven at 60°C for 1 hour, followed by 80°C for 23 hours. The metal plates and PTFE-coated foils were then removed from the cured film. The film was then stored in a standard atmosphere for 24 hours, after which dumbbell-shaped samples with a length of 75 mm, a bridge length of 30 mm, and a bridge width of 4 mm were punched out of the cured film. The tensile strength, elongation (at break), and 5% modulus (modulus of elasticity from 0.5 to 5% elongation) of the thus prepared samples were measured according to DIN EN 53504 at a crosshead speed of 200 mm / min. To measure tear propagation, additional specimens were punched from the cured films and tested according to DIN ISO 34-1, method B (square specimens) at a crosshead speed of 500 mm / min. These results are denoted as "Cure 1 h 60°C / 23 h 80°C."

[0154] As an indicator of thermal stability, additional dumbbell-shaped samples were stored in a 100°C oven for 7 days, followed by 24 hours at standard temperature. These samples were then tested for tensile strength, elongation, and 5% modulus as described above. These results are labeled "After 7d storage at 100°C."

[0155] The Shore A hardness was determined according to DIN 53505 using cylindrical samples 20 mm in diameter and 5 mm thick that were covered with a PTFE-coated metal plate and cured in an oven at 60°C for 1 hour, followed by 23 hours at 80°C, and then stored in a standard climate for 24 hours.

[0156] DMTA measurements were performed using an Anton Paar Rheoplus MCR 302 instrument on strip samples (2.5 mm wide, 8.5 mm long, 2 mm thick) cut from the cured films prepared for mechanical property measurements. Measurement conditions were as follows: shear mode, 1 Hz excitation frequency, and 5 K / min heating rate. The samples were cooled to -100°C and heated to 200°C while measuring the storage and loss moduli; the temperature at which the loss modulus was maximum was taken as the Tg value (glass transition temperature).

[0157] In Figure 1, the storage modulus and loss modulus curves for Example 15 are shown versus temperature.

[0158] The dimensional stability after compression at 70 ° C was measured based on DIN ISO 815-1 (measurement of compression set). For this test, several test samples were prepared by applying the composition to a cylindrical mold with a diameter of 13 mm and a height of 6 mm. The surface was covered with a metal lid, and the sample was cured in an oven at 60 ° C for 1 hour, followed by 23 hours at 80 ° C., then removed from the mold and stored in a standard atmosphere for 24 hours. The exact height (thickness) of each cylindrical sample was then measured, and the sample was then compressed to 25% of its height (i.e., to a height that was 75% of its initial height) using a press equipped with two metal plates held together by four screws. The compressed samples were then stored in an oven at 70 ° C for 94 hours. After the sample was cooled to room temperature, the compression was released, and the cylindrical sample was allowed to recover. After waiting 30 minutes under standard conditions, the recovered height was measured and the deformation was calculated in % by dividing the height loss (i.e., initial height minus recovered height) based on the compressed height (i.e., 25% of the initial height).

[0159] To compare the dimensional stability after compression, a carbon black-filled commercial two-component polyurethane adhesive, SikaForce® 803 L45 (manufactured by Sika), having a Shore A hardness of 82, a tensile strength of 10 MPa, an elongation at break of 300% and a Tg of -40°C, was also stored in the form of cylindrical samples with a diameter of 13 mm and a height of 6 mm under standard conditions for 7 days and then cured in an oven at 60°C for 24 hours and again under standard conditions for 24 hours, and then the samples were tested in the same way as described.

[0160] The results are shown in Tables 6 and 7.

[0161] References made to SikaForce® 803 L45 are marked with "(Reference)".

[0162] [Table 6]

[0163] [Table 7]

[0164] Example 3 100 parts by weight of the isocyanate component of Example 2 was mixed in a centrifugal mixer with various amounts of catalyst TMR-2 (parts by weight) as shown in Table 8. For each mixed composition, the pot life was measured by viscosity measurements (viscosity measurements as described in Example 2), where the bottom plate of the rheometer was heated to the temperature shown in Table 8. Measurements continued until the viscosity at the given temperature reached or exceeded 500 Pa s (=end of pot life).

[0165] [Table 8]

[0166] Examples 4 and 5 (suitable for use as thermally conductive gap fillers) For each composition, the isocyanate component was prepared by mixing the formulation components shown in Table 9 in the given amounts (parts by weight) using a centrifugal mixer (SpeedMixer™ DAC 150, FlackTek Inc.) under conditions that excluded moisture, and stored in a moisture-tight container.

[0167] A catalyst component was similarly prepared by mixing the ingredients shown in Table 9 and stored in a moisture-tight container.

[0168] At the time of use, the isocyanate component and catalyst component were mixed in a centrifugal mixer to obtain a homogeneous paste which was immediately tested as follows.

[0169] The Shore A hardness was determined according to DIN 53505 using cylindrical samples with a diameter of 20 mm and a thickness of 6 mm, which were covered with a PTFE-coated foil and a metal lid and cured for 7 days in a standard climate.

[0170] The aspect was determined visually on samples prepared for Shore A measurements by judging the surface and by cutting to expose the interior of the material.

[0171] Thermal conductivity was measured according to ASTM D5470-12 on samples cured for 7 days under standard climatic conditions. A TIM (Thermal Interface Material) testing device using the stationary cylinder method (obtained from Zentrum für Waermemanagement, Stuttgart, Germany) was used for the measurements. The sample dimensions were as follows: diameter 30 mm, thickness 2 mm and 6 mm. The pressure parameters for the measurements were 1, 2, 3, 5, 7 and 10 bar.

[0172] The results are shown in Table 9.

[0173] [Table 9]

Claims

1. A polyisocyanurate plastic comprising: a) a cured polymer, based on the total amount of polymer: at least 75% by weight of polyether chains, - 1 to 5.2% by weight of urethane groups, and - 0.7 to 7% by weight of isocyanurate groups a cured polymer comprising b) at least 20% by weight of at least one filler, based on the total weight of the plastic Polyisocyanurate plastic containing

2. 2. The polyisocyanurate plastic according to claim 1, wherein the content of polyether chains relative to the total amount of the polymer is 75 to 97% by weight, preferably 80 to 94% by weight.

3. 3. Polyisocyanurate plastic according to claim 1 or 2, wherein the polyether chains consist of repeating units selected from oxyethylene, oxy-1,2-propylene, oxy-1,3-propylene, oxy-1,4-butylene, oxy-1,2-butylene and mixtures thereof, and the content of oxyethylene units is less than 20% by weight, preferably less than 10% by weight, in particular less than 5% by weight, based on the total amount of the polyether chains.

4. 4. Polyisocyanurate plastic according to claim 1, wherein the content of isocyanurate groups is 1 to 6% by weight, preferably 1.2 to 5% by weight, more preferably 1.4 to 4% by weight, in particular 1.5 to 3% by weight, based on the total weight of the polymer.

5. The polyisocyanurate plastic according to any one of claims 1 to 4, wherein the cured polymer contains a moiety obtained after removal of two isocyanate groups selected from the group consisting of isomeric diphenylmethane diisocyanates, isomeric toluene diisocyanates, naphthalene-1,5-diisocyanate, 1,5-pentane diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, isomeric dicyclohexylmethane diisocyanates, and mixtures thereof.

6. 6. The polyisocyanurate plastic according to any one of claims 1 to 5, wherein the at least one filler is selected from the group consisting of calcium carbonate, barium sulfate, slate, silicate, magnesium silicate, aluminum silicate, dolomite, mica, fumed silica, carbon black, graphite, titanium dioxide, calcium oxide, calcium hydroxide, aluminum oxide, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, magnesium hydroxide, zinc oxide, and mixtures of any of these fillers.

7. 7. Polyisocyanurate plastic according to any one of claims 1 to 6, wherein the amount of filler relative to the total amount of plastic is at least 50% by weight, preferably at least 60% by weight, more preferably at least 70% by weight, in particular at least 80% by weight, and the polyisocyanurate plastic optionally further comprises at least one plasticizer.

8. 8. The polyisocyanurate plastic of claim 7, wherein the polyisocyanurate plastic contains at least one filler selected from graphite, aluminum oxide, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, magnesium hydroxide, zinc oxide, and mixtures of any of these fillers.

9. For all plastics, - 2 to 10% by weight of said cured polymer, - 70 to 95% by weight of fillers selected from graphite, aluminum oxide, aluminum hydroxide, boron nitride, aluminum nitride, magnesium oxide, magnesium hydroxide and zinc oxide, and - 0 to 30% by weight of plasticizer The polyisocyanurate plastic according to any one of claims 1 to 8, comprising:

10. 7. The polyisocyanurate plastic according to claim 1, wherein the polyisocyanurate plastic contains at least 10% by weight, based on the total weight of the plastic, of a filler having an average particle size of less than 1 μm, preferably carbon black or fumed silica, in particular at least 20% by weight, preferably at least 30% by weight, of carbon black, the average particle size being determined by laser diffraction analysis according to ISO 13320:2009, e.g. with a CILAS 920 particle size analyzer or a Malvern Mastersizer 3000.

11. For all plastics, - 40 to 80% by weight of said cured polymer, - 20 to 50% by weight of carbon black, and - 0 to 40% by weight of plasticizer The polyisocyanurate plastic according to claim 10, comprising:

12. 12. Polyisocyanurate plastics according to any one of claims 1 to 11, wherein the deformation of the polyisocyanurate plastic after compression at 70°C is less than 50%, preferably less than 40%, in particular less than 30%, as measured for a cylindrical sample of 13 mm diameter and 6 mm height by compressing the sample by 25% to a height of 4.5 mm at 70°C for 94 hours, followed by cooling the compressed sample to room temperature, releasing the pressure and measuring the loss in height in % based on a compression height of 1.5 mm.

13. A process for obtaining the polyisocyanurate plastics according to any one of claims 1 to 12, comprising: i) a composition comprising: at least one isocyanate-functional polymer containing at least 75% by weight of polyether chains, 1 to 5.2% by weight of urethane groups and 0.7 to 4% by weight of isocyanate groups, based on the total weight of the polymer; and - at least 20% by weight, relative to the total weight of the composition, of at least one filler; providing a composition comprising: ii) adding at least one catalyst for the trimerization of said isocyanate groups; iii) curing the composition by trimerization of the isocyanate groups, preferably at a temperature of from 5 to 100°C, more preferably from 10 to 90°C, especially from 15 to 80°C; The process includes:

14. 14. The process of claim 13, wherein the addition of the at least one catalyst in step ii) is carried out by static or dynamic mixing.

15. 13. Use of the polyisocyanurate plastics according to any one of claims 1 to 12 as gap fillers, in particular as gap fillers with high thermal conductivity, or as shock absorbers, vibration or noise damping materials, as coatings, as adhesives or as sealing materials.

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