Patent Application
20240059891
Priority is claimed of European patent application no. 20 212 438.4 that was filed on Dec. 8, 2020.
The invention relates to a curable one-component composition comprising (i) humidity-curable prepolymer, preferably silyl-modified prepolymer; (ii) optionally, highly structured carbon black; (iii) optionally, fumed silica; (iv) optionally, polycarbonate, preferably polycarbonate diol; (v) optionally, plasticizer, preferably SAN-grafted polyol; (vi) optionally, silane compatibilizer; and (vii) optionally, curing catalyst, with the proviso that the composition comprises (ii), or (iii), or both (ii) and (iii). The composition is useful inter alia for bonding glass into vehicles and buildings
Adhesive or sealant compositions are used for fenestration, i.e. to affix windows into buildings and vehicles. In this regard, reference is made to e.g. U.S. Pat. Nos. 4,780,520, 5,976,305, 5,922,809, 6,015,475, 6,709,539, 7,226,523, 6,512, 7,101,950, 7,361,292, 6,657,035, CA 2,564,992, and WO 2010 074768A1.
Nowadays, adhesive or sealant compositions need to satisfy certain performance properties such as high strength paired with high elongation, but also durable adhesion under various climate conditions. Climate cycle tests have been developed by original equipment manufacturers (OEM) involving sample testing under harsh conditions such as 70° C. cataplasm with freezing step. Modern adhesive or sealant compositions need to pass such tests.
Conventional adhesive or sealant compositions are often based upon polyurethanes containing reactive isocyanate groups such as toluene diisocyanate (TDI), methylene bisphenyl diisocyanate (MDI), hexamethylene diisocyanate (HDI), naphthalene diisocyanate (NDI), and diisocyanate dicyclohexyl urethane. Such isocyanate products are hazardous as they are powerful irritants to the mucous membranes of the eyes, gastrointestinal and respiratory tracts. Health effects of isocyanate exposure include irritation of skin and mucous membranes, chest tightness, and difficult breathing. Isocyanates include compounds classified as potential human carcinogens and known to cause cancer in animals. The main effects of hazardous exposures are occupational asthma and other lung problems, as well as irritation of the eyes, nose, throat, and skin.
Further, conventional adhesive or sealant compositions often contain phthalates as plasticizers. Phthalate plasticizers are not chemically bound in the cured adhesive compositions, but can leach, migrate or evaporate into indoor air. Building materials such as vinyl flooring and other consumer products containing phthalates can result in human exposure through direct contact and use, indirectly through leaching into other products, or general environmental contamination. Humans are exposed through ingestion, inhalation, and dermal exposure during their whole lifetime. Many phthalates are hormone-disrupting chemicals that interfere with the production of testosterone. Prenatal exposure to certain phthalates causes common adverse effects on male reproductive development in animals, causing what is known as “phthalate syndrome”, which has many similarities to “testicular dysgenesis syndrome” in humans.
US 2019 0048190 A1 relates to moisture curing alkoxysilyl-functional polymer compositions containing a high phenyl-content silicone resin and carbon black.
WO 2017 189057 A1 relates to moisture-curable, one component adhesives contain an isocyanate-terminated prepolymer, a low molecular weight polyisocyanate compound, a hydrolysable mercaptosilane, a urethane catalyst and a carbon black filler.
WO 2014 073593 A1 relates to a curable composition which contains (A) a branched polyoxyalkylene polymer having a reactive silicon group, (C) calcium carbonate and (D) carbon black.
US 2018 0134932 A1 relates to an one part moisture curable composition comprised of an isocyanate functional prepolymer, a cyclic silane, a filler and a catalyst.
WO 2017 142714 A1 relates to compositions containing isocyanate functional prepolymers, quaternary ammonium modified nanoclays and thixotropic fillers; adhesives based on such compositions; and methods for bonding substrates together utilizing the compositions.
US 2019 0233335 A1 relates to a porous inorganic additive manufactured article that is comprised of at least two layers of inorganic particulates bound together by a carbon binding phase throughout.
There is thus a demand for adhesive or sealant compositions that neither contain isocyanates nor phthalates. While certain adhesive compositions based upon silicone polymers, e.g. polysiloxanes, are also well known sealants, durable elastic adhesive compositions that achieve equal performance like compositions based upon polyurethane prepolymers have not been available for decades.
Still further, conventional adhesive or sealant compositions often rely upon dual-curing systems and thus require post-curing in an oven. It would be desirable, however, to provide adhesive or sealant compositions that completely cure at the initial curing step such that upon subsequent storage for 42 days (1000 hours) at 80° C. no post-curing can be observed and original strength is retained.
Furthermore, conventional adhesive or sealant compositions often require a pretreatment of substrate surfaces before the compositions may be applied thereto in order to provide satisfactory bonding. Such pretreatment, however, is time-consuming and laborious and there is a demand for adhesive or sealant compositions that do not require such pretreatment but nonetheless provide excellent adherence to surfaces of various materials including glass, plastics and metals.
Moreover, after a certain while of use or e.g. after an accident, the adhesive bonds or sealings need to be repaired are renewed. However, conventional adhesive or sealant compositions are often difficult the be removed or repaired, especially when they are bonded to polyurethane substrates. It would thus be desirable to provide adhesive or sealant compositions that facilitate renewal and repair.
What is thus needed are adhesive or sealant compositions that are useful for bonding glass and other substrates into a structure which may be formulated to exhibit a variety of high performance properties such as durable adhesion satisfying climate cycle testing including 70° C. cataplasm with freezing step, high strength paired with high elongation, and that show no post-cure after storage for 42 days at 80° C. Further, there is a need for adhesive or sealant compositions that are ready to use and do not require pretreatment of substrate surfaces such as glass surfaces, and that provide repairability on polyurethane substrates.
It is an object of the invention to provide adhesive or sealant compositions that overcome the drawbacks of the prior art and that satisfy one or more of the above needs.
This object has been achieved by the subject-matter of the patent claims.
It has been surprisingly found that humidity-curable prepolymers, preferably silyl-modified prepolymers, in combination with highly structured carbon black provide advantageous adhesive or sealant compositions. The use of silyl-modified prepolymers, preferably in combination with silane compatibilizers, achieves robust primerless adhesion to glass surfaces, i.e. does not require pretreatment. Various silyl-modified prepolymers such as polyols are commercially available and have well defined molecular weight distribution and polymer polarity. It has been found that the properties of the one-component curable compositions according to the invention can be tailored to the specific needs by selecting the proper silyl-modified polymers, preferably polyols, or combinations thereof.
Further, it has been surprisingly found that compared to other types of carbon black, the use of highly structured carbon black according to the invention also contributes to primerless adhesion to glass substrates and other substrates, and additionally provides high strength at high elongation as well as excellent climate durability.
Still further, it has been surprisingly found that the combination of silyl-modified polymers with highly structured carbon black achieves reduced post-cure effects at elevated temperatures (e.g. at 100° C.). Thus, increased brittleness upon storage at elevated temperatures, which is typically observed with polyurethanes, can be suppressed with the compositions according to the invention.
Yet further, it has been surprisingly found that polycarbonate diols, i.e. polycarbonates having terminal hydroxyl groups, provide a quick fixation after heating and recrystallizing as they can be liquids and crystalline solids. Further, it has been surprisingly found that utilization of polycarbonates having various melting points allows for adjusting rheology like shear thinning, sag resistance, recovery and tailing for improved application properties in mass application environment requiring short handling times. It has been surprisingly found that polycarbonates, especially polycarbonate diols, further enhance multi-substrate adhesion, durability and high strength performance.
Furthermore, it has been surprisingly found that fumed silica, especially certain grades of fumed silica, have a positive effect on multi-substrate adhesion including glass, durability and high strength.
A first aspect of the invention relates to a curable one-component composition comprising the following components:
Another aspect of the invention relates to a curable one-component composition comprising the following components:
Another aspect of the invention relates to a curable one-component composition comprising the following components:
Preferably, the curable one-component composition according to the invention contains highly structured carbon black and/or organically modified fumed silica.
In preferred embodiments, the curable one-component composition according to the invention contains highly structured carbon black. The term “highly structured carbon black” also referred to as HSCB is a terminus technicus well known to the skilled person. The property of this type of carbon black being highly structured is reflected in its capability of absorbing oil. For the purpose of the specification, any carbon black having an oil absorption number (OAN, ASTM D 2414) of at least 115 ml/100 g is to be regarded as highly structured carbon black according to the invention.
For the purpose of the specification, unless expressly stated otherwise, percentages are percent by weight. Unless expressly stated otherwise, any norms such as EN ISO, ASTM and the like are in the official version that is valid on Dec. 1, 2020. The expression “essentially consists of” means a content of at least 95 wt.-%, preferably at least 99 wt.-%, relative to the total weight of the component to which the definition refers.
The composition according to the invention is a one-component composition. Thus, the composition according to the invention is preferably a ready-to use composition that already contains all ingredients that are needed for the desired purpose, except air humidity. In particular, prior to use, the composition according to the invention does preferably not require any addition of further additives nor admixture with other compositions.
The composition according to the invention is curable, i.e. is capable of autonomously undergoing a curing reaction, typically by cross-linking, after proper stimulation, preferably by subjecting the composition to humidity. Typically, the humidity that is contained in the atmosphere is sufficient in order to stimulate, i.e. induce the curing reaction to a partial or full extent. Partial curing or curing (i.e. full curing) may be effected by reacting one or more ingredients that are contained in the composition with one another thereby forming covalent bonds.
Components (iv), (v), (vi) and (vii) of the composition according to the invention are independently of one another optional, whereas component (i) and components (ii) and/or (iii) are mandatory. In preferred embodiments, the composition comprises components (i) and (ii) but not (iii). In other preferred embodiments, the composition comprises components (i) and (iii) but not (ii). In further preferred embodiments, the composition comprises components (i), (ii), and (iii). Besides components (i) through (vii), the composition according to the invention may contain additional ingredients.
In preferred embodiments, the composition according to the invention is an adhesive.
In preferred embodiments, the composition according to the invention is a sealant.
In preferred embodiments, the composition according to the invention is capable of curing spontaneously at 23° C. upon contact with air humidity.
The curable one-component composition according to the invention comprises a humidity-curable prepolymer. The curable one-component composition according to the invention may comprise a single humidity-curable prepolymer or a mixture of two or more humidity-curable prepolymers. In case of the presence of two or more humidity-curable prepolymers, all weights and percentages refer to the total weight of all humidity-curable prepolymers that are contained in the curable one-component composition.
Preferably, the humidity-curable prepolymer comprises or essentially consist of a silyl-modified prepolymer.
For the purpose of the specification, a prepolymer (polymer precursor) is a monomer or system of monomers that have been reacted to an intermediate molecular mass state. This material is capable of further polymerization by reactive groups to a fully cured high molecular weight state. Prepolymers encompass mixtures of reactive polymers with unreacted monomers. The prepolymer is humidity-curable, i.e. upon contact with humidity undergoes spontaneous curing, optionally also involving other ingredients that are contained in the composition such as curing agents.
Humidity-curable prepolymers are known to the skilled person and commercially available.
In preferred embodiments of the curable composition according to the invention, the humiditycurable prepolymer is a silyl-modified prepolymer. As the preferred silyl-modified polymer is a curable prepolymer, it is a reactive prepolymer (reactive silyl-modified prepolymer). Silyl-modified prepolymers (SMP, silane-modified polymers, modified-silane polymers, MS polymers, silane-terminated polymers, etc.) are known to the skilled person and commercially available. For details on silyl-modified prepolymers, it can be referred to e.g. S. M. Guillaume, Advances in the synthesis of silyl-modified polymers (SMPs), Polym. Chem., 2018, 9, 1911-1926; A. Pizzi et al., Handbook of Adhesive Technology, CRC Press, 3rd edition, 2018. Examples of silyl-modified polymers include but are not limited to silyl-modified polyethers and copolyethers, silyl modified polyisobutylenes (SMPIB), silyl-modified polyacrylates and copolyacrylates (SMA) and silyl-modified polyurethanes (SPUR, PUH).
Preferably the silyl-modified prepolymer has a non-silicone backbone, more preferably this silyl-modified prepolymer has a polyether backbone. For example, the silyl modified prepolymer can be dimethoxysilane modified polymer, trimethoxysilane modified polymer, or triethoxysilane modified polymer. For example, the silyl modified prepolymer can be a silyl-modified polyether or copolyether.
Preferred silyl-modified prepolymers according to the invention are selected from
In other preferred embodiments, the silyl-modified prepolymers according to the invention do not comprise ethylenically unsaturated functional groups.
Preferably, the silyl-modified prepolymer comprises a polymeric backbone and one or more hydrolyzable silyl groups.
Preferably, the silyl-modified prepolymer has two ends and is terminated with one or more hydrolyzable silyl groups on one end (semi-telechelic) or on both ends (telechelic); preferably on two ends.
Preferably, the silyl-modified prepolymer has side chains carrying one or more hydrolyzable silyl groups.
Preferably, hydrolysis of at least one of the one or more hydrolyzable silyl groups leads to the formation of a silanol group.
Preferably, the condensation of the silanol group with another silanol group or with a hydrolyzable silyl group leads to the formation of a siloxane group.
In preferred embodiments, the one or more hydrolyzable silyl groups independently of one another are
or
wherein in each case R1, R2, R3, R4, R5 and R6 independently of one another are selected from
In preferred embodiments, R1, R2, R3, R4, R5 and R6 independently of one another represent —CH3, —CH2CH3, —CH2CH2CH3, —CH(CH3)2, —CH2CH2CH2CH3, —CH(CH3)CH2CH3, —CH2CH(CH3)2, —C(CH3)3, —CH2CH2OCH3, —CH2CH2OCH2CH3, —CH2CH2CH2OCH3, —CH2CH2CH2OCH2CH3, —OCH3, —OCH2CH3, —OCH2CH2CH3, —OCH(CH3)2, —OCH2CH2CH2CH3, —OCH(CH3)CH2CH3, —OCH2CH(CH3)2, —OC(CH3)3, —OCH2CH2OCH3, —OCH2CH2OCH2CH3, —OCH2CH2CH2OCH3, or —OCH2CH2CH2OCH2CH3.
Preferably, the one or more hydrolyzable silyl groups independently of one another are selected from the group consisting of monomethoxy silyl groups, monoethoxy silyl groups, dimethoxy silyl groups, diethoxy silyl groups, trimethoxy silyl groups, and triethoxy silyl groups.
Preferably, the one or more hydrolyzable silyl groups are covalently bonded to the polymeric backbone through spacers, wherein the spacers independently of one another are selected from -C1-12alkylene-, -C3-8-cycloalkylene-, -phenyl-, -C1-6-alkylene-phenyl-, -C1-6-alkylene-phenyl-C1-6-alkylene-, —C(═O)C1-6-alkylene-, —S(═O)2C1-6-alkylene-, —NHC(═O)—C1-6-alkylene-, —C(═O)NHC1-6-alkylene-, —NHS(═O)2-C1-6-alkylene-, —S(═O)2NHC1-6-alkylene-, —OC(═O)—C1-6-alkylene-, —C(═O)OC1-6-alkylene-, —OS(═O)2-C1-6-alkylene-, —S(═O)2OC1-6-alkylene-, —OC(═O)NH—C1-6-alkylene-, —NHC(═O)O—C1-6-alkylene-, —OC(═O)O—C1-6-alkylene-, —NHC(═O)NH—C1-6-alkylene-, —O—[Si(CH3)2—O]1-12-, azasilanes, and combinations thereof.
In preferred embodiments, the silyl-modified prepolymer is
Preferably, the humidity-curable prepolymer comprises a polymeric backbone selected from the group consisting of polyethers, copolyethers, polyurethanes, copolyurethanes, polyesters, copolyesters, polyamides, copolyamids, polyolefins, copolyolefins, polystyrenes, copolystyrenes, polyacrylates, copolyacrylates, and mixtures thereof; preferably polyethers or copolyethers.
In preferred embodiments, the polymeric backbone is a linear or branched, aliphatic and/or aromatic polyether comprising ether repetition units.
In preferred embodiments, the polymeric backbone is a linear or branched, aliphatic and/or aromatic copolyether comprising ether repetition units and comonomer repetition units; preferably wherein the comonomer repetition units are selected from urethane repetition units, ester repetition units, amide repetition units, carbonate repetition units, urea repetition units, alkyl repetition units, and mixtures thereof.
In preferred embodiments, the humidity-curable prepolymer is selected from the group consisting of dimethoxy-silyl-terminated polyether or copolyether, trimethoxy-silyl-terminated polyether or copolyether, dimethoxy-silyl-terminated polyether or copolyether in each case reinforced with silicone moieties, trimethoxy-silyl-terminated polyether or copolyether in each case reinforced with silicone moieties, hydrophobically modified dimethoxy-silyl-terminated polyether or copolyether, monofunctional dimethoxy-silyl-terminated polyether or copolyether, and monofunctional trimethoxy-silyl-terminated polyether or copolyether.
The silyl-modified polyether or copolyether can be obtained by reacting a polyether or copolyether with at least one ethylenically unsaturated silane in the presence of a radical starter, the ethylenically unsaturated silane carrying at least one hydrolyzable group on the silicon atom. The ethylenically unsaturated silane is particularly preferably selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, vinyldimethoxymethylsilane, vinyldiethoxymethylsilane, trans-p-methylacrylic acid trimethoxysilylmethyl ester, and trans-b-methylacrylic acid trimethoxysilylpropyl ester.
Silyl-modified prepolymers such as silyl-modified polyether and copolyether are available, for example, as dimethoxysilane modified MS polymer from Kaneka, trimethoxysilane modified ST polymer from Evonik, triethoxysilane modified Tegopac polymer from Evonik, silane modified Desmoseal polymer from Covestro, or silane modified SMP polymer from Henkel.
In preferred embodiments, the humidity-curable prepolymer has a weight average molecular weight (ASTM D5296-19)
In preferred embodiments, the humidity-curable prepolymer has a Brookfield viscosity at 23° C. (ASTM D789, D4878)
In particularly preferred embodiments of the curable one-component composition according to the invention, the weight content of the humidity-curable prepolymer is at most 45 wt.-%.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the humidity-curable prepolymer is
The curable one-component composition according to the invention comprises highly structured carbon black. The curable one-component composition according to the invention may comprise a single kind of highly structured carbon black or a mixture of two or more kinds of highly structured carbon black. In case of the presence of two or more kinds of highly structured carbon black, all weights and percentages refer to the total weight of all kinds of highly structured carbon black that are contained in the curable one-component composition.
Highly structured carbon black (high structure carbon black) has more porous aggregates per unit weight than other kinds of carbon black. In the classification systems used to classify carbon black, highly structured carbon black is typically referred to as “HS” (high structure) as opposed to “LS” (low structure).
In a simplified manner, the carbon black particles can be described as an aggregate of a number of smaller particles, which are referred to as “primary particles.” The carbon black aggregates can be, for example, assemblies of primary carbon black particles that are fused at the contact points and cannot readily be separated by shearing. The size of primary particles in a carbon black particle can vary. The number of primary particles in the aggregate can also vary, for example, from few to tens, or possibly hundreds. The number of primary particles and the arrangement of them in the carbon black aggregate not only dictate the size of the carbon black aggregate but also the structure of the carbon black.
The ASTM D 1765 classification system uses a four-character code for the identification of carbon black grades, composed of one letter and three numbers. The letter refers to the rate of vulcanization of a rubber loaded compound with this type of carbon black; “N” means “normal rate of vulcanization”, “S” means “slow rate of vulcanization”. The first number after the letter is related to the primary particle size, whereas the other two numbers further specify surface area and structure. Representative examples of carbon blacks are classified as follows:
Thus, as indicated by the above table, highly structured (“HS”) carbon black is a terminus technicus well acknowledged in the art. Highly structured variants of carbon black exist for different kinds of carbon black, i.e. different primary particle sizes and different surface areas.
Preferably, the highly structured carbon black comprises or essentially consist of furnace black.
Particularly preferred highly structured carbon black has a iodine number (ASTM D1510) of at least 95 g/kg and an oil absorption number (OAN, ASTM D 2414) of at least 110 ml/100 g, preferably at least 115 ml/100 g.
Preferably, the highly structured carbon black is typified according to ASTM D 1765 as super abrasion resistant furnace black (SAF-HS), intermediate super abrasion resistant furnace black (ISAF-HS), high abrasion resistant furnace black (HAF-HS), general purpose furnace black (GPF-HS), or semi reinforcing furnace black (SRF-HS).
Preferably, the highly structured carbon black is classified according to ASTM D 1765 in a group selected from N110, N115, N120, N121, N125, N134, N135, N219, N220, N231, N234, N293, N299, N326, N330, N335, N339, N343, N347, N351, N356, N358, N375, N539, N550, N582, N630, N642, N650, N660, N683, N754, N762, N765, N772, N774, and N787; preferably N115, N121, N234, N339, N375, N539, N550, N650, and N765.
Carbon black may be classified according to iodine number, CTAB surface area and nitrogen absorption surface area which reflect different surface properties. The iodine number (iodine adsorption) reflects a “not true” surface area, because it is affected by porosity, surface impurities, and surface oxidation. The cetyltrimethyl ammonium bromide (CTAB) surface area analyzes the so-called external surface area which corresponds to the accessible surface area e.g. for an elastomer. The BET (Brunauer, Emmett, and Teller) nitrogen adsorption surface area provides the “total” surface area including porosity.
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has an iodine number (ASTM D1510)
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has a cetytrimethyl ammonium bromide absorption (CTAB number, statistical thickness surface area (STSA), ASTM D 3765)
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has a Brunauer-Emmett-Teller (BET) surface area (nitrogen absorption, nitrogen surface area (NSA), ASTM D 6556)
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has a Brunauer-Emmett-Teller (BET) surface area (nitrogen absorption, nitrogen surface area (NSA), ASTM D 6556) to cetytrimethyl ammonium bromide absorption (CTAB number, statistical thickness surface area (STSA), ASTM D 3765) (BET:STSA ratio) of at least about 1.01, preferably at least about 1.02, more preferably at least about 1.03, still more preferably at least about 1.04, yet more preferably at least about 1.05, even more preferably at least about 1.06, most preferably at least about 1.07, and in particular at least about 1.08.
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has an oil absorption number (OAN, ASTM D 2414)
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has a dibutyl phthalate absorption (24M4-DBP number, dibutyl phthalate absorption (DBA), ASTM D 2414)
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has an average primary particle size (ASTM D 3849-14a)
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has a surface energy (based upon measuring dynamic water vapor sorption, preferably as described in EP 3 544 097 A1)
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has an L a crystallite size (based upon Raman spectroscopy, resonance bands at about 1340 cm−1 (D band) and 1580 cm−1 (G band), preferably as described in EP 3 544 097 A1)
The highly structured carbon black can have a high degree of graphitization, as indicated by a high % crystallinity, which is obtained from Raman measurements as a ratio of the area of the G band and the areas of G and D bands (IG/IG+D). In certain embodiments, the highly structured carbon black particles have % crystallinities (IG IG+D) ranging from 35% to 45%, as determined by Raman spectroscopy. The % crystallinity (IG/IG+D) can have or include, for example, one of the following ranges: from 35% to 43%, or from 35% to 41%, or from 35% to 39%, or from 37% to 45%, or from 37% to 43%, or from 37% to 41%, from 39% to 45%, or from 39% to 43%, or from 41% to 45%.
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has an water content (determined according to Karl Fischer method) of at most about 1000 ppm, preferably at most about 500 ppm, more preferably at most about 100 ppm, still more preferably at most about 50 ppm.
In preferred embodiments of the curable one-component composition according to the invention, the highly structured carbon black has a relatively low oxygen content, which can be indicative of the particles' purity and electrical conductivity properties. In some embodiments, the highly structured carbon black has an oxygen content of less than or equal to about 1.0 wt.-%, or less than or equal to about 0.8 wt.-%, or less than or equal to about 0.6 wt.-%, or less than or equal to about 0.4 wt.-%. The oxygen content can have or include, for example, one of the following ranges: from about 0.01 to 1.0 wt.-%, or from about 0.03 to 1.0 wt.-%, or from about 0.03 to 0.8 wt.-%, or from about 0.03 to 0.6 wt.-% or from about 0.03 to 0.4 wt.-%. The oxygen content can be determined by inert gas fusion in which a sample of carbon black particles are exposed to very high temperatures (e.g., about 3000° C.) under inert gas conditions. The oxygen in the sample reacts with carbon to form CO and CO2, which can be monitored by a non-dispersive infrared technique. The total oxygen content is reported in weight percent relative to the total weight of the sample. Various oxygen analyzers based on the inert gas fusion methods are known in the art and commercially available, for example a LECO® TCH600 analyzer.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the highly structured carbon black is at least about 0.05 wt.-%, preferably at least about 0.1 wt.-%, more preferably at least about 0.15 wt.-%, still more preferably at least about 0.2 wt.-%, yet more preferably at least about 0.25 wt.-%, even more preferably at least about 0.3 wt.-%, most preferably at least about 0.4 wt.-%, and in particular at least about 0.5 wt.-%; in each case relative to the total weight of the curable one-component composition.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the highly structured carbon black is at most 18 wt.-%.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the highly structured carbon black is
The curable one-component composition according to the invention preferably comprises polycarbonate. The curable one-component composition according to the invention may comprise a single polycarbonate or a mixture of two or more polycarbonates. In case of the presence of two or more polycarbonates, all weights and percentages refer to the total weight of all polycarbonates that are contained in the curable one-component composition.
In preferred embodiments, the polycarbonate comprises or essentially consist of a polycarbonate polyol, preferably polycarbonate diol.
Polycarbonate polyols are preferably synthesized from CO2 and epoxides, the CO2 is sequestered in the backbone of a polycarbonate polyol by reaction with an epoxide during synthesis. Many different substituents can be used, to provide a broad range of polycarbonate polyol molecular structures:
The functionality of a polycarbonate polyol can also be chosen as desired, by using any one of many different possible starting molecules X. For example, a diol or diacid as starting molecule X provides a polycarbonate diol, a triol or triacid as starting molecule X provides a polycarbonate triol, and a tetrol or tetraacid as starting molecule X provides a polycarbonate tetrol.
It has been surprisingly found that polycarbonate diols, i.e. polycarbonates derived from difunctional starting molecules X having terminal hydroxyl groups, provide a quick fixation after heating and recrystallizing as they can be liquids and crystalline solids.
Further, it has been surprisingly found that utilization of polycarbonates having various melting points allows for adjusting rheology like shear thinning, sag resistance, recovery and tailing for improved application properties in mass application environment requiring short handling times. It has been surprisingly found that polycarbonates, especially polycarbonate diols, further enhance multi-substrate adhesion, durability and high strength performance.
In preferred embodiments, the polycarbonate diol has general formula (III)
HO—R1-[O—C(═O)—O—R2]n—OH (III);
wherein R1 and R2 are independently of one another selected from the group consisting of —C1-12-alkylene-, -C4-10-cycloalkylene-, -C1-12-alkylene-C4-10-cycloalkylene-C1-12-alkylene-, -C6-10-aryl-, -C1-12 -alkylene-C6-10-aryl-C1-12-alkylene-, —C6-10- aryl-C1-12-alkylene-C6-10-aryl-, —[C1-6-alkylene-O]m—C1-6-alkylene-, —[C1-6-alkylene-O]m—C6-10-aryl-, —C(═O)—O—C1-12-alkylene-, —C(═O)—O—C1-6-alkylene-O—C1-6-alkylene-, —C(═O)—O—C6-10-aryl-, —C(═O)—O—C1-6-alkylene-C6-10-aryl-, —C(═O)—O—C1-6-alkylene-O—C6-10-aryl-, wherein m is an integer within the range of from 1 to 10; and
wherein n is an integer within the range of from 1 to 25, preferably 1, 2, 3, or 4.
In other preferred embodiments, the polycarbonate diol has general formula (IV)
H—[O—CHR1CH2—O—C(═O)]p—O—X—O—[C(═O)—O—CH2—CHR2-—O]q—H (IV);
wherein
In preferred embodiments, the polycarbonate, preferably the polycarbonate diol, has a weight average molecular weight
In preferred embodiments, the polycarbonate, preferably the polycarbonate diol, has a melting point
In preferred embodiments, the polycarbonate, preferably the polycarbonate diol, has a melting point
In preferred embodiments, the polycarbonate, preferably the polycarbonate diol, has a Brookfield viscosity at 75° C. (ASTM D789, D4878)
In preferred embodiments, the polycarbonate, preferably the polycarbonate diol, has a hydroxyl number (ASTM D4274)
In preferred embodiments, the polycarbonate, preferably the polycarbonate diol, has an acid value (ASTM D4662) of at most about 0.6 mg KOH/g, preferably at most about 0.4 mg KOH/g, more preferably at most about 0.2 mg KOH/g, still more preferably at most about 0.1 mg KOH/g.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the polycarbonate, preferably the polycarbonate diol, is
The curable one-component composition according to the invention preferably comprises fumed silica. The curable one-component composition according to the invention may comprise a single kind of fumed silica or a mixture of two or more kinds of fumed silica. In case of the presence of two or more kinds of fumed silica, all weights and percentages refer to the total weight of all kinds of fumed silica that are contained in the curable one-component composition.
It has been surprisingly found that fumed silica, especially certain grades of fumed silica, have a positive effect on multi-substrate adhesion including glass, durability and high strength.
Preferably, the fumed silica is hydrophobic fumed silica. Hydrophobic types of fumed silica are commercially available, e.g. Huifull® HB-132, HB-139, or HB-152; or Cab-O-Sil® TS-720, TS-710, TS-610 or TS-530. Hydrophobicity is typically achieved by surface modification with various treatment agents such as polydimethylsiloxane (PDMS), hexamethyldisilazane (HDMZ), dimethyldichlorosilane (DiMeDi , DDS). Fumed silica treated with PDMS is preferred.
In preferred embodiments, the fumed silica has a Brunauer-Emmett-Teller (BET) surface area (ISO 9277)
In particularly preferred embodiments, the fumed silica has a Brunauer-Emmett-Teller (BET) surface area (ISO 9277) within the range of from about 150 to 250 m2/g, preferably about 160 to 240 m2/g, more preferably about 170 to 230 m2/g.
In preferred embodiments, the fumed silica has a mean primary particle size determined by photon correlation spectroscopy (PCS)
In preferred embodiments, the fumed silica has a tamped density (ISO 787/11)
In particularly preferred embodiments, the fumed silica has a tamped density (DIN EN ISO 78711) within the range of about 50±20 g/l, preferably about 50±10 g/l, more preferably about 50±5.0 g/l.
In particularly preferred embodiments, the fumed silica has a density (DIN 51757) within the range of about 2.3±0.3 g/cm3, preferably about 2.3±0.2 g/cm3, more preferably about 2.3±0.1 g/cm2.
In preferred embodiments, the fumed silica has a dioctyl adipate absorption (ISO CD 19246)
In preferred embodiments, the fumed silica is untreated.
In preferred embodiments, the fumed silica is organically modified, preferably treated with optionally functionalized halotrialkylsilane or optionally functionalized dihalodialkylsilane, more preferably with trimethyl silyl groups; still more preferably with polydimethylsiloxane.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the fumed silica is
In preferred embodiments of the curable one-component composition according to the invention, the total weight content of the highly structured carbon black and the fumed silica (both together) is
The curable one-component composition according to the invention preferably comprises plasticizer. The curable one-component composition according to the invention may comprise a single plasticizer or a mixture of two or more plasticizers. In case of the presence of two or more plasticizers, all weights and percentages refer to the total weight of all plasticizers that are contained in the curable one-component composition.
Preferably, the plasticizer comprises or essentially consist of a copolymer polyol, preferably a copolymer of a polymeric material grafted onto a main polyol chain, more preferably a SAN (styrene/acrylonitrile) or an AN (acrylonitrile) grafted onto a polyether polyol or onto a polyester polyol.
Preferably, the plasticizer comprises or essentially consist of a SAN (styrene/acrylonitrile) grafted onto a polyol.
In preferred embodiments, the polyol is a polyether polyol selected from polyoxymethylene, polyoxyethylene, polyoxypropylene, and polyoxybutylene.
In preferred embodiments, the polyol is a polyester polyol, preferably an ester of a polyol of two to five carbon atoms and one or more aliphatic saturated organic acids.
Preferably, the copolymer polyol is selected from the group consisting of SAN-grafted polyether polyols and SAN-grafted polyester polyols; preferably SAN-grafted polyoxymethylene, SAN-grafted polyoxyethylene, SAN-grafted polyoxypropylene, and SAN-grafted polyoxybutylene.
In preferred embodiments, the plasticizer has a weight average molecular weight
In preferred embodiments, the curable one-component composition according to the invention comprises a polyol plasticizer. Suitable polyol plasticizers are known to the skilled person and commercially available.
Preferably, the polyol plasticizer has a weight average molecular weight within the range of from about 2,000 to 20,000 g/mol.
Preferably, the polyol plasticizer is
Other preferred plasticizers that may be present in the curable one-component composition according to the invention, optionally in addition to one or more of the plasticizers described above, include but are not limited to dioctyl terephthalate (DOTP), 1,2-cyclohexane dicarboxylic acid esters such as the diisononyl ester (DINCH), diethylene glycol dibenzoate (DE), dipropylene glycol dibenzoate (DPGDB) and bio-based plasticizers.
While being less preferred, it is also contemplated that the plasticizer may be a phthalate plasticizer.
Thus, in preferred embodiments, the plasticizer is selected from the group consisting of
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the plasticizer is
in each case relative to the total weight of the curable one-component composition.
The curable one-component composition according to the invention preferably comprises silane compatibilizer. The curable one-component composition according to the invention may comprise a single silane compatibilizer or a mixture of two or more silane compatibilizers. In case of the presence of two or more silane compatibilizers, all weights and percentages refer to the total weight of all silane compatibilizers that are contained in the curable one-component composition. Silane compatibilizers are known to the skilled person and commercially available.
Preferably, the silane compatibilizer comprises or essentially consist of a functional silane.
In preferred embodiments, the silane compatibilizer is
Trimethoxy(vinyl)silane (VTMO) is a particularly preferred silane compatibilizer and additionally may act as moisture scavenger.
N-2-aminoethyl-3-aminopropyltrimethoxysilane (DAMO) is another particularly preferred silane compatibilizer.
In preferred embodiments, the curable one-component composition according to the invention contains as silane compatibilizer a combination of trimethoxy(vinyl)silane (VTMO) and N-2-aminoethyl-3-aminopropyltrimethoxysilane (DAMO).
In preferred embodiments, the silane compatibilizer comprises a hydrolyzable group and a nonhydrolyzable group.
Preferably, the hydrolyzable group is a hydrolyzable silyl group as defined above in connection with the silyl-modified prepolymer according to the invention.
Preferably, the nonhydrolyzable group is selected from -C1-12-alkyl, —CH═CH2, —NH2, —NHC1-12-alkyl, and —N(C1-12-alkyl)2.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the silane compatibilizer is
The curable one-component composition according to the invention preferably comprises curing catalyst. The curable one-component composition according to the invention may comprise a single curing catalyst or a mixture of two or more curing catalysts. In case of the presence of two or more curing catalysts, all weights and percentages refer to the total weight of all curing catalysts that are contained in the curable one-component composition. Curing catalysts for humidity-curable prepolymers such as silyl-modified prepolymers are known to the skilled person and commercially available.
In preferred embodiments, the curing catalyst is selected from
Tin curing catalysts are particularly preferred such as dibutyltin dilaurate (DBTDL), dibutyltin diacetate, or dioctyltin dilaurate.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the curing catalyst is
In preferred embodiments, the curable one-component composition according the invention additionally comprises one or more additives selected from the group consisting of curing accelerators, adhesion promoters, stabilizers, antioxidants, colorants, pigments, fillers, toughening agents, impact modifiers, blowing agents, flame retardants and moisture scavengers.
Preferred pigments or colorants provide sufficient opacity so as to cover the black color of the highly structured carbon black.
Preferably, the adhesion promoter is selected from the group consisting of glycidoxypropyltrimethoxy silane, aminoethyl-aminopropyl-trimethoxy silane, aminopropyltriethoxy silane, hydrolyzed aminoethyl-aminopropylmethyldimethoxy silane, aminopropyltrimethoxy silane, and mixtures thereof.
Preferably, the antioxidant is a 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid ester, e.g. the methyl ester, the octyl ester (Irganox® 1135), the octadecyl ester (Irganox® 1076, or the pentaerythrityl ester (Irganox ® 1010)), the latter being particularly preferred (pentaerythritol tetrakis[343,5-di-tertbutyl-4-hydroxyphenyl]propionate).
Preferably, the filler is calcium carbonate which may be untreated or treated e.g. with stearic acid. Other suitable fillers include but are not limited to one or more mineral or stone type fillers such as sodium carbonate or magnesium carbonate.
Preferably, the filler is carbon black, with the proviso that it is not “highly structured carbon black”, wherein the non-highly structured carbon black has an oil absorption number (OAN, ASTM D 2414) of less than 115 ml/100 g. Said non-highly structured carbon black is also referred to as “standard carbon black” for the purpose of the specification.
In preferred embodiments of the curable one-component composition according to the invention, the weight content of the filler is within the range of from about 5.0 wt.-% to 70 wt.-%, preferably from about 7.5 wt.-% to 65 wt.-%, more preferably from about 10 wt.-% to 60 wt.-%, still more preferably from about 12 wt.-% to 50 wt.-%, yet more preferably from about 14 wt.-% to 40 wt.-%.
Preferably, the flame retardant is triethyl phosphate.
Preferably, the moisture scavenger is selected from vinyltrimethoxy silane (VTMO), phenyltrimethoxy silane, and mixtures thereof.
Preferably, the curable one-component composition according to the invention is polyurethane free.
Preferably, the curable one-component composition according to the invention does not contain phthalate plasticizers, preferably no phthalate at all.
Particularly preferred curable one-component compositions according to the invention A1 to A4 contain the following components in the following quantities:
In preferred embodiments, the composition according to the invention comprises the following components: silyl-modified prepolymer; highly structured carbon black; silane compatibilizer (e.g. 2aminoethyl-3-amino-propylmethyldi-methoxysilan (DAMO) and/or trimethoxy(vinyl)silane (VTMO); fumed silica (e.g. Aerosil H18); and curing catalyst (e.g. tin catalyst). Preferably, said composition according to the invention additionally comprises one or more of the following: filler (e.g. calcium carbonate treated with stearic acid and/or untreated); plasticizer (e.g. 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH)); antioxidant (e.g. Irganox 1010); and/or rheological agent (e.g. TST).
In other preferred embodiments, the composition according to the invention comprises the following components:
In still other preferred embodiments, the composition according to the invention comprises the following components:
In still other preferred embodiments, the composition according to the invention comprises the following components:
In still other preferred embodiments, the composition according to the invention comprises the following components:
In still other preferred embodiments, the composition according to the invention comprises the following components:
In preferred embodiments, the curable one-component composition according to the invention comprises components
The curable one-component composition according to the invention, in its uncured state, is preferably characterized by various properties.
In preferred embodiments, the curable one-component composition according to the invention has a Brookfield viscosity (ASTM D789, D4878)
In preferred embodiments, the curable one-component composition according to the invention has an open time within the range of from about 5.0 to 40 minutes, wherein the open time is determined by means of a spatula in contact to the curing composition. When no material of the curing composition is transferred to the spatula anymore, this is defined as the open time. Typically, the spatula is made from stainless steel.
In preferred embodiments, the curable one-component composition according to the invention has a handling time to reach a lap shear strength of 0.5 MPa determined according to DIN 53504:201703 within the range of from about 0.5 to 8 hours.
In preferred embodiments, the curable one-component composition according to the invention has a handling time to reach a lap shear strength of 0.5 MPa determined according to DIN 53504:2017-03 of
In preferred embodiments, the curable one-component composition according to the invention has an open time determined according to the description as described above of
In preferred embodiments, the curable one-component composition according to the invention a curing time of at least about 3 mm/24 h, wherein the curing time is determined by applying a bead of the curable composition, cutting the bead, and measuring the thickness of the cut bead skin over time. The applied bead has a diameter typically within the ranges of from 1.0 to 5.0 cm.
Another aspect of the invention relates to a cartridge containing the curable one-component composition according to the invention as described above.
Another aspect of the invention relates to a cured composition that is obtainable by curing the curable one-component composition according to the invention as described above.
In preferred embodiments, the cured composition according to the invention has a slippage resistance within the range from about 0 to 2 mm, wherein the slippage resistance is determined by using a conventional lap shear test set up, in a vertical arrangement, with a weight applied to the lower substrate. Displacement is then measured over time.
In preferred embodiments, the cured composition according to the invention has a tensile strength determined according to EN ISO DIN 53504:2017-03 of at least about 2.0 MPa, preferably at least about 3.0 MPa, more preferably at least about 4.5 MPa.
In preferred embodiments, the cured composition according to the invention has an electrical conductivity determined according to ASTM D257-14 at 23° C. determined within the range from about 1·10−8 Ωcm to about 1·10−11 Ωcm.
In preferred embodiments, the cured composition according to the invention has a G-modulus determined according to DIN EN 1465 of at least about 1.0 MPa, preferably within the range from about 1.0 to 3.5 MPa.
In preferred embodiments, the cured composition according to the invention a G-modulus determined according to DIN EN 1465
In preferred embodiments, the cured composition according to the invention has an elongation determined according to DIN EN 1465 of at least about 250%.
In preferred embodiments, the cured composition according to the invention has an elongation determined according to DIN EN 1465 of
Another aspect of the invention relates to the use of a curable one-component composition according to the invention as described above as a sealant and/or an adhesive.
In preferred embodiments, the use according to the invention is for fenestration.
In preferred embodiments, the use according to the invention is in the production of a vehicle selected from the group consisting of automobiles, railway vehicles, and commercial vehicles.
For applications in rail industry, the curable one-component composition according to the invention preferably provides
For applications in bus industry the curable one-component composition according to the invention preferably provides
For applications in automotive industry, the curable one-component composition according to the invention preferably provides
For applications in fenestration, the curable one-component composition according to the invention preferably provides
Another aspect of the invention relates to a method of bonding a first substrate to a second substrate comprising the steps of
Preferably, the first substrate and/or the second substrate is glass.
Another aspect of the invention relates to a method of sealing a contact area of a first substrate and a second substrate comprising the steps of
Preferably, the first substrate and/or the second substrate is glass.
The following examples further illustrate the invention but are not to be construed as limiting its scope:
Three samples with and without highly structured carbon black were tested. The samples contained the following ingredients:
1oil absorption number
Thus, inventive sample 1-3 differed from comparative samples 1-1 and 1-2 only in the content of highly structured carbon black. The amount of highly structured carbon black was substituted in comparative samples 1-1 and 1-2 with the corresponding amount of standard carbon black in order to allow for meaningful conclusions so that differences in performance of the samples are directly attributable to the presence and absence of highly structured carbon black.
A peel adhesion test was performed in accordance with DIN EN 14457 with regard to improved adhesion after storage under various storage conditions. The results of the measurements are compiled in the following table:
Cohesive failure (CF) indicates advantages, whereas adhesive failure (AF) is not desirable. As demonstrated by the above comparative data, the inventive sample 1-3 has significant advantages compared to comparative sample 1-1 after storage under conditions “+7d H2O” and “+7d cataplasma”. This advantage is attributable to the highly structured carbon black.
Post cure performance was investigated in terms of tensile strength and elongation. Tensile strength and elongation were measured in accordance with DIN EN ISO 527 with regard to improved stability after storage at 80° C. for 1000 hours compared to the respective values before storage. The results of the measurements are compiled in the following table:
As demonstrated by the above comparative data, the inventive sample 1-3 has significant advantages compared to comparative samples 1-1 and 1-2 with respect to tensile strength and elongation after storage compared to before storage. This advantage is attributable to the highly structured carbon black.
Analogous results are obtained when the plasticizer 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH) is replaced by other plasticizers, in particular by a polyol plasticizer or a SAN-grafted polyol plasticizer.
Four samples with and without polycarbonate diol were tested. The samples contained the following ingredients:
1oil absorption number
Thus, samples 2-1 and 2-3 differed from samples 2-2 and 2-4 only in the content of polycarbonate diol, respectively. The amount of polycarbonate diol was substituted in samples 2-2 and 2-4 with the corresponding amount of silyl-modified prepolymer and/or calcium carbonate in order to allow for meaningful conclusions so that differences in performance of the samples are directly attributable to the presence and absence of polycarbonate diol.
Short-time strength and improved cycle time performance was investigated in terms of lap shear strength. Lap shear strength was measured in accordance with DIN EN 1465 after curing for 200 seconds and 15 minutes, respectively. The results of the measurements are compiled in the following table:
As demonstrated by the above comparative data, the samples 2-1 and 2-3 have significant advantages compared to samples 2-2 and 2-4 with respect to short-time strength and cycle time. This advantage is attributable to the polycarbonate diol.
Two samples with and without fumed silica were tested. The samples contained the following ingredients:
Thus, sample 3-1 differed from samples 3-2 and 3-3 only in the content/type of fumed silica. The amount of fumed silica was substituted in samples 3-2 and 3-3 with the corresponding amount of standard carbon clack in order to allow for meaningful conclusions so that differences in performance of the samples are directly attributable to the presence and absence of fumed silica.
A peel adhesion test was performed in accordance with DIN EN 14457 with regard to improved adhesion after storage under various storage conditions. The results of the measurements are compiled in the following table:
Cohesive failure (CF) indicates advantages, whereas adhesive failure (AF) is not desirable. As demonstrated by the above comparative data, the sample 3-1 has significant advantages compared to samples 3-2 and 3-3. This advantage is attributable to the hydrophobic fumed silica.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20212438.4 | Dec 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/084695 | 12/8/2021 | WO |
