Products and their preparation methods

Abstract

This invention discloses an article comprising a substrate having a first portion comprising at least one of a metal or a ceramic metal oxide. A composite foam is bonded to the metal or ceramic metal oxide. The composite foam comprises: at least one polymer capable of being prepared by ring-opening metathesis polymerization; at least one catalyst for ring-opening metathesis polymerization; at least one bifunctional coupling agent represented by Z-X-Z. Each Z independently represents a group that chemically reacts with at least one of the chemically bonded surface hydroxyl groups to form at least one covalent bond. Each X independently represents a divalent organic linker group with a number average molecular weight of 500 g / mol to 10000 g / mol. And at least one of hollow glass microspheres or expanded polymer microspheres. This invention also discloses a method for preparing the article.

Description

Technical Field

[0001] This disclosure broadly relates to articles including substrates and composite foams, and methods for preparing them. Background Technology

[0002] Fifth-generation wireless (5G) is the latest iteration of cellular technology, designed to significantly improve the speed and responsiveness of wireless networks. 5G communication technology promises major advancements such as faster speeds, lower latency, improved connection density, and wider coverage; thus enabling the implementation of the Internet of Things (IoT), augmented reality (AR) or virtual reality (VR) applications, factory automation, vehicle communication, and other applications where security, reliability, quality of service, and efficiency are critical.

[0003] With 5G, data transmitted via wireless broadband connections can reach gigabits per second, with peak speeds estimated to be as high as 20 gigabits per second (Gbps). This increased speed is achieved in part by using radio waves at higher frequencies than current cellular networks. However, high-frequency radio waves have a shorter range than the frequencies used by previous networks. To ensure widespread service, 5G networks can operate on up to three frequency bands (low, medium, and high). 5G networks will consist of up to three different types of cellular networks, each requiring different antennas, and each type will make different trade-offs between download speeds and distance and service area. 5G phones and wireless devices will connect to the network using the highest-speed antenna within their location's range.

[0004] Low-band 5G uses a frequency range similar to current 4G phones, with download speeds of 600-700MHz slightly higher than 4G: 30-250 megabits per second (Mbit / s). Low-band cell towers will have similar range and coverage area as current 4G towers. Mid-band 5G uses microwaves of 2.5-3.7GHz, currently allowing speeds of 100-900 Mbit / s, with each cell tower providing service within a radius of several miles. High-band 5G typically uses frequencies of 25GHz-39GHz, near the bottom of the millimeter wave band, to achieve download speeds of 1-3 gigabits per second (Gbit / s), comparable to wired internet.

[0005] Many materials used in the telecommunications industry today perform poorly at 5G frequencies. Therefore, the higher frequencies of 5G necessitate the identification and development of materials that can operate at those frequencies without interfering with the normal functioning of electronic devices communicating at higher wavelengths. Examples include mobile phones, additional base stations beyond existing cell towers, and automotive radar / self-driving vehicles.

[0006] A low-dielectric / low-loss tanδ material is required that can operate at high-frequency bands (GHz, mmWave). Other desirable material properties include low hygroscopicity (because water significantly increases the dielectric constant) and thermal management capabilities (because higher power generates more heat), as well as good adhesion to copper and stability at 250°C (for solder reflow) for mmWave antenna substrates. Summary of the Invention

[0007] This disclosure provides low dielectric constant, low dielectric loss, and water-resistant materials suitable for applications such as 5G.

[0008] In one aspect, this disclosure provides an article of manufacture comprising:

[0009] A first substrate having a first portion, the first portion comprising a first metal; and

[0010] A composite foam, wherein the composite foam is combined with at least one of a first metal or a ceramic metal oxide, the composite foam comprising:

[0011] At least one polymer that can be prepared by ring-opening metathesis polymerization;

[0012] At least one catalyst for ring-opening metathesis polymerization;

[0013] At least one bifunctional coupling agent represented by the following formula

[0014] ZXZ

[0015] Each Z independently represents a group that has undergone a chemical reaction with at least one surface hydroxyl group to form at least one covalent bond, and

[0016] Each X independently represents a divalent organic linker with a number-average molecular weight of 500 g / mol to 10000 g / mol; and

[0017] At least one of hollow glass microspheres or expanded polymer microspheres.

[0018] In some implementations, the article includes electronic devices.

[0019] In a second aspect, this disclosure provides a method for manufacturing an article of article, the method comprising the following steps:

[0020] a) Contacting at least one metal portion of at least one substrate with the curable composition, wherein:

[0021] Each at least one metal portion has surface hydroxyl groups; and

[0022] The curable composition comprises:

[0023] At least one monomer capable of being polymerized via ring-opening metathesis polymerization;

[0024] At least one catalyst for ring-opening metathesis polymerization;

[0025] At least one bifunctional coupling agent represented by the following formula

[0026] ZXZ

[0027] Each Z independently represents a group that chemically reacts with at least one surface hydroxyl group of one of the surface hydroxyl groups of an abrasive particle to form at least one covalent bond, and

[0028] Each X independently represents a divalent organic linker with a number-average molecular weight of 500 g / mol to 10000 g / mol; and

[0029] At least one of hollow glass microspheres, expanded polymer microspheres, or unexpanded polymer microspheres;

[0030] b) Curing the curable composition at least partially; and

[0031] c) If any unexpanded polymer microspheres are present, expand any unexpanded polymer microspheres.

[0032] As used in this article:

[0033] When used alone, the term "metal" refers to metals in groups 3 through 14 of the periodic table that are in their elemental state; and

[0034] The term "metal oxide" refers to a composition containing individual metal atoms bonded to oxygen, and may contain a variety of different types of metal atoms.

[0035] The features and advantages of this disclosure will be further understood upon consideration of the specific embodiments and the appended claims. Attached Figure Description

[0036] Figure 1 This is a schematic side view of an exemplary article 100 according to the present disclosure.

[0037] It should be understood that those skilled in the art can devise many other modifications and embodiments that fall within the scope and spirit of this disclosure. The accompanying drawings may not be drawn to scale. Detailed Implementation

[0038] See now Figure 1The exemplary article 100 includes a first substrate 110 having a first portion 115 in contact with a composite foam 120. The first portion 115 comprises at least one of a first metal or a first ceramic metal oxide. The composite foam 120 comprises at least one polymer prepared by ring-opening metathesis polymerization, at least one catalyst for ring-opening metathesis polymerization, at least one bifunctional coupling agent, and at least one of hollow glass microspheres or expanded polymer microspheres. Optionally, a second substrate 130 has a second portion 135 comprising at least one of a second metal or a second ceramic metal oxide. The composite foam 120 contacts and is bonded to the first portion 115 of the first substrate 110 and, if present, the second portion 135 of the second substrate 130.

[0039] The article may include a component (e.g., a frame, panel, or electronic component) having a first portion containing a first metal bonded to the composite foam. The first metal should generally be exposed such that it can directly contact the composite foam, but a short-lived (e.g., soluble) coating may be permitted.

[0040] Exemplary article 100 may include electronic articles such as circuit boards, cellular phones, computers (especially tablet and laptop computers that connect to the Internet using wireless communication), electronic components (such as integrated circuits), electronic displays, electrical switches, diodes, transistors, capacitors, resistors (including rheostats), wires / cables, cell tower transponders, AM / FM / UHF / VHF / microwave receivers, microwave antennas, radios, earphones, and headphones. The exemplary first part includes wires, electrical connectors / pins, circuit traces, antennas, metal plates, and metal panels.

[0041] The first part comprises a first metal having surface hydroxyl groups, which is typically most metals that form an oxide surface layer due to oxidation in air. Examples of such metals include aluminum, copper, silver, platinum, nickel, iron, tin, scandium, tantalum, tungsten, chromium, zinc, indium, and alloys thereof. Particularly preferred metals include copper, silver, aluminum, and alloys thereof.

[0042] An optional second substrate has a second portion that may include a second metal (e.g., as described above with respect to the first metal), which may be the same as or different from the first metal; for example, metal oxide ceramics such as alpha-alumina, sapphire, zirconium oxide; ceramics; glass; quartz; plastics or thermosetting polymers; or combinations thereof. An exemplary optional second substrate may include electrical components such as integrated circuits, electronic displays, diodes, transistors, capacitors, resistors (including varistors), wires / cables, microwave antennas, and metal sheets and frames. An exemplary first portion includes wires, electrical connectors / pins, circuit traces, antennas, metal plates, and metal panels.

[0043] The composite foam comprises one or more polymers that can be prepared (e.g., prepared by means of) ring-opening metathesis polymerization (ROMP). ROMP is a well-known process for converting cyclic olefins into polymers using a ROMP catalyst. Ring-opening metathesis polymerization of cyclic olefin monomers typically yields cross-linked polymers with an unsaturated linear backbone. The degree of unsaturation of the repeating backbone units of the polymer is the same as that of the monomer. For example, in the presence of a suitable catalyst, the polymer obtained using norbornene reactants can be represented as:

[0044]

[0045] Where 'a' is the number of repeating monomer units in the polymer chain.

[0046] For example, in the presence of a suitable catalyst, polymers obtained using dienes such as dicyclopentadiene can be represented as:

[0047]

[0048] Where b+c is the molar number of monomers, and c / (b+c) is the molar number of monomer units that open the ring at the two active sites, and * indicates a continuous polymeric structure. As shown in the above reaction, metathesis polymerization of dienes, trienes, etc., can produce crosslinked polymers. Representative cycloolefin monomers, catalysts, methods, etc., that can be used for metathesis polymerization are described, for example, in U.S. Patents 4,400,340 (Klosiewicz); 4,751,337 (Espy et al.); 5,849,851 (Grubbs et al.); and 6,800,170B2 (Kendall et al.), and U.S. Patent Application Publication 2007 / 0037940A1 (Lazzari et al.).

[0049] As used herein, the term "cyclic monomer" refers to a monomer having at least one cyclic group and may include bicyclic and tricyclic monomers.

[0050] Exemplary cyclic monomers suitable for ROMP polymerization include 7-oxabicyclo[2.2.1]hept-2-ene, alkyl norbornene, cis-cyclooctene, cyclopentadiene, cyclopentene, dicyclopentadiene, hexyl norbornene, norbornene, norbornene (2-norbornene), tetracyclo[6.2.13.6.0]dodecyl-4,9-diene, tetracyclopentadiene, tricyclopentadiene, and their derivatives having substituents including aliphatic groups, aromatic groups, esters, amides, ethers, and silanes.

[0051] Combinations of cyclic monomers can be used. For example, combinations of dicyclopentadiene and norbornene, or dicyclopentadiene and alkyl norbornene, can be used.

[0052] Available alkyl norbornene can be represented by the following formula:

[0053]

[0054] Wherein R is an alkyl group comprising 1 to 12 carbon atoms (e.g., 6 carbon atoms). A useful combination of cyclic monomers comprises dicyclopentadiene and hexylnorbornene in a weight ratio of about 10:90 to about 50:50. Another useful combination of cyclic monomers comprises dicyclopentadiene and cyclooctene in a weight ratio of about 30:70 to about 70:30.

[0055] Other examples of useful cyclic monomers include the following polycyclic dienes:

[0056]

[0057]

[0058] Where X 1 It is a divalent aliphatic or aromatic group having 0 to 20 carbon atoms; X 2 It is a multivalent aliphatic or aromatic group having 0 to 20 carbon atoms; the optional group Y 1 It is a divalent functional group selected from the group consisting of esters, amides, ethers and silanes; and z is 2 or greater.

[0059] As described above regarding dicyclopentadiene, metasomatic polymerization of dienes, trienes, etc., produces crosslinked polymers. The degree of crosslinking depends on the relative amounts of different monomers and the conversion rate of reactive groups in these monomers, which in turn is affected by reaction conditions including time, temperature, catalyst selection, and monomer purity. Generally, at least some crosslinking is required to provide suitable mechanical properties for abrasive articles. Crosslinking is indicated when the cured composition is insoluble in some solvents such as toluene but can swell in such solvents. Furthermore, crosslinked polymers are thermosetting rather than thermoplastic and do not become flowable upon heating. Typically, at least partially cured compositions become harder with increasing crosslinking, so the desired amount of crosslinking can depend on the desired stiffness of the cured composition (e.g., in abrasive articles).

[0060] In some embodiments, the available ROMP polymer may comprise a crosslinked unsaturated polymer formed by ring-opening metathesis polymerization of a crosslinking agent (a polycyclic monomer comprising at least two reactive double bonds) and a monofunctional monomer. For example, the unsaturated polymer may consist of dicyclopentadiene and a monofunctional monomer. The monofunctional monomer may be selected from cyclooctene, cyclopentadiene, alkylnorbornene, and derivatives thereof. The monomer composition may also comprise from about 0.1 wt% to about 75 wt% of the crosslinking agent relative to the total weight of the monomer composition. If dicyclopentadiene is used as the crosslinking agent, the amount of dicyclopentadiene available is from about 10 wt% to about 75 wt% relative to the total weight of the monomer composition. If the polycyclic diene described above is used as the crosslinking agent, the amount available is from about 0.1 wt% to about 10 wt% relative to the total weight of the monomer composition.

[0061] In embodiments where at least two different cyclic monomers are used to prepare at least partially cured compositions (e.g., in abrasive articles), the relative amounts of monomers may vary depending on the specific monomers of the article and the desired properties. The unsaturated polymer may comprise: about 0% to about 100% by weight of a multifunctional polycyclic monomer and about 0% to about 100% by weight of a monofunctional cyclic monomer, relative to the total weight of the polymer. In some embodiments, the molar ratio of the multifunctional polycyclic monomer to the monofunctional cyclic monomer comprises about 1:3 to about 1:7.

[0062] The desired physical properties of a given, at least partially cured composition can be used to select specific monomers for use in the corresponding curable composition. If more than one monomer is used, these physical properties may also affect the relative amounts of monomers used. Physical properties that may need to be considered include the glass transition temperature (Tg). g And Young's modulus. For example, if a rigid composition is desired, specific monomers and their relative amounts (if more than one monomer is used) can be selected such that the unsaturated polymer has a T0 greater than about 25°C. g And a Young's modulus greater than approximately 100 MPa.

[0063] When selecting the relative amounts of comonomers, an appropriate ratio can be chosen using the contribution of each monomer to the glass transition temperature of the unsaturated polymer. If a rigid-curing composition is desired, the unsaturated polymer can have a glass transition temperature (Tglass transition temperature) greater than about 25°C. g And a Young's modulus greater than about 100 MPa. Monomers that can be used to prepare hard compositions include any of those monomers described herein, particularly norbornene, ethylene norbornene, dicyclopentadiene, and tricyclopentadiene, with dicyclopentadiene being particularly preferred. Any amount of crosslinking may be present.

[0064] If a flexible curable composition is desired, the unsaturated polymer can have a Tc of less than about 25°C. gAnd a Young's modulus less than about 100 MPa. Monomers that can be used to prepare flexible curable compositions may include combinations of crosslinking agents and monofunctional cyclic monomers. Monomers that can be used to prepare flexible curable compositions include any of those monomers described herein, particularly dicyclopentadiene, cyclooctene, cyclopentene, and alkyl norbornene (such as R described above). 1 Alkyl norbornene comprising 1 to 12 carbon atoms. The monomer composition may contain about 0.1 wt% to about 75 wt% of a crosslinking agent relative to the total weight of the monomer composition, preferably about 1 wt% to about 50 wt% or about 20 wt% to about 50 wt%. An exemplary curable composition contains dicyclopentadiene and cyclooctene in a weight ratio of about 30:70 to about 70:30, preferably about 50:50. Another exemplary curable composition contains dicyclopentadiene and hexyl norbornene in a weight ratio of about 10:90 to about 50:50, preferably about 20:80 to about 40:60.

[0065] One or more ROMP catalysts can be used to polymerize cyclic monomers to form one or more ROMP polymers. Available ROMP catalysts include, for example, transition metal carbene catalysts, such as those made of ruthenium, osmium, tungsten, molybdenum, and rhenium, including those types of Grubbs catalysts and Grubbs-Hoveyda catalysts; see, for example, U.S. Patent No. 5,849,851 (Grubbs et al.).

[0066] In some embodiments, the translocation catalyst system comprises a compound of the following formula:

[0067]

[0068] in:

[0069] M is selected from the group consisting of Os and Ru;

[0070] R 1 and R 2 The group consisting of hydrogen and substituents is independently selected, and the substituents are selected from C1-C2. 20 Alkyl, C2-C 20 alkenyl, C2-C 20 Alkoxycarbonyl, aryl, C1-C 20 Carboxylic esters, C1-C 20 Alkoxy, C2-C 20 Alkenyl groups, C2-C 20 The group consisting of alkynyloxy and aryloxy groups; the substituent is optionally partially substituted by a group consisting of C1-C5 alkyl, halogen, C1-C5 alkoxy and phenyl groups; the phenyl group is optionally partially substituted by a group consisting of halogen, C1-C5 alkyl and C1-C5 alkoxy groups;

[0071] X 3 and X 4 Independently selected from any anionic ligand; and

[0072] L and L 1 Independently selected from PR 3 R 4 R 5 Any phosphine, where R 3 Selected from the group consisting of neopentyl, secondary alkyl, and cycloalkyl, wherein R 4 and R 5 Independently selectable from aryl, neopentyl, C1-C 10 The group consisting of primary alkyl, secondary alkyl, and cycloalkyl groups.

[0073] The translocation catalyst system may also include a transition metal catalyst and an organoaluminum activator. The transition metal catalyst may include tungsten or molybdenum, including their halides, halide oxides, and oxides. A particularly preferred catalyst is WCl6. The organoaluminum activator may include trialkylaluminum, dialkylaluminum halides, or alkylaluminum dihalides. Organotin and organolead compounds may also be used as activators; for example, tetraalkyltin and alkyltin hydrides may be used. A particularly preferred catalyst system comprises WCl6 / (C2H5)2AlCl.

[0074] The specific catalyst system and its amount can be chosen depending on the specific monomers used, the required reaction conditions, the desired curing rate, etc. Specifically, it may be preferable to use the above-mentioned osmium and ruthenium catalysts in amounts of about 0.001 wt% to about 0.3 wt%, based on the total weight of the unsaturated polymer. For curable compositions containing cyclooctene, osmium and ruthenium catalysts can be used. For curable compositions containing dicyclopentadiene and alkyl norbornene, a tungsten-containing translocation catalyst system can be used.

[0075] The curable composition may contain additional components. For example, if the metathesis catalyst system contains WCl6 / (C2H5)2AlCl, water, alcohol, oxygen, or any oxygen-containing compound may be added to improve the activity of the catalyst system. Other additives may include chelating agents, Lewis bases, plasticizers, inorganic fillers, and antioxidants, preferably phenolic antioxidants.

[0076] The photocatalyst for catalyzing ROMP is described in U.S. Patent No. 5,198,511 (Brown-Wensley et al.), the disclosure of which is incorporated herein by reference and may be used in cases where photocuring is desired.

[0077] The foam composition contains one or more bifunctional coupling agents represented by the following formula.

[0078] ZXZ

[0079] Each Z independently represents a group that chemically reacts with at least one surface hydroxyl group of the surface hydroxyl group of one of the abrasive particles to form at least one covalent bond. Examples include isocyanate groups (i.e., -N=C=O) and silyl groups having 1 to 3 hydrolyzable groups bonded thereto. Exemplary silyl groups can be of the formula –SiR 6 a L 2 (3-a) This indicates that each L 2 Independently representing a hydrolyzable group (e.g., Cl, Br, acetoxy, methoxy, ethoxy, and / or hydroxyl), where R 6 This indicates an alkyl group having 1 to 4 carbon atoms, wherein a is 0, 1, or 2. In a preferred embodiment, a is 0.

[0080] Each X independently represents the number-average molecular weight (M). n The divalent organic linker is 500 g / mol to 10000 g / mol, preferably 600 g / mol to 6000 g / mol. For example, X may have any combination of 500 g / mol, 600 g / mol, 700 g / mol, 800 g / mol, 900 g / mol, 1000 g / mol up to 6000 g / mol, 7000 g / mol, 8000 g / mol, 9000 g / mol or 10000 g / mol. n .

[0081] In some preferred embodiments, the bifunctional coupling agent comprises isocyanate-terminated polyurethane prepolymers; for example, diphenylmethane diisocyanate (e.g., 4,4'-methylenebis(phenyl isocyanate))-terminated polyether prepolymers based on polytetramethylene ether glycol. Exemplary polyalkylene ether glycols include polyethylene glycol, polypropylene glycol, and polytrimethylene ether glycol (i.e., HO(CH2CH2CH2O)). n H) and polytetramethylene ether glycol (i.e., HO(CH2CH2CH2CH2O)). n H). The resulting prepolymer may have polyoxyethylene divalent segments, such as polyoxyethylene segments, polyoxypropylene segments, and / or polyoxybutene segments.

[0082] A preferred isocyanate-terminated polyurethane prepolymer is a modified polytetramethylene ether glycol (PTMEG)-terminated diphenylmethane diisocyanate (MDI) polyether prepolymer, which can be obtained from Covestro, Pittsburgh, Pennsylvania (BAYTEC ME-230).

[0083] Isocyanate-terminated polybutadiene prepolymers can be prepared, for example, by reacting diisocyanate with hydroxyl-terminated polyoxyethylene or hydroxyl-terminated polybutadiene. Polyoxyethylene polymers having hydrolyzable silyl end groups can be prepared, for example, by reacting the corresponding hydroxyl-terminated polyoxyethylene with isocyanate-functionalized hydrolyzable organosilanes (e.g., isocyanate-ethyltrimethoxysilane or isocyanate-ethyltriethoxysilane).

[0084] Exemplary commercially available OH-terminated polybutadienes include POLYVESTHT (Mn = 2,900 g / mol) from Evonik Industries AG (Essen, Germany) and POLY BD R-45HTLO (Mn = 2,900 g / mol). n =2800g / mol), POLY BD R-20LM(M n =1200), KRASOL LBH 2000 (2100g / mol) and KRASOL LBH 3000 (M n =3000 g / mol) obtained from Total Cray Valley, Exton, Pennsylvania.

[0085] Silane-terminated polybutadiene can be prepared by anionic polymerization and by terminating the active ends of the polybutadiene with a hydrolyzable silane (e.g., tetramethoxysilane or tetraethoxysilane). Suitable hydrolyzable silane-terminated liquid polybutadiene is also commercially available; for example, POLYVEST EP ST-M 60 (M n RICON 603 silane-functionalized polybutadiene (M) was purchased from Evonik Industries, Inc. for approximately 3300 g / mol and is marketed as RICON 603 silane-functionalized polybutadiene (M). n =3300 g / mol, bifunctional) was purchased from Total Cray Valley, Exton, Pennsylvania.

[0086] The composite foam contains at least one of hollow glass microspheres or expanded polymer microspheres.

[0087] Exemplary expanded polymer microspheres include those commercially available under the trade name EXPANCEL from Nouryon GmbH, Amsterdam, The Netherlands. Details about EXPANCEL microspheres can be found in U.S. Patent No. 6,509,384 (Bjerke et al.). They are available in various forms, such as expanded and in a solvent (EXPANCEL WE) or expanded and dried (EXPANCEL DE). EXPANCEL is also available in a dried, unexpanded form as a powder (EXPANCEL DU). EXPANCEL DU microspheres expand with heat during the processing of polymer films or coatings.

[0088] The EXPANCEL WE rating includes EXPANCEL 461 WE 20 d36(D) 50 =20-30 micrometers), EXPANCEL461 WE 40d36 (D 50 =30 micrometers-50 micrometers) and EXPANCEL 921 WE 40d24 (D 50 =35 micrometers-55 micrometers). EXPANCEL DE grades include EXPANCEL 551 DE 40 d42 (D 50 =25 micrometers-50 micrometers), EXPANCEL 461DE20d70(D 50 =15 micrometers-25 micrometers), EXPANCEL 461DE 40d60 (D 50 =20 micrometers-40 micrometers), EXPANCEL461DE 40d25 (D 50 =35 micrometers-55 micrometers), EXPANCEL 920DE 40d30 (D 50 =35 micrometers-55 micrometers), EXPANCEL 920DE 40d25 (D 50 =30 micrometers-60 micrometers), EXPANCEL920DE 80d30 (D 50 =55 micrometers-85 micrometers) and EXPANCEL 043DET 80d20 (D 50 =60 microns-95 microns). EXPANCEL DU grades include 461DU 20 and 043DU 80. The dimensions of EXPANCEL DU grade composites are temperature and time dependent, so the reduction in size and density of composites with EXPANCEL DU grade composites is largely dependent on thermal history.

[0089] In other embodiments, hollow glass microspheres may also be used. Hollow glass microspheres can be manufactured as discussed in the following documents: U.S. Patent Nos. 3,365,315 (Beck); 4,391,646 (Howell); and 4,618,525 (Chamberlain et al.). Such exemplary hollow glass microspheres have a shell material comprising glass. For example, in some embodiments, the shell material includes SiO2, Na2O, CaO, K2O, Li2O, BaO, MgO, SrO, ZnO, PbO, TiO2, MnO2, ZrO2, B2O3, Al2O3, Fe2O3, Sb2O3, P2O5, V2O5, or combinations thereof. In some embodiments, the shell material comprises mostly (by weight) SiO2, along with optional other components. Hollow glass microspheres can contain a variety of different gases within the glass shell material. Exemplary gases include H2O, CO2, SO2, SO3, F2, N2, O2, or mixtures thereof.

[0090] Commercially available hollow glass microspheres (also known as glass bubbles, glass microbubbles, and glass microspheres) include microspheres obtained under the trade name 3M GLASS BUBBLES from 3M Company, Maplewood, Minnesota, of grade K37 (D). 50 =45 micrometers), S38(D 50 =40 micrometers), S38HS(D 50 =40 micrometers), K42HS(D 50 =22 micrometers), S60(D 50 =30 micrometers), S60HS(D 50 =30 micrometers) and iM30K(D 50 =16 micrometers).

[0091] Alternatively or otherwise, unexpanded (i.e., thermally expandable) polymer microspheres can be included in the composite foam precursor composition. If heated to a sufficient temperature, they become expanded polymer microspheres. Expansion can occur before or during the formation of the composite foam. For example, unexpanded polymer microspheres can be added to a composite foam precursor composition containing ROMP cyclic monomers and a ROMP catalyst before curing, and then heated to a sufficient temperature to induce expansion, thereby providing expanded polymer microspheres.

[0092] Expandable polymer microspheres with various unexpanded average particle sizes are commercially available, for example, in the ranges of 6 to 9 micrometers, 9 to 15 micrometers, 10 to 16 micrometers, 18 to 24 micrometers, 35 to 45 micrometers, and 28 to 38 micrometers. For more than one material, several unexpanded particle size ranges are also available.

[0093] Expandable polymeric microspheres typically encapsulate a propellant that is liquid at room temperature and has a boiling point at atmospheric pressure lower than the softening point of the shell material. The propellant expands when heated, causing the outer shell of the polymeric microspheres to expand. For example, the polymeric microspheres may comprise a liquid or gas selected from isooctane, (2,2,4-trimethylpentane), butane, pentane, hexane, heptane, petroleum distillates, or other liquids or combinations thereof having a suitable boiling point or boiling point range. In one embodiment, hydrocarbons such as isobutane, isopentane, n-pentane, n-hexane, petroleum ether, or n-heptane may be used alone or in combination with isooctane.

[0094] In some preferred embodiments, the size of the hollow glass microspheres and / or expanded polymer microspheres is from 1 micrometer to 200 micrometers, more preferably from 5 micrometers to 100 micrometers, and even more preferably from 10 micrometers to 85 micrometers, but this is not required.

[0095] Based on the total weight of the curable and / or at least partially curable composition, the total amount of hollow glass microspheres, expanded polymer microspheres and expandable polymer microspheres in the curable composition can range, for example, from 1% to 50% by weight, preferably from 5% to 30% by weight, but other amounts may also be used.

[0096] To maximize the dimensional stability of composite foams, it is generally desirable that the composite foam does not contain solvents. If a solvent is initially used to help dissolve some components (e.g., dissolving a ROMP catalyst prior to the ROMP polymerization of cycloolefins), it is generally desirable to remove the solvent under vacuum before polymerizing the mixture. If the mixture is sensitive to ambient moisture and oxygen, it may be desirable to keep the mixture under inert conditions.

[0097] In some preferred embodiments (e.g., for wireless communication), the composite foam has a dielectric constant of less than or equal to 3.0, less than or equal to 2.5, less than or equal to 2.2, or even less than or equal to 2.0; however, this is not required. Similarly, the composite foam may have a loss tangent of less than 0.10, less than 0.05, less than 0.03, or even less than 0.02.

[0098] Composite foams may also contain one or more optional additives. Examples include plasticizers, antioxidants, UV stabilizers, colorants (e.g., carbon black), fillers, and polymers and / or inorganic fibers.

[0099] Exemplary fillers include silica (e.g., fumed silica), alumina (e.g., alpha-alumina), zirconium oxide, carbon black, titanium dioxide, zirconium aluminate, and combinations thereof. Combinations of fillers may be used. Typical amounts can be up to 10 vol%, 20 vol%, 30 vol%, 40 vol%, or even up to 50 vol%, but this is not required.

[0100] Exemplary plasticizers include esters such as dioctyl phthalate (i.e., di(ethylhexyl) phthalate), dioctyl sebacate, butyl oleate, and aromatic oils and paraffin oils (e.g., mineral oils). Combinations of plasticizers may be used. The amount of plasticizer will be determined by the target glass transition temperature (T0) of the composition to which it is at least partially cured. g The higher the amount, the lower the T. g value.

[0101] The composite foam according to this disclosure can have an average cell size (i.e., pore diameter) ranging from 10 micrometers to 3000 micrometers (in some embodiments, 10 micrometers to 2000 micrometers, 10 micrometers to 1000 micrometers, 10 micrometers to 500 micrometers, or even 10 micrometers to 100 micrometers), but other cell sizes are also permitted. In some embodiments, based on the total volume of the composite foam, the composite foam according to this disclosure has a total porosity of at least 5% by volume (in some embodiments, at least 10%, 20%, 25%, 30%, 40%, 50%, 60%, or even at least 70% by volume; in some embodiments, in the range of 10% to 70%, 10% to 60%, or even 10% to 50% by volume). Similarly, the composite foam can have a porosity of 0.05 to 0.95 g / cm³. 3 0.05 to 0.75 g / cm³ 3 0.05 to 0.50 g / cm 3 0.05 to 0.40 g / cm³ 3 Or even 0.05 to 0.30 g / cm³ 3 The density.

[0102] Composite foams can have, for example, a T value in the range of -50°C to 350°C. g Although other values ​​(including no T) g This is also permissible. In some preferred embodiments, the Tg of the composite foam is at least 100°C, at least 110°C, at least 120°C, at least 130°C, or even at least 140°C.

[0103] The composite foam according to this disclosure can be prepared, for example, by heating the curable composition at a sufficient temperature for a sufficient time to cause at least partial curing of the curable composition, preferably substantially complete curing, and by expanding any unexpanded polymer microspheres if present.

[0104] The curable composition may contain (e.g., as described above):

[0105] At least one monomer capable of being polymerized via ring-opening metathesis polymerization;

[0106] At least one catalyst for ring-opening metathesis polymerization;

[0107] At least one bifunctional coupling agent represented by the following formula

[0108] ZXZ

[0109] Each Z independently represents a group that chemically reacts with at least one surface hydroxyl group of one of the surface hydroxyl groups of an abrasive particle to form at least one covalent bond, and

[0110] Each X independently represents a divalent organic linker with a number-average molecular weight of 500 g / mol to 10000 g / mol; and

[0111] And at least one of hollow glass microspheres, expanded polymer microspheres, or unexpanded polymer microspheres.

[0112] Exemplary unexpanded polymer microspheres include those commercially available from Nouryon under the trade names EXPANCEL WU and EXPANCEL DU. Exemplary EXPANCEL WU microspheres include EXPANCEL 551 WU 40(D) 50 =9 micrometers-15 micrometers), EXPANCEL 461 WU 20 (D 50 =6 micrometers-9 micrometers), EXPANCEL 461 WU 40 (D 50 =9 micrometers-15 micrometers), EXPANCEL 551 WU 40 (D 50 =9 micrometers-15 micrometers), EXPANCEL 053 WU 40 (D 50 =10 micrometers-16 micrometers), EXPANCEL 909 WU 80 (D 50 =18 micrometers-24 micrometers), EXPANCEL 920 WUF 80 (D 50=10 micrometers-16 micrometers). Exemplary EXPANCEL DU unexpanded polymer microspheres include EXPANCEL 551 DU 40 (D50 = 9 micrometers-15 micrometers); EXPANCEL 461 DU 20 (D50 = 10 micrometers-16 micrometers). 50 =6 micrometers - 9 micrometers); EXPANCEL 461 DU 40 (D 50 =9 micrometers - 15 micrometers); EXPANCEL 051 DU 40 (D 50 =9 micrometers - 15 micrometers); EXPANCEL 053 DU 40 (D 50 =10 micrometers - 16 micrometers); EXPANCEL 093 DU 120 (D 50 =28 micrometers - 38 micrometers); EXPANCEL 909 DU 80 (D 50 =18 micrometers - 24 micrometers); EXPANCEL 920 DU 80 (D 50 =18 micrometers - 24 micrometers); EXPANCEL 920 DU 120 (D 50 =28 micrometers - 38 micrometers); EXPANCEL 930 DU 120 (D 50 =28 micrometers - 38 micrometers); EXPANCEL 920 DU 40 (D 50 =10 micrometers - 16 micrometers); EXPANCEL 930 DU 120 (D 50 =28 micrometers - 38 micrometers); EXPANCEL 950 DU 80 (D 50 =18 micrometers - 24 micrometers); EXPANCEL 980 DU 120 (D 50 =25 micrometers - 40 micrometers).

[0113] The curable composition can be applied to a substrate using any suitable technique, such as dipping, spraying, brushing, and nozzle dispensing. Once applied to the substrate, the curable composition can be heated to accelerate curing, for example, to at least 50°C, at least 75°C, at least 100°C, or at least 150°C to provide an article of articles according to this disclosure.

[0114] The purposes and advantages of this disclosure are further illustrated by the following non-limiting embodiments, but the specific materials and quantities referenced in these embodiments, as well as other conditions and details, should not be construed as undue limitation of this disclosure.

[0115] Example

[0116] Unless otherwise stated, all parts, percentages, ratios, etc., in the examples and the remainder of this specification are by weight. Table 1 (hereinafter) lists the materials used in the examples and their sources.

[0117] Table 1

[0118]

[0119] Test methods

[0120] Overlap shear test method

[0121] For the metal substrate, clean two 1-inch (2.54 cm wide × 4-inch (10 cm long) × 0.125-inch (0.32 cm) thick specimens with toluene. Cover the top of one specimen with a 1-inch × 1-inch (2.54 cm × 2.54 cm) square of the mixed compound, then place it in contact with the other specimen at the opposite top. Use clamps to hold the two halves together during the curing process. The approximate thickness of the material between the specimens is between 2–5 mils (0.05–0.13 mm). The samples are then conditioned at room temperature for 24 hours, followed by an overlap shear test.

[0122] OLS tests were performed on an Instron Model 1122 universal testing machine (INSTRON Corporation, Norwood, MA) according to ASTM D1002-01 (2001), “Standard Test Method for Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Metal Specimens by Tension Loading (Metal-to-Metal)”. The clamp speed was 0.1 inches per minute (2.5 mm / min).

[0123] Dielectric property measurement and testing methods

[0124] Dielectric breakdown strength measurements were performed according to ASTM D149-20, "Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power Frequencies" (2020), using a Phoenix Technologies model 6TC4100-10 / 50-2 / D149, specifically designed for testing breakdown in the 1–50 kV, 60 Hz (high voltage) AC range and the 3–100 kV (high voltage) DC range. Each measurement was performed with the sample immersed in the indicated fluid. The average breakdown strength was typically based on the average of measurements from 10 or more samples. A frequency of 60 Hz and a ramp rate of 500 V / s were used.

[0125] The dielectric constant and loss were measured using a split-type dielectric resonator according to ASTM 2520-13, "Standard Test Methods for Complex Permittivity (Dielectric Constant) of Solid Electrical Insulating Materials at Microwave Frequencies and Temperatures to 1650 °C" (2013), with an uncertainty of approximately 0.5% and a dielectric loss tangent resolution of 5 × 10⁻⁶ for the layered dielectric sample. -5 .

[0126] Dynamic mechanical analysis and testing methods

[0127] Dynamic mechanical properties are determined according to ASTM D7028-07(2015) "Standard Test Method for Glass Transition Temperature (DMAT)". g Glass transition temperature (T) of polymer matrix composites determined by Dynamic Mechanical Analysis (DMA) gThe standard test method (2015) was used, and measurements were taken in tensile mode using a DMA Q800 instrument (TA Instruments, Eden Prairie, Minnesota). The strain module was used to perform the tests at a heating rate of 2°C / min and a frequency of 1 Hz.

[0128] Process for preparing adhesive foam

[0129] The composition was prepared by manually mixing all components together in the amounts reported in Table 2 in a wide-mouthed glass flask with continuous stirring using a tongue depressor. First, air bubbles or expandable microspheres were added and incorporated as the liquid matrix was poured in. Then, the adhesion promoter and catalyst were added, and mixing continued until a homogeneous mixture was obtained. The mixture was then poured into a mold or a prepared glass plate with septa. "Prepared glass plate" refers to a plate coated with a release agent or spray. The poured mixture was allowed to dissipate for a few minutes to allow any air bubbles to reach the surface and disappear, and then placed in an oven at 100°C for 30 minutes. The foam was then removed from the oven and allowed to cool without removing it from the mold. Once at room temperature, the foamed film or component was removed from the mold and tested. Table 2 reports the foam compositions. Table 3 shows the test results.

[0130]

[0131]

[0132] The foregoing description, given to enable those skilled in the art to practice this disclosure protected by the claims, should not be construed as a limitation on the scope of this disclosure, which is defined by the claims and all their equivalents.

Claims

1. An article comprising: A first substrate having a first portion, the first portion comprising a first metal or a first ceramic metal oxide, the first metal or the first ceramic metal oxide comprising surface hydroxyl groups; and The composite foam is combined with at least one of the first metal or the first ceramic metal oxide, and the composite foam comprises: At least one polymer that can be prepared by ring-opening metathesis polymerization of at least one cyclic olefin; At least one catalyst for the ring-opening metathesis polymerization; At least one bifunctional coupling agent represented by the following formula ZXZ Each Z independently represents a group that reacts chemically with the surface hydroxyl group to form at least one covalent bond, and Where X independently represents a divalent organic linker with a number-average molecular weight of 500 g / mol to 10000 g / mol; and At least one of hollow glass microspheres or expanded polymer microspheres.

2. The article of claim 1, wherein X independently represents a divalent organic linker group having a number-average molecular weight of 600 g / mol to 6000 g / mol.

3. The article according to claim 1, wherein the at least one polymer is capable of being prepared by ring-opening metathesis polymerization of at least one cyclic olefin, wherein the cyclic olefin comprises at least one selected from dicyclopentadiene, norbornene, ethylidene norbornene, cyclopentene, cyclooctene, tricyclopentadiene, tetracyclopentadiene, norbornene, 7-oxabicyclo[2.2.1]hept-2-ene, tetracyclo[6.2.13.6.0]dodecyl-4,9-diene, hexyl norbornene, cyclopentadiene, alkyl norbornene, or oligomers thereof.

4. The article of claim 1, wherein the at least one catalyst used for the ring-opening metathesis polymerization comprises at least one of ruthenium, tungsten, osmium, or molybdenum ring-opening metathesis polymerization catalysts.

5. The article of claim 1, wherein each Z is –N=C=O.

6. The article of claim 1, wherein the at least one bifunctional coupling agent comprises an isocyanate-terminated polyurethane prepolymer of 4,4'-diphenylmethane and polyalkylene glycol.

7. The article of claim 1, wherein the at least one bifunctional coupling agent comprises a polyether prepolymer terminated in diphenylmethane diisocyanate based on polytetramethylene ether glycol.

8. The article of claim 1, wherein X independently comprises a polyoxyethylene segment.

9. The article of claim 1, wherein X independently comprises at least one of a polyethylene oxide segment, a polypropylene oxide segment, or a polybutane oxide segment.

10. The article of claim 1, wherein X independently comprises a polybutadiene segment.

11. The article of claim 1, wherein Z is -SiR 6 a L 2 (3-a) wherein L 2 represents a hydrolysable group, wherein R 6 represents an alkyl group having 1 to 4 carbon atoms, and wherein a is 0, 1 or 2.

12. The article of claim 1, wherein the composite foam comprises the hollow glass microspheres.

13. The article of claim 1, wherein the composite foam comprises the expanded polymer microspheres.

14. The article of claim 1, wherein the composite foam has a dielectric constant of less than or equal to 2.5 and a loss tangent of less than 0.

02.

15. The article of claim 1, wherein the first portion comprises at least one of copper, silver or aluminum.

16. The article of claim 1, wherein the first portion comprises the first ceramic metal oxide.

17. The article of claim 1, further comprising a second substrate having a second portion comprising at least one of a second metal or a second ceramic metal oxide, wherein the composite foam is in contact with the second portion.

18. The article of claim 17, wherein the second portion comprises the second metal.

19. The article of claim 17, wherein the second metal comprises at least one of copper, silver or aluminum.

20. The article of claim 17, wherein the second portion comprises the second ceramic metal oxide.

21. The article of claim 1, wherein the article of claim 1 comprises an electronic device.

22. A method for preparing an article of articles, the method comprising the following steps: a) Contacting at least one metal or ceramic metal oxide portion of at least one substrate with the curable composition, wherein Each at least one metal or ceramic oxide portion has surface hydroxyl groups; and The curable composition comprises: At least one monomer capable of being polymerized via ring-opening metathesis polymerization of at least one cyclic olefin; At least one catalyst for the ring-opening metathesis polymerization; At least one bifunctional coupling agent represented by the following formula ZXZ Each Z independently represents a group that chemically reacts with a surface hydroxyl group of one abrasive particle to form at least one covalent bond, and X independently represents a divalent organic linker group with a number-average molecular weight of 500 g / mol to 10000 g / mol; and At least one of hollow glass microspheres, expanded polymer microspheres, or unexpanded polymer microspheres; b) Curing the curable composition at least partially; as well as c) If any unexpanded polymer microspheres are present, expand any unexpanded polymer microspheres.

23. The method of claim 22, wherein steps b) and c) are performed simultaneously.

24. The method of claim 22, wherein step c) is performed after step b).

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