Compositions and methods for forming 3D printable materials capable of achieving low dielectric loss

Abstract

Disclosed are photocurable compositions and processes for fabricating 3D high-frequency dielectric materials for use as insulators in circuits, for example, high-performance RF components such as antennas, filters, transmission lines, or high-frequency interconnects for electromagnetic transmission. The high-frequency circuit structures exhibit very low dielectric loss at operating frequencies (1-60 GHz).

Description

Background Art

[0001] The present disclosure provides photocurable compositions and their use as 3D printing inks for printing 3D high-frequency dielectric materials used as circuit structures (e.g., insulators for antennas).

[0002] In recent years, with the development of electronic information technology, the miniaturization and high density of electronic equipment installation, and the large capacity and high frequency of information, higher requirements are placed on the overall properties of circuit substrates (such as heat resistance, water absorption, chemical resistance, mechanical properties and dielectric properties).

[0003] Regarding dielectric properties, the signal transmission rate and dielectric constant Dk of insulating materials in high-frequency circuits have the following relationship: the lower the dielectric constant Dk of the insulating material, the faster the signal transmission rate. Therefore, it is necessary to develop substrates with low dielectric constants to achieve high-speed signal transmission rates. As the signal becomes more frequent, the signal loss (Df) of the substrate cannot be ignored. Therefore, for copper clad laminate (CCL) manufacturers, developing high-frequency circuit substrates with low dielectric loss DF and low but modulated dielectric constant Dk has become a common research direction.

[0004] 3D printing has enabled new designs for substrates, and more specifically, RF structures such as antennas. Typically, antennas are fabricated on flat, 2D substrates made of materials with low losses at the frequencies of use. In most cases, this material is based on PTFE, LCP, or other non-polar resins (including epoxies, SMAs, polybutadiene, and PPE / PPO) and filled with inorganic materials to help lower the coefficient of thermal expansion, reduce losses, and increase breakdown strength. In these cases, the antenna insulator cannot always be in an optimal orientation, as it needs to be deposited onto the 2D substrate. With the advent of 3D printing, antenna designs can now be optimized for signal propagation / reception, but the dielectric materials surrounding the antenna have less-than-ideal electronic properties. Extrusion-based fused deposition modeling (FDM) 3D printing is suitable for low-loss thermoplastic resins such as PC, PEI, PPS, PP, ABS, etc., but FDM printing cannot provide the high resolution and low surface roughness required to surround high-frequency signals, as can UV or other energy-curable systems. This is because the signal is located in the outermost region of the conductor (usually conductive ink or rod, foil or wire), and signal transmission is related to the surface roughness and current carrying capacity of the conductor, and the surface roughness of the dielectric material surrounding the conductor.

[0005] Recent research has shown that 3D-printed RF structures can achieve a 43dB increase in maximum S-parameter suppression over a wider frequency range compared to their planar counterparts (Hester et al.). Current 3D-printed UV-based materials do not have sufficiently low dielectric loss compared to conventional FDM thermoplastics, yet possess the resolution / surface roughness required for high-frequency applications. Traditional UV-curable 3D printing resins are based on acrylics, which typically have very high dielectric loss over a wide range of useful frequencies because the backbone and end groups of many of these materials are highly polar.

[0006] Therefore, there is a need in the art for low-loss dielectric materials that are UV or energy curable and highly non-polar. Long non-polar backbones with low to no water absorption are desirable, and the non-polar backbone Mw is as high as possible (yet still processable at printing temperatures) to offset the polarity required by the polar acrylate and methacrylate based end groups (or other functional groups). Summary of the Invention

[0007] In one aspect, disclosed herein is a photocurable composition suitable for printing three-dimensional (3D) high-frequency circuit structures, the photocurable composition comprising, consisting essentially of, or consisting of:

[0008] a. at least one (meth)acrylated polydiene derivative;

[0009] b. at least one ethylenically unsaturated isocyanurate (isocyanurate) or cyanurate (cyanurate);

[0010] c. Optionally, at least one aromatic vinyl monomer;

[0011] d. Optionally, at least one functionalized poly(phenylene ether) having the structure:

[0012]

[0013] Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; the example is 15 <x+y<30;25<x+y<40;30<x+y<55;60<x+y<85;80<x+y<98;

[0014] M is selected from:

[0015]

[0016] wherein Q is selected from any one of the following: ─O─, ─CO─, SO, ─SO2─, and ─CH2─, ─C(CH3)2─;

[0017] R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17 are independently selected from any one of the following: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group and a substituted or unsubstituted phenyl group;

[0018] R1, R3, R5, R7, R 10 , R 12 , R 14 and R 16 are independently selected from: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and

[0019] R9 is selected from:

[0020]

[0021] wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; and R 21 , R 22 and R 23 are independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms;

[0022] e. at least one photoinitiator;

[0023] f. at least one diluent selected from: an aromatic difunctional (meth) acrylate monomer; an alkyl (meth) acrylate monomer; and a multifunctional (meth) acrylate monomer; and

[0024] g. Optionally, at least one photoblocker.

[0025] In another aspect, disclosed herein is a process for forming a three-dimensional (3D) high-frequency dielectric material for use as an insulating component in a circuit, the process comprising the steps of:

[0026] 1) irradiating an area of ​​the photocurable composition at the irradiation site to form a cured area; and

[0027] II) causing relative motion between the irradiation site and the cured region so that the cured region grows in the direction of the moving layer,

[0028] wherein the photocurable composition comprises, consists essentially of, or consists of:

[0029] a. at least one (meth)acrylated polydiene derivative;

[0030] b. at least one ethylenically unsaturated isocyanurate or cyanurate;

[0031] c. Optionally, at least one aromatic vinyl monomer;

[0032] d. Optionally, at least one functionalized poly(phenylene ether) having the structure:

[0033]

[0034] Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; the example is 15 <x+y<30;25<x+y<40;30<x+y<55;60<x+y<85;80<x+y<98;

[0035] M is selected from:

[0036]

[0037] wherein Q is any one selected from the following: ─O─, ─CO─, SO, ─SO2─, and ─CH2─, ─C(CH3)2─;

[0038] R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17 are independently selected from any one of the following: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group;

[0039] R1, R3, R5, R7, R 10 , R 12 , R 14 and R 16 are independently selected from the group consisting of: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and

[0040] R9 is selected from:

[0041]

[0042] wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; and R 21 , R 22 and R 23 are independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms;

[0043] e. at least one photoinitiator;

[0044] f. at least one diluent selected from: an aromatic difunctional (meth) acrylate monomer; an alkyl (meth) acrylate monomer; and a multifunctional (meth) acrylate monomer; and

[0045] g. Optionally, at least one photoresist.

[0046] In another aspect, the present invention contemplates an article that is an electrical circuit comprising a conductor and an insulating component made according to the process for forming a three-dimensional (3D) high frequency dielectric material as described herein. DETAILED DESCRIPTION

[0047] By referring to the following specific embodiments, examples and drawings, the embodiments described herein can be more easily understood. However, the elements, devices and processes described herein are not limited to the specific embodiments in the specific embodiments, examples and drawings. It should be appreciated that these embodiments are merely illustrations of the principles of the present disclosure. Various modifications and changes will be apparent to those skilled in the art without departing from the spirit and scope of the present disclosure.

[0048] Furthermore, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of "1.0 to 10.0" is to be understood to include any and all subranges beginning with a minimum value of 1.0 or greater and ending with a maximum value of 10.0 or less, e.g., 1.0 to 5.3, or 4.7 to 10.0, or 3.6 to 7.9.

[0049] Unless otherwise stated, all ranges disclosed herein are also considered to include the endpoints of the range. For example, a range of "between 5 and 10" or "5 to 10" or "5-10" should generally be considered to include the endpoints 5 and 10.

[0050] When the phrase "up to" is used in conjunction with an amount or quantity, it is understood that the amount is at least a detectable amount or quantity. For example, a material present in an amount "up to" a particular amount can be present in a detectable amount and up to and including the particular amount.

[0051] Herein, ranges may be expressed as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another aspect includes from that particular value and / or to the other particular value. Similarly, when approximations are expressed by using the antecedent "about," it will be understood that the particular values ​​form additional aspects. It will further be understood that the endpoints of each range are important both in relation to and independently of the other endpoints.

[0052] As used herein in the specification and claims, the phrase "at least one" in reference to a list of one or more elements should be understood to mean at least one element selected from any one or more of the list of elements, but does not necessarily include at least one of every element specifically listed in the list of elements, and does not exclude any combination of elements in the list of elements. This definition also allows that elements may optionally be present in addition to the elements specifically identified in the list of elements to which the phrase "at least one" refers, whether or not related to those elements specifically identified. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B," or equivalently "one of A and / or B") may refer, in one embodiment, to at least one, optionally including more than one, of A, in the absence of B (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, of B, in the absence of A (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, of A, and at least one, optionally including more than one, of B (and optionally including other elements); and so on.

[0053] The terms "three-dimensional printing system," "three-dimensional printer," "printing," and the like generally describe various solid free-form manufacturing techniques for making three-dimensional articles or objects by stereolithography, selective deposition, jetting, fused deposition modeling, multi-jet modeling, digital light processing, gel deposition, continuous light interface printing, and other additive manufacturing techniques now known in the art or to be known in the future that use build materials or inks to make three-dimensional articles.

[0054] As used herein, "(meth)acrylate" includes both acrylate and methacrylate functionality.

[0055] As used herein, "resin" means a composition that can be polymerized or cured, further polymerized or fixed, or cross-linked. The resin may include a monomer, an oligomer, a prepolymer, or a mixture thereof.

[0056] As used herein, a dash ("-") that is not between two letters or symbols is used to indicate the point of attachment of a substituent. For example, (C1-C4 alkyl)S- is attached through the sulfur atom.

[0057] As used herein, "alkyl" includes branched and straight-chain saturated aliphatic hydrocarbon groups having a specified number of carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, 3-methylbutyl, tert-butyl, n-pentyl, and sec-pentyl.

[0058] As used herein, the term "monomer" refers to an organic compound having a relatively low molecular weight (e.g., typically less than 200 Da) and which can undergo chemical reactions with itself (e.g., polymerization) or with other monomers (e.g., copolymerization) to form long-chain oligomers, polymers, and copolymers.

[0059] As used herein, the term "oligomer" is understood to refer to an organic compound containing multiple repeating units (e.g., oxyalkylene repeating units) and a polydispersity (Mw / Mn) greater than 1. A monomer may or may not contain multiple repeating units but is a discrete, single molecule. For example, 2(2-ethoxyethoxy)ethyl acrylate contains two oxyethylene repeating units but is considered a monomer rather than an oligomer because it is a compound with a defined structure rather than a mixture of structurally related compounds with a distribution of molecular weights (and therefore a polydispersity > 1).

[0060] Unless otherwise indicated, the term "molecular weight" as used in this specification refers to the discrete molecular weight of a monomer and, for an oligomer or polymer, to the number average molecular weight, and unless expressly indicated otherwise, molecular weight is determined by gel permeation chromatography using polystyrene standards and tetrahydrofuran as the mobile phase for comparison and measured within five minutes after the completion of the oligomer synthesis.

[0061] Composition

[0062] The present disclosure provides a resin composition having low dielectric constant Dk and low dielectric loss factor Df as well as excellent heat resistance and interlayer adhesion to meet the requirements of high-frequency circuit substrates for dielectric properties, heat resistance and interlayer adhesion, and can be used to prepare high-frequency circuit substrates.

[0063] In one aspect, provided herein are photocurable compositions suitable for 3D printing materials for realizing high-performance RF components, such as antennas, filters, transmission lines, and interconnects. The compositions disclosed herein produce high-performance insulating RF components that exhibit reduced dielectric loss, reduced surface roughness, and improved print resolution compared to prior art compositions. The compositions disclosed herein comprise:

[0064] a. at least one (meth)acrylated polydiene derivative;

[0065] b. at least one ethylenically unsaturated isocyanurate or cyanurate;

[0066] c. Optionally, at least one aromatic vinyl monomer;

[0067] d. Optionally, at least one functionalized poly(phenylene ether) having the structure:

[0068]

[0069] Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; the example is 15 <x+y<30;25<x+y<40;30<x+y<55;60<x+y<85;80<x+y<98;

[0070] M is selected from:

[0071]

[0072] wherein Q is any one selected from the following: ─O─, ─CO─, SO, ─SO2─, and ─CH2─, ─C(CH3)2─;

[0073] R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17 are independently selected from any one of the following: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group;

[0074] R1, R3, R5, R7, R 10 , R 12 , R 14 and R 16 are independently selected from the group consisting of: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and

[0075] R9 is selected from:

[0076]

[0077] wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; and R 21 , R 22 and R 23 independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms;

[0078] e. at least one photoinitiator;

[0079] f. at least one diluent selected from: an aromatic difunctional (meth) acrylate monomer; an alkyl (meth) acrylate monomer; and a multifunctional (meth) acrylate monomer; and

[0080] g. Optionally, at least one photoresist.

[0081] Each component is described in more detail herein.

[0082] At least one (meth)acrylated polydiene derivative

[0083] The compositions disclosed herein comprise at least one (meth)acrylated polydiene derivative. This ingredient acts as an elastomer and helps to block moisture.

[0084] Suitable (meth)acrylated polydiene derivatives include oligomers that can be described as comprising an oligomeric polydiene backbone functionalized with one or more (meth)acrylate groups (which can be terminal and / or pendant to the polydiene backbone). The polydiene backbone can be at least partially hydrogenated. The polydiene backbone can be alkoxylated. The polydiene backbone can be a homopolymer, a random copolymer, or a block copolymer comprising repeating units derived from the polymerization of at least one diene monomer. Examples of suitable diene monomers include any monomeric conjugated dienes, such as 1,3-butadiene, isoprene, 1,3-pentadiene, 1,3-hexadiene, 2,3-dimethyl-1,3-butadiene, 2-ethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 3-methyl-1,3-pentadiene, 4-methyl-1,3-pentadiene, 2,4-hexadiene, and mixtures thereof, preferably 1,3-butadiene. The polydiene backbone may further comprise repeating units derived from the polymerization of at least one non-diene monomer, such as a monoethylenically unsaturated monomer (e.g., styrene, acrylonitrile), a polycarboxylic acid, a cyclic anhydride, a polyol, a cyclic ether, a polyisocyanate, a polyepoxide, and mixtures thereof. Preferably, the (meth)acrylated polydiene derivative comprises a (meth)acrylated homopolymer or copolymer of optionally hydrogenated 1,3-butadiene.

[0085] The at least one (meth)acrylated polydiene derivative may be selected from at least one of (meth)acrylated hydroxy polydienes, polydiene-based epoxy (meth)acrylates, polydiene-based polyester (meth)acrylates, polydiene-based urethane (meth)acrylates, and combinations thereof.

[0086] The (meth)acrylated hydroxy-polydiene can be the reaction product of a hydroxy-polydiene with (meth)acrylic acid or a derivative thereof. As used herein, the term "hydroxy-polydiene" refers to a polydiene having one or more hydroxyl groups. The hydroxy-polydiene can be a hydroxylated polybutadiene, particularly a hydroxylated polybutadiene having two hydroxyl groups. (Meth)acrylic acid derivatives include any compound having a (meth)acryloyl group capable of forming an ester bond with a hydroxy-functional compound, such as (meth)acrylic acid halide, (meth)acrylic anhydride, and C1-C10 alkyl esters of (meth)acrylic acid.

[0087] The polydiene-based epoxy (meth)acrylate can be an epoxy (meth)acrylate comprising one or more epoxy-polydiene-derived moieties. As used herein, the term "epoxy (meth)acrylate" refers to the reaction product of at least one epoxy-functional compound and (meth)acrylic acid. As used herein, the term "epoxy-polydiene" refers to a polydiene having one or more epoxy groups. Epoxy-polydiene can be obtained by epoxidizing at least some of the double bonds contained in the polydiene. In particular, the epoxy-polydiene can be an epoxidized polybutadiene.

[0088] Polydiene-based polyester (meth)acrylates may be polyester (meth)acrylates comprising one or more moieties derived from hydroxyl polydiene or carboxy polydiene. As used herein, the term "carboxy-polydiene" means a polydiene with one or more carboxylic acid groups. As used herein, the term "polyester (meth)acrylate" means the reaction product of at least one hydroxyl-terminated polyester with (meth)acrylic acid or a derivative thereof, or the reaction product of at least one carboxylic acid-terminated polyester with glycidyl (meth)acrylate. Hydroxyl-terminated polyesters or carboxylic acid-terminated polyesters may be obtained by the polycondensation reaction of at least one polyol (particularly a diol) and at least one polycarboxylic acid or a derivative thereof (particularly a dicarboxylic acid or a cyclic anhydride). In particular, the polyol may comprise a polybutadiene polyol, more particularly a polybutadiene diol. In particular, the polycarboxylic acid may comprise a polybutadiene polycarboxylic acid, more particularly a polybutadiene dicarboxylic acid.

[0089] The polydiene-based urethane (meth)acrylate can be a urethane (meth)acrylate comprising one or more hydroxy-polydiene-derived moieties. As used herein, the term "urethane (meth)acrylate" means the reaction product of at least one polyol, at least one polyisocyanate, and at least one hydroxyl-functional (meth)acrylate.

[0090] Examples of (meth)acrylated polydiene derivative oligomers include, for example, hydrophobic aliphatic urethane diacrylate (CN310, available from Sartomer Chemical Co., Exton, PA); hydrophobic diacrylates (e.g., CN307, CN 308); polydiene methacrylate (CN303, available from Sartomer Chemical Co., Exton, PA); and blends of polydiene methacrylate and alkyl diacrylate (CN301, available from Sartomer Americas of Exton, PA).

[0091] The structural characteristics defined above are: low water absorption, high molecular weight with a highly symmetrical backbone, low shrinkage, and good flexibility. They provide flexibility to rigid and / or brittle matrices but do have higher viscosities, which must be taken into account due to processing challenges.

[0092] The at least one (meth)acrylated polydiene derivative may be present in the composition at about 2 wt % to about 30 wt %, preferably about 10 wt % to about 25 wt %, and more preferably about 11 wt % to about 20 wt %, and most preferably about 12 wt % to about 18 wt %, based on the total weight of the composition.

[0093] At least one ethylenically unsaturated isocyanurate

[0094] The composition disclosed herein comprises at least one ethylenically unsaturated isocyanurate. The at least one ethylenically unsaturated isocyanurate is primarily used to reduce high frequency dielectric loss while maintaining good crosslinking properties.

[0095] In some embodiments, the at least one ethylenically unsaturated isocyanurate or cyanurate is at least one compound of Formula I:

[0096]

[0097] where R 2 The same or different, and are selected from the group consisting of hydrogen, lower alkyl, aryl, aralkyl, polynuclear aryl, heteroaryl, monofunctional lower-alkenyl, and substituted derivatives thereof. Alkyl and substituted alkyl groups are intended to include 1 to about 20 carbon atoms, linear or branched, and include, for example, (meth)acrylate, methyl, ethyl, chloroethyl, cyanopropyl, propyl, isopropyl, butyl, dibromobutyl, isobutyl, pentyl, hexyl, dodecyl, and the like. Aryl, aralkyl, polynuclear aryl, heteroaryl, and substituted derivatives thereof are intended to include phenyl, chlorophenyl, dibromophenyl, naphthyl, benzyl, pyridyl, cyanophenyl, tolyl, xylyl, phenanthrenyl, and the like.

[0098] In a preferred embodiment, the at least one ethylenically unsaturated isocyanurate is triallyl isocyanurate (TAIC) (product name, SR533, manufactured by Sartomer Americas, Exton, PA):

[0099]

[0100] In another embodiment, the at least one ethylenically unsaturated isocyanurate is tris(2-hydroxyethyl)isocyanurate triacrylate (THEICTA) (product name SR368, Sartomer Americas, Exton, PA):

[0101]

[0102] As another example, the at least one ethylenically unsaturated isocyanurate is tris(2-hydroxyethyl)isocyanurate trimethacrylate (THEICTMA) (product designation SR290, Sartomer Americas, Exton, PA).

[0103]

[0104] An example of an ethylenically unsaturated cyanurate is triallyl cyanurate (TAC) (product designation SR 507A, Sartomer Americas, Exton, PA):

[0105]

[0106] The above defined structures are characterized by very low dielectric losses due to high symmetry, medium viscosity, low hygroscopicity, but they can be brittle in the matrix at high loading levels.

[0107] The at least one ethylenically unsaturated isocyanurate or cyanurate may be present in the composition at about 1 wt % to about 70 wt %, preferably about 10 wt % to about 55 wt %, and more preferably about 35 wt % to about 50 wt %, based on the total weight of the composition.

[0108] Preferably, the at least one ethylenically unsaturated isocyanurate or cyanurate is present in the composition in as high a concentration as possible without making the final product too brittle.

[0109] Optional aromatic vinyl monomer

[0110] The compositions disclosed herein optionally include at least one aromatic vinyl monomer. The at least one aromatic vinyl monomer primarily functions to increase Tg and crosslink density while maintaining low dielectric properties.

[0111] Examples of aromatic vinyl monomers include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, divinylbenzene, dibromostyrene, p-tert-butylstyrene, tert-butoxystyrene, vinylbenzyldimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-dimethylaminoethylstyrene, vinylpyridine, etc. In some embodiments, the at least one aromatic vinyl monomer is selected from p-methylstyrene, divinylbenzene, dibromostyrene, and 4-tert-butylstyrene.

[0112] The at least one aromatic vinyl monomer, when used, may be present in the composition at about 1 wt % to about 25 wt %, preferably about 3 wt % to about 20 wt %, and more preferably about 5 wt % to about 10 wt %, based on the total weight of the composition.

[0113] Optionally functionalized poly(phenylene ether)

[0114] The compositions disclosed herein optionally include at least one functionalized poly(phenylene ether).The at least one functionalized poly(phenylene ether) can be used to provide a hydrophobic, ultra-low dielectric loss component to the composition, as well as improved mechanical properties.

[0115] Preferably, the functionalized poly(phenylene ether) resin has the following structure:

[0116]

[0117] Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; the example is 15 <x+y<30;25<x+y<40;30<x+y<55;60<x+y<85;80<x+y<98;

[0118] M is selected from:

[0119]

[0120] wherein N is any one selected from the group consisting of: ─O─, ─CO─, SO, ─SC─, ─SO2─, and ─C(CH3)2─;

[0121] R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17 are independently selected from: a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group;

[0122] R1, R3, R5, R7, R 10, R 12 , R 14 and R 16 are independently selected from the group consisting of: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and

[0123] R9 is selected from:

[0124]

[0125] wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; R 21 、R 22 and R 23 are independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0126] Preferably, the functionalized poly(phenylene ether) resin has a number average molecular weight of 500-10,000 g / mol, preferably 800-8,000 g / mol, and more preferably 1,000-7,000 g / mol, as measured by the method provided by the supplier. This material is solid at room temperature and tends to increase the viscosity of the composition, which limits the maximum amount available in the matrix. However, due to its symmetrical backbone, low hygroscopicity, and high glass transition temperature (Tg), it does feature low dielectric loss while adding a more rigid component to the matrix.

[0127] An example of a methacrylate-functionalized poly(phenylene ether) resin is SA9000 (SABIC), which is difunctional and has the following structure:

[0128]

[0129] where x and y are as defined above.

[0130] The at least one functionalized poly(phenylene ether) can be present in the composition at about 0 weight percent to about 30 weight percent, or about 1 weight percent to about 30 weight percent, more preferably about 3 weight percent to about 25 weight percent, and more preferably about 5 weight percent to about 20 weight percent, based on the total weight of the composition.

[0131] Preferably, the compositions disclosed herein have as high an amount of at least one functionalized poly(phenylene ether) as possible without losing control of the viscosity of the composition or failing to completely dissolve into solution.

[0132] Photoinitiator

[0133] The compositions disclosed herein include a photoinitiator for initiating curing of the composition upon exposure to actinic radiation (eg, UV or visible radiation).

[0134] A single type of photoinitiator or a combination of different types of photoinitiators can be used. Any photoinitiator that absorbs radiation (e.g., UV or visible radiation) to initiate free radical polymerization between selected oligomers and / or selected monomers can be used. Suitable exemplary photoinitiators include benzophenones, benzoin ethers, benzil ketals, α-hydroxyalkyl phenones, α-alkoxyalkyl phenones, aminoalkyl phenones, and acylphosphine photoinitiators. The photoinitiator 2,4,6-trimethylbenzoyldiphenylphosphine oxide (TPO) can be used.

[0135] The photoinitiator can be included in the composition in various suitable amounts. In embodiments, the composition includes from about 0.2% to about 15% by weight of the photoinitiator, based on the total weight of the composition. This includes embodiments in which the composition includes from about 0.2% to about 10% by weight or from about 1.0% to about 5% by weight of the photoinitiator, based on the total weight of the composition. In embodiments in which more than one photoinitiator is present in the composition, these amounts may refer to the total amount of photoinitiator in the composition.

[0136] At least one diluent

[0137] The composition disclosed herein comprises a diluent selected from the group consisting of: an aromatic difunctional (meth)acrylate monomer, an alkyl (meth)acrylate monomer; and a multifunctional (meth)acrylate monomer. Preferably, the sole diluent is an alkyl difunctional (meth)acrylate monomer or a stearyl methacrylate, preferably an alkyl difunctional (meth)acrylate monomer. The first diluent is a low-loss, high-hardness, low-viscosity compound. Preferably, the first diluent contributes to the hardness of the cured product made by curing the photocurable composition of the present invention. Preferably, the first diluent is used to maintain crosslinking to enable printability while maintaining the viscosity within the printable range.

[0138] In one embodiment of the present invention, the diluent comprises an alkyl (meth)acrylate monomer, which is at least one of an alkyl monofunctional acrylate and an alkyl monofunctional methacrylate. In another embodiment of the present invention, the diluent comprises a multifunctional (meth)acrylate monomer, which is at least one of an alkyl difunctional acrylate and an alkyl difunctional methacrylate. In an embodiment, the diluent comprises one or more of each of these or a combination thereof.

[0139] The first monomer can be an alkyl difunctional (meth) acrylate monomer, which is an alkyl difunctional (meth) acrylate, and its alkyl group has 1 to 20 carbon atoms. Its specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate and other suitable di(meth) acrylates. They can be used as a species in a single manner, or in a combination of two or more. In one embodiment of the invention, the first diluent is a cycloalkyl difunctional methacrylate. Most preferably, the first diluent is tricyclodecane dimethanol dimethacrylate, commercially available as SR834 from Sartomer Americas. The first diluent preferably has a high Tg (e.g., at least about 160°C, preferably at least about 180°C, and most preferably at least about 200°C), and preferably has a Tg of at most 240°C, more preferably at most 220°C. Preferably, the first diluent has a viscosity at 25°C of at most 2,500 mPa·s, more preferably at most 1,000 mPa·s, even more preferably at most 500 mPa·s, and most preferably at most 200 (mPa·s 25°C) using a 21 spindle at 50 RPM.

[0140] The first diluent can be included in the curable composition of the present invention in various suitable amounts. In an embodiment, the first diluent can be present in the curable composition in an amount of about 1 wt % to about 40 wt %, based on the total weight of the curable composition. Preferably, the first diluent is present in an amount of about 1 wt % to about 30 wt %, about 5 wt % to about 20 wt %, about 8 wt % to about 18 wt %, based on the curable composition.

[0141] In an embodiment of the present invention, the photocurable composition further comprises a second diluent selected from the group consisting of an alkyl (meth)acrylate monomer and a multifunctional (meth)acrylate monomer, preferably a difunctional (meth)acrylate monomer. The second diluent is used to reduce viscosity, maintain low dielectric loss, and prevent brittleness. In the absence of any second diluent, if viscosity, dielectric loss, and brittleness are sufficient for a particular application, then a second diluent is not required.

[0142] The alkyl (meth)acrylate compound is an alkyl (meth)acrylate having an alkyl group with 1 to 20 carbon atoms. Specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and the like. These may be used singly as one species or in combination of two or more.

[0143] Preferred (meth)acrylate monomers include: lauryl acrylate; SR 587 (acrylates, behenyl acrylate); CD 421A / SR421 (3,3,5-trimethylcyclohexyl methacrylate); SR 484 (octyldecyl acrylate); SR489D (tridecyl acrylate); SR 242 (isodecyl methacrylate); SR 313 (lauryl methacrylate); SR257 (stearyl acrylate); and SR 324 (stearyl methacrylate), all commercially available from Sartomer Americas, Exton, Pa. In a preferred embodiment for achieving particularly low dielectric loss, the alkyl (meth)acrylate monomer is stearyl (meth)acrylate or lauryl (meth)acrylate, preferably stearyl methacrylate.

[0144] Multifunctional (meth)acrylate monomers include difunctional and trifunctional (meth)acrylates. Suitable exemplary difunctional (meth)acrylates include 1,12-dodecanediol diacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate (e.g., SR238B from Sartomer Chemical Co.), alkoxylated hexanediol diacrylates, alkoxylated neopentyl glycol diacrylates, cyclohexanedimethanol diacrylate, diethylene glycol diacrylate (e.g., SR230 from Sartomer Chemical Co.), ethoxylated (4) bisphenol A diacrylate (e.g., SR601 from Sartomer Chemical Co.), neopentyl glycol diacrylate, polyethylene glycol (400) diacrylate (e.g., SR344 from Sartomer Chemical Co.), propoxylated (2) neopentyl glycol diacrylate (e.g., SR9003B from Sartomer Chemical Co.), tetraethylene glycol diacrylate (e.g., SR230 from Sartomer Chemical Co.), ethoxylated (4) bisphenol A diacrylate (e.g., SR601 from Sartomer Chemical Co.), neopentyl glycol diacrylate, polyethylene glycol (400) diacrylate (e.g., SR344 from Sartomer Chemical Co.), propoxylated (2) neopentyl glycol diacrylate (e.g., SR9003B from Sartomer Chemical Co.), tetraethylene glycol diacrylate (e.g., SR230 from Sartomer Chemical Co.), Co.), tricyclodecane dimethanol diacrylate (such as SR833S from Sartomer Chemical Co.), triethylene glycol diacrylate (such as SR272 from Sartomer Chemical Co.), and tripropylene glycol diacrylate.

[0145] Suitable exemplary trifunctional (meth)acrylates include ethoxylated (9) trimethylolpropane triacrylate, pentaerythritol triacrylate, propoxylated (3) glycerol triacrylate (e.g., SR9020 from Sartomer Chemical Co.), propoxylated (3) trimethylolpropane triacrylate (e.g., SR492 from Sartomer Chemical Co.).

[0146] Preferred examples of suitable multifunctional (meth)acrylate monomers include SR 834 (tricyclodecane dimethanol dimethacrylate), SR 348 (ethoxylated (n) bisphenol A dimethacrylate), SR 238 (1,6-hexanediol diacrylate), SR 262 (1,12-dodecanediol dimethacrylate), CD 595 (acrylates), SR 239 (1,6-hexanediol dimethacrylate), SR 214 (1,4-butanediol dimethacrylate), and SARBIO 5201 (acrylates), all commercially available from Sartomer Chemical Co., Exton, PA.

[0147] At least one unsaturated compound selected from alkyl (meth)acrylate monomers and multifunctional (meth)acrylate monomers can be included in the curable composition of the present invention in various suitable amounts. In an embodiment, the at least one unsaturated compound selected from alkyl (meth)acrylate monomers and multifunctional (meth)acrylate monomers is present in the curable composition in an amount ranging from about 1 wt % to about 40 wt %, based on the total weight of the curable composition. This includes embodiments in which the at least one unsaturated compound selected from alkyl (meth)acrylate monomers and multifunctional (meth)acrylate monomers is present in an amount ranging from about 1 wt % to about 30 wt %, from about 5 wt % to about 20 wt %, from about 10 wt % to about 18 wt %, based on the total weight of the curable composition.

[0148] The at least one unsaturated compound selected from the group consisting of the alkyl (meth)acrylate monomers and the multifunctional (meth)acrylate monomers disclosed above may be partially or fully hydrogenated.

[0149] In an embodiment, the total amount of at least one unsaturated compound selected from the group consisting of alkyl (meth)acrylate monomers and multifunctional (meth)acrylate monomers present in the curable composition does not exceed 70% by weight, based on the total amount of the curable composition. This includes embodiments in which the total amount does not exceed 65% by weight, does not exceed 60% by weight, does not exceed 55% by weight, does not exceed 50% by weight, does not exceed 45% by weight, or does not exceed 40% by weight, based on the total weight of the curable composition. This includes embodiments in which the total amount is in the range of from about 35% by weight to less than 60% by weight, from about 35% by weight to less than 55% by weight, from about 35% by weight to about 50% by weight, or from about 35% by weight to about 45% by weight, based on the total weight of the curable composition.

[0150] Optional photoresist

[0151] The compositions disclosed herein may include a photoresist that acts to block the passage of light or absorb light, thereby reducing the curing rate of the composition when exposed to actinic radiation (e.g., UV or visible radiation). The specific photoresist can be selected based on the specific wavelength of radiation to be blocked, the extinction coefficient of the light absorbing material at the specified wavelength, and the absence of adverse photoreactions or adverse participation in polymerization reactions. An example of a photoresist used with an ultraviolet radiation source having a peak emission wavelength of 350 nm is 2,2'-dihydroxy-4,4'-dimethoxybenzophenone. Another example is Reactint Yellow X36HS, a polyol containing a colorant, commercially available from Milliken.

[0152] If used, the photoresist may be included in the composition in various suitable amounts. In embodiments, the composition includes from about 0.2% to about 15% by weight of the photoresist, based on the total weight of the composition. This includes embodiments in which the composition includes from about 0.2% to about 10% by weight or from about 1.0% to about 5% by weight of the photoresist, based on the total weight of the composition. In embodiments in which more than one photoresist is present in the composition, these amounts may refer to the total amount of photoinitiator in the composition.

[0153] Miscellaneous optional components

[0154] In addition to these compounds, the curable compositions disclosed herein may also include conventional polymerization inhibitors, conventional fillers, other pigments and conventional additives, such as those used in the 2D RF industry, the coating industry or the printing ink industry. Also suitable as pigments are phyllosilicates, titanium dioxide, colored pigments, calcium carbonate and kaolin, and suitable fillers are, for example, silicon dioxide or aluminum silicate. As additives, conventional additives from the coating industry or the printing ink industry, in particular dispersants, redispersants, polymerization inhibitors, defoamers, catalysts, adhesion promoters, flow agents, thickeners or matting agents can be used.

[0155] In some embodiments, fillers are added to increase thermal conductivity and mechanical strength, and / or reduce thermal expansion. Suitable fillers may be: fused silica, quartz, talc aluminum silicate, and soft silica. Suitable fillers may have a particle size in the range of 0.5 μm to 15 μm.

[0156] If used, fillers may be present in the compositions disclosed herein in amounts of about 1 to about 60 weight percent, preferably about 5 to about 45 weight percent, and most preferably about 20 to about 35 weight percent.

[0157] In other embodiments, at least one polymerization inhibitor is added in an amount to prevent gelation of the photocurable composition.

[0158] The compositions disclosed herein optionally include a flame retardant to reduce the flammability of the low dielectric material. Halogen-containing flame retardants and halogen-free flame retardants can be used. Halogen-containing flame retardants can include decabromodiphenyl ethane. Halogen-free flame retardants can include phosphorus-containing flame retardants and phosphates. Phosphorus-containing flame retardants and phosphates are produced by ALBEMARLE CO., LTD.

[0159] If used, flame retardants may be present in the compositions disclosed herein in amounts of about 1 to about 35 weight percent, preferably about 5 to about 28 weight percent.

[0160] The components of the composition disclosed herein can be mixed together by any means known to those skilled in the art. The method for preparing the resin composition of the present invention comprises matching, stirring, and mixing the following in a conventional manner: a methacrylate-modified poly(phenylene ether) resin, an MQ silicone resin containing unsaturated double bonds and having a three-dimensional network structure composed of monofunctional siloxane units (M units) and tetrafunctional silica units (Q units) condensed in a hydrolytic manner; a free radical initiator, a flame retardant, and a powder filler; and various thermosetting resins and additives.

[0161] The photocurable composition disclosed herein may have a wide range of viscosities. Preferably, the composition has a viscosity in a range suitable for processing by a 3D printer at a printing temperature. In most cases, the printing temperature is room temperature (e.g., about 25°C), but some 3D printers are configured to print products at higher temperatures. Preferably, the composition of the present invention exhibits a viscosity of about 200 cPs to about 100 kcPs, preferably 500 cPs to about 20 kcPs, and most preferably 1000 cPs to about 10 kcPs at the printing temperature, the viscosity being measured by a Brookfield viscometer at 25°C using a spindle 31sp at 50-100 rpm.

[0162] In one embodiment of the present invention, the following ingredients are used: (1) about 12 wt % to about 18 wt % of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35 wt % to 50 wt % of triallyl isocyanurate; (3) about 10 wt % to about 20 wt % of SA9000; (4) about 10 wt % to about 15 wt % of a first diluent, which is tricyclodecane dimethanol dimethacrylate; (5) about 10 wt % to about 18 wt % of a second diluent, which is stearyl methacrylate; and (6) about 2 wt % to about 5 wt % of a photoinitiator, which is BPO Speedcure.

[0163] Craftsmanship

[0164] Disclosed are photocurable compositions and processes for making 3D high-frequency dielectric materials for use as insulators in circuits, for example, high-performance RF components such as antennas, filters, transmission lines, or high-frequency interconnects for electromagnetic transmission. The high-frequency circuit structures exhibit very low dielectric losses at operating frequencies (1-60 GHz).

[0165] The present invention discloses a process for forming a three-dimensional (3D) high-frequency circuit structure, comprising the steps of: I) irradiating a region of a photocurable composition at an irradiation site to form a cured region; and II) causing relative movement between the irradiation site and the cured region to cause the cured region to grow in the direction of movement, wherein the photocurable ink composition comprises: a. at least one (meth)acrylated polydiene derivative; b. at least one ethylenically unsaturated isocyanurate or cyanurate; c. optionally, at least one aromatic vinyl monomer; d. optionally, at least one functionalized poly(phenylene ether) having the following structure:

[0166]

[0167] Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; the example is 15 <x+y<30;25<x+y<40;30<x+y<55;60<x+y<85;80<x+y<98;

[0168] M is selected from:

[0169]

[0170] wherein Q is any one selected from the following: ─O─, ─CO─, SO, ─SO2─, and ─CH2─, ─C(CH3)2─;

[0171] R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17 are independently selected from any one of the following: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group;

[0172] R1, R3, R5, R7, R 10 , R 12 , R 14 and R 16 are independently selected from the group consisting of: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and

[0173] R9 is selected from:

[0174]

[0175] wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; and R 21 , R 22 and R 23Independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; at least one photoinitiator; at least one first diluent comprising an unsaturated alkyl difunctional (meth)acrylate monomer; and optionally at least one photoresist.

[0176] The process may be a continuous process or a discontinuous process (i.e., step-by-step or layer-by-layer). Suitable continuous-type processes are sometimes referred to in the art as "Continuous Liquid Interface (or Interphase) Production (or Printing)" ("CLIP") processes. Such methods are described, for example, in WO 2014 / 126830; WO 2014 / 126834; WO 2014 / 126837; and Tumbleston et al., "Continuous Liquid Interface Production of 3D Objects," Science Vol. 347, Issue 6228, pp. 1349-1352 (March 20, 2015), the entire contents of which are incorporated herein by reference for all purposes.

[0177] When stereolithography is performed above an oxygen permeable build window, the production of articles using the curable composition according to the present invention can be achieved in the CLIP step by creating an oxygen-containing "dead zone", which is a thin uncured layer of curable composition between the window and the surface of the cured article as the cured product is produced. In such a process, a curable composition is used in which curing (polymerization) is inhibited due to the presence of molecular oxygen; such inhibition is typically observed in curable compositions that can be cured by free radical mechanisms, for example. The desired dead zone thickness can be maintained by selecting various control parameters (such as photon flux) and the optical and curing properties of the curable composition. The CLIP process is performed as follows: a continuous sequence of actinic radiation (e.g., UV) images (e.g., which can be generated by a digital light processing imaging unit) is projected through an oxygen permeable, actinic radiation (e.g., UV-) transparent window below a liquid curable composition bath. The liquid interface below the advancing (growing) article (i.e., the cured area) is maintained by the dead zone created above the window. The curing article is continuously pulled from a bath of curable composition above a dead zone, which can be replenished by feeding additional amounts of curable composition into the bath to compensate for the amount of curable composition being cured and incorporated into the growing article. In another embodiment, a continuous process typically involves conveying the target substrate to be printed on, such as by a conveyor belt.

[0178] In a non-continuous or layer-by-layer process, the cured area is a first cured layer and the process further includes the following steps: III) irradiating the photocurable composition adjacent to the cured first layer to form a subsequent cured layer; IV) optionally, repeating steps II) and III) to form any additional layers to form a 3D high-frequency circuit structure.

[0179] The layer (or first layer, preceding layer or previous layer), subsequent layer (or second layer or following layer) and any additional layers (which are optionally present, as described below) are collectively referred to herein as "the layers". "Layer(s)" as used herein in the plural form may relate to layers at any stage of the process, for example, in an uncured state, in a partially cured state, in a final cured state, etc.

[0180] For this layer, the subsequent layer (or any subsequent layer) formed by printing the photocurable composition can have any shape and size. For example, the subsequent layer does not need to be continuous or have a uniform thickness. Further, the subsequent layer can be different from the layer in shape, dimensions, size, etc.

[0181] In some embodiments, the printing of subsequent layers occurs before the at least partially cured layer has reached the final cured state, that is, while the at least partially cured layer is still "green". As used herein, the term "green" encompasses partial curing but not the final cured state. The distinction between a partially cured layer and a final cured state is whether the partially cured layer can be further cured or cross-linked. Even in the final cured state, functional groups may be present but may remain unreacted due to steric hindrance or other factors. In these embodiments, the printing of the layers can be considered to be "wet-on-wet", so that adjacent layers are at least physically bonded and may also be chemically bonded to each other.

[0182] The layers may each have different dimensions (including thickness and width). The thickness and / or width tolerance of the layers may depend on the 3D printing process used, with some printing processes having high resolution and other printing processes having low resolution. The thickness of the layers may be uniform or variable, and the average thickness of the layers may be the same or different. The average thickness is generally related to the thickness of the layer immediately after printing. In various embodiments, the layers independently have an average thickness of about 1 to about 10,000, about 2 to about 1,000, about 5 to about 750, about 10 to about 500, about 25 to about 250, or about 50 to about 100 μm. Thinner and thicker thicknesses are also contemplated. The present disclosure is not limited to any particular dimensions of any layer.

[0183] In one embodiment of the present invention, step III) irradiating the photocurable composition adjacent to the cured first layer to form a subsequent cured layer comprises irradiating the subsequent layer with an energy source to form an at least partially cured subsequent layer. This step may be the same as or different from step I) irradiating the region of the photocurable composition at the irradiation site to form a cured region, with respect to the curing conditions and relevant parameters employed.

[0184] The photocurable compositions disclosed herein can also be printed on substrates such as electronic substrates to form a layer of a target component on the substrate. The substrate can be rigid or flexible and can be discontinuous or continuous in at least one of thickness and composition.

[0185] As is understood in the art, the rate and mechanism by which a photocurable ink composition cures depends on various factors, including its components, the functional groups of the components, the parameters of the curing conditions, etc. Once irradiated, the layer generally begins to cure. Exothermic and / or applied heat can accelerate the curing of the layer.

[0186] In certain embodiments, the solidified layer substantially retains its shape when exposed to ambient conditions. Environmental conditions refer to at least temperature, pressure, relative humidity, and any other conditions that may affect the shape or size of at least a portion of the solidified layer. For example, the ambient temperature is room temperature.

[0187] More specifically, prior to irradiation, the photocurable ink composition is typically viscous but flowable and may be in the form of a liquid, slurry, or gel, alternatively a liquid or slurry, alternatively a liquid. The viscosity of the photocurable ink composition may be adjusted depending on the type of 3D printer and its dispensing technique and other considerations. The viscosity may be adjusted, for example, by heating or cooling the photocurable ink composition, adding or removing solvents, carriers, and / or diluents, or adding fillers or thixotropic agents, among others.

[0188] The energy source used independently for the curing step can emit various wavelengths across the electromagnetic spectrum. In various embodiments, the energy source emits at least one of ultraviolet (UV) radiation, infrared (IR) radiation, visible light, X-rays, gamma rays, or an electron beam (e-beam). One or more energy sources can be used.

[0189] In certain embodiments, the energy source emits at least UV radiation. In physics, UV radiation is traditionally divided into four regions: near (400-300 nm), mid (300-200 nm), far (200-100 nm), and extreme (below 100 nm). Three general partitions have been observed for UV radiation: near (400-315 nm); actinic (315-200 nm); and vacuum (less than 200 nm). In certain embodiments, the energy source emits UV radiation, alternatively actinic radiation. Terms such as UVA, UVB, and UVC are also common in the industry to describe different wavelength ranges of UV radiation.

[0190] In certain embodiments, the radiation used to cure the layer(s) may have a wavelength outside the UV range. For example, visible light with a wavelength of 400 nm to 800 nm may be used. As another example, IR radiation with a wavelength exceeding 800 nm may be used.

[0191] In other embodiments, an electron beam may be used to cure the layer(s). In these embodiments, the accelerating voltage may be from about 0.1 to about 100 keV, and the vacuum may be from about 10 to about 10 -3 Pa, the electron current can be from about 0.0001 to about 1 ampere, and the power can vary from about 0.1 watt to about 1 kilowatt. The dose is typically about 100 microcoulombs / cm 2 (micro-coulomb / cm 2 ) to approximately 100 coulombs / cm 2 , alternatively from about 1 to about 10 coulombs / cm 2 Exposure times are typically about 10 seconds to 1 hour, depending on the voltage; however, shorter or longer exposure times can also be used.

[0192] Optionally, steps II) and III) may be repeated for any additional layers to form a 3D article.The total number of layers required depends, for example, on the desired RF component or other article.

[0193] Furthermore, if desired, the composite comprising all or some of the layers may be subjected to a final curing step. For example, to ensure that the 3D article is in a desired cured state, the composite formed by printing and at least partially curing the layers may be subjected to a further irradiation step. If desired, the final curing step may be the same as or different from the previous curing steps in terms of curing conditions, relevant parameters, and the radiation source used.

[0194] The present disclosure generally incorporates by reference in its entirety the ASTM designation F2792-12a, “Standard Terminology for Additive Manufacturing Technologies.” Under this ASTM standard, a “3D printer” is defined as a “machine for 3D printing,” and “3D printing” is defined as “the fabrication of an object by depositing material using a print head, nozzle, or other printer technology.” “Additive manufacturing (AM)” is defined as “the process of joining materials to fabricate an object from 3D model data, typically layer upon layer, as opposed to subtractive manufacturing methods. Synonyms related to and encompassed by 3D printing include additive manufacturing, additive process, additive technology, additive layer manufacturing, layer manufacturing, and free-form manufacturing.” AM may also be referred to as rapid prototyping (RP). As used herein, “3D printing” is generally interchangeable with “additive manufacturing,” and vice versa.

[0195] The disclosed process enables the production of insulating components of 3D high-frequency circuit structures, such as high-performance RF components, such as antennas, filters, transmission lines, or interconnects for electromagnetic transmission. The high-frequency circuit structures have very low dielectric losses at operating frequencies (1 GHz-60 GHz).

[0196] Photocurable compositions disclosed herein, when printed and photocured, show a dielectric loss (Df) of 0.007 or less, 0.006 or less, 0.005 or less, 0.004 or less, 0.003 or less from 10Mhz to 20GHz, with excellent breakdown strength. Photocurable compositions disclosed herein, when printed and photocured, show a dielectric constant (Dk) of 2.4 to 2.9 from 10Mhz to 20GHz. The frequency of the cured composition can be varied in a wide range and can include values ​​such as 1, 5, 7, 8, 10, 12, 15 and 20GHz.

[0197] In one embodiment, the printed and photocured 3D structure exhibits at least one, preferably both, of the following: a dielectric loss (Df) of less than 0.0035, preferably 0.0030, and most preferably 0.0028, measured at 25°C using a network analyzer; and a dielectric constant (Dk) of less than 2.75, preferably about 2.70, and most preferably about 2.68 at a frequency of 10.04 GHz.

[0198] In another embodiment of the present invention, the articles produced by the 3D printing process described herein are smooth and preferably have an Rz surface roughness of preferably less than 10 microns, more preferably less than 5 microns, and most preferably less than 3 microns, as measured by a profilometer.

[0199] Aspects of the invention

[0200] The present invention relates to the following aspects:

[0201] [Aspect 1] A photocurable composition suitable for 3D printing, the photocurable composition comprising:

[0202] a. at least one (meth)acrylated polydiene derivative;

[0203] b. at least one ethylenically unsaturated isocyanurate or cyanurate;

[0204] c. Optionally, at least one aromatic vinyl monomer;

[0205] d. Optionally, at least one functionalized poly(phenylene ether) having the structure:

[0206]

[0207] Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; the example is 15 <x+y<30;25<x+y<40;30<x+y<55;60<x+y<85;80<x+y<98;

[0208] M is selected from:

[0209]

[0210] wherein Q is any one selected from the following: ─O─, ─CO─, SO, ─SO2─, and ─CH2─, ─C(CH3)2─;

[0211] R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17 are independently selected from any one of the following: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group;

[0212] R1, R3, R5, R7, R 10 , R 12 , R 14 and R 16are independently selected from the group consisting of: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and

[0213] R9 is selected from:

[0214]

[0215] wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; and R 21 , R 22 and R 23 are independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms;

[0216] e. at least one photoinitiator;

[0217] f. at least one diluent selected from: an aromatic difunctional (meth) acrylate monomer; an alkyl (meth) acrylate monomer; and a multifunctional (meth) acrylate monomer; and

[0218] g. Optionally, at least one photoresist.

[0219] [Aspect 2] The composition of aspect 1, wherein the at least one diluent comprises an unsaturated alkyl difunctional (meth)acrylate monomer, and the composition further comprises at least one second diluent selected from alkyl (meth)acrylate monomers and multifunctional (meth)acrylate monomers.

[0220] [Aspect 3] The composition of aspect 1 or 2, wherein the at least one (meth)acrylated polydiene derivative is selected from at least one of the following: (meth)acrylated hydroxy polydienes, polydiene-based epoxy (meth)acrylates, polydiene-based polyester (meth)acrylates, polydiene-based urethane (meth)acrylates, and combinations thereof; in particular, selected from hydrophobic aliphatic urethane methacrylates, hydrophobic acrylates, and polybutadiene diacrylates.

[0221] [Aspect 4] The composition of any of Aspects 1-3, wherein the at least one ethylenically unsaturated isocyanurate or cyanurate is selected from triallyl cyanurate, triallyl isocyanurate, and tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate.

[0222] [Aspect 5] The composition of any of Aspects 1 to 4, wherein the at least one aromatic vinyl monomer is present and is at least one selected from the group consisting of p-methylstyrene, divinylbenzene, dibromostyrene, and p-tert-butylstyrene.

[0223] [Aspect 6] The composition of any of Aspects 1-5, wherein the at least one methacrylate-functionalized poly(phenylene ether) is present; preferably the methacrylate-functionalized poly(phenylene ether) is difunctional and has the structure:

[0224]

[0225] [Aspect 7] The composition of any of Aspects 1-6, wherein the photoinitiator is selected from the group consisting of benzophenone and its derivatives, benzoin and its derivatives, acetophenone and its derivatives, anthraquinone, thioxanthone and its derivatives, and organophosphorus compounds.

[0226] [Aspect 8] The composition of any of Aspects 1 to 7, wherein the composition does not contain a bismaleimide resin.

[0227] [Aspect 9] The composition of any of Aspects 1 or 3-8, wherein the diluent is a cycloalkyl difunctional methacrylate.

[0228] [Aspect 10] The composition of any of Aspects 2-9, wherein the second diluent is selected from stearyl methacrylate, lauryl methacrylate, stearyl acrylate, lauryl acrylate, behenyl acrylate, 3,3,5-trimethylcyclohexyl methacrylate, octyldecyl acrylate, tridecyl acrylate, and isodecyl methacrylate.

[0229] [Aspect 11] The composition of any one of Aspects 2 to 9, wherein the second diluent is stearyl (meth)acrylate or lauryl (meth)acrylate, preferably stearyl methacrylate.

[0230] [Aspect 12] The composition of any of Aspects 2-9, wherein the second diluent is a multifunctional (meth)acrylate monomer.

[0231] [Aspect 13] The composition of aspect 12, wherein the multifunctional (meth)acrylate monomer is selected from: ethoxylated (n) bisphenol A dimethacrylate, tricyclodecane dimethanol dimethacrylate, 1,6-hexanediol diacrylate, 1,12-dodecanediol dimethacrylate, 1,10-decanediol diacrylate, 1,6-hexanediol dimethacrylate, and 1,4-butanediol dimethacrylate.

[0232] [Aspect 14] The composition of any of Aspects 1-13, wherein the composition does not contain a thermal initiator.

[0233] [Aspect 15] The composition of any of Aspects 1 to 14, further comprising a flame retardant compound.

[0234] [Aspect 16] The composition according to any of Aspects 1 to 15, further comprising an inorganic filler.

[0235] [Aspect 17] The composition of aspect 16, wherein the inorganic filler is selected from high-purity quartz, alumina, beryllium oxide, aluminum nitride and glass.

[0236] [Aspect 18] The composition of any of Aspects 1 to 17, wherein a photoresist is present.

[0237] [Aspect 19] A process for forming a three-dimensional (3D) high-frequency circuit structure, the process comprising the following steps:

[0238] 1) irradiating an area of ​​the photocurable composition at the irradiation site to form a cured area; and

[0239] II) causing relative movement between the irradiation site and the cured region so that the cured region grows in the direction of movement,

[0240] Wherein, the photocurable composition comprises:

[0241] a. at least one (meth)acrylated polydiene derivative;

[0242] b. at least one ethylenically unsaturated isocyanurate or cyanurate;

[0243] c. Optionally, at least one aromatic vinyl monomer;

[0244] d. Optionally, at least one functionalized poly(phenylene ether) having the structure:

[0245]

[0246] Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; the example is 15 <x+y<30;25<x+y<40;30<x+y<55;60<x+y<85;80<x+y<98;

[0247] M is selected from:

[0248]

[0249]

[0250] wherein Q is any one selected from the following: ─O─, ─CO─, SO, ─SO2─, and ─CH2─, ─C(CH3)2─;

[0251] R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17are independently selected from any one of the following: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group;

[0252] R1, R3, R5, R7, R 10 , R 12 , R 14 and R 16 are independently selected from the group consisting of: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and

[0253] R9 is selected from:

[0254]

[0255] wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; and R 21 , R 22 and R 23 independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms;

[0256] e. at least one photoinitiator;

[0257] f. at least one diluent selected from: an aromatic difunctional (meth) acrylate monomer; an alkyl (meth) acrylate monomer; and a multifunctional (meth) acrylate monomer; and

[0258] g. Optionally, at least one photoresist.

[0259] [Aspect 20] The process of aspect 19, wherein the 3D structure is a cured resin for accommodating an antenna for electromagnetic transmission.

[0260] [Aspect 21] The process of Aspect 19 or 20, wherein the process is a continuous process carried out at least in part on a conveyor.

[0261] [Aspect 22] The process of any of aspects 19-21, wherein the cured region is a first cured layer, and the process further comprises the following steps:

[0262] III) irradiating the photocurable composition adjacent to the cured first layer to form a subsequent cured layer; and

[0263] IV) Optionally, repeating steps II) and III) to form any (one or more) additional layers to form a three-dimensional (3D) high frequency circuit structure.

[0264] [Aspect 23] The process of any of Aspects 19-22, wherein the 3D structure exhibits a dielectric loss (Df) of less than about 0.0028, as measured at 25°C using a network analyzer.

[0265] [Aspect 24] The process of any of Aspects 19-23, wherein the at least one diluent comprises an unsaturated alkyl difunctional (meth)acrylate monomer, and the photocurable composition further comprises at least one second diluent selected from an alkyl (meth)acrylate monomer and a multifunctional (meth)acrylate monomer.

[0266] [Aspect 25] The method of any of Aspects 19-24, wherein the at least one (meth)acrylated polydiene derivative is selected from the group consisting of: hydrophobic aliphatic urethane acrylates, hydrophobic acrylates, and polybutadiene diacrylates.

[0267] [Aspect 26] The process of any of Aspects 19-25, wherein the at least one ethylenically unsaturated isocyanurate or cyanurate is selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, and tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate.

[0268] [Aspect 27] The process of any of Aspects 19 to 26, wherein the at least one aromatic vinyl monomer is present and is at least one selected from the group consisting of p-methylstyrene, divinylbenzene, dibromostyrene, and p-tert-butylstyrene.

[0269] [Aspect 28] The process of any of Aspects 19-27, wherein at least one methacrylate-functionalized poly(phenylene ether) is present; preferably, the methacrylate-functionalized poly(phenylene ether) is difunctional and has the structure:

[0270]

[0271] [Aspect 29] The process of any of aspects 19-28, wherein the photoinitiator is selected from: benzophenone and its derivatives, benzoin and its derivatives, acetophenone and its derivatives, anthraquinone, thioxanthone and its derivatives, organophosphorus compounds

[0272] [Aspect 30] The process of any of Aspects 19-29, wherein the composition does not contain a bismaleimide resin.

[0273] [Aspect 31] The process of any of Aspects 19-23 or 25-30, wherein the first diluent is a cycloalkyl difunctional methacrylate.

[0274] [Aspect 32] The process of any of Aspects 24-30, wherein the second diluent is selected from: stearyl methacrylate, lauryl methacrylate, stearyl acrylate, lauryl acrylate, behenyl acrylate, 3,3,5-trimethylcyclohexyl methacrylate, octyldecyl acrylate, tridecyl acrylate, and isodecyl methacrylate.

[0275] [Aspect 33] The process of any of Aspects 24-30, wherein the second diluent is stearyl (meth)acrylate or lauryl (meth)acrylate, preferably stearyl methacrylate.

[0276] [Aspect 34] The process of any of Aspects 24-30, wherein the second diluent is a multifunctional (meth)acrylate monomer.

[0277] [Aspect 35] The process of Aspect 34, wherein the multifunctional (meth)acrylate monomer is selected from: ethoxylated (n) bisphenol A dimethacrylate, tricyclodecane dimethanol dimethacrylate, 1,6-hexanediol diacrylate, 1,12-dodecanediol dimethacrylate, 1,10-decanediol diacrylate, 1,6-hexanediol dimethacrylate, and 1,4-butanediol dimethacrylate.

[0278] [Aspect 36] The process of any of Aspects 19-35, wherein the composition does not contain a thermal initiator.

[0279] [Aspect 37] The process of any of Aspects 19-36, wherein the composition further comprises a flame retardant compound.

[0280] [Aspect 38] The process of any of Aspects 19-37, wherein the composition further comprises an inorganic filler.

[0281] [Aspect 39] The process of Aspect 38, wherein the inorganic filler is selected from high-purity quartz, alumina, beryllium oxide, aluminum nitride and glass.

[0282] [Aspect 40] The process of any of Aspects 19-39, wherein a photoresist is present in the composition.

[0283] [Aspect 41] The composition of any of Aspects 1, 3-9, or 14-18, wherein at least one diluent comprises stearyl methacrylate.

[0284] [Aspect 42] The process of any of Aspects 19-23, 24-30, or 36-40, wherein the at least one diluent comprises stearyl methacrylate.

[0285] The compositions and processes disclosed herein will be described in more detail with reference to the following examples, but it should be understood that they are not to be construed as being limited thereto.

[0286] Example

[0287] Material

[0288] The following materials were used in the examples:

[0289]

[0290] method

[0291] The following methods are used in this article:

[0292] Curing

[0293] The liquid curable composition was UV cured between glass plates in a Dymax flood lamp to a target thickness of 500 microns for 15 seconds per side to ensure complete cure, characterized by a thickness uniformity of less than ±4%. The cured product was then dried in a hot chamber at 60°C for 1 hour before testing to ensure removal of moisture.

[0294] thickness

[0295] The thickness was measured using a Heidenhain Metro gauge accurate to ±0.2 μm. Five thicknesses on the area to be measured and their average were used for the calculation.

[0296] Dielectric constant and dielectric loss

[0297] The dielectric constant (Dk) and dielectric loss (Df) were measured at 25°C using a Keysight N5222A PNA equipped with an 85072A 10 GHz split-cylinder test fixture.

[0298] Breakdown strength and shape factor

[0299] The breakdown strength (BDS) was measured at 25°C following ASTM D-149 (at a slope of 500 V / s). The test uses a 1 / 4" stainless steel ball on a brass plate immersed in silicone oil to minimize electric field inhomogeneities and the possibility of film defects at the test location. ASTM D-149 returns a value close to the sample's BDS. The breakdown strength thickness was measured in a 2mm diameter circle drawn on each 20-30μm thick film using a permanent marker, and the respective thickness was recorded before breakdown. This was done so that the ball in the planar measurement could be placed at the exact location where the thickness measurement was taken. Twenty measurements were taken for each test film, and a two-parameter Weibull distribution was fit to the data set.

[0300] Example 1

[0301] The curable composition was obtained by mixing the following ingredients at 60° C. until completely mixed and homogeneous (amounts expressed in % by weight based on the weight of the composition):

[0302]

[0303]

[0304] The compositions were cured according to the methods described herein, and the dielectric constant (Dk) and dielectric loss (Df) were measured according to the methods described herein. The following table shows the dielectric properties obtained for Samples 1-18. At 10 GHz, the effect of various monomers and oligomers on the resulting Dk and Df properties can be seen.

[0305] sample Dk (10GHz average) Df (10GHz average) 1 2,52 0,00459 2 2,50 0,00408 3 2,54 0,00435 4 2,61 0,00272 5 2,61 0,00275 6 2,67 0,00414 7 2,79 0,00345 8 2,74 0,00237 9 2,80 0,00343 10 2,94 0,00386 11 2,70 0,00397 12 2,71 0,00453 13 2,67 0,00280 14 2,62 0,00382 15 2,78 0,00410 16 2,60 0,00351 17 2,72 0,00360 18 2,60 0,00377

[0306] Example 2

[0307] The curable composition was obtained by mixing the following ingredients (amounts expressed as weight % based on the weight of the composition). The composition was cured according to the method described herein, and the dielectric constant (Dk) and dielectric loss (Df) were measured at 100°C according to the method described herein.

[0308]

[0309]

[0310] This example shows that, compared with conventional trifunctional acrylate monomers (such as SR351H or SR523), trifunctional acrylate monomers having an isocyanurate structure (such as SR533) have the advantageous effects of reducing Df and increasing Dk at 10 GHz.

[0311] The breakdown strength and shape factor were measured according to the methods described herein. Figure 1 and Figure 2 The statistical difference between the samples composed of SR351H, which is characterized by a lower breakdown strength and shape factor (426-452 V / μm), and the samples composed of SR533, which is characterized by a higher breakdown strength and shape factor (501-507 V / μm), is clearly shown. The breakdown strength of this resin is a very important property for end-use applications, as these materials pass very high currents and must continue to perform as insulators throughout their application life.

[0312] Prophetic Embodiments

[0313] The formulations according to the following embodiments of the present invention can be prepared. The following ingredients can be used in the following amounts: (1) about 12% to about 18% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 10% to about 20% by weight of SA9000; (4) about 10% to about 15% by weight of a first diluent, which is tricyclodecane dimethanol dimethacrylate; (5) about 10% to about 18% by weight of a second diluent, which is stearyl methacrylate; (6) about 3% to about 5% by weight of a photoinitiator, which is Speedcure BPO. The viscosity of these formulations can range from 2,000 to 10,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of the present invention will have a dielectric loss (Df) of less than about 0.0035 and a dielectric constant (Dk) of about 2.68, as measured at 25°C using a network analyzer.

[0314] The following ingredients can be used in the following amounts: (1) about 15% to about 22% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 4% to about 10% by weight of SA9000; (4) about 10% to about 20% by weight of a first diluent, which is tricyclodecane dimethanol dimethacrylate; (5) about 10% to about 18% by weight of a second diluent, which is stearyl methacrylate; and (6) about 1% to about 5% by weight of a photoinitiator, which is Speedcure BPO. The viscosity of these formulations can range from 2,000 to 20,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.004 and a dielectric constant (Dk) of about 2.70, as measured at 25°C using a network analyzer.

[0315] The following ingredients can be used in the following amounts: (1) about 20% to about 27% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 10% to about 20% by weight of SA9000; (4) about 10% to about 18% by weight of a second diluent, which is stearyl methacrylate; and (5) about 1% to about 5% by weight of a photoinitiator, which is Speedcure BPO. The viscosity of these formulations can range from 2,000 to 20,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.003 and a dielectric constant (Dk) of about 2.67, as measured at 25°C using a network analyzer.

[0316] The following ingredients can be used in the following amounts: (1) about 10% to about 15% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 15% to about 20% by weight of SA9000; (4) about 18% to about 28% by weight of a diluent, which is lauryl methacrylate; and (5) about 1% to about 5% by weight of a photoinitiator, which is Speedcure BPO. The viscosity of these formulations can range from 2,000 to 20,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.0044 and a dielectric constant (Dk) of about 2.67, as measured at 25°C using a network analyzer.

[0317] The following ingredients can be used in the following amounts: (1) about 10% to about 15% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 15% to about 20% by weight of SA9000; (4) about 18% to about 28% by weight of a diluent, which is stearyl acrylate; and (5) about 1% to about 5% by weight of a photoinitiator, which is Speedcure BPO. The viscosity of these formulations can range from 2,000 to 20,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.0040 and a dielectric constant (Dk) of about 2.69, as measured at 25°C using a network analyzer.

[0318] The following ingredients can be used in the following amounts: (1) about 10% to about 15% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 15% to about 20% by weight of SA9000; (4) about 18% to about 28% by weight of a diluent, which is stearyl methacrylate; and (5) about 1% to about 5% by weight of a photoinitiator, which is Speedcure BPO. The viscosity of these formulations can range from 2,000 to 15,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.0035 and a dielectric constant (Dk) of about 2.74, as measured at 25°C using a network analyzer.

[0319] The following ingredients can be used in the following amounts: (1) about 10% to about 15% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic aliphatic urethane diacrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 15% to about 20% by weight of SA9000; (4) about 18% to about 28% by weight of a diluent, which is stearyl methacrylate; and (5) about 1% to about 5% by weight of a photoinitiator, which is Speedcure TPOL. The viscosity of these formulations can range from 2,000 to 15,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.0036 and a dielectric constant (Dk) of about 2.75, as measured at 25°C using a network analyzer.

[0320] The following ingredients can be used in the following amounts: (1) about 10% to about 15% by weight of a (meth)acrylated polydiene derivative, which is a hydrophobic acrylate; (2) about 35% to about 50% by weight of triallyl isocyanurate; (3) about 15% to about 25% by weight of SA9000; (4) about 10% to about 23% by weight of a diluent, which is stearyl methacrylate; and (5) about 1% to about 5% by weight of a photoinitiator, which is Speedcure BPO. The viscosity of these formulations can range from 2,000 to 15,000 cPs. Such compositions can be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.0035 and a dielectric constant (Dk) of about 2.77, as measured at 25°C using a network analyzer.

[0321] The following ingredients may be used in the following amounts: (1) about 20% to about 28% by weight of a (meth)acrylated polydiene derivative that is a hydrophobic aliphatic urethane diacrylate; (2) about 10% to about 20% by weight of triallyl isocyanurate; (3) about 17% to about 25% by weight of SA9000; (4) about 10% to about 20% by weight of a first diluent that is tricyclodecane dimethanol dimethacrylate; (5) about 10% to about 18% by weight of a second diluent that is stearyl methacrylate; and (6) about 10% to about 18% by weight of a third diluent that is 1,12-dodecanediol dimethacrylate; and (7) about 1% to about 5% by weight of a photoinitiator that is Speedcure BPO. The viscosity of these formulations may range from 2,000 to 20,000 cPs. Such compositions may be cured using any known 3D printer. The cured product can then be tested for dielectric loss and dielectric constant at 10.04 GHz according to IPC Test Method TM-650 2.5.5.13. It is believed that certain optimized formulations of this embodiment of the invention will have a dielectric loss (Df) of less than about 0.0037 and a dielectric constant (Dk) of about 2.45, as measured at 25°C using a network analyzer.

[0322] Although illustrated and described above with reference to certain specific embodiments and prophetic embodiments, the embodiments disclosed herein are not intended to be limited to the details shown. Rather, various modifications may be made to the details within the scope and range of equivalents of the claims without departing from the spirit of the invention. For example, all references to broad ranges in this document include within their scope all narrower ranges that fall within the broader ranges.

Claims

1. A photocurable composition suitable for 3D printing, comprising: a. at least one (meth)acrylated polydiene derivative; b for maintaining crosslinking properties of at least one ethylenically unsaturated isocyanurate or cyanurate; c. Optionally, at least one aromatic vinyl monomer; d. Optionally, at least one functionalized poly(phenylene ether) having the structure: Where 1≤x≤100; 1≤y≤100; 2≤x+y≤100; M is selected from: wherein Q is any one selected from the following: ─O─, ─CO─, SO, ─SO2─, and ─CH2─, ─C(CH3)2─; R2, R4, R6, R8, R 11 , R 13 , R 15 and R 17 are independently selected from any one of the following: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; R1, R3, R5, R7, R 10 , R 12 , R 14 and R 16 are independently selected from the group consisting of: a hydrogen atom, a substituted or unsubstituted C1-C8 straight-chain alkyl group, a substituted or unsubstituted C1-C8 branched-chain alkyl group, and a substituted or unsubstituted phenyl group; and R9 is selected from: wherein A is selected from: an arylene group, a carbonyl group, or an alkylene group having 1 to 10 carbon atoms; Z is an integer from 0 to 10; and R 21 , R 22 and R 23 are independently selected from: a hydrogen atom or an alkyl group having 1 to 10 carbon atoms; e. at least one photoinitiator; f at least one diluent selected from: aromatic difunctional (meth) acrylate monomers; (meth) alkyl acrylate monomers; and multifunctional (meth) acrylate monomers; and Optionally, at least one photoresist.

2. The composition of claim 1, wherein 15 <x+y<30。 3. The composition of claim 1, wherein 25 <x+y<40。 4. The composition of claim 1, wherein 30 <x+y<55。 5. The composition of claim 1, wherein 60 <x+y<85。 6. The composition of claim 1, wherein 80 <x+y<98。 7. The composition of claim 1, wherein the at least one diluent comprises an unsaturated alkyl difunctional (meth)acrylate monomer, and the composition further comprises at least one second diluent selected from the group consisting of an alkyl (meth)acrylate monomer and a multifunctional (meth)acrylate monomer.

8. The composition of any one of claims 1 to 7, wherein the at least one (meth)acrylated polydiene derivative is selected from at least one of the group consisting of (meth)acrylated hydroxy polydienes, polydiene-based epoxy (meth)acrylates, polydiene-based polyester (meth)acrylates, polydiene-based urethane (meth)acrylates, and combinations thereof.

9. The composition of claim 8, wherein the at least one (meth)acrylated polydiene derivative is selected from at least one of the group consisting of a hydrophobic acrylate, and a polybutadiene diacrylate.

10. The composition of claim 9, wherein the hydrophobic acrylate is a hydrophobic aliphatic urethane acrylate.

11. The composition of any one of claims 1 to 7, wherein the at least one ethylenically unsaturated isocyanurate or cyanurate is selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, and tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate.

12. The composition of any one of claims 1 to 7, wherein the at least one aromatic vinyl monomer is present and is at least one member selected from the group consisting of p-methylstyrene, divinylbenzene, dibromostyrene, and p-tert-butylstyrene.

13. The composition of any one of claims 1 to 7, wherein the at least one methacrylate-functionalized poly(phenylene ether) is present.

14. The composition of claim 13, wherein the methacrylic acid-functionalized poly(phenylene ether) is difunctional and has the structure:

15. The composition of any one of claims 1 to 7, wherein the photoinitiator is selected from the group consisting of benzophenone and its derivatives, benzoin and its derivatives, acetophenone and its derivatives, anthraquinone, thioxanthone and its derivatives, and organophosphorus compounds.

16. The composition of any one of claims 1 to 7, wherein the composition is free of bismaleimide resin.

17. The composition of any one of claims 1 to 7, wherein the diluent is a cycloalkyl difunctional methacrylate.

18. The composition of claim 7, wherein the second diluent is selected from the group consisting of stearyl methacrylate, lauryl methacrylate, stearyl acrylate, lauryl acrylate, behenyl acrylate, 3,3,5-trimethylcyclohexyl methacrylate, octyldecyl acrylate, tridecyl acrylate, and isodecyl methacrylate.

19. The composition of claim 7, wherein the second diluent is stearyl (meth)acrylate or lauryl (meth)acrylate.

20. The composition of claim 7, wherein the second diluent is a multifunctional (meth)acrylic monomer.

21. The composition of claim 20, wherein the multifunctional (meth)acrylic monomer is selected from the group consisting of ethoxylated (n) bisphenol A dimethacrylate, tricyclodecane dimethanol dimethacrylate, 1,6-hexanediol diacrylate, 1,12-dodecanediol dimethacrylate, 1,10-decanediol diacrylate, 1,6-hexanediol dimethacrylate, and 1,4-butanediol dimethacrylate.

22. The composition of any one of claims 1 to 7, wherein the composition is free of thermal initiators.

23. The composition of any one of claims 1 to 7, further comprising a flame retardant compound.

24. The composition of any one of claims 1 to 7, further comprising an inorganic filler.

25. The composition of claim 24, wherein the inorganic filler is an inorganic filler selected from the group consisting of high purity quartz, alumina, beryllium oxide, aluminum nitride, and glass.

26. The composition of any one of claims 1 to 7, wherein the photoresist is present.

27. The composition of any one of claims 1 to 7, wherein the at least one diluent comprises stearyl methacrylate.

28. A process for forming a three-dimensional (3D) high-frequency circuit structure, the process comprising the following steps: 1) irradiating an area of ​​the photocurable composition as defined in any one of claims 1 to 27 at an irradiation site to form a cured area; and II) causing relative motion between the irradiation site and the cured region to cause the cured region to grow in the direction of motion.

29. The process of claim 28, wherein the 3D structure is a cured resin for housing an antenna for electromagnetic transmission.

30. The process of claim 28 or 29, wherein the process is a continuous process running at least partially on a conveyor.

31. The process of claim 28 or 29, wherein the cured region is a first cured layer, and the process further comprises the steps of: III) irradiating the photocurable composition adjacent to the cured first layer to form a subsequent cured layer; and IV) Optionally, repeating steps II) and III) to form any additional layers to form a 3D high frequency circuit structure.

32. The process of claim 29, wherein the 3D structure exhibits a dielectric loss (Df) less than 0.0028, as measured at 25°C using a network analyzer.

Images