A low-dielectric phosphorus-containing flame-retardant resin, a preparation method and application thereof

Abstract

The present application relates to the technical field of high polymer materials, in particular to a low dielectric phosphorus-containing flame-retardant resin and a preparation method and application thereof. The low dielectric phosphorus-containing flame-retardant resin comprises one or more structures as shown in the following formula I: A 2 one or more selected from substituted or unsubstituted arylene, substituted or unsubstituted arylidene; R 1 , R 2 are each independently selected from one or more of substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, hydrogen, substituted or unsubstituted linear or branched alkyl, substituted or unsubstituted cyclic alkyl, substituted or unsubstituted heteroaryl. The resin of the present application is good in solubility, heat resistance and flame retardancy, low in dielectric property, and is convenient to apply in prepreg, copper-clad plate and printed circuit board.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a low-dielectric phosphorus-containing flame-retardant resin, its preparation method, and its applications. Background Technology

[0002] In the field of electronic and electrical materials, electronic devices, represented by smartphones, are developing rapidly, especially in the field of information and communication, where the amount of information processed is constantly increasing and the trend of signal frequency is significant. With the development of high functionality and miniaturization of electronic devices, communication devices, personal computers, etc., the circuit boards used are also developing towards multi-layering, high-density wiring, and high-speed signal transmission, which puts forward higher requirements for the overall performance of printed circuit boards.

[0003] To maintain high transmission rates and signal integrity, printed circuit boards (PCBs), the core components of electronic products, require resin materials with lower dielectric constants and lower dielectric loss tangents. Therefore, further reducing the dielectric constant and dielectric loss of resin materials is a critical technical challenge that urgently needs to be addressed.

[0004] Vinyl compounds have attracted much attention due to their good reactivity and low dielectric constant and low dielectric loss tangent. However, vinyl resins do not have flame retardancy, resulting in poor flame retardancy of copper-clad laminates.

[0005] To improve the flame retardant properties of copper-clad laminates made from vinyl ester resins, flame retardants are often added, such as halogenated flame retardants, inorganic flame retardants, and phosphine-based flame retardants. Among these, halogenated flame retardants are gradually being phased out because they can produce dioxins, which are highly carcinogenic; inorganic flame retardants are difficult to disperse evenly, affecting their performance; and phosphine-containing flame retardants are difficult to process due to their poor solubility.

[0006] Therefore, there is an urgent need to provide a low-dielectric resin that has good solubility, good flame retardancy, and is easy to process. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a low dielectric phosphorus-containing flame-retardant resin, its preparation method, and its application, in order to solve the problems of poor flame retardancy, solubility, and processability of resins used in the preparation of copper-clad laminates in the prior art.

[0008] To achieve the above and other related objectives, the present invention is obtained through the following technical solution.

[0009] A first aspect of the present invention is to provide a low-dielectric phosphine-containing flame-retardant resin, comprising one or more structures as shown in Formula I below:

[0010]

[0011] Where * indicates the connection position;

[0012] A 2 Selected from one or more of substituted or unsubstituted aryl groups and substituted or unsubstituted metaaryl groups;

[0013] R 1 R 2 Each is independently selected from one or more of the following: substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, hydrogen, substituted or unsubstituted straight-chain or branched alkyl, substituted or unsubstituted cyclic alkyl, and substituted or unsubstituted heteroaryl.

[0014] In the presence of multiple A 2 In the case of multiple A's 2 They can be the same or different;

[0015] When A 2 When located at the end base, A 2 Selected from substituted or unsubstituted aryl groups, i.e. for

[0016] When A 2 When not at the end base, A 2 Selected from substituted or unsubstituted metaaryl groups, i.e. for

[0017] In the existence of multiple R 1 In the case of multiple R 1 They can be the same or different;

[0018] In the existence of multiple R 2 In the case of multiple R 2 They can be the same or different;

[0019] R 1 R 2 Interconnected to form a ring for or R 1 R 2 They are not connected to form a loop. for

[0020] A second aspect of the present invention is to provide a method for preparing a low-dielectric phosphorus-containing flame-retardant resin as described above, comprising the following steps:

[0021] (1) The raw material XR 3 -A 1 -R 4 -X, XR 5 -A 3 -R 6 -X、 The mixture is then reacted under acidic conditions to give an intermediate; wherein X is selected from halogens;

[0022] (2) Take the intermediate obtained in step (1), Solvents are mixed and then reacted under alkaline conditions to obtain a low-dielectric phosphorus-containing flame-retardant resin.

[0023] The third aspect of this invention provides the application of low-dielectric phosphorus-containing flame retardant resins prepared by the methods described above and / or the methods described above in the preparation of low-dielectric phosphorus-containing flame retardant resins in prepregs, copper-clad laminates, and printed circuit boards.

[0024] As described above, the low-dielectric phosphorus-containing flame-retardant resin, its preparation method, and its application of the present invention have the following beneficial effects compared with the prior art:

[0025] The low-dielectric phosphorus-containing flame-retardant resin of the present invention has good solubility, can be uniformly dispersed, effectively solves the processability problem, and has low dielectric properties, high heat resistance, and good flame retardancy. Attached Figure Description

[0026] Figure 1 The image shows the low-dielectric phosphorus-containing flame-retardant resin prepared in Example 1 of this invention. 1 Schematic diagram of H-NMR. Detailed Implementation

[0027] To make the inventive objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. Those skilled in the art can easily understand other advantages and effects of this invention from the content disclosed in this specification.

[0028] Unless otherwise stated, the following words, phrases and symbols used in this specification generally have the meanings described below.

[0029] Before further describing the specific embodiments of this application, it should be understood that the scope of protection of this application is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of this application is for describing specific embodiments and not for limiting the scope of protection of this application. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0030] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in this application, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description in this application, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this application may be used to implement this application.

[0031] In this article,

[0032] The circled portion indicates non-positional replacement, including...

[0033] * indicates the connection position. Indicates the connection location.

[0034] Generally, the nomenclature used herein (e.g., IUPAC nomenclature) and the laboratory procedures described below (including those for organic chemistry and analytical chemistry) are those well-known and commonly used in the art. Unless otherwise defined, all scientific and technical terms used herein in conjunction with the disclosure described herein have the same meaning as commonly understood by one of ordinary skill in the art. Additionally, in the claims and / or description, the term “a” or “an” used in conjunction with the term “comprising” or a noun may mean “one,” but also is consistent with the meanings of “one or more,” “at least one,” and “one or more.” Similarly, the term “another” or “other” may mean at least a second or more.

[0035] In this document, the term “substituted or unsubstituted”, used alone or in combination, means substituted with one or more of the following substituents: halogen, alkyl, cycloalkyl, alkoxy, silyl, alkenyl, aryl, aralkyl, aryl-alkenyl, aryloxy, heteroaryl.

[0036] In this document, the term "alkyl" used alone or in combination may be straight-chain or branched, and the number of carbon atoms may be, for example, C1–C10, C1–C9, C1–C8, C1–C7, C1–C6, C1–C5, C1–C4, C1–C3, C1–C2, etc. As examples, alkyl includes, but is not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, etc. Alkylene refers to divalent alkyl groups.

[0037] In this document, the term "alkenyl" used alone or in combination may have the following number of carbon atoms, for example: C2-C10, C3-C10, C2-C5, C2-C4, C2-C3, etc. As examples, alkenyl includes, but is not limited to, vinyl, allyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, etc.

[0038] In this document, the term "cyclic hydrocarbon group," used alone or in combination, refers to a saturated and partially unsaturated (i.e., having one or more double bonds, but not fully conjugated) monocyclic, bicyclic, or polycyclic hydrocarbon group having, in some embodiments, 3 to 10 carbon atoms (i.e., C3-C10 cyclic hydrocarbon group), 3 to 6 carbon atoms (i.e., C3-C6 cyclic hydrocarbon group), C3-C5 cyclic hydrocarbon group, or C3-C4 cyclic hydrocarbon group, etc. Representative examples of cyclic hydrocarbon groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclohexyl, and cyclohexenyl.

[0039] In this document, the term "aryl" used alone or in combination refers to a combination of aromatic hydrocarbon groups having a monocyclic or two- or more rings, such as C6-C30, C6-C20, C6-C13 aryl groups, etc. Further, the combination of two or more rings refers to a form where they are simply side-attached or fused together. Examples of monocyclic groups include, but are not limited to, phenyl; two or more rings side-attached together include, but are not limited to, biphenyl; two or more rings fused together include, but are not limited to, naphthyl and 9,9-diphenylfluorenyl. C6-C30 aryl refers to an aryl group having 6-30 carbon atoms and containing no substituents. In this disclosure, "aryl" may optionally refer to a substituted aryl group, meaning an aryl group substituted by one or more substituents, such as a monosubstituted, disubstituted, or trisubstituted aryl group, where the substituents may optionally be selected, for example, from one or more combinations of halogens, C1-C3 alkyl groups, and C6-C12 aryl groups. A arylene is a divalent aryl group, and a mesaryl is a trivalent aryl group.

[0040] In this document, the term "heteroaryl" used alone or in combination refers to a monovalent heteroaryl group of C3-C10, consisting of a monocyclic, bicyclic, or polycyclic aromatic ring having one or more (e.g., one to four, one to three, or one to two) heteroatoms independently selected from oxygen, nitrogen, and sulfur. Heteroaryl groups include, but are not limited to, pyridyl, pyrrolithyl, pyrimidinyl, and triazineyl. In this disclosure, "heteroaryl" may optionally refer to a substituted heteroaryl group, meaning a heteroaryl group substituted with one or more substituents, such as monosubstituted, disubstituted, or trisubstituted heteroaryl groups, wherein the substituents may optionally be selected, for example, from one or more combinations of halogens, C1-C3 alkyl groups, and C6-C12 aryl groups.

[0041] A first aspect of the present invention is to provide a low-dielectric phosphine-containing flame-retardant resin, comprising one or more structures as shown in Formula I below:

[0042]

[0043] Where * indicates the connection position;

[0044] A 2 Selected from one or more of substituted or unsubstituted aryl groups and substituted or unsubstituted metaaryl groups;

[0045] R 1 R 2 Each is independently selected from one or more of the following: substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, hydrogen, substituted or unsubstituted straight-chain or branched alkyl, substituted or unsubstituted cyclic alkyl, and substituted or unsubstituted heteroaryl.

[0046] In some embodiments of the present invention, unless otherwise specified, the substituents involved in the present invention are selected from one or more of halogenated atoms, alkyl groups, cycloalkyl groups, alkenyl groups, alkoxy groups, aryl groups, aralkyl groups, and heteroaryl groups. Preferably, the substituents are selected from C1-C6 alkyl groups and halogenated atoms; more preferably, the substituents are selected from one or more of methyl, ethyl, chlorine, and bromine.

[0047] In some embodiments of the present invention, when A 2 When located at the end base, A 2 Selected from substituted or unsubstituted aryl groups, i.e. for When A 2 When not at the end base, A 2 Selected from substituted or unsubstituted metaaryl groups, i.e. for That is, when A 2 When located at the end base, A 2 It contains only two substituents, which is equivalent to one of the substituents of the mesoaryl group being H.

[0048] In some embodiments of the present invention, the A 2 It is selected from one or more of substituted or unsubstituted C6-C30 arylene and substituted or unsubstituted C6-C30 metaarylene.

[0049] In some embodiments of the present invention, A 2 It is selected from one or more of substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted biphenylene, substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, or substituted or unsubstituted biphenylene. The substituted substituents are as described above.

[0050] In some embodiments of the present invention, when there are multiple A's 2 In the case of multiple A's 2 They can be the same or different.

[0051] In some embodiments of the present invention, when there are multiple R 1 In the case of multiple R 1 They can be the same or different.

[0052] In some embodiments of the present invention, when there are multiple R 2 In the case of multiple R 2 They can be the same or different.

[0053] In some embodiments of the present invention, the R 1 R 2 Each of the substituents is independently selected from one or more of the following: substituted or unsubstituted aryl groups, substituted or unsubstituted aryloxy groups, H, substituted or unsubstituted C1-C10 straight-chain or branched alkyl groups, substituted or unsubstituted C3-C10 branched or straight-chain cyclic alkyl groups, and substituted or unsubstituted heteroaryl groups. The substituted substituents are as described above.

[0054] In some embodiments of the present invention, R 1 R 2 Interconnected to form a ring for

[0055] In some embodiments of the present invention, R 1 R 2 They are not connected to form a loop. for

[0056] In some embodiments of the present invention, one or more structures as shown in Formula II below are also included:

[0057]

[0058] in,

[0059] A 4 It is selected from one or more of substituted or unsubstituted aryl groups and substituted or unsubstituted metaaryl groups.

[0060] In some embodiments of the present invention, the substituted substituents are as described above.

[0061] In some embodiments of the present invention, the A 4 It is selected from one or more of substituted or unsubstituted C6-C30 arylene and substituted or unsubstituted C6-C30 metaarylene.

[0062] In some embodiments of the present invention, the A 4 It is selected from one or more of substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, substituted or unsubstituted biphenylene, substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, or substituted or unsubstituted biphenylene.

[0063] In some embodiments of the present invention, when A 4 When located at the end base, A 4 Selected from substituted or unsubstituted aryl groups, i.e. for When A 4 When not at the end base, A 4 Selected from substituted or unsubstituted metaaryl groups, i.e. for That is, when A 4 When located at the end base, A 4 It contains only two substituents, which is equivalent to one of the substituents of the mesoaryl group being H.

[0064] In some embodiments of the present invention, when there are multiple A's 4 At that time, multiple A's 4 They can be the same or different.

[0065] In some embodiments of the present invention, Formula I is selected from the structure shown in Formula I-1:

[0066]

[0067] In some embodiments of the present invention, Formula II is selected from the structure shown in Formula II-1:

[0068]

[0069] In some embodiments of the present invention, the A 1 A 3 Independently selected from substituted or unsubstituted aryl groups; preferably, the A 1 A 3Independently selected from substituted or unsubstituted C6-30 aryl groups; more preferably, the A 1 A 3 It is independently selected from one or more of substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, and substituted or unsubstituted biphenylene.

[0070] In some embodiments of the present invention, when there are multiple A's 1 Or A 3 At that time, multiple A's 1 Or A 3 They can be the same or different. Specifically, when there are multiple A's... 1 At that time, multiple A's 1 They can be the same or different. When there are multiple A's... 3 At that time, multiple A's 3 They can be the same or different.

[0071] In some embodiments of the present invention, the A 1 A 3 One or more of the following groups, selected independently, whether substituted or unsubstituted:

[0072] In some embodiments of the present invention, the R 3 R 4 R 5 R 6 Each is independently selected from one or more of substituted or unsubstituted straight-chain or branched alkylene groups, substituted or unsubstituted cyclic alkylene groups, and substituted or unsubstituted ester groups; the substituents are selected from one or more of halogenated atoms, alkyl groups, cyclic hydrocarbon groups, alkenyl groups, alkoxy groups, aryl groups, aralkyl groups, and heteroaryl groups; preferably, the R 3 R 4 R 5 R 6 Each is independently selected from substituted or unsubstituted straight-chain or branched C1-C6 alkylene groups; more preferably, the R 3 R 4 R 5 R 6 Each is independently selected from one or more of methylene (CH2), ethylene (CH2CH2), isopropylene (CH3CCH3), and propylene (CH2CH2CH2).

[0073] In some embodiments of the present invention, when there are multiple R 3 R 4 R 5 or R 6 At that time, multiple R 3 R4 R 5 or R 6 They can be the same or different. Specifically, when there are multiple R... 3 At that time, multiple R 3 They can be the same or different. When there are multiple R... 4 At that time, multiple R 4 They can be the same or different. When there are multiple R... 5 At that time, multiple R 5 They can be the same or different. When there are multiple R... 6 At that time, multiple R 6 They can be the same or different.

[0074] In some embodiments of the present invention, the *-R 3 -A 1 -R 4 -*、*-R 5 -A 3 -R 6 -*Selected independently from the following groups, either unsubstituted or methyl-substituted. Preferably, when there is a methyl substitution, the number of substituents is one or more.

[0075] In some embodiments of the present invention, the structure represented by Formula I-1 is selected from one or more of the following structural formulas, the specific structural formulas being as follows:

[0076]

[0077]

[0078] In some embodiments of the present invention, the structure represented by Formula II-1 is selected from one or more of the following structural formulas, the specific structural formulas being as follows:

[0079]

[0080] In some embodiments of the present invention, the weight-average molecular weight of the low-dielectric phosphine-containing flame-retardant resin is 300-10000; specifically, the weight-average molecular weight of the low-dielectric phosphine-containing flame-retardant resin can be 300-450, 450-500, 500-1000, 300-2000, 300-1000, 300-5000, 1000-5000, 5000-8000, or 8000-10000. Typical, but not limiting, examples include 570, 575, 578, 585, 633, 638, and 710.

[0081] In some embodiments of the present invention, the equivalent of the unsaturated double bonds in the low-dielectric phosphine-containing flame-retardant resin is 200-5000 g / eq; specifically, the equivalent of the unsaturated double bonds in the low-dielectric phosphine-containing flame-retardant resin can be 200-250 g / eq, 250-300 g / eq, 300-1000 g / eq, 250-1500 g / eq, 1000-3000 g / eq, or 3000-5000 g / eq. Typical, but not limiting, examples include 505 g / eq, 918 g / eq, 920 g / eq, 932 g / eq, 941 g / eq, 955 g / eq, and 956 g / eq.

[0082] In some embodiments of the present invention, the phosphine content of the low-dielectric phosphine-containing flame retardant resin is 0.5-10%; specifically, the phosphine content of the low-dielectric phosphine-containing flame retardant resin can be 0.5-2%, 2-5%, 2-8%, 5-8%, or 8-10%; typically, but not limitingly, for example, 2.8%, 5.8%, 6.0%, or 6.1%.

[0083] In some embodiments of the present invention, the bromine residue of the low-dielectric phosphine-containing flame-retardant resin is less than 5000 ppm; preferably, the bromine residue of the low-dielectric phosphine-containing flame-retardant resin is less than 2000 ppm; more preferably, the bromine residue of the low-dielectric phosphine-containing flame-retardant resin is less than 500 ppm. Typical, but not limiting, values ​​are, for example, 60 ppm, 55 ppm, 54 ppm, and 52 ppm.

[0084] In some embodiments of the present invention, the low-dielectric phosphine-containing flame-retardant resin comprises the following structural formula:

[0085] and / or

[0086]

[0087] in, Represents an organic unit. Preferably, it is... Repeating units or A repeating unit or a combination of both, and the position is not fixed.

[0088] A second aspect of the present invention is to provide a method for preparing a low-dielectric phosphorus-containing flame-retardant resin as described above, comprising the following steps:

[0089] (1) The raw material XR 3 -A 1 -R 4 -X, XR 5 -A 3 -R 6 -X、 The mixture is then reacted under acidic conditions to give an intermediate; wherein X is selected from halogens;

[0090] (2) Take the intermediate obtained in step (1), Solvents are mixed and then reacted under alkaline conditions to obtain a low-dielectric phosphine-containing flame-retardant resin. The intermediates involved in the alkaline reaction include... or contain Further dehydrohalogenation under alkaline conditions yields a low-dielectric phosphorus-containing flame-retardant resin.

[0091] In some embodiments of the present invention, the acid used under acidic conditions in step (1) is selected from one or more of sulfuric acid, hydrochloric acid, phosphoric acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, Lewis acid, solid acid, acidic ion exchange resin, aluminum chloride or zinc chloride, activated clay, acidic clay, silica, zeolite, and silica-alumina.

[0092] In some embodiments of the present invention, the reaction temperature in step (1) is 80-150°C; the reaction time is 1-10h.

[0093] In some embodiments of the present invention, the solvent in step (2) is selected from one or more of toluene, xylene, trimethylbenzene, cyclohexane, n-hexane, diethyl ether, diisopropyl ether, ethyl acetate, butyl acetate, isobutyl ketone, cyclopentanone, dimethyl sulfone, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, 1,3-dimethyl-2-imidazolinone, and N-methylpyrrolidone.

[0094] In some embodiments of the present invention, the reaction temperature in step (2) is 40-100°C; the reaction time is 0.5-10h.

[0095] In some embodiments of the present invention, step (2) further includes the addition of a phase transfer catalyst during the reaction process. Preferably, the phase transfer catalyst is selected from one or more of tetrabutylammonium bromide, tetradecyltrimethylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride, benzyltriethylammonium chloride (TEBA), dodecyltrimethylammonium chloride, or tetrabutylammonium bisulfate.

[0096] In some embodiments of the present invention, the XR in step (1) 3 -A 1 -R 4 -X, XR 5 -A 3 -R 6 -X total and The total molar ratio is 1:50 to 50:1.

[0097] In some embodiments of the present invention, the halogenated ethyl group (e.g., bromoethyl, chloroethyl) in the product of step (1) is: The molar ratio is 1:50 to 50:1.

[0098] In some embodiments of the present invention, alkaline conditions may include sodium hydroxide, potassium hydroxide, triethylamine, pyridine, etc.

[0099]

application

[0100] The present invention also provides the application of the low dielectric phosphine-containing flame retardant resin as described above, or the low dielectric phosphine-containing flame retardant resin prepared by the preparation method of the low dielectric phosphine-containing flame retardant resin, in prepregs, copper clad laminates, and printed circuit boards.

[0101] Prepreg

[0102] This application also provides a prepreg, which is obtained by impregnating a reinforcing substrate with a low dielectric phosphorus-containing flame-retardant resin as described above, and then semi-curing the resulting reinforcing substrate.

[0103] The reinforcing substrate is selected from at least one of natural fibers, organic synthetic fibers, organic fabrics, and inorganic fabrics. Preferably, the reinforcing substrate is glass fiber cloth; the glass fiber cloth is preferably open-fiber cloth or flat cloth; the glass fiber cloth is preferably E glass fiber cloth, S glass fiber cloth, or Q glass fiber cloth.

[0104] Copper-clad laminate

[0105] This application provides a copper-clad laminate, which is obtained by mixing a low-dielectric phosphorus-containing flame-retardant resin as described above with an organic solvent to obtain a varnish, and then forming the varnish and copper foil into a plate shape under heating and pressure.

[0106] Printed Circuit Boards

[0107] Printed circuit boards are copper-clad laminates that have been processed. Predetermined conductive patterns are formed on copper foil through processes such as etching, drilling, and electroplating, and electronic components are then installed on the foil.

[0108] The detection method involved in this invention is as follows:

[0109] Double bond equivalence test method: Infrared method (905~915cm) -1 Quantitative analysis using the standard curve method.

[0110] Phosphorus content testing method: oxygen-nitrogen method.

[0111] Bromine content: JISK7243-2-2005.

[0112] GPC instrument: Agilent 1260 Infinity II; conditions: THF flow rate 1 mL / min, 35 °C. Monodisperse polystyrene of known molecular weight was used.

[0113] Methods for determining dielectric constant and dielectric loss tangent: GB / T 40564-2021.

[0114] Glass transition temperature Tg: Determined by dynamic thermomechanical analysis (DMA) according to the DMA method specified in 2.4.24.4 of IPC-TM-650.

[0115] Flame retardancy: UL94.

[0116] Example

[0117] Example 1

[0118] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin, comprising the following steps:

[0119] (1) 2-Bromoethylbenzene (185 g, 1 mol), α,α'-dichloro-p-xylene (40 g, 0.23 mol), and concentrated sulfuric acid (6.6 g) were added to a flask equipped with a thermometer, condenser, and stirrer, and reacted at 130 °C for 8 hours. After natural cooling, toluene was dissolved in 1000 ml, neutralized with sodium hydroxide aqueous solution, and the organic layer was washed 5 times with 100 ml of water. The solvent and excess 2-bromoethylbenzene were removed by distillation under heating and reduced pressure to obtain compound A1 (Mn: 560, Mw: 680); wherein, the CAS of α,α'-dichloro-p-xylene is 623-25-6;

[0120] (2) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A1 (180g), diphenylphosphine oxide (80g, 0.4mol), toluene (1L), 48% sodium hydroxide aqueous solution (40g), and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Separate the aqueous phase, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B1 with a solid content of 60%. The solids are: Mn = 565, Mw = 670; double bond equivalent: 955g / eq; phosphine content: 6.1%; bromine content: 60ppm. The CAS number of diphenylphosphine oxide is 4559-70-0. The fragments of B1 include...

[0121] like Figure 1 As shown, the characterization data for yellow liquid B1 are as follows:

[0122] 1¹H NMR (CDCl₃, 400MHz): The peak at 2.86 ppm is the methylene hydrogen at the phosphine oxide edge, and the peaks at 5.65 and 5.16 ppm are the outermost hydrogens of the vinyl group in styrene.

[0123] Example 2

[0124] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin, comprising the following steps:

[0125] (1) 2-Bromoethylbenzene (185 g, 1 mol), α,α'-dichlorom-xylene (40 g, 0.23 mol), and concentrated sulfuric acid (6.6 g) were added to a flask equipped with a thermometer, condenser, and stirrer, and reacted at 130 °C for 8 hours. After natural cooling, toluene was dissolved in 1000 ml, neutralized with sodium hydroxide aqueous solution, and the organic layer was washed 5 times with 100 ml of water. The solvent and excess 2-bromoethylbenzene were removed by distillation under heating and reduced pressure to obtain compound A2 (Mn: 554, Mw: 692); wherein, the CAS of α,α'-dichlorom-xylene is 626-16-4;

[0126] (2) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A2 (180g), diphenylphosphine oxide (80g, 0.4mol), toluene (1L), 48% sodium hydroxide aqueous solution (40g), and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Separate the aqueous phase, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B2 with a solid content of 60%. The solids are: Mn = 550, Mw = 685; double bond equivalent: 956g / eq; phosphine content: 6.1%; bromine content: 60ppm. The fragments of B2 include...

[0127] Example 3

[0128] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin, comprising the following steps:

[0129] (1) 2-bromoethylbenzene (185 g, 1 mol), 4,4'-bis(chloromethyl)biphenyl (58 g, 0.23 mol), and concentrated sulfuric acid (6.6 g) were added to a flask equipped with a thermometer, condenser, and stirrer, and reacted at 130 °C for 8 hours. After natural cooling, the flask was dissolved in 1000 ml of toluene, neutralized with an aqueous sodium hydroxide solution, and the organic layer was washed five times with 100 ml of water. The solvent and excess 2-bromoethylbenzene were removed by distillation under heating and reduced pressure to obtain compound A3 (Mn: 685, Mw: 790); wherein, the CAS of 4,4'-bis(chloromethyl)biphenyl is 1667-10-3;

[0130] (2) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A3 (220g), diphenylphosphine oxide (80g, 0.4mol), toluene (1L), 48% sodium hydroxide aqueous solution (40g), and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Separate the aqueous phase, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B3 with a solid content of 60%. The B3 contains Mn = 696, Mw = 792, double bond equivalent: 918g / eq; phosphine content: 5.8%; bromine content: 54ppm. The fragments of B3 include...

[0131] Example 4

[0132] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin, comprising the following steps:

[0133] (1) 2-Bromoethylbenzene (185 g, 1 mol), 1,4-diisopropenylbenzene (36 g, 0.23 mol), and concentrated sulfuric acid (10 g) were added to a flask equipped with a thermometer, condenser, and stirrer, and reacted at 130 °C for 8 hours. After natural cooling, the mixture was neutralized with an aqueous sodium hydroxide solution, extracted with 1200 g of toluene, and the organic layer was washed five times with 100 g of water. The solvent and excess 2-bromoethylbenzene were removed by distillation under heating and reduced pressure to obtain resin A4 (Mn: 603, Mw: 705); wherein, the CAS of 1,4-diisopropenylbenzene is 1605-18-1;

[0134] (2) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A4 (185g), diphenylphosphine oxide (80g, 0.4mol), toluene (1L), 48% sodium hydroxide aqueous solution (40g), and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Separate the aqueous phase, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B4 with a solid content of 60%. The B4 contains Mn = 600, Mw = 720, double bond equivalent: 932g / eq; phosphine content: 6.0%; and bromine content: 55ppm. The fragments of B4 include...

[0135] Example 5

[0136] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin, comprising the following steps:

[0137] (1) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A1 (180g), 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (86g, 0.4mol), toluene (1L), 48% sodium hydroxide aqueous solution (40g), and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Remove the aqueous phase by separation, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B5 with a solid content of 60%. Mn = 565, Mw = 674, double bond equivalent: 902g / eq; phosphine content: 5.7%; bromine content: 52ppm. The CAS of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 35948-25-5. The fragments of B5 include...

[0138] Example 6

[0139] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin, comprising the following steps:

[0140] (1) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A4 (185g), 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (86g, 0.4mol), toluene (1L), 40g of 48% sodium hydroxide aqueous solution, and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Separate the aqueous phase, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B6 with a solid content of 60%. The B6 contains Mn = 605, Mw = 732, double bond equivalent: 920g / eq; phosphine content: 5.7%; bromine content: 59ppm. The fragments of B6 include...

[0141] Example 7

[0142] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin. The difference from Embodiment 1 is that the amount of diphenylphosphine oxide added in step (2) is different, as shown below:

[0143] (2) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A1 (180g), diphenylphosphine oxide (40g, 0.2mol), toluene (1L), 48% sodium hydroxide aqueous solution (40g), and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Separate the liquid to remove the aqueous phase, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B7 with a solid content of 60%. The composition is: Mn = 505, Mw = 620, double bond equivalent: 505g / eq; phosphine content: 3%; bromine content: 52ppm. The fragment of B7 is the same as that of B1.

[0144] Example 8

[0145] This embodiment provides a method for preparing a low-dielectric phosphorus-containing flame-retardant resin. The difference from Embodiment 1 is that the amount of diphenylphosphine oxide added in step (2) is different, as shown below:

[0146] (2) In a flask equipped with a thermometer, condenser, and stirrer, add the above-mentioned A1 (180g), diphenylphosphine oxide (160g, 0.8mol), toluene (1L), 48% sodium hydroxide aqueous solution (40g), and tetrabutylammonium bromide (8g). Under nitrogen protection, react at 70°C for 2 hours. Separate the aqueous phase, wash three times with water, and remove the solvent under reduced pressure to obtain a yellow liquid B8 with a solid content of 60%. Among these components, Mn = 625, Mw = 750; double bond equivalent: not detected; phosphine content: 8%; bromine content: 54ppm. The fragments of B8 include...

[0147] Comparative Example

[0148] Comparative Example 1

[0149] This comparative example provides a resin D1, comprising the following raw materials by weight percentage: 80% Phosphorus Flame Retardant 20%. Among them, The phosphine-containing flame retardant was prepared according to the method in Example 2 of CN114650979A. The phosphine-containing flame retardant is commercially available, CAS: 38661-56-2.

[0150] Comparative Example 2

[0151] This comparative example provides a resin D2, which differs from Comparative Example 1 in that it contains a phosphorus-containing flame retardant with the following structural formula: The phosphine-containing flame retardant is commercially available, CAS: 139189-30-3.

[0152] Performance testing

[0153] According to the proportions shown in Table 1, each material (parts by mass) was mixed and dissolved in toluene, with a solid content of 60%. The mixture was heated and melted in a metal container to remove the solvent. It was then cured at 160°C for 1 hour and then at 200°C for 2 hours. The dielectric properties, flame retardancy, and glass transition temperature of each material were tested, and the results are shown in Table 1.

[0154] Table 1. Test results of dielectric properties, flame retardancy, and glass transition temperature of Examples 1-8 and Comparative Examples 1-2.

[0155]

[0156] DCP: α,α'-Di(tert-butylperoxide)diisopropylbenzene

[0157] Solubility test: The low-dielectric phosphorus-containing flame-retardant resins of Examples 1-8 and Comparative Examples 1-2 without solvent were dissolved in chloroform, toluene, or methyl ethyl ketone. The results were visually evaluated when the solid content was 60%, and are shown in Table 2. Among them, A, no precipitation after 30 minutes at room temperature; B, slow precipitation after 30 minutes at room temperature; C, difficult to dissolve at room temperature.

[0158] Table 2. Solubility test results of low dielectric phosphorus-containing flame retardant resins in Examples 1-8 and Comparative Examples 1-2.

[0159] B1 B2 B3 B4 B5 B6 B7 B8 D1 D2 chloroform A A A A A A A A C C Toluene A A A A A A A A C C Butanone A A B A A A A A C C

[0160] Based on Examples 1-8 and the data in Tables 1 and 2, it can be seen that the low-dielectric phosphorus-containing flame-retardant resins prepared in Examples 1-8 of this invention have lower dielectric properties, higher glass transition temperatures, and better flame retardancy. Simultaneously, they exhibit good solubility, enabling uniform dispersion and facilitating the effective resolution of processability issues. In contrast, the resins prepared in Comparative Examples 1-2 show poor solubility, and their heat resistance and dielectric properties are inferior to those of Examples 1-8.

[0161] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A low-dielectric phosphorus-containing flame-retardant resin, characterized in that, Includes one or more structures as shown in Equation I below: Where * indicates the connection position; A 2 Selected from one or more of substituted or unsubstituted aryl groups and substituted or unsubstituted metaaryl groups; R 1 R 2 Each is independently selected from one or more of the following: substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, hydrogen, substituted or unsubstituted straight-chain or branched alkyl, substituted or unsubstituted cyclic alkyl, and substituted or unsubstituted heteroaryl. In the presence of multiple A 2 In the case of multiple A's 2 They can be the same or different; When A 2 When located at the end base, A 2 Selected from substituted or unsubstituted aryl groups, i.e. for When A 2 When not at the end base, A 2 Selected from substituted or unsubstituted metaaryl groups, i.e. for In the existence of multiple R 1 In the case of multiple R 1 They can be the same or different; In the existence of multiple R 2 In the case of multiple R 2 They can be the same or different; R 1 R 2 Interconnected to form a ring for or R 1 R 2 They are not connected to form a loop. for 2. The low-dielectric phosphorus-containing flame-retardant resin according to claim 1, characterized in that: It also includes one or more structures as shown in Equation II below: in, A 4 Selected from one or more of substituted or unsubstituted aryl groups and substituted or unsubstituted metaaryl groups; There are multiple A's 4 At that time, multiple A's 4 They can be the same or different; When the A 4 When located at the end base, A 4 Selected from substituted or unsubstituted aryl groups, i.e. for When A 4 When not at the end base, A 4 Selected from substituted or unsubstituted metaaryl groups, i.e. for Preferably, the A 4 It is selected from one or more of substituted or unsubstituted C6-C30 arylene and substituted or unsubstituted C6-C30 metaarylene.

3. The low-dielectric phosphorus-containing flame-retardant resin according to any one of claims 1, characterized in that: It also includes one or more of the following features: a1) A 2 Selected from one or more of substituted or unsubstituted C6-C30 arylene and substituted or unsubstituted C6-C30 metaarylene; a2)R 1 R 2 Each is independently selected from one or more of substituted or unsubstituted C6-C20 aryl groups and substituted or unsubstituted C6-C20 aryloxy groups; preferably, R 1 R 2 Each is independently selected from one or more of substituted or unsubstituted phenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted naphthyl, and substituted or unsubstituted phenoxy.

4. The low-dielectric phosphorus-containing flame-retardant resin according to any one of claims 1, characterized in that: Formula I is selected from the structure shown in Formula I-1: in, A 1 Selected from substituted or unsubstituted aryl groups; When there are multiple A 1 At that time, multiple A's 1 They can be the same or different; preferably, A 1 Selected from substituted or unsubstituted C6-C30 arylene groups; more preferably, the A 1 Selected from one or more of substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, and substituted or unsubstituted biphenylene; R 3 R 4 Each is independently selected from one or more of substituted or unsubstituted straight-chain or branched alkylene groups, substituted or unsubstituted cyclic alkylene groups, and substituted or unsubstituted ester groups; When there are multiple R 3 or R 4 At that time, multiple R 3 or R 4 They can be the same or different; preferably, the R 3 R 4 Each is independently selected from substituted or unsubstituted C1-C6 alkylene groups; more preferably, R 3 R 4 Each is independently selected from one or more of methylene, ethylene, isopropylene, and propylene.

5. The low-dielectric phosphorus-containing flame-retardant resin according to any one of claims 2, characterized in that: Formula II is selected from the structure shown in Formula II-1: in, A 3 Selected from substituted or unsubstituted aryl groups; When there are multiple A 3 At that time, multiple A's 3 They can be the same or different; preferably, A 3 Selected from substituted or unsubstituted C6-C30 arylene groups; more preferably, the A 3 Selected from one or more of substituted or unsubstituted phenylene, substituted or unsubstituted naphthylene, and substituted or unsubstituted biphenylene; R 5 R 6 Each is independently selected from one or more of substituted or unsubstituted straight-chain or branched alkylene groups, substituted or unsubstituted cyclic alkylene groups, and substituted or unsubstituted ester groups; When there are multiple R 5 or R 6 At that time, multiple R 5 or R 6 They can be the same or different; preferably, the R 5 R 6 Each is independently selected from substituted or unsubstituted C1-C6 alkylene groups; more preferably, R 5 R 6 Each is independently selected from one or more of methylene, ethylene, isopropylene, and propylene.

6. The low-dielectric phosphorus-containing flame-retardant resin according to claim 4, characterized in that: It also includes one or more of the following features: b1) A 1 Selected from one or more of the following groups, whether substituted or unsubstituted: b2) The *-R 3 -A 1 -R 4 -*Selected from the following groups, either unsubstituted or methyl-substituted. Preferably, when there is methyl substitution, the number of substituents is one or more; b3) The structure shown in Equation I-1 is selected from one or more of the following structural formulas, the specific structural formulas are as follows:

7. The low-dielectric phosphorus-containing flame-retardant resin according to claim 5, characterized in that: It also includes one or more of the following features: c1) A 3 Selected from one or more of the following groups, whether substituted or unsubstituted: c2) The *-R 5 -A 3 -R 6 -*Selected from the following groups, either unsubstituted or methyl-substituted. Preferably, when there is methyl substitution, the number of substituents is one or more; c3) The structure shown in Formula II-1 is selected from one or more of the following structural formulas, the specific structural formulas are as follows:

8. The low-dielectric phosphorus-containing flame-retardant resin according to any one of claims 1-7, characterized in that: It also includes one or more of the following features: d1) The weight-average molecular weight of the low-dielectric phosphorus-containing flame-retardant resin is 300-10000; preferably, the weight-average molecular weight of the low-dielectric phosphorus-containing flame-retardant resin is 300-5000; more preferably, the weight-average molecular weight of the low-dielectric phosphorus-containing flame-retardant resin is 300-2000; d2) The equivalent weight of the unsaturated double bonds in the low-dielectric phosphorus-containing flame-retardant resin is 200-5000 g / eq; preferably, the equivalent weight of the unsaturated double bonds in the low-dielectric phosphorus-containing flame-retardant resin is 250-1500 g / eq; more preferably, the equivalent weight of the unsaturated double bonds in the low-dielectric phosphorus-containing flame-retardant resin is 300-1000 g / eq. d3) The low dielectric phosphorus-containing flame retardant resin has a phosphorus content of 0.5-10%; preferably, the low dielectric phosphorus-containing flame retardant resin has a phosphorus content of 2-8%. d4) The bromine residue of the low-dielectric phosphorus-containing flame retardant resin is less than 5000 ppm; preferably, the bromine residue of the low-dielectric phosphorus-containing flame retardant resin is less than 2000 ppm; more preferably, the bromine residue of the low-dielectric phosphorus-containing flame retardant resin is less than 500 ppm.

9. A method for preparing a low-dielectric phosphorus-containing flame-retardant resin as described in any one of claims 4-8, characterized in that, Includes the following steps: (1) The raw material XR 3 -A 1 -R 4 -X, XR 5 -A 3 -R 6 -X、 The mixture is then reacted under acidic conditions to give an intermediate; wherein X is selected from halogens; A 2 The definition is the same as in claim 1; A 4 The definition is the same as in claim 2; A 1 R 3 R 4 The definition is the same as in claim 3; A 3 R 5 R 6 The definition is the same as in claim 5; (2) Take the intermediate obtained in step (1), Solvents are mixed and then reacted under alkaline conditions to obtain a low-dielectric phosphine-containing flame-retardant resin, wherein R 1 R 2 The definition is the same as in claim 1.

10. The application of the low-dielectric phosphorus-containing flame retardant resin prepared by the preparation method of the low-dielectric phosphorus-containing flame retardant resin according to any one of claims 1-8 in prepregs, copper-clad laminates, and printed circuit boards.

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