Static prepreg and application thereof

Abstract

The invention discloses a non-flowing prepreg and application thereof. The prepreg comprises a curable resin insulating layer and a reinforcing material, the curable resin insulating layer comprises the following components in parts by weight: 5-50 parts of epoxy resin I; 5 to 100 parts of a modified polybutadiene prepolymer; 5 to 30 parts of core-shell rubber premixed liquid; 5-100 parts of a curing agent; the modified polybutadiene prepolymer is obtained by carrying out prepolymerization reaction on isocyanate, epoxy resin II and hydroxyl-containing polybutadiene; the core-shell rubber premixed liquid is a mixed dispersion liquid of core-shell rubber, epoxy resin III and an organic solvent; the resin composition with excellent compatibility, cohesiveness and heat resistance can be obtained by matching the prepolymer synthesized through the prepolymerization reaction of the hydroxyl-terminated polybutadiene, the isocyanate and the epoxy resin with the core-shell rubber epoxy resin premixed liquid, the epoxy resin and the epoxy resin curing agent; the method is mainly applicable to the field of non-flowing prepregs with requirements on heat resistance and high cohesiveness.

Description

Technical Field

[0001] The invention relates to the technical field of electronic materials, and in particular to a no-flow prepreg and application thereof. Background Art

[0002] With the rapid development of consumer electronic products, the requirements of electronic products for circuit boards are getting higher and higher, and a special circuit board-rigid-flex board came into being. Rigid-flex board has the advantages of both rigid board and flexible board. It can not only weld complex electronic components on rigid board, but also has the characteristics of flexible board that it is thin, foldable, bendable, and takes up little space, effectively reducing the volume of electronic products. No-Flow Prepreg for Rigid-Flex Board is a special adhesive material used in the preparation process of Rigid-Flex Board to tightly connect the rigid board and the flexible board through a specific pressing process. No-Flow Prepreg for Rigid-Flex Board usually refers to a semi-cured solid film prepared by impregnating epoxy resin adhesive with glass fiber cloth as a carrier, and then semi-curing treatment. It is characterized by the resin not flowing or having very low fluidity, and having certain adhesive characteristics, which meets the process requirements of rigid-flex printed circuit boards.

[0003] In order to enhance the toughness of resin in the prior art, HTPB is usually used directly with a thermosetting epoxy resin and then mixed for use, resulting in poor compatibility and a low glass transition temperature of the resin composition, reducing its heat resistance and adhesion, and causing varying degrees of prepreg surface problems. In view of the problems caused by the direct use of HTPB with an epoxy resin, the present invention provides a no-flow prepreg and an application thereof. The no-flow prepreg of the present invention is a low-flow prepreg material having heat resistance, high adhesion and excellent compatibility. Summary of the invention

[0004] The object of the present invention is to provide a no-flow prepreg and application thereof, so as to realize a low-flow prepreg material having heat resistance, high adhesion and excellent compatibility.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A no-flow prepreg, comprising: a curable resin insulating layer and a reinforcing material;

[0007] In parts by weight, the curable resin insulation layer is a curable resin composition layer, and the curable resin composition includes the following components:

[0008] (A) epoxy resin I: 5-50 parts;

[0009] (B) modified polybutadiene prepolymer: 5-100 parts;

[0010] (C) core-shell rubber premix: 5-30 parts;

[0011] (D) curing agent: 5-100 parts;

[0012] The modified polybutadiene prepolymer is obtained by prepolymerization of isocyanate, epoxy resin II and hydroxyl-containing polybutadiene;

[0013] The core-shell rubber premix is ​​a mixed dispersion of core-shell rubber, epoxy resin III and organic solvent, wherein the content of the core-shell rubber is 20%-40% by mass percentage.

[0014] Preferably, the shell part of the core-shell rubber is selected from at least one of methacrylates, acrylates, and styrenes; the core part is selected from at least one of butadiene rubber, acrylate rubber, silicone rubber, NBR rubber, and SBR rubber.

[0015] For example, the core-shell rubber premix is ​​MX-154 manufactured by KANEKA.

[0016] In the above technical solution, the synthesis method of the modified polybutadiene prepolymer is not particularly limited, and the specific synthesis method is as follows:

[0017] A certain amount of catalyst organic solution is added to a three-necked flask equipped with a stirrer and a thermometer, a certain amount of hydroxyl-containing polybutadiene is added to the solution and stirred evenly, a certain amount of isocyanate is added after complete dissolution and stirred continuously, and reflux prepolymerization is carried out in an oil bath at 80-130°C for 0.1-6h; then a certain amount of epoxy resin II is added and stirred continuously, and reflux prepolymerization is continued at this temperature for 0.1-5h to obtain a prepolymer solution, and then vacuum and condense to recover the solvent for about 0.1-3h, and cool to room temperature to obtain a prepolymer.

[0018] The catalyst organic solution is preferably ethyl acetate of stannous octoate.

[0019] The epoxy group and the oxazolidinone structure are introduced into the modified polybutadiene prepolymer through a prepolymerization reaction, thereby improving the compatibility of the polybutadiene with the epoxy resin and the reactivity in the subsequent curing process.

[0020] Preferably, the epoxy resin I, epoxy resin II and epoxy resin III are the same or different, and are respectively selected from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, tetraphenylethane epoxy resin, triphenylmethane epoxy resin, biphenyl epoxy resin, naphthalene ring epoxy resin, dicyclopentadiene epoxy resin, isocyanate epoxy resin, aralkyl linear phenolic epoxy resin, bisphenol A novolac epoxy resin, polyphenylene ether modified epoxy resin, alicyclic epoxy resin, glycidyl amine epoxy resin, glycidyl ester epoxy resin, phosphorus-containing epoxy resin, nitrogen-containing epoxy resin, and multifunctional epoxy resin.

[0021] Further preferably, the epoxy resin I, epoxy resin II and epoxy resin III are epoxy resins with the same structure.

[0022] More preferably, the epoxy resin I, epoxy resin II and epoxy resin III are selected from at least one of the following structures:

[0023]

[0024] Wherein, n is an integer of 1-20.

[0025] Preferably, the isocyanate is selected from one or more of toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate (MDI), p-xylylene diisocyanate (XDI), hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexane diisocyanate (TMHDI), tetramethyl metaxylylene diisocyanate (TMXDI), dicyclohexylmethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), naphthalene 1,5-diisocyanate (NDI), 1,4-cyclohexane diisocyanate (CHDI), methylcyclohexane diisocyanate (HTDI), 1,4-phenylene diisocyanate (PPDI), and norbornane diisocyanate (NBDI).

[0026] More preferably, the isocyanate resin is 4,4'-diphenylmethane diisocyanate (MDI).

[0027] Preferably, the hydroxyl-containing polybutadiene is a butadiene homopolymer or copolymer containing two or more hydroxyl groups at one or both ends of each molecule.

[0028] Preferably, the hydroxyl-containing polybutadiene is a hydroxyl-containing butadiene-styrene copolymer or a hydroxyl-containing butadiene-acrylonitrile copolymer.

[0029] For example, the hydroxyl-containing polybutadiene is selected from GI-1000, GI-2000 or GI-3000 manufactured by Soda.

[0030] Preferably, the curing agent is selected from one or more of aliphatic amines, alicyclic amines, polyamides, aromatic amines, polymercaptans, isocyanates, cyanates, active esters, anhydrides, phenolic resins, imidazoles, tertiary amines, boron trifluoride and its complexes, dicyandiamide, and hydrazides.

[0031] More preferably, the curing agent is selected from at least one of active esters, cyanate esters, dicyandiamide and phenolic resins.

[0032] More preferably, the active ester is a DCPD-type active ester or a naphthalene-type active ester, and specifically, an active ester compound with a brand name of HPC-8000 or EXB-8150 produced by DIC Corporation is selected.

[0033] More preferably, the cyanate resin is selected from one or more of bisphenol A cyanate resin, bisphenol F cyanate resin, bisphenol S cyanate resin, bisphenol E cyanate resin, bisphenol M cyanate resin, double bond-containing cyanate resin, phosphorus-containing cyanate resin, phenolic cyanate resin, biphenyl cyanate resin, naphthalene ring cyanate resin, and dicyclopentadiene cyanate resin.

[0034] More preferably, the phenolic resin is selected from at least one of the following structures:

[0035] R 11 is a methyl group, and n is an integer of 1 to 10;

[0036] kz is an integer from 1 to 10;

[0037] n is an integer from 1 to 10;

[0038] p is an integer from 1 to 10, R 3 and R 4 is a C1-C5 alkyl group;

[0039] n is an integer from 1 to 10.

[0040] Preferably, the curable resin composition further comprises an inorganic filler in an amount of 30-150 parts.

[0041] Preferably, the inorganic filler is selected from at least one of silicon dioxide, aluminum hydroxide, aluminum oxide, talc, aluminum nitride, boron nitride, silicon carbide, barium sulfate, barium titanate, strontium titanate, calcium carbonate, calcium silicate, mica, and glass fiber powder.

[0042] Further preferably, the inorganic filler is spherical silica, alumina or aluminum hydroxide.

[0043] More preferably, the inorganic filler is spherical silica.

[0044] Furthermore, the inorganic filler is a filler surface-treated with a silane coupling agent; the silane coupling agent is selected from at least one of an aminosilane coupling agent, a carbon-carbon double bond-containing silane coupling agent or an epoxy silane coupling agent.

[0045] In the above technical solution, the curable resin composition also includes a catalyst, and the content of the catalyst is 0.01-5 parts.

[0046] Preferably, the catalyst is selected from at least one of imidazole catalysts, pyridine catalysts and organic metal salt catalysts.

[0047] More preferably, the catalyst is selected from at least one of 4-dimethylaminopyridine, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, modified imidazole and zinc octoate.

[0048] In the above technical solution, the curable resin composition also includes a flame retardant, the content of which is 1-60 parts; the flame retardant can improve the flame retardancy of the final cured product, and the cured product is a semi-cured sheet, a laminate, or a printed circuit board.

[0049] Preferably, the flame retardant is selected from at least one of a bromine flame retardant, a phosphorus flame retardant, a nitrogen flame retardant, an organosilicon flame retardant, an organometallic flame retardant, and an inorganic flame retardant.

[0050] Wherein, the brominated flame retardant is selected from at least one of decabromodiphenyl ether, decabromodiphenyl ethane, brominated styrene or tetrabromophthalamide;

[0051] The phosphorus flame retardant is selected from inorganic phosphorus, condensed phosphate compounds, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, 9,10-dihydro-9-oxa-10-phosphophananthrene-10-oxide, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphophananthrene-10-oxide, 10-phenyl-9,10-dihydro-9-oxa-10-phosphophananthrene-10-oxide, tri(2,6-dimethylphenyl)phosphine, (m is an integer from 1 to 5), at least one of phosphazenes;

[0052] The nitrogen-based flame retardant is selected from at least one of triazine compounds, cyanuric acid compounds, isocyanic acid compounds, and phenothiazine;

[0053] The organic silicon flame retardant is selected from at least one of organic silicon oil, organic silicon rubber and organic silicon resin;

[0054] The organic metal salt flame retardant is selected from at least one of ferrocene, acetylacetone metal complex, and organic metal carbonyl compound;

[0055] The inorganic flame retardant is selected from at least one of aluminum hydroxide, magnesium hydroxide, aluminum oxide and barium oxide.

[0056] Preferably, the reinforcing material is selected from at least one of natural fibers, organic synthetic fibers, organic fabrics, and inorganic fabrics.

[0057] Preferably, the reinforcing material is glass fiber cloth, and the glass fiber cloth is surface treated with a silane coupling agent; the glass fiber cloth is preferably open fiber cloth or flat cloth; more preferably, the glass fiber cloth is E glass fiber cloth, S glass fiber cloth or Q glass fiber cloth; the silane coupling agent is selected from at least one of an aminosilane coupling agent, a carbon-carbon double bond-containing silane coupling agent or an epoxy silane coupling agent.

[0058] The present application also claims to protect an application of the no-flow prepreg.

[0059] Due to the application of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0060] The present invention uses a prepolymer synthesized by prepolymerization reaction of terminal hydroxyl polybutadiene, isocyanate and epoxy resin, and is combined with a core-shell rubber epoxy resin premix, epoxy resin and epoxy resin curing agent to obtain a resin composition with excellent compatibility, adhesion and heat resistance. The resin composition can be mainly used in the field of non-flowing semi-cured sheets requiring heat resistance and high adhesion. DETAILED DESCRIPTION

[0061] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, a specific implementation scheme is now described in detail.

[0062] The present invention is further described below in conjunction with the examples, but the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not indicated are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0063] Synthesis Example 1: Preparation of modified polybutadiene prepolymer A;

[0064] In a three-necked flask equipped with a stirrer and a thermometer, 20 g of stannous octoate ethyl acetate solution (5%) was added, 20 g of hydroxyl-containing polybutadiene (Caoda GI-1000) was added to the solution and stirred evenly. After complete dissolution, 40 g of toluene diisocyanate was added and stirred continuously. The mixture was refluxed in an oil bath at 105°C for prepolymerization for 3 h. Subsequently, 100 g of bisphenol A liquid epoxy resin (epoxy equivalent 187 g / eq) was added and stirred continuously. The prepolymerization was refluxed at this temperature for 2 h to obtain a prepolymer solution. The solution was then evacuated and condensed to recover the solvent for about 1 h, and the temperature was cooled to obtain a prepolymer.

[0065] Synthesis Example 2: Preparation of modified polybutadiene prepolymer B;

[0066] In a three-necked flask equipped with a stirrer and a thermometer, 20 g of stannous octoate ethyl acetate solution (5%) was added, 20 g of hydroxyl-containing polybutadiene-styrene copolymer (Tianyuan Aerospace Materials HFHTPB-I type) was added to the solution and stirred evenly. After complete dissolution, 40 g of 4,4'-diphenylmethane diisocyanate was added and stirred continuously. The mixture was refluxed in an oil bath at 120°C for prepolymerization for 4 hours. Subsequently, 100 g of bisphenol A liquid epoxy resin (epoxy equivalent 187 g / eq) was added and stirred continuously. The prepolymerization was refluxed at this temperature for 2 hours to obtain a prepolymer solution. The solution was then evacuated and condensed to recover the solvent for about 1 hour, and the temperature was cooled to obtain a prepolymer.

[0067] Example 1

[0068] This embodiment is a curable resin composition, which includes, by weight: 60 parts of modified polybutadiene prepolymer, 30 parts of epoxy resin A, 10 parts of core-shell rubber premix, 5 parts of dicyandiamide, 40 parts of spherical silica, and 0.1 parts of 2-methylimidazole.

[0069] Example 2

[0070] The present embodiment is a curable resin composition, which includes, by weight: 30 parts of modified polybutadiene prepolymer, 30 parts of epoxy resin B, 10 parts of core-shell rubber premix, 5 parts of dicyandiamide, 40 parts of spherical silica, and 0.1 parts of 2-methylimidazole.

[0071] Example 3

[0072] This embodiment is a curable resin composition, which includes, by weight: 60 parts of modified polybutadiene prepolymer, 30 parts of epoxy resin C, 10 parts of core-shell rubber premix, 5 parts of dicyandiamide, 40 parts of spherical silica, and 0.1 parts of 2-methylimidazole.

[0073] Example 4

[0074] This embodiment is a curable resin composition, which includes, by weight: 60 parts of modified polybutadiene prepolymer, 30 parts of epoxy resin A, 10 parts of core-shell rubber premix, 20 parts of phenolic resin, 40 parts of spherical silica, and 0.1 parts of 2-methylimidazole.

[0075] Comparative Example 1

[0076] This embodiment is a curable resin composition, which includes, by weight: 60 parts of modified polybutadiene prepolymer, 30 parts of epoxy resin A, 10 parts of core-shell rubber premix, 2.5 parts of dicyandiamide, 40 parts of spherical silica, and 0.1 parts of 2-methylimidazole.

[0077] Comparative Example 2

[0078] This embodiment is a curable resin composition, which includes, by weight: 60 parts of unmodified polybutadiene prepolymer, 30 parts of epoxy resin A, 10 parts of core-shell rubber premix, 5 parts of dicyandiamide, 40 parts of spherical silica, and 0.1 parts of 2-methylimidazole.

[0079] Comparative Example 3

[0080] This embodiment is a curable resin composition, which includes, by weight: 60 parts of modified polybutadiene prepolymer, 30 parts of epoxy resin A, 10 parts of core-shell rubber, 5 parts of dicyandiamide, 40 parts of spherical silica, and 0.1 parts of 2-methylimidazole.

[0081] The components and addition amounts of Examples 1-4 and Comparative Examples 1-3 are shown in Table 1 below.

[0082] Table 1

[0083]

[0084] The raw material manufacturers and models of each component used in Examples 1-4 and Comparative Examples 1-3 are shown in Table 2 below.

[0085] Table 2

[0086] Components Brand Epoxy Resin A Hongchang, GELR-128 Epoxy resin B Holy Spring, SQAN-201 Epoxy resin C DIC, HP-7200H Hydroxyl-terminated polybutadiene prepolymer self made Hydroxyl-terminated polybutadiene resin Caoda GI-1000 Core-shell rubber premix Kaneka, MX154 Core-shell rubber Kaneka, M521 Dicyandiamide Industrial pure Phenolic resin Holy Spring, PF8010 Spherical silica Lianrui, D100=14um

[0087] The above-mentioned embodiments and comparative examples also disclose a prepreg, comprising glass fiber cloth as a reinforcing material and a resin composition coated on the glass fiber cloth by an impregnation method; wherein the glass fiber cloth is a fiber-spreading cloth pre-treated with an epoxy silane coupling agent.

[0088] Specifically, the components of the resin compositions of the above-mentioned embodiments 1-4 and comparative examples 1-3 were dissolved in butanone, stirred and mixed, and then diluted into a glue solution with a solid content of 55wt%; the E glass fiber cloth 1078 used as a reinforcing material was pretreated with an epoxy silane coupling agent, immersed in the above-mentioned glue solution, taken out after infiltration, placed in a blast drying oven at 160-180°C, and baked for 3-6 minutes to obtain a semi-cured sheet.

[0089] The above-mentioned embodiments and comparative examples also disclose a laminated board, which is prepared by the following method: take two of the above-mentioned semi-cured sheets, cut them into 300×300 mm, and stack them into a combined sheet with a certain stacking structure. Then, a piece of electrolytic copper foil with a thickness of 18 microns is placed on both sides of the combined sheet, respectively, and placed in a vacuum hot press. It is hot pressed for 1.5 hours at a pressure of 1.5 MPa and a temperature of 200°C to obtain a copper-clad laminated board.

[0090] The performance tests were conducted on the prepregs obtained in the above Examples 1-4 and Comparative Examples 1-3 and the copper-clad laminates pressed therefrom, and the test results are shown in Table 3 below.

[0091] Table 3

[0092]

[0093] The properties of the copper-clad laminates prepared in the above examples and comparative examples were tested as follows:

[0094] (1) Glue overflow: measured according to IPC-TM650, 2.3.17.2 method;

[0095] (2) CVL adhesion: Sample width 10 mm, tested using a peel force tester;

[0096] (3) Powder loss rate: The prepreg sheet is 10 cm × 10 cm in size. Use a utility knife to score 20 times before calculating the weight loss.

[0097] (4) Tg: DMA, heating rate 10°C / min, frequency 10 Hz;

[0098] (5) Dk and Df: Dielectric properties at 10 GHz using the flat plate method in accordance with IPC-TM-650, 2.5.5.9;

[0099] (6) Peel strength: According to the "after thermal stress" experimental conditions in IPC-TM-650, method 2.4.8, the peel strength of the metal cover layer was tested;

[0100] (7) Precured sheet apparent quality: Observe the apparent quality of the precured sheet. If there is no resin agglomeration within the area of ​​300 mm × 300 mm, it is represented as 0. If there is resin agglomeration, it is represented as ╳.

[0101] In summary, the present invention uses a prepolymer synthesized by prepolymerization reaction of terminal hydroxyl polybutadiene, isocyanate and epoxy resin, combined with a core-shell rubber epoxy resin premix, epoxy resin and epoxy resin curing agent, to obtain a resin composition with excellent compatibility, adhesion and heat resistance, which can be mainly used in the field of non-flowing semi-cured sheets requiring heat resistance and high adhesion.

[0102] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A non-flowing prepreg, characterized in that: include: Curable resin insulation layer and reinforcement material; In parts by weight, the curable resin insulation layer is a curable resin composition layer, and the curable resin composition includes the following components: (A) epoxy resin I: 5-50 parts; (B) modified polybutadiene prepolymer: 5-100 parts; (C) core-shell rubber premix: 5-30 parts; (D) curing agent: 5-100 parts; The modified polybutadiene prepolymer is obtained by prepolymerization of isocyanate, epoxy resin II and hydroxyl-containing polybutadiene; The core-shell rubber premix is ​​a mixed dispersion of core-shell rubber, epoxy resin III and organic solvent, wherein the content of the core-shell rubber is 20%-40% by mass percentage.

2. The no-flow prepreg according to claim 1, characterized in that: The epoxy resin I, epoxy resin II and epoxy resin III are the same or different, and are respectively selected from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, tetraphenylethane epoxy resin, triphenylmethane epoxy resin, biphenyl epoxy resin, naphthalene epoxy resin, dicyclopentadiene epoxy resin, isocyanate epoxy resin, aralkyl linear phenolic epoxy resin, bisphenol A novolac epoxy resin, polyphenylene ether modified epoxy resin, alicyclic epoxy resin, glycidylamine epoxy resin, glycidylester epoxy resin, phosphorus-containing epoxy resin, nitrogen-containing epoxy resin, and multifunctional epoxy resin.

3. The no-flow prepreg according to claim 1, characterized in that: The isocyanate is selected from one or more of toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, p-xylylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, tetramethyl-m-xylylene diisocyanate, dicyclohexylmethylene diisocyanate, isophorone diisocyanate, naphthalene 1,5-diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexane diisocyanate, 1,4-phenylene diisocyanate, and norbornane diisocyanate.

4. The no-flow prepreg according to claim 1, characterized in that: The hydroxyl-containing polybutadiene is a butadiene homopolymer or copolymer containing two or more hydroxyl groups at one or both ends of each molecule.

5. The no-flow prepreg according to claim 4, characterized in that: The hydroxyl-containing polybutadiene is a hydroxyl-containing butadiene-styrene copolymer or a hydroxyl-containing butadiene-acrylonitrile copolymer.

6. The no-flow prepreg according to claim 1, characterized in that: The shell part of the core-shell rubber is selected from at least one of methacrylates, acrylates, and styrenes; the core part is selected from at least one of butadiene rubber, acrylate rubber, silicone rubber, NBR rubber, and SBR rubber.

7. The no-flow prepreg according to claim 1, characterized in that: The curing agent is selected from one or more of aliphatic amines, alicyclic amines, polyamides, aromatic amines, polymercaptans, isocyanates, cyanates, active esters, anhydrides, phenolic resins, imidazoles, tertiary amines, boron trifluoride and its complexes, dicyandiamide, and hydrazides.

8. The no-flow prepreg according to claim 1, characterized in that: The curable resin composition further includes an inorganic filler, the content of which is 30-150 parts.

9. The no-flow prepreg according to claim 1, characterized in that: The reinforcing material is selected from at least one of natural fibers, organic synthetic fibers, organic fabrics, and inorganic fabrics.

10. Use of the no-flow prepreg according to any one of claims 1 to 9.

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