Plant fiber modifier, modified plant fiber reinforced material and application thereof

Abstract

The present application provides a plant fiber modifier, a modified plant fiber reinforced material and application thereof, the plant fiber modifier comprises the following components by mass fraction: phenolic resin 100 parts, organic acid 40-170 parts, coupling agent 80-300 parts, epoxy diluent 70-240 parts, and silicon oil 10-60 parts. Through the design and compounding of components, the plant fiber modifier can realize the modification of the plant fiber reinforced material, and the modified plant fiber reinforced material prepared by using the plant fiber modifier has significantly improved heat resistance, moisture resistance and impregnation. The modified plant fiber reinforced material is used as a reinforcing material for prepreg and metal foil laminated board, so that the board has low water absorption, excellent heat resistance, moisture resistance, interlayer bonding force and processability, while reducing the board life cycle greenhouse gas emission intensity, and meeting the low-carbon and environmentally friendly development route.

Description

Technical Field

[0001] This invention belongs to the field of copper clad laminate technology, specifically relating to a plant fiber modifier, modified plant fiber reinforcing material, and their applications. Background Technology

[0002] Copper-clad laminate (CCL) is a sheet material used in the production of printed circuit boards (PCBs). It serves to support and assemble electronic components, form conductive circuit patterns, and provide insulation between layers / lines, making it a crucial basic material in electronics. CCLs are typically made by impregnating reinforcing materials such as electronic fiberglass cloth or fiber paper with resin, covering one or both sides with copper foil, and then hot-pressing them together.

[0003] Traditional copper-clad laminates primarily use reinforcing materials such as fiberglass cloth and fiberglass paper (non-woven fabric). However, fiberglass production and manufacturing processes pose significant environmental pollution problems and generate high levels of greenhouse gas emissions, including carbon dioxide. With the development of a low-carbon economy and increasing emphasis on environmental protection across industries, developing reinforcing materials and copper-clad laminates that can reduce carbon emission intensity has become a crucial research topic within the industry.

[0004] Plant fibers are a type of natural raw material with advantages such as low carbon dioxide emission intensity and minimal environmental pollution. However, currently only plant fiber paper is used to a certain extent in copper clad laminates. For example, the core material in CEM-1 type composite base copper clad laminate uses fiber paper-based prepreg. However, plant fiber cloth cannot meet the application requirements of copper clad laminates. The reason is that plant fiber paper has undergone deep and refined processing in papermaking technology, forming a special fiber structure that enables it to meet the basic performance requirements of copper clad laminates. On the other hand, plant fiber cloth is generally woven directly from natural fibers, and the original characteristics of the plant structure are not changed. This results in copper clad laminates made from plant fiber cloth having serious problems such as poor heat resistance, poor resistance to damp heat, and poor electrical insulation.

[0005] Currently, plant fiber fabrics are widely used in the field of composite materials. For example, CN117343472A discloses a natural fiber composite material, which includes a matrix composed of natural fibers (e.g., woven fiber fabric) and fillers. The fillers are filled in the matrix and within the tubular structures of the natural fibers. The raw materials of the fillers include thermosetting resins, functional components, and curing agents. The thermosetting resin is at least one of epoxy resin or bismaleimide. The hydrophobic filler has a water droplet angle ≥100° and a particle size ≤20μm, and the inorganic filler has a particle size ≤20μm. The introduction of fillers improves the microstructure of natural fibers, giving natural fiber composite materials better hydrophobic properties, oxidation resistance, and mechanical properties. However, such natural fiber composite materials still cannot meet the standards for use as copper clad laminate reinforcement materials in terms of heat resistance, damp heat resistance, and electrical insulation.

[0006] Therefore, optimizing the heat resistance, damp heat resistance, and electrical insulation properties of plant fiber cloth to meet the performance requirements of copper clad laminates is an urgent problem to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a plant fiber modifier, modified plant fiber reinforcing materials, and their applications. Through the design and compounding of components, the plant fiber modifier enables the modification of plant fiber reinforcing materials. The modified plant fiber reinforcing materials prepared using this modifier exhibit significantly improved heat resistance, damp heat resistance, and impregnation properties. When used as reinforcing materials in prepregs and metal foil-coated laminates, these modified plant fiber reinforcing materials enable the boards to possess low water absorption, excellent heat resistance, damp heat resistance, interlayer bonding strength, and processability. Simultaneously, they reduce the greenhouse gas emission intensity throughout the lifecycle of the boards, aligning with a low-carbon and environmentally friendly development path.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a plant fiber modifier, wherein the plant fiber modifier comprises, by weight, the following components:

[0010]

[0011]

[0012] In the plant fiber modifier provided by this invention, the organic acid has a high molecular polarity, enabling it to undergo esterification with the hydroxyl groups in plant fibers, thus blocking the hydrophilic hydroxyl groups in the plant fiber fabric and reducing water absorption while improving resistance to damp heat. The coupling agent and silicone oil synergistically improve the surface affinity of the plant fiber fabric, giving it superior wettability. The phenolic resin and epoxy diluent, when combined, can wet and impregnate the plant fiber fabric and undergo cross-linking reactions, fully coating and filling the surface and internal cavities of the plant fibers. This invention, through the design and mutual compounding of phenolic resin, organic acid, coupling agent, epoxy diluent, and silicone oil, enables the plant fiber modifier to not only improve the surface affinity and impregnation properties of plant fiber fabric, but also to achieve chemical reactions (esterification and cross-linking reactions) between the components of the plant fiber modifier and between the plant fiber modifier and plant fibers, forming a multidimensional chemical cross-linked network structure. This fills and repairs the cavities and defects in the plant fibers, resulting in significantly improved heat resistance and damp heat resistance. Simultaneously, the hydroxyl groups in the plant fibers are blocked by the reaction, thereby reducing water absorption and further enhancing heat resistance. The modified plant fiber reinforced material prepared using the aforementioned plant fiber modifier exhibits excellent heat resistance, damp heat resistance, and impregnation properties. As a reinforcing material for prepregs and metal foil laminates, it enables the boards to have low water absorption, excellent heat resistance, damp heat resistance, interlayer bonding strength, insulation reliability, and processability. Furthermore, it reduces the carbon dioxide emission intensity throughout the board's life cycle, aligning with the green, low-carbon, and environmentally friendly development path.

[0013] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0014] In the plant fiber modifier of the present invention, the organic acid is 40-170 parts by mass of 100 parts of the phenolic resin, for example, 50 parts, 60 parts, 70 parts, 80 parts, 90 parts, 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, 150 parts or 160 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0015] Based on 100 parts by weight of the phenolic resin, the coupling agent has a mass of 80-300 parts, for example, 90 parts, 100 parts, 120 parts, 140 parts, 150 parts, 160 parts, 180 parts, 200 parts, 220 parts, 240 parts, 250 parts, 260 parts, or 280 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range.

[0016] Based on 100 parts by weight of the phenolic resin, the mass of the epoxy diluent is 70-240 parts, for example, 80 parts, 90 parts, 100 parts, 120 parts, 140 parts, 150 parts, 160 parts, 180 parts, 200 parts or 220 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0017] Based on 100 parts by weight of the phenolic resin, the silicone oil is 10-60 parts by weight, for example, 15 parts, 20 parts, 25 parts, 30 parts, 35 parts, 40 parts, 45 parts, 50 parts or 55 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0018] The terms "parts" and "parts by weight" used in this invention are calculated based on solid content and do not include solvents, dispersants, etc.

[0019] Preferably, the number average molecular weight of the phenolic resin is 150-700, for example, it can be 160, 180, 200, 220, 250, 280, 300, 320, 350, 380, 400, 420, 450, 480, 500, 520, 550, 580, 600, 620, 650 or 680, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0020] Preferably, the phenolic resin includes a thermosetting phenolic resin.

[0021] Preferably, the phenolic resin includes a water-soluble phenolic resin.

[0022] Preferably, the phenolic resin includes any one or a combination of at least two of the following: o-cresol type phenolic resin, trifunctional phenolic resin, biphenyl phenolic resin, phenolic resin, bisphenol A type phenolic resin, triphenolic resin, naphthalene type phenolic resin, biphenyl phenolic resin, and dicyclopentadiene type phenolic resin.

[0023] Preferably, the organic acid includes any one or a combination of at least two of benzoic acid, salicylic acid, caffeic acid, tartaric acid, oxalic acid, malic acid, acetic acid, and citric acid.

[0024] Preferably, the coupling agent comprises a silicone-based coupling agent, and more preferably any one or a combination of at least two of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3-(methoxy)propyltrimethoxysilane, 3-propenoxypropyltrimethoxysilane, 3-hydroxypropyltrimethoxysilane, and vinyltrimethoxysilane.

[0025] Preferably, the epoxy diluent comprises any one or a combination of at least two of 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, propylene oxide o-tolyl ether, propylene oxide o-tolyl glycidyl ether, and neopentyl glycol diglycidyl ether.

[0026] Preferably, the silicone oil includes any one or a combination of at least two of the following: methyl hydrogen silicone oil, polyether-modified polydimethylsiloxane, epoxy-modified silicone oil, amino-modified silicone oil, methyl silicone oil, and benzyl silicone oil.

[0027] Preferably, the viscosity of the silicone oil at 25°C is 50-800 cps, for example, it can be 80 cps, 100 cps, 150 cps, 200 cps, 250 cps, 300 cps, 350 cps, 400 cps, 450 cps, 500 cps, 550 cps, 600 cps, 650 cps, 700 cps or 750 cps, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0028] Preferably, the number average molecular weight of the silicone oil is 5000-20000, for example, it can be 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000 or 19000, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0029] In a second aspect, the present invention provides the application of the plant fiber modifier as described in the first aspect in modified plant fiber reinforced materials or prepregs.

[0030] Thirdly, the present invention provides a modified plant fiber reinforced material, which is prepared by using a plant-based reinforcing material and a plant fiber modifier as described in the first aspect.

[0031] Preferably, the plant-based reinforcing material comprises plant fiber cloth.

[0032] Preferably, the plant fiber cloth includes any one or a combination of at least two of ramie fiber cloth, flax fiber cloth, jute fiber cloth, sisal fiber cloth, hemp fiber cloth, bamboo fiber cloth, corn fiber cloth, and banana fiber cloth.

[0033] Preferably, the weight of the plant fiber cloth is 50-280 g / m². 2 For example, it can be 60g / m2 80g / m 2 100g / m 2 120g / m 2 150g / m 2 180g / m 2 200g / m 2 220g / m 2 250g / m 2 Or 270g / m 2 As well as the specific point values ​​between the above point values, due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0034] Preferably, the loading of the modifier in the modified plant fiber reinforced material is 7-40 g / m³. 2 For example, it can be 8g / m 2 10g / m 2 12g / m 2 15g / m 2 18g / m 2 20g / m 2 22g / m 2 25g / m 2 28g / m 2 30g / m 2 32g / m 2 35g / m 2 Or 38g / m 2 As well as the specific point values ​​between the above point values, due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0035] Preferably, the loading of the modifier in the modified plant fiber reinforced material is equal to the basis weight of the modified plant fiber reinforced material minus the basis weight of the plant fiber cloth.

[0036] Fourthly, the present invention provides a method for preparing a modified plant fiber reinforced material as described in the third aspect, the method comprising the following steps:

[0037] A modified adhesive solution is provided, the modified adhesive solution comprising a plant fiber modifier as described in the first aspect and a first solvent;

[0038] The plant-based reinforcing material is impregnated in the modified adhesive solution and then subjected to a first curing process to obtain the modified plant fiber reinforcing material.

[0039] Preferably, the first solvent includes water and / or an organic solvent.

[0040] Preferably, the boiling point of the first solvent is 50-180℃, for example, it can be 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, or 170℃, as well as specific values ​​between the above ranges. For space limitations and for the sake of brevity, this invention will not exhaustively list all the specific values ​​included in the range. The boiling point of the first solvent matches the processing temperature, which can meet the solvent removal requirements of the first curing stage; at the same time, the first solvent satisfies the requirements for the penetration of the modified adhesive into the plant fiber cloth and its compatibility with the plant fiber modifier.

[0041] Preferably, the first solvent includes any one or a combination of at least two of the following: water, methanol, ethanol, acetone, butanone, ethylene glycol monobutyl ether, methyl acetate, ethyl acetate, and cyclohexanone.

[0042] Preferably, the plant fiber modifier in the modified adhesive solution has a mass percentage content of 8-30%, for example, it can be 9%, 10%, 12%, 14%, 15%, 16%, 18%, 20%, 22%, 24%, 25%, 26% or 28%, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0043] Preferably, the impregnation process further includes a step of heat-treating the plant-based reinforcing material.

[0044] Preferably, the heat treatment temperature is 150-220℃, for example, it can be 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, 200℃, 205℃, 210℃ or 215℃, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0045] Preferably, the heat treatment time is 10-50 min, for example, it can be 15 min, 20 min, 25 min, 30 min, 35 min, 40 min or 45 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0046] Preferably, the heat treatment further includes a cooling step (to room temperature / normal temperature) followed by impregnation.

[0047] Preferably, the first curing temperature is 160-190℃, for example, it can be 165℃, 170℃, 175℃, 180℃ or 185℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0048] Preferably, the first curing time is 5-60 min, for example, it can be 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min or 55 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0049] In a preferred embodiment, the preparation method of the modified plant fiber reinforced material includes the following steps:

[0050] A modified adhesive solution is provided, the modified adhesive solution comprising a plant fiber modifier as described in the first aspect and a first solvent;

[0051] The plant fiber cloth is heat-treated at 150-220℃ for 10-50 minutes, cooled, and then impregnated in the modified adhesive solution. After impregnation, it is cured at 160-190℃ for 5-60 minutes to obtain the modified plant fiber reinforced material.

[0052] Fifthly, the present invention provides a prepreg comprising a modified plant fiber reinforcing material as described in the third aspect and a thermosetting resin composition attached to the modified plant fiber reinforcing material.

[0053] Preferably, the thermosetting resin composition is attached to the modified plant fiber reinforced material after impregnation and drying.

[0054] In this invention, the components of the thermosetting resin composition are not specifically limited. Thermosetting resin systems that can be used in prepregs and metal foil laminates are all applicable to this invention.

[0055] Preferably, the thermosetting resin composition comprises a combination of epoxy resin and a curing agent.

[0056] Preferably, the number-average molecular weight (M) of the epoxy resin is... n The range is 200-2000, for example, it can be 220, 250, 280, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000, 1200, 1500 or 1800, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0057] Preferably, the epoxy equivalent of the epoxy resin is 150-570 g / eq, for example, it can be 160 g / eq, 180 g / eq, 195 g / eq, 200 g / eq, 220 g / eq, 250 g / eq, 280 g / eq, 300 g / eq, 320 g / eq, 350 g / eq, 380 g / eq, 400 g / eq, 420 g / eq, 450 g / eq, 480 g / eq, 500 g / eq, 520 g / eq, or 550 g / eq, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0058] In this invention, the term "epoxy equivalent" refers to the weight of epoxy resin equivalent to one gram equivalent of epoxy groups; the epoxy value refers to the number of gram equivalents of epoxy groups contained in 100g of resin. The epoxy equivalent and epoxy value are related by the following formula: Epoxy value = 100 / Epoxy equivalent.

[0059] The present invention does not impose any special restrictions on the type of epoxy resin, as long as each molecule of the epoxy resin contains at least two epoxy groups.

[0060] Preferably, the epoxy resin has a functionality of 2-6, for example, 2, 3, 4, 5 or 6.

[0061] For example, the epoxy resin includes, but is not limited to, any one or a combination of at least two of the following: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenolic epoxy resin, biphenyl type epoxy resin, phenolic epoxy resin, o-cresol phenolic epoxy resin, XYLOK phenolic epoxy resin, dicyclopentadiene (DCPD) type epoxy resin, bisphenol A phenolic epoxy resin, organosilicon modified epoxy resin, phosphorus-containing epoxy resin, aliphatic epoxy resin, alicyclic epoxy resin, and o-cresol epoxy resin.

[0062] Preferably, the viscosity of the epoxy resin is 250-5500 mPa·s, for example, it can be 300 mPa·s, 400 mPa·s, 500 mPa·s, 800 mPa·s, 1000 mPa·s, 1200 mPa·s, 1500 mPa·s, 1800 mPa·s, 2000 mPa·s, 2200 mPa·s, 2500 mPa·s, 2800 mPa·s, 3000 mPa·s, etc. The specific point values ​​included in the ranges are 3200 mPa·s, 3500 mPa·s, 3800 mPa·s, 4000 mPa·s, 4200 mPa·s, 4500 mPa·s, 4800 mPa·s, 5000 mPa·s, 5200 mPa·s, or 5400 mPa·s, as well as specific point values ​​between the above-mentioned point values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the ranges.

[0063] In this invention, the viscosity of the epoxy resin was obtained by testing at 25°C.

[0064] Preferably, the curing agent includes any one or a combination of at least two of amine curing agents, phenolic curing agents, acid anhydride curing agents, and organic acid hydrazide curing agents.

[0065] Preferably, the amine curing agent includes any one or a combination of at least two of dicyandiamide, 4,4'-diaminodiphenylmethane (DDM), 4,4'-diaminodiphenyl sulfone (DDS), and polyamide.

[0066] Preferably, the phenolic curing agent includes phenolic resin, and more preferably any one or a combination of at least two of linear phenolic resin, o-cresol phenolic resin, biphenyl phenolic resin, phenolic resin of the phenol type, bisphenol A phenolic resin, triphenol phenolic resin, naphthalene phenolic resin, biphenyl phenolic resin, and dicyclopentadiene phenolic resin.

[0067] Preferably, based on 100 parts by weight of the epoxy resin, the curing agent comprises 5-45 parts by weight, for example, 6 parts, 8 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts, 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 42 parts, or 44 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0068] Preferably, the thermosetting resin composition further includes any one or a combination of at least two of the following: a curing accelerator, a filler, a coupling agent, and a toughening agent.

[0069] As a preferred embodiment of the present invention, the thermosetting resin composition includes a curing accelerator to control the curing reaction rate of the thermosetting resin composition. The amount of curing accelerator added should not be too much, as too much will lead to an excessively fast reaction rate of the thermosetting resin composition, excessive by-products, reduced performance of the cured product, and poor processability. If the amount of curing accelerator is too little, the reaction will be too slow, which is not conducive to the production of prepreg and affects production efficiency. Therefore, it is generally advisable to control the gelation time of the resin liquid of the thermosetting resin composition to 100-200s by using a curing accelerator.

[0070] Preferably, the curing accelerator comprises any one or a combination of at least two of tertiary amines, tertiary phosphines, organometallic complexes, quaternary ammonium salts, and imidazole compounds, with imidazole compounds being more preferred.

[0071] Preferably, the imidazole compound includes any one or a combination of at least two of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 1-cyanoethyl-2-methylimidazole.

[0072] Preferably, based on 100 parts by weight of the epoxy resin, the curing accelerator is 0.02-3 parts by weight, for example, 0.05 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.8 parts, 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, 2.2 parts, 2.5 parts, or 2.8 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0073] Preferably, the thermosetting resin composition further includes any one or a combination of at least two of the following: flame retardant, filler, coupling agent, and toughening agent.

[0074] In this invention, the type of flame retardant is not particularly limited, and any flame retardant with flame retardant effect (small molecule, resin, powder, etc.) can be used in the resin composition.

[0075] Preferably, the flame retardant includes any one or a combination of at least two of the following: halogenated flame retardants (e.g., bromine-containing flame retardants), phosphorus-containing flame retardants, and nitrogen-containing flame retardants.

[0076] Preferably, the flame retardant contains any one or a combination of at least two of the elements bromine, phosphorus, and nitrogen.

[0077] For example, the flame retardant contains bromine, with a bromine content of 15%-60%, such as 18%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or 55%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0078] For example, the flame retardant contains phosphorus, with a phosphorus content of 2%-30%, such as 3%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, or 28%, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0079] For example, the flame retardant contains nitrogen, with a nitrogen content of 5%-50%, such as 10%, 15%, 20%, 25%, 30%, 35%, 40% or 45%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0080] Preferably, the decomposition temperature Td-5% (5% thermal decomposition temperature) of the flame retardant is ≥250℃, for example, it can be 255℃, 260℃, 265℃, 270℃, 275℃, 280℃, 290℃, 300℃, 310℃, 320℃, 350℃ or 380℃, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0081] Preferably, the flame retardant includes reactive flame retardants and / or additive flame retardants.

[0082] Preferably, the flame retardant includes, but is not limited to, any one or a combination of at least two of the following: tetrabromobisphenol A, tribromophenol, melamine cyanurate, zinc borate, modified zinc borate, polysiloxane, phosphazene, magnesium hydroxide, antimony trioxide, aluminum hydroxide, phosphorus-containing phenolic resin, phosphorus-containing maleimide phenolic resin, phenoxyphosphazene, DOPO-based phosphorus-containing epoxy resin, DOPO-based phosphorus-containing phenolic resin, phosphazene-based phenolic resin, modified benzoxazine resin, nitrogen-containing phenolic resin, epoxy-containing flame retardant resin, hydroxyl-containing flame retardant resin, and amino-containing flame retardant resin.

[0083] Preferably, based on 100 parts by weight of the epoxy resin, the flame retardant is 10-110 parts by weight, for example, 15 parts, 20 parts, 25 parts, 30 parts, 40 parts, 50 parts, 60 parts, 70 parts, 80 parts, 90 parts or 100 parts, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0084] Preferably, the filler comprises any one or a combination of at least two of the following: titanium dioxide (titanium white), silicon dioxide, aluminum oxide, kaolin, aluminum hydroxide, magnesium hydroxide, magnesium oxide, calcium carbonate, boron nitride, silicon carbide, titanium dioxide, zinc borate, zinc molybdate, barium metaborate, zinc sulfide, aluminum silicate, zinc oxide, zirconium oxide, mica, boehmite, talc, and calcium nitride.

[0085] Preferably, the average particle size (D) of the filler is 50 The value can be 0.01-20μm, for example, 0.05μm, 0.1μm, 0.3μm, 0.5μm, 0.8μm, 1μm, 3μm, 5μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm or 18μm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range.

[0086] Preferably, based on 100 parts by weight of the epoxy resin, the filler is 10-300 parts by weight, for example, 12 parts, 20 parts, 30 parts, 50 parts, 70 parts, 80 parts, 100 parts, 120 parts, 150 parts, 180 parts, 200 parts, 220 parts, 240 parts, 250 parts, 260 parts, or 280 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 15-210 parts is further preferred.

[0087] Preferably, the coupling agent includes any one or a combination of at least two of silane coupling agents, organochromium coupling agents, and titanate coupling agents.

[0088] Preferably, based on 100 parts by weight of the epoxy resin, the coupling agent is 0.2-6 parts by weight, for example, 0.3 parts, 0.5 parts, 0.8 parts, 1.0 parts, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, or 5.5 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0089] Preferably, the toughening agent comprises any one or a combination of at least two of the following: epoxy soybean oil resin, cashew phenol modified resin, tung oil modified resin, castor oil modified resin, phenoxy resin, rubber resin, and core-shell rubber material.

[0090] Preferably, based on 100 parts by weight of the epoxy resin, the toughening agent has a mass of ≤50 parts, for example, it can be 0, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, 45, or 48 parts, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0091] As a preferred embodiment of the present invention, the resin composition comprises the following components in parts by weight:

[0092]

[0093] Preferably, the thermosetting resin composition further includes other additives that those skilled in the art are motivated to add, such as antioxidants and / or viscosity modifiers.

[0094] A second solvent may be added to the above-mentioned thermosetting resin composition. Other components of the thermosetting resin composition are dissolved or dispersed in the second solvent to form a resin adhesive. The amount of the second solvent added is selected by those skilled in the art based on experience and process requirements, so that the thermosetting resin composition reaches a suitable viscosity for use, facilitating impregnation, coating, etc. Subsequently, during drying, semi-curing, or complete curing stages, the solvent in the thermosetting resin composition will partially or completely evaporate.

[0095] Preferably, the solid content of the resin solution is 60%-80%, for example, it can be 62%, 65%, 68%, 70%, 72%, 75%, or 78%, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 68%-78% is further preferred. The resin solution with this solid content can improve the permeability to the reinforcing material, thereby obtaining a prepreg with a highly uniform resin layer thickness.

[0096] The second solvent used in this invention is not particularly limited. Generally, ketones such as acetone, butanone, and cyclohexanone; aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; alcohols such as methanol, ethanol, or butanol; alcohol ethers such as ethyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, carbitol, or butyl carbitol; and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, or N-methyl-2-pyrrolidone are preferred. The solvent can be used alone or in combination of two or more. Preferably, any one or a combination of at least two of methanol, ethanol, acetone, butanone, ethylene glycol monobutyl ether, methyl acetate, ethyl acetate, and cyclohexanone are preferred.

[0097] Preferably, the boiling point of the second solvent is 50-180℃, for example, it can be 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, or 170℃, as well as specific values ​​between the above ranges. For space limitations and for the sake of brevity, the present invention will not exhaustively list all the specific values ​​included in the range. The boiling point of the second solvent matches the drying / semi-curing processing temperature of the prepreg, which can meet the solvent removal requirements of the semi-curing stage; at the same time, the second solvent satisfies the requirements for the resin's permeability to the reinforcing material and its compatibility with the thermosetting resin composition.

[0098] For example, the thermosetting resin composition is prepared by a method comprising: mixing and dispersing the components of the thermosetting resin composition uniformly to obtain the thermosetting resin composition.

[0099] For example, the method for preparing the resin solution includes: mixing each component in the thermosetting resin composition with a second solvent and dispersing them evenly to obtain the resin solution.

[0100] For example, the prepreg is prepared by impregnating the modified plant fiber reinforcing material provided by the present invention with the resin solution of the thermosetting resin composition, and then drying it to obtain the prepreg.

[0101] Preferably, the drying temperature is 50-180℃, for example, it can be 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃ or 170℃, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0102] Preferably, the drying time is sufficient to ensure that the prepreg meets the pressing requirements for the production of metal foil laminates, and a flowability of 10-20% is recommended.

[0103] Preferably, the drying time is 1-30 min, for example, it can be 2 min, 5 min, 8 min, 10 min, 15 min, 20 min or 25 min, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0104] Preferably, the loading of the thermosetting resin composition in the prepreg is 120-280 g / m³. 2 For example, it can be 140g / m 2 150g / m 2 180g / m 2 200g / m 2 220g / m 2 240g / m 2 250g / m 2 Or 270g / m 2 As well as the specific point values ​​between the above point values, due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific point values ​​included in the range.

[0105] Wherein, the loading of the thermosetting resin composition in the prepreg is equal to the weight of the prepreg minus the weight of the modified plant fiber reinforcement.

[0106] On the other hand, the present invention provides a laminate comprising at least one prepreg as described in the fifth aspect.

[0107] In a sixth aspect, the present invention provides a metal foil laminate, the metal foil laminate comprising a metal foil and at least one sheet of prepreg as described in the fifth aspect.

[0108] Preferably, the number of prepreg sheets in the metal foil laminate is 1-20, for example, 2, 3, 5, 6, 8, 10, 12, 15, 18 or 19, and specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values ​​included in the range.

[0109] Preferably, the metal foil is copper foil, and thus, the metal foil laminate is a copper-clad laminate.

[0110] For example, the method for preparing the metal foil laminate includes: pressing a metal foil onto one or both sides of a prepreg and curing it to obtain the metal foil laminate; or, stacking at least two prepregs into a laminate, then pressing a metal foil onto one or both sides of the laminate and hot-pressing it to obtain the metal foil laminate.

[0111] Preferably, the hot pressing curing is carried out in a press.

[0112] Preferably, the hot-press curing temperature is 120-280℃, for example 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃ or 270℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0113] Preferably, the pressure for hot pressing and curing is 1-10 MPa, such as 1.5 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa or 9 MPa, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0114] Preferably, the hot-press curing time is 30-150 min, for example 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, 130 min, 140 min or 145 min, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0115] On the other hand, the present invention provides a printed circuit board comprising at least one of the prepreg as described in the fifth aspect and the metal foil laminate as described in the sixth aspect.

[0116] Compared with the prior art, the present invention has the following beneficial effects:

[0117] (1) The plant fiber modifier provided by the present invention, through the design and mutual compounding of phenolic resin, organic acid, coupling agent, epoxy diluent and silicone oil, can effectively improve the surface affinity and impregnation of plant fiber cloth, and react to form a rich cross-linked network structure, which fills and repairs the cavity defects in plant fiber, and seals the hydrophilic groups in plant fiber, so that the prepared modified plant fiber reinforced material has low water absorption, excellent heat resistance, damp heat resistance, impregnation and adhesion.

[0118] (2) The modified plant fiber reinforced material provided by the present invention can be used in prepreg and metal foil laminate to give the board excellent heat resistance, moisture resistance, damp heat resistance, interlayer bonding strength, impregnation processability, insulation reliability and processability, which fully meets the high performance requirements of printed circuits for copper clad laminate.

[0119] (3) The modified plant fiber reinforcement material provided by the present invention not only expands the application field of plant fiber, but also increases the proportion of plant-based materials in copper clad laminates and reduces the carbon dioxide emission intensity during the life cycle of copper clad laminates, which is in line with the green, low-carbon and environmentally friendly development concept. Detailed Implementation

[0120] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0121] In the following specific embodiments of the present invention, the materials involved are all commercially available chemicals, and the specific information is as follows:

[0122]

[0123]

[0124] Preparation Example 1

[0125] A thermosetting resin composition H1 comprises, by weight, the following components: 100 parts of bisphenol A type epoxy resin (M n The composition is 280, epoxy equivalent is 183-200 g / eq, Laizhou Baichen Insulation Materials), 43 parts bisphenol A type phenolic resin (SH-2107, Shandong Shengquan), 0.7 parts 2-methylimidazole, 55 parts flame retardant (tetrabromobisphenol A), 40 parts titanium dioxide (particle size 0.5-1.5μm), and 2.1 parts silane coupling agent KH550.

[0126] According to the above formula, each component of thermosetting resin composition H1 is mixed with solvent (a mixed solvent of methanol and acetone in a mass ratio of 3:7), and stirred evenly with a high-speed disperser to prepare H1 adhesive with a solid content of 76%.

[0127] The following will use several embodiments as examples to describe in detail the plant fiber modifier, modified plant fiber reinforcing material and its application of the present invention, but the plant fiber modifier, modified plant fiber reinforcing material and its application of the present invention are not limited to these embodiments.

[0128] Examples 1-5, Comparative Examples 1-13

[0129] A plant fiber modifier, the types and amounts of each component are shown in Table 1 and Table 2, and the unit of amount of each component is "parts" (parts by mass).

[0130] A modified plant fiber reinforced material (modified plant fiber cloth) prepared using the aforementioned plant fiber modifier, a prepreg containing the modified plant fiber cloth, and a metal foil-coated laminate (copper-clad laminate) are prepared by the following method:

[0131] (1) Mix the plant fiber modifier with the solvent (methanol) according to the formula amount, and stir evenly with a high-speed disperser to prepare a modified adhesive solution with a plant fiber modifier mass ratio of 26%.

[0132] (2) The plant fiber cloth was heat-treated at 200℃ for 30 minutes. After the temperature of the plant fiber cloth dropped to room temperature, it was impregnated with the modified adhesive obtained in step (1). After impregnation, it was dried and cured at 170℃ for 20 minutes to obtain the modified plant fiber cloth. The loading of the modifier was 30 g / m. 2 .

[0133] (3) The modified plant fiber cloth obtained in step (2) is impregnated with H1 adhesive solution, then baked at 120°C for 5 minutes, and then baked in an oven at 170°C for 3 minutes to obtain a prepreg. The loading of the thermosetting resin composition is 190 g / m. 2 .

[0134] (4) Stack the three prepregs obtained in step (3), cover the two outer sides of the stack with copper foil, and hot press at 175°C and 3.5MPa for 60 minutes in a press to make a copper-clad laminate with a thickness of 1.0mm.

[0135] The performance testing of copper-clad laminates is conducted using the following methods:

[0136]

[0137]

[0138] Table 1

[0139]

[0140]

[0141] Table 2

[0142]

[0143]

[0144] In Table 2, Comparative Example 12 used unmodified plant fiber cloth as a reinforcing material and directly impregnated it with H1 adhesive to prepare prepreg and copper-clad laminate; Comparative Example 13 used conventional electronic-grade glass fiber cloth as a reinforcing material and impregnated it with H1 adhesive to prepare prepreg and copper-clad laminate.

[0145] According to the performance test data in Tables 1 and 2, this invention, through the design and mutual compounding of phenolic resin, organic acid, coupling agent, epoxy diluent, and silicone oil, enables the plant fiber modifier to effectively improve the surface affinity and impregnation properties of plant fiber fabric, fill and repair cavities and defects in plant fibers, and seal hydrophilic groups. This results in a modified plant fiber fabric with lower water absorption and significantly improved heat resistance, damp heat resistance, impregnation properties, and adhesion. When used as a reinforcing material in the preparation of prepregs and copper-clad laminates, it achieves a 288℃ dip-soldering time of ≥236s, a PCT dip-soldering time of ≥281s, a PCT water absorption rate of ≤0.3%, a peel strength of ≥1.49 N / mm, and can achieve a V-0 flame retardant rating with a volume resistivity of ≥5.11 × 10⁻⁶. 9 The copper clad laminate exhibits excellent comprehensive performance in terms of heat resistance, damp heat resistance, interlayer bonding strength, processability, and insulation reliability, measured in MΩ·cm. Compared to the copper clad laminate using unmodified plant fiber cloth as a reinforcing material in Comparative Example 12, Examples 1-5 of this invention achieve a performance breakthrough in plant fiber cloth-based copper clad laminates, reaching the same level as glass fiber cloth-based copper clad laminates (Comparative Example 13), thus meeting the performance requirements of printed circuit boards for copper clad laminates. Furthermore, this invention increases the proportion of plant-based materials in the copper clad laminate, expands the application fields of plant fibers, reduces the intensity of carbon dioxide emissions during the life cycle of the copper clad laminate, and is environmentally friendly.

[0146] As can be seen from Example 1 and Comparative Examples 1-11, if the modifier is not a compound of phenolic resin, organic acid, coupling agent, epoxy diluent and silicone oil as defined in this invention, or if the amount of components exceeds the scope defined in this invention, the modification effect on plant fiber cloth will be poor, resulting in varying degrees of deterioration in the heat resistance, damp heat resistance, adhesion (peel strength) and insulation reliability of the copper clad laminate, which cannot meet the requirements for use of printed circuit copper clad laminate.

[0147] The applicant declares that this invention illustrates the plant fiber modifier, modified plant fiber reinforcing material, and their applications through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials in the product, addition of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A plant fiber modifier, characterized in that, The plant fiber modifier comprises the following components in parts by weight:

2. The plant fiber modifier according to claim 1, characterized in that, The number-average molecular weight of the phenolic resin is 150-700; Preferably, the organic acid includes any one or a combination of at least two of benzoic acid, salicylic acid, caffeic acid, tartaric acid, oxalic acid, malic acid, acetic acid, and citric acid; Preferably, the coupling agent comprises a silicone-based coupling agent, and more preferably any one or a combination of at least two of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, 3-(methoxy)propyltrimethoxysilane, 3-propenoxypropyltrimethoxysilane, 3-hydroxypropyltrimethoxysilane, and vinyltrimethoxysilane.

3. The plant fiber modifier according to claim 1 or 2, characterized in that, The epoxy diluent includes any one or a combination of at least two of the following: 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, propylene oxide o-tolyl ether, propylene oxide o-tolyl glycidyl ether, and neopentyl glycol diglycidyl ether. Preferably, the silicone oil includes any one or a combination of at least two of the following: methyl hydrogen silicone oil, epoxy-modified silicone oil, polyether-modified polydimethylsiloxane, amino-modified silicone oil, methyl silicone oil, and benzyl silicone oil.

4. The application of a plant fiber modifier as described in any one of claims 1-3 in modified plant fiber reinforced materials or prepregs.

5. A modified plant fiber reinforced material, characterized in that, The modified plant fiber reinforced material is prepared by using plant-based reinforcing materials and plant fiber modifiers as described in any one of claims 1-3.

6. The modified plant fiber reinforced material according to claim 5, characterized in that, The plant-based reinforcing material includes plant fiber cloth, preferably any one or a combination of at least two of ramie fiber cloth, flax fiber cloth, jute fiber cloth, sisal fiber cloth, hemp fiber cloth, bamboo fiber cloth, corn fiber cloth, and banana fiber cloth; Preferably, the weight of the plant fiber cloth is 50-280 g / m². 2 ; Preferably, the loading of the modifier in the modified plant fiber reinforced material is 7-40 g / m³. 2 .

7. A method for preparing a modified plant fiber reinforced material as described in claim 5 or 6, characterized in that, The preparation method includes the following steps: A modified adhesive solution is provided, the modified adhesive solution comprising the plant fiber modifier as described in any one of claims 1-3 and a first solvent; The plant-based reinforcing material is impregnated in the modified adhesive solution and then subjected to a first curing process to obtain the modified plant fiber reinforcing material.

8. The preparation method according to claim 7, characterized in that, The impregnation process also includes a heat treatment step of the plant-based reinforcing material; Preferably, the heat treatment temperature is 150-220℃; Preferably, the heat treatment time is 10-50 minutes; Preferably, the first curing temperature is 160-190℃; Preferably, the first curing time is 5-60 minutes.

9. A prepreg, characterized in that, The prepreg comprises the modified plant fiber reinforcing material as described in claim 5 or 6 and a thermosetting resin composition attached to the modified plant fiber reinforcing material; Preferably, the thermosetting resin composition is attached to the modified plant fiber reinforced material after impregnation and drying.

10. A metal foil-coated laminate, characterized in that, The metal foil laminate includes a metal foil and at least one sheet of prepreg as described in claim 9.

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