阅读说明：本技术 一种满足EN45545阻燃标准的OoA工艺用预浸料 (OoA process prepreg meeting EN45545 flame-retardant standard ) 是由 李志涛 钱京 尹国强 单瑞俊 毛慧文 于 2019-09-26 设计创作，主要内容包括：本发明公开了一种满足EN45545阻燃标准的OoA工艺用预浸料,包括碳纤维和阻燃树脂基体；阻燃树脂基体包括一定质量组分的环氧树脂、阻燃剂、固化剂；且阻燃剂至少为2种。其通过最优的阻燃剂组合,分别于燃烧的不同阶段实现阻燃效果,使得阻燃树脂既满足EN45545阻燃标准中HL1或HL2级别,又适用低成本OoA工艺,降低对最终产品力学性能的影响,使得其经预浸料固化后具有优异的力学性能。同时界面改性剂改善阻燃剂和树脂之间的界面极性,让树脂在完全浸润粉体后更加充分的接触和浸润纤维,实现纤维和树脂间的应力传递,充分发挥碳纤维复合材料优异力学性能的特点。(The invention discloses a OoA technical prepreg meeting EN45545 flame retardant standard, which comprises carbon fibers and a flame-retardant resin matrix; the flame-retardant resin matrix comprises epoxy resin, a flame retardant and a curing agent which are prepared from a certain mass component; and at least 2 flame retardants. The flame retardant resin achieves flame retardant effects at different stages of combustion through optimal flame retardant combinations, so that the flame retardant resin not only meets the HL1 or HL2 level in the EN45545 flame retardant standard, but also is suitable for a low-cost OoA process, the influence on the mechanical property of a final product is reduced, and the prepreg has excellent mechanical property after being cured. Meanwhile, the interface modifier improves the interface polarity between the flame retardant and the resin, so that the resin can more fully contact and infiltrate the fiber after completely infiltrating the powder, the stress transfer between the fiber and the resin is realized, and the characteristics of excellent mechanical properties of the carbon fiber composite material are fully exerted.)

1. A OoA technical prepreg meeting EN45545 flame retardant standard, which is characterized by comprising carbon fibers and a flame retardant resin matrix,

the flame-retardant resin matrix comprises the following components in parts by mass: 60-80 parts of epoxy resin, 15-30 parts of flame retardant and 9-12 parts of curing agent;

the mass percentage of the flame-retardant resin matrix in the prepreg is 40-45%;

the flame retardant is a combination suitable for at least two combustion stages including:

an initial stage: at least one of magnesium hydroxide and aluminum hydroxide,

in the middle stage: at least one of melamine urate, organic phosphonate, melamine polyphosphate and ammonium polyphosphate,

and (3) later stage: at least one of triazine polyol, pentaerythritol, organo montmorillonite, borate, and silicate.

2. The prepreg meeting EN45545 flame retardant standard for OoA process, according to claim 1, wherein the flame retardant resin matrix further comprises 1-3 parts by mass of an interfacial modifier, and the interfacial modifier comprises one or more of BYK-W-969, BYK-W-980, BYK-W-996, BYK-088 and BYK-9912.

3. The prepreg for OoA process meeting EN45545 flame retardant standard according to claim 1, wherein the epoxy resin comprises bisphenol A epoxy resin, novolac epoxy resin and macromolecular phenoxy resin.

4. The prepreg for OoA process meeting EN45545 flame retardant standard according to claim 1, wherein the curing agent is one or more of dicyandiamide, 4' -diaminodiphenyl sulfone, organic ureas, thioureas, imidazoles and Lewis acids.

5. The preparation method of the prepreg meeting EN45545 flame retardant standard OoA process according to claim 1, wherein the prepreg is prepared by coating and impregnating carbon fibers and a flame-retardant resin matrix prepared by mixing the components in parts by mass by a hot melting method.

6. The preparation method of the prepreg meeting the EN45545 flame retardant standard for the OoA process, according to claim 5, characterized in that the mixing step comprises:

adding epoxy resin into a mixing kettle according to the mass part, and heating and stirring uniformly; adding a flame retardant and uniformly stirring; adding interface modifier, and stirring; cooling, adding a curing agent, uniformly stirring, and discharging to obtain the flame-retardant resin matrix.

7. The method for preparing the prepreg meeting the EN45545 flame retardant standard OoA process, as claimed in claim 5, wherein in the coating step, the temperature of the coating is controlled to be 70-75 ℃, the metering roll gap is 0.1-0.2mm, the supporting roll pressure is 100-160kg, and the coating speed is 7-12 m/min.

8. The preparation method of the prepreg meeting EN45545 flame retardant standard for OoA process, according to claim 5, characterized in that in the impregnation step, the fiber opening roller temperature is controlled to be 75-85 ℃, the heating plate temperature is 90-110 ℃, the impregnation roller temperature is 60-80 ℃, the cold air box temperature is 7-12 ℃, and the impregnation speed is 3-5 m/min.

9. The method for preparing the prepreg meeting the EN45545 flame retardant standard OoA process, according to claim 5, wherein the carbon fibers in the prepreg are arranged in parallel in the same direction or in 2/2 directions perpendicular to each other.

Technical Field

The invention relates to a prepreg, in particular to a OoA technical prepreg meeting EN45545 flame retardant standard, and belongs to the technical field of flame retardance.

Background

At present, the fire-proof standard of rail transit rolling stock at home and abroad mainly has European Union EN 45545: 2013 series of standards, "railway applications-railway vehicle fire protection", BS 6853 in uk: 1999 general Specifications for fire protection in passenger train design and construction, German DIN 5510: 2009 series of standards "fire-proof measures for rail vehicles", UIC 564-2 of the international union of railways "fire-proof and fire-fighting regulations for passenger cars or international union of railways for similar vehicles", NFPA 130 "fixed track traffic and passenger railway systems" in the united states, NF F16-101/102 "fire-proof properties for rail vehicles" in france, and TB/T3237-: the 2013 series of standards can simulate the real fire environment most, so the standards are adopted by most countries.

With the continuous innovation of new materials, fiber reinforced resin matrix composite materials have the characteristics of high modulus, high strength, low weight and the like, and the brand-new materials show a corner and gradually begin to obtain traditional steel and aluminum alloy materials, but the resin matrix materials as the matrix materials do not have the flame resistance of the traditional steel and aluminum alloy, so that the improvement of the flame resistance of the resin matrix materials is of great importance.

Currently, the market has met german DIN 5510: 2009 and TB/T3237-: 2013, almost no epoxy flame-retardant carbon fiber prepreg system exists at present.

Glass fiber prepreg for interior decoration meeting EN45545 standards is mostly appeared in the market, the materials are basically non-stressed parts, and the traditional glass fiber reinforced plastic can meet the requirements on mechanical properties, so that excessive flame retardant such as ATH (antimony tin oxide) and the like can be added into phenolic resin or epoxy resin, the overall flame retardant property of the cured plate can be greatly improved, and the requirements of the interior decoration materials on the mechanical properties can be simultaneously met.

For carbon fiber flame-retardant prepreg, the bearable function of carbon fiber needs to be exerted at the same time, so that higher mechanical property and flame retardant property meeting the requirement need to be considered simultaneously in development and use. The most common form of flame retardancy of epoxy resins commonly used in carbon fiber flame retardant prepregs remains additive flame retardancy. The additive type is mainly characterized in that various additives with flame retardant property are introduced into the epoxy resin, so that the material has flame retardant property. Additive flame retardants are inexpensive and easy to implement, but are often added in very large proportions to achieve the desired flame retardancy requirements, which can affect the mechanical properties of the post-cured laminate.

Halogen-free reactive flame retardants are currently on the market, of which DOPO is a typical representative, and they are mostly novel reactive flame retardant resins formed by grafting onto different epoxy resins. Because the epoxy resin is grafted on a polar group, the content of the whole flame retardant is generally lower, the part amount needed when the flame retardant resin is introduced is generally more than 60 parts, and the cost of grafting the epoxy resin by the flame retardant is high, although the addition of flame retardant powder can be reduced to a certain extent, because the flame retardant group introduces an epoxy resin branched chain, the reaction steric hindrance is increased, the whole polarity of the resin is changed, and the reaction activity of the final resin and the wettability of fibers are adversely affected.

Disclosure of Invention

In order to solve the defects of the prior art, the invention aims to provide a prepreg which can still meet the prepreg resin impregnation process even after a large amount of additive flame retardant is introduced, and simultaneously the flame retardant performance of a laminated board after being cured by the OoA process can also reach the HL1 or HL2 grade in European standard EN 45545.

In order to achieve the above object, the present invention adopts the following technical solutions:

a OoA technical prepreg meeting EN45545 flame retardant standard, comprising carbon fibers and a flame retardant resin matrix,

the flame-retardant resin matrix comprises the following components in parts by mass: 60-80 parts of epoxy resin, 15-30 parts of flame retardant and 9-12 parts of curing agent;

the mass percentage of the flame-retardant resin matrix in the prepreg is 40-45%;

the flame retardant is a combination suitable for at least two combustion stages including:

an initial stage: at least one of magnesium hydroxide and aluminum hydroxide absorbs heat through decomposition of the flame retardant in the initial stage (in the temperature range of 150 ℃ to 350 ℃) of the whole combustion process, so that the combustion speed of the resin is slowed down, and the heat energy release in the combustion process is reduced.

In the middle stage: at least one of melamine urate, organic phosphonate, melamine polyphosphate and ammonium polyphosphate reacts with epoxy resin to form carbon under the catalysis of heat in the middle stage (within the temperature range of 350-550 ℃) of the whole combustion process, so that the probability of decomposing the main chain of the resin into small molecular chains is reduced, and the generation of a gas-phase carbon source in the combustion process is reduced.

And (3) later stage: at least one of triazine polyol, pentaerythritol, organo montmorillonite, borate, and silicate. In the later stage of the whole combustion process (within the temperature range of 550-900 ℃), the formation of smoke dust is reduced by the dehydration of hydroxyl groups to assist the carbonization and the capturing of reactive group micromolecules by subgroup elements, the forming and the stability of a coke layer are promoted, and meanwhile, the heat insulation and oxygen insulation effects are realized, so that the resin combustion is reduced, and the flame retardant property is improved. The flame-retardant resin matrix also comprises 1-3 parts of an interface modifier, wherein the interface modifier comprises one or more of BYK-W-969, BYK-W-980, BYK-W-996, BYK-088 and BYK-9912.

The epoxy resin comprises bisphenol A type epoxy resin, novolac epoxy resin and macromolecular phenoxy resin.

The curing agent is one or more of dicyandiamide, 4' -diaminodiphenyl sulfone, organic ureas, thiourea compounds, imidazole compounds and Lewis acid compounds.

According to the preparation method of the OoA technical prepreg meeting the EN45545 flame-retardant standard, the flame-retardant resin matrix prepared by mixing the materials in parts by mass and the carbon fiber are subjected to film coating and impregnation by a hot melting method to prepare the prepreg.

Further, the mixing materials are as follows:

adding a certain amount of epoxy resin into a mixing kettle according to the mass parts, and heating and uniformly stirring; adding a flame retardant and uniformly stirring; adding interface modifier, and stirring; cooling, adding a curing agent, uniformly stirring, and discharging to obtain the flame-retardant resin matrix.

Furthermore, the temperature of the coating is controlled to be 70-75 ℃, the measuring roller gap is 0.1-0.2mm, the pressure of the supporting roller is 100-160kg, and the coating speed is 7-12 m/min.

Further, the impregnation is carried out by controlling the temperature of the fiber opening roller to be 75-85 ℃, the temperature of the heating plate to be 90-110 ℃, the temperature of the impregnation roller to be 60-80 ℃, the temperature of the cold air box to be 7-12 ℃ and the impregnation speed to be 3-5 m/min.

Further, the carbon fibers in the prepreg are arranged in parallel in the same direction or arranged so as to be orthogonal to each other in the direction 2/2.

The invention has the advantages that:

the OoA technical prepreg meeting EN45545 flame retardant standard aims at solving the problems that flame retardant resin is difficult to soak after being modified due to the addition of excessive low-efficiency flame retardant in the prior art, a high-cost autoclave process is required, and the low-cost OoA process is difficult to apply; by selecting the optimal flame retardant, the effects of different flame retardants in the initial stage, the middle stage, the later stage and the like of combustion are exerted, and the flame retardant effect is realized by using the most efficient amount, so that the flame retardant resin can well meet the flame retardant grade HL1 or HL2 in the EN45545 flame retardant standard, can be applied to a low-cost OoA production process, simultaneously reduces the influence on the mechanical property of a final product, and has excellent mechanical property after prepreg is cured.

The invention also introduces an interface modifier to improve the interface polarity between the flame retardant and the resin, so that the flame retardant and the resin are effectively infiltrated, the resin is more fully contacted and infiltrated into fibers after being completely infiltrated into the flame retardant powder, the stress transfer between the fibers and the resin is realized, and the characteristics of excellent mechanical properties of the carbon fiber composite material are fully exerted.

The invention improves the prior prepreg by using the flame retardants and the interface modifiers with different combinations, so that the prepreg can be based on and suitable for low-cost mixing, film coating, impregnation and OoA processes, and a high-performance product is prepared, the preparation efficiency is greatly improved, the cost of raw materials, the process and equipment is reduced, and the prepreg has strong practicability and wide applicability.

Drawings

FIG. 1 is a schematic view of the process of coating film of the present invention.

Fig. 2 is a schematic view of the impregnation process of the present invention.

Fig. 3 is a C-scan of a cured laminate of prepreg a of the present invention.

Fig. 4 is a C-scan of a laminate after prepreg B of the present invention has been cured.

Fig. 5 is a C-scan of a laminate after curing prepreg C of the present invention.

FIG. 6 is a C-scan of a prepreg D-cured laminate of the present invention

Detailed Description

The invention is described in detail below with reference to the figures and the embodiments.

The specification of the carbon fiber used in the invention is HFW200T-A3-2/2-1000 (Jiangsu Hengshen GmbH), and the rest reagents are commercially available.