TWI784693B - Sizing agent for carbon fiber - Google Patents

Abstract

A sizing agent for carbon fiber includes 2 parts by weight to 30 parts by weight of a resin main agent (A) having at least one epoxy compound, 2 parts by weight to 30 parts by weight of a resin main agent (B) having at least one acrylate compound, 0.5 parts by weight to 15 parts by weight of surfactant (C), and 0.01 parts by weight to 0.5 parts by weight of a hindered phenol agent (D), in which a particle diameter of the sizing agent is between 0.01 to 0.5

Description

Sizing agent for carbon fiber

The present disclosure relates to a sizing agent for carbon fibers, and in particular to a sizing agent that prolongs the hardening time of carbon fiber bundles.

Carbon fiber is an important reinforcing material, which is widely used in various fields. Due to the advantages of high specific strength, specific modulus, high temperature resistance, chemical resistance, small friction coefficient and good electrical conductivity, carbon fiber can be used to enhance material properties. Carbon fiber composite materials can be used in various fields, for example, aviation, aerospace, sporting goods, civil engineering, electronic products, medical equipment and other fields.

However, the processability of carbon fiber is affected due to the low stretching rate and brittleness of carbon fiber. During the processing of carbon fiber, hairiness or broken filaments will occur due to mechanical friction, which will reduce the strength of carbon fiber. The carbon fiber hardness is one of the factors that affect hairiness or broken wires due to mechanical friction during processing. The higher the hardness of the carbon fiber, the easier it is for the carbon fiber to produce hairiness or broken filaments during processing.

In view of the above, there is an urgent need to develop a method of increasing the processability of carbon fibers to overcome the aforementioned problems.

之間。 The present disclosure provides a sizing agent for carbon fiber, comprising resin main agent (A) of at least one epoxy compound accounting for 2 to 30 parts by weight, resin main agent (A) of at least one acrylate compound accounting for 2 to 30 parts by weight Agent (B), surfactant (C) accounting for 0.5 to 15 parts by weight and hindered phenolic agent (D) accounting for 0.01 to 0.5 parts by weight, wherein the particle size of the sizing agent is between 0.01 and 0.5

between.

In some embodiments, the resin main agent (A) of at least one epoxy-based compound comprises bisphenol A epoxy compound, bisphenol F epoxy compound, bisphenol S epoxy compound, novolak epoxy resin or combination.

In some embodiments, at least one epoxy-based resin main agent (A) accounts for 10 to 25 parts by weight.

In some embodiments, the resin main agent (B) of at least one acrylate compound includes acrylate having an oxyalkylene group in the molecule, methacrylate having an oxyalkylene group in the molecule, and methacrylate having an oxyalkylene group in the molecule. Acrylate, methacrylate with oxyalkylene in the molecule, acrylate without oxyalkylene in the molecule, methacrylate without oxyalkylene in the molecule, acrylic acid without oxyalkylene in the molecule Esters, methacrylates without oxyalkyl groups in the molecule, or combinations thereof.

In some embodiments, the main resin (B) of at least one acrylate compound accounts for 10 to 25 parts by weight.

In some embodiments, the surfactant (C) comprises a nonionic surfactant, anionic surfactant, cationic surfactant, or a combination thereof.

In some embodiments, the surfactant (C) comprises 5 to 12.5 parts by weight.

In some embodiments, the hindered phenolic reagent (D) comprises 0.05 to 0.1 parts by weight.

The present disclosure provides a carbon fiber applied with the aforementioned sizing agent, and the sizing agent ratio of the carbon fiber is between 0.1 and 5 weight percent.

The present disclosure provides a carbon fiber applied with the aforementioned sizing agent, and the hardness of the carbon fiber increases by less than 100% after 14 days of time-lapse detection.

The above-mentioned description will be described in detail in the following implementation manners, and further explanations will be provided for the technical solution of the present disclosure.

Herein, a range indicated by "one value to another value" is a general representation which avoids enumerating all values in the range in the specification. Therefore, the description of a specific numerical range covers any numerical value in the numerical range and the smaller numerical range bounded by any numerical value in the numerical range, as if the arbitrary numerical value and the smaller numerical value are expressly written in the specification. same range.

As used herein, "about," "approximately," "essentially," or "essentially" includes the stated value and averages within acceptable deviations from the particular value as determined by those skilled in the art, taking into account the A specific amount of measurement and the error associated with the measurement (i.e., the limits of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or for example within ±30%, ±20%, ±15%, ±10%, ±5%. Furthermore, the terms "about", "approximately", "essentially" or "substantially" used herein can select a more acceptable range of deviation or standard deviation according to measurement properties, coating properties or other properties, and It is not necessary to apply one standard deviation to all properties.

In order to make carbon fiber exert its original good performance and at the same time avoid reducing the processability of carbon fiber, a sizing agent can be applied to carbon fiber (carbon fiber), so that carbon fiber can reduce mechanical friction during processing. There is no hairiness or broken wire, so it has good processability. Through the treatment of the sizing agent, the processability, operability and bonding force of the matrix resin of the carbon fiber can be improved, so that the carbon fiber composite material has excellent mechanical properties.

The sizing agent can improve the main functions as follows. (1) Clustering, so that carbon fibers can be collected into rolls, which is easy to store and transport, and when manufacturing and processing composite materials, carbon fibers can be neatly arranged for easy operation. (2) Protect the carbon fiber and reduce the mechanical friction hairiness or broken wire of the carbon fiber during processing. (3) As an interfacial coupling agent between carbon fiber and resin, it improves the problem of poor impregnation of carbon fiber and resin.

Generally speaking, the main component of the sizing agent contains epoxy resin. This is because the epoxy resin itself has good film-forming properties and can form a strong and firm film on the surface of the fiber to protect the carbon fiber. Most composite materials The base resin is an epoxy resin system.

Epoxy resin has reactive epoxy functional groups. Therefore, under the action of appropriate catalysts, it can react with different types of hardeners (such as functional groups such as amines or acid anhydrides) to form a three-dimensional network. shape structure. Epoxy resins are excellent thermoset materials. In some embodiments, bisphenol A epoxy resin can be utilized as the main component of the sizing agent.

In a conventional sizing agent composition, it includes epoxy resin, acrylate (and/or methacrylate), and polyester resin with bisphenol A skeleton and polyoxyethylene chain. However, its ester structure is easy to absorb moisture in the air, and it has polar-polar (dipole-dipole) bond stacking arrangement, which makes the carbon fiber bundles stick together. In addition, the double bond structure of the propylene group may also produce crosslinking due to free radical reactions, thereby accelerating the hardening of carbon fibers, making it difficult for carbon fibers to spread yarns during composite material processing, or prone to problems such as hairiness due to mechanical friction. Therefore, Reduced processability of carbon fiber.

It has been known that the hardening of carbon fiber is due to the ring opening of epoxy resin and the breaking of the double bond structure of vinyl ester resin, resulting in free radical polymerization. For example, double bonds react with free radicals when exposed to sunlight and oxygen. After the reaction, a network-like three-dimensional cross-linking occurs between the molecules and hardens (hardens), thereby resulting in a decrease in subsequent machinability. Since the initiated free radical reaction is a chain reaction, it will continue to circulate. Therefore, delaying (or terminating) the occurrence of free radical reaction can delay the hardening of carbon fibers.

Regarding the hardening of carbon fibers, it has been known that since the epoxy system is only affected by the ring-opening rate of the epoxy concentration ([epoxy]), the rate is much slower than that of the double bond free radical reaction. Therefore, the hardening factor is determined by the double bond, and the reaction rate = K*[VE]*[oxygen free radical], where K is based on the Arrhenius reaction rate formula K=A*exp(-E/RT), VE is the resin concentration, Both the resin concentration and the oxygen free radical concentration in the open system are set as constants. The activation energy of the double bond of acrylic acid is 124KJ/mol. When stored at 25°C, the reaction speed increases by 5 times for every 10°C increase. Therefore, the test temperature Tt and the number of days of acceleration 5^[(Tt-25)/10].

In view of the problems that the above-mentioned sized carbon fibers are easy to absorb moisture and cause stickiness and hardening over time, the bonding force and machinability of carbon fibers are further reduced. Therefore, the present disclosure provides a sizing material for carbon fibers to overcome the above-mentioned problems. The sizing agent disclosed in the disclosure can strengthen the bonding force between the carbon fiber and the matrix resin, prevent hairiness or broken filaments of the carbon fiber during processing, inhibit hardening over time, and increase the stability of long-term storage.

The sizing compositions of the present disclosure comprise hindered phenolic agents (D). By adding hindered phenolic reagents (D), hydrogen radicals (hydrogen radicals) are provided to block the chain reaction of oxygen radicals in the process of polymer hardening. In the process of forming the sizing material of the present disclosure, the hindered phenolic reagent (D) generates relatively stable aromatic oxygen radicals, and the aromatic oxygen radicals have the ability to further capture active free radicals, therefore, the free radical reaction can be terminated , to delay the hardening of carbon fibers.

式(I) Adding an inhibitor for capturing free radicals (for example, hindered phenolic reagent (D)) can delay the occurrence of free radical reactions. Hindered phenols are a kind of free radical reaction inhibitors. Please refer to the following reaction formula (I). Substituted by an alkyl group, its hydrogen (H) atom is easier to fall off from the molecule, and further combines with free radicals to terminate the chain reaction of free radicals to achieve the effect of delaying hardening.

Formula (I)

The present disclosure provides a sizing agent for carbon fibers, comprising at least one epoxy compound resin main agent (A), at least one acrylate compound resin main agent (B), surfactant (C), hindered phenol Reagent (D) and the rest of the solvent, wherein the particle size of the sizing agent is between 0.01 and 0.5 μm. In some embodiments, the content of at least one acrylate compound in the main resin (B) is the same as that of the surfactant (C).

The resin main agent (A) of at least one epoxy-based compound in the sizing agent of the present disclosure includes bisphenol A epoxy compound, bisphenol F epoxy compound, bisphenol S epoxy compound, and novolak epoxy resin or a combination thereof. In some embodiments, the epoxy equivalent of the main resin (A) of at least one epoxy compound is between about 100g/eq and about 1500g/eq, for example, between about 130g/eq and about 1000g /eq, or between about 160 g/eq and about 900 g/eq. If the epoxy equivalent is less than about 100 g/eq, the degree of hardening of the fiber bundles (for example, carbon fiber bundles) over time will be enhanced. If the epoxy equivalent is greater than about 1500 g/eq, the combination with the matrix resin will be reduced.

In some embodiments, based on the total weight of the above sizing agent being 100 parts by weight, the content of the main resin (A) of at least one epoxy compound is about 2 to about 30 parts by weight. In other embodiments, the content of the main resin (A) of at least one epoxy compound is about 10 to about 25 parts by weight, for example, 12.5, 15, 17.5, 20, 22.5 parts by weight. If the content of at least one epoxy-based resin main agent (A) is less than 2 parts by weight, the fiber bundles will be looser and softer. If the content of the main resin (A) of at least one epoxy-based compound is greater than 30 parts by weight, it may affect the combination with the matrix resin.

Bisphenol A epoxy compounds can be commercially available, for example, NPEL ^TM 127, NPEL ^TM 128, NPEL ^TM 134, NPEL ^TM 901, NPEL ^TM 902, NPEL ^TM 904 produced by Nan Ya Plastic Industry Co., Ltd.; EPON ^TM Resin 828, EPON ^TM Resin 830, EPON ^TM Resin 834, EPON ^TM Resin 1001F; BE ^TM 114, BE ^TM 186, BE ^TM 188 produced by Changchun Artificial Resin Factory; ADEKA Resin EP-4100 produced by ADEKA Corporation , ADEKA Resin EP-4300, ADEKA Resin EP-4700 and other epoxy compounds.

Bisphenol F epoxy compounds can be commercially available, for example, NPEL ^TM 170 produced by Nan Ya Plastic Industry Co., Ltd.; EPON ^TM Resin 869 produced by HEXION; jER ^TM 806 and jER ^TM 807 produced by Mitsubishi Chemical Corporation; Changchun Epoxy compounds such as BE ^TM 170, BE ^TM 235, BE ^TM 283 produced by Artificial Resin Factory.

The bisphenol S epoxy compound can be commercially available, for example, epoxy compounds such as 185S and 300S produced by Compton Company.

Novolac epoxy resins can be commercially available, for example, NPEL ^TM 630, NPEL ^TM 638, NPEL ^TM 640 produced by Nan Ya Plastic Industry Co., Ltd.; NPCN ^TM 701, NPCN ^TM 702, NPCN ^TM 703, NPCN ^TM 704, NPCN ^TM 704L; H, HF-series produced by Meiwa Kasei Co., Ltd.; PNE ^TM 171, PNE ^TM 172, PNE ^TM 174, PNE ^TM 175, PNE ^TM 176, PNE ^TM 177 produced by Changchun Artificial Resin Factory and other epoxy compounds.

The resin main agent (B) of at least one acrylate compound of the sizing agent of the present disclosure includes acrylate having an oxyalkylene group in the molecule, methacrylate having an oxyalkylene group in the molecule, and methacrylate having an oxyalkylene group in the molecule. Acrylates with oxyalkylene groups, methacrylates with oxyalkylene groups in the molecule, acrylates without oxyalkylene groups in the molecule, methacrylates without oxyalkylene groups in the molecule, oxyalkylene groups in the molecule Acrylic esters, methacrylates without oxyalkyl groups in the molecule, or combinations thereof.

In some embodiments, based on the total weight of the above sizing agent being 100 parts by weight, the content of at least one acrylate compound main resin (B) is about 2 to about 30 parts by weight. In other embodiments, the content of at least one acrylate compound in the main resin (B) is about 10 to about 25 parts by weight, for example, 12.5, 15, 17.5, 20, 22.5 parts by weight. If the content of the main resin (B) of at least one acrylate compound is less than 2 parts by weight, the binding property with the matrix resin will be affected. If the content of the main resin (B) of at least one acrylate compound is greater than 30 parts by weight, the fiber bundles will be less likely to be bundled or too soft.

The main resin (B) of at least one acrylate compound can be commercially available, for example, QualiCure ^™ GM62S70, QualiCure ^™ GM62V20, QualiCure ^™ GM62V40, QualiCure ^™ GM62V60 and other acrylate compounds produced by Guojing Chemical Co., Ltd.

The surfactant (C) of the sizing agent of the present disclosure comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant or a combination thereof. In some embodiments, one of an anionic surfactant and a cationic surfactant may be used in combination with the nonionic surfactant.

In some embodiments, the content of the surfactant (C) is about 0.5 to about 15 parts by weight based on 100 parts by weight of the above slurry. In other embodiments, the content of the surfactant (C) is about 5 to about 12.5 parts by weight, for example, 6.5, 8, 9.5, 11 parts by weight. If the content of the surfactant (C) is less than 0.5 parts by weight, it has no emulsifying effect. If the content of the surfactant (C) exceeds 15 parts by weight, the processability of the fiber bundle will be reduced.

The nonionic surfactant can be, for example, an aliphatic nonionic surfactant or an aromatic nonionic surfactant. The types of aliphatic nonionic surfactants can be, for example, higher alcohol ethylene oxide additives, polyol polyoxyethylene ethers, carbon 16-18 alcohol polyoxyethylene ethers, alkyl polyoxyethylene ethers, polyethylene glycol fatty acids Esters etc. The aromatic nonionic surfactant may be, for example, polyethylene glycol octylphenyl ether, polyethylene glycol nonylphenyl ether, polyethylene glycol bisphenol A derivatives, and the like.

Anionic surfactants can be, for example, sulfate esters, sulfonates or phosphates. Examples of sulfates include higher alcohol sulfates, higher alkyl polyethylene glycol ether sulfates, polycyclic phenyl ether polyethylene glycol ether sulfates, and the like. Examples of sulfonates include alkylbenzenesulfonates, polycyclic phenyl ether sulfonates, alkylsulfonates, dialkylsulfosuccinates, and the like. Examples of phosphates include polyethylene glycol nonylphenyl phosphate, polyoxyethylene alkylphenylene ether phosphate triethanolamine, polyethylene glycol styrenated aryl ether phosphate, and the like.

Cationic surfactants can be, for example, quaternary ammonium salts, for example, alkyl dimethylbenzene quaternary ammonium salts, alkyltrimethyl quaternary ammonium salts, dialkyldimethyl quaternary ammonium salts, Esters quaternary ammonium salts, imidazoline quaternary ammonium salts, etc.

式(II) 受阻酚類試劑(D)可為市售品，舉例來說，Everlight Chemical生產的Everaox ^®101；AO-1135或XP-690。具體而言，Everaox ^®101具有由式(II-1)所表示的結構式，其中n介於7至9之間。AO-1135具有由式(II-2)所表示的結構式。

式(II-1)

式(II-2) The hindered phenolic agent (D) of the sizing agent of the present disclosure may have a structural formula represented by formula (II), wherein R is a long carbon chain ester.

Formula (II) The hindered phenolic reagent (D) can be commercially available, for example, Everaox ^® 101 produced by Everlight Chemical; AO-1135 or XP-690. Specifically, Everaox ^® 101 has a structural formula represented by formula (II-1), wherein n is between 7 and 9. AO-1135 has a structural formula represented by formula (II-2).

Formula (II-1)

Formula (II-2)

In detail, the hydroxyl group (-OH) on the benzene ring of hindered phenols is replaced by alkyl groups with large steric barriers on both sides, and its hydrogen (H) atoms are easier to fall off from the molecule, and further combine with free radicals to terminate The chain reaction of free radicals achieves the effect of delaying hardening.

In some embodiments, based on 100 parts by weight of the total weight of the above sizing agent, the content of the hindered phenolic agent (D) is about 0.01 to about 0.5 parts by weight, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 parts by weight. In other embodiments, the content of hindered phenolic reagent (D) is about 0.05 to about 0.1 parts by weight, for example, 0.06, 0.07, 0.08, 0.09 parts by weight. If the content of the hindered phenolic reagent (D) is less than 0.01 parts by weight, it is not easy to terminate the chain reaction of free radicals, so it does not have the effect of delaying the hardening of carbon fibers. If the content of the hindered phenolic agent (D) is greater than 0.5 parts by weight, it has no beneficial effect on delaying the hardening of carbon fibers.

The solvent of the sizing agent of the present disclosure can be deionized water. In some embodiments, the content of the solvent of the sizing agent is about 25 to about 95.5 parts by weight, for example, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95 parts by weight. In some embodiments, the sizing agent of the present disclosure is applied to the carbon fibers in the form of a dispersion dispersed in water without any organic solvent.

The device for making the sizing agent disclosed in this disclosure uses mechanical shearing force to prepare an emulsion-type uniformly dispersed carbon fiber sizing agent. In some embodiments, the device can be a paddle-type mixing blade, where the blade shape can be dissolving, tri-lobal, or quadri-lobal. In yet other embodiments, the device is equipped with an anchored stirring blade. In some embodiments, the carbon fiber sizing agent can be prepared by using ultrasonic crushing homogenizer, high-speed homogenizer, high-speed emulsifier and other devices.

，舉例來說，介於約0.01至約0.5

之間，例如，0.05、0.1、0.15、0.2、0.25、0.3、0.35、0.4、0.45

。當平均粒徑大於1

時，可能會使上漿劑不能均勻地附著在碳纖維上，且粒子自由能不足以進行布朗運動而造成沉降，因此，保存安定性不佳。 The sizing agent of the present disclosure is an aqueous solution that is self-emulsified and/or emulsified and dispersed in water, and the average particle diameter of the sizing agent is less than 1

, for example, between about 0.01 to about 0.5

Between, for example, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45

. When the average particle size is greater than 1

When it is used, the sizing agent may not be evenly attached to the carbon fiber, and the free energy of the particles is not enough to carry out Brownian motion and cause sedimentation. Therefore, the storage stability is not good.

＜Particle size analysis of sizing agent＞

The average particle size of the sizing agent is measured according to the principle of laser light scattering. When the laser light is irradiated on the particle solution, the particles in the solution will scatter the laser light. Due to the different degrees of Brownian motion of particles of different sizes, the degree of laser light scattering is also different, and then the collective size and size distribution can be calculated. In some embodiments of the present disclosure, the measurement of the average particle size of the sizing agent is performed using a Brookhaven Nanobrook Omni instrument.

＜Carbon fiber application sizing agent＞

The sizing agent in the present disclosure sizing the carbon fiber surface by impregnation. Dip carbon fiber TC35R-24K (manufactured by Taiwan Plastic Industry, TARIFIL, total 24,000 single-bundle fibers, single-bundle fiber strength about 4000 MPa, single-bundle fiber modulus 240GPa) without sizing agent in the impregnated carbon fiber with sizing agent In the tank, heat drying treatment is carried out at about 100~250°C, and the drying time is about 2 to 10 minutes. If it is lower than 100°C, the water cannot evaporate completely. If it is higher than 250°C, the sizing agent will produce thermal reaction and cause deterioration. As for the heat drying method, heating methods such as hot air method, hot roller contact method, infrared ray, etc., or the combination of the above two or three methods can be used and collected into rolls.

The above-mentioned emulsion type carbon fiber sizing agent can be used in carbon fiber composite materials as an interface layer connecting carbon fiber and matrix resin. In some embodiments, the weight of the sizing agent is about 0.1 to about 5 wt%, for example, about 0.5 to about 3 wt%, such as 1, 1.5, 2, 2.5 wt%, relative to the weight of the carbon fibers. If the amount of sizing is less than 0.1% by weight, the sizing agent cannot provide good bundling properties of carbon fibers, interfacial bonding force with matrix resin and abrasion resistance. If the amount of sizing exceeds 5% by weight, the carbon fiber will not be easy to spread, making it difficult to spread the yarn in subsequent processing and molding of composite materials.

＜Evaluation of carbon fiber sizing rate＞

Take a 1 meter (m) length of carbon fiber bundle treated with sizing agent, weigh its weight W1, put it in an oven at about 400°C to burn off the sizing agent, take it out after about 40 minutes, and wait for the temperature to return to approx. After 10 minutes, weigh its weight W2, and its sizing rate carbon fiber sizing rate is (W2-W1)/W1*100%. In some embodiments, the carbon fiber sizing is about 0.1 to about 5% by weight, for example, about 0.5 to about 3% by weight. It should be noted that the sizing ratio of the comparative examples and examples 1 to 5 herein is fixed at 1.0±0.2% by weight.

＜Evaluation of moisture absorption rate of sizing agent＞

Take a carbon fiber bundle (fiber bundle 1) with a length of 5 centimeters (cm) that has not been treated with a sizing agent, and weigh its weight W3. Take another 5 cm carbon fiber bundle (fiber bundle 2) treated with the sizing agent, and weigh its front weight W4. Place fiber bundle 1 and fiber bundle 2 in a constant temperature and humidity environment box at about 70°C and humidity about 85% RH, and after at least 35 days, weigh the back weight W5 of fiber bundle 1 and the back weight W6 of fiber bundle 2 . Sizing agent moisture absorption %=[(W6-W4)-(W5-W3)]/W4*100%. In some embodiments, the sizing agent has a moisture absorption rate of less than about 0.05%, eg, 0.01, 0.02, 0.03, 0.04%.

＜Carbon fiber hairiness test＞

Please refer to FIG. 1 , which is a schematic diagram of a device 100 for detecting carbon fiber hairiness. Take the 100-meter-long carbon fiber bundle 110 treated with sizing agent, and under the tension of 600cN, go through the friction of seven metal rollers 120 (without transmission and no special surface treatment), and set a sponge pad 130 behind the metal rollers 120 to collect Hairiness of the carbon fiber bundle 110 due to abrasion. Finally, dry the hairs at a temperature of about 105° C. for about 40 minutes, and weigh the hairs (unit: mg).

＜Carbon fiber hardness testing＞

Please refer to FIG. 2A and FIG. 2B , which are schematic diagrams of a device 200 for testing the hardness of carbon fibers. In detail, FIG. 2A is a schematic diagram of the carbon fiber bundle before the force is applied by the force source 210 , and FIG. 2B is a schematic diagram of the carbon fiber bundle before the force is applied by the force source 210 . Lay the carbon fiber bundle 110 treated with the sizing agent on the platform 220 with the gap 230, the force source 210 applies force to bend the carbon fiber bundle 110, and the force required when pressing down to a fixed depth is the carbon fiber hardness (unit: g ). The gap 230 of the disclosed device for detecting the hardness of carbon fibers is about 5 millimeters (mm).

＜Carbon fiber change detection over time＞

The carbon fiber bundles are placed in a constant temperature and humidity environment box at about 70°C and a humidity of about 85% RH to accelerate hardening. Every 1 day, 3 days, 7 days and 14 days, the carbon fiber bundles are taken out for carbon fiber hairiness testing and carbon fiber hardness testing.

＜Preparation of sizing agent in comparative example＞

之間。樹脂主劑(A)和樹脂主劑(B)的熔點溫度介於約60°C至約95°C之間。界面活性劑(C)的曇點溫度介於約60°C至約70°C之間。 The resin main agent (A) of at least one epoxy-based compound, the resin main agent (B) and the surfactant (C) of at least one acrylate compound are higher than the resin main agent (A) and the resin main agent (B). ) at the melting point temperature of the surfactant (C), after mixing uniformly with an IKA mixer, the temperature of the mixed state is lowered to the boiling point temperature of the surfactant (C), and dripping water at a speed of about 5000 to about 10000 rpm for 6 hours to obtain an emulsified and uniformly dispersed solution , which is the sizing agent of the comparative example. The particle size (Dv50; nm) of the sizing agent in the comparative example is between about 0.01 to about 0.5

between. The melting point of the main resin (A) and the main resin (B) is between about 60°C and about 95°C. Surfactant (C) has a cloud point temperature between about 60°C and about 70°C.

<Preparation of the sizing agent in the example>

之間。樹脂主劑(A)和樹脂主劑(B)的熔點溫度介於約60°C至約95°C之間。界面活性劑(C)的曇點溫度介於約60°C至約70°C之間。 The resin main agent (A) of at least one epoxy-based compound, the resin main agent (B) and the surfactant (C) of at least one acrylate compound are higher than the resin main agent (A) and the resin main agent (B). ) at the melting point temperature of the surfactant (C), after mixing uniformly with an IKA mixer, the temperature of the mixed state is lowered to the boiling point temperature of the surfactant (C), and dripping water at a speed of about 5000 to about 10000 rpm for 6 hours to obtain an emulsified and uniformly dispersed solution , and finally add the hindered phenolic reagent (D) to obtain the sizing agent of the examples (Example 1 to Example 5). The particle size (Dv50; nm) of the sizing agent in the embodiments is between about 0.01 to about 0.5

between. The melting point of the main resin (A) and the main resin (B) is between about 60°C and about 95°C. Surfactant (C) has a cloud point temperature between about 60°C and about 70°C.

It should be noted that, in some alternative embodiments, the hindered phenolic reagent (D) can also be mixed with the resin main agent (A), the resin main agent (B) and the surfactant (C) at the same time, and then carry out the same method as above The operation forms the sizing agent of the embodiment.

Experimental example: evaluation of carbon fiber hardness and carbon fiber change over time

According to the composition formulation in Table 1 below, referring to the preparation of the sizing agents of the above-mentioned comparative examples and examples, the sizing agents of the comparative examples and the sizing agents of Examples 1 to 5 were prepared.

Table I comparative example Example 1 Example 2 Example 3 Example 4 Example 5 A (%) 30 29.995 29.975 29.95 29.9 29.75 B (%) 15 14.9975 14.9875 14.975 14.95 14.875 C (%) 15 14.9975 14.9875 14.975 14.95 14.875 D (%) 0 0.01 0.05 0.1 0.2 0.5 water(%) 40 40 40 40 40 40

According to the sizing agent in Table 1 above, after the carbon fiber hardness test and the carbon fiber change test over time, the test results are shown in Table 2 below. It can be seen from Table 2 that, compared with the comparative example, applying the sizing agent containing the hindered phenolic agent (D) to the carbon fiber reduces the hairiness of the carbon fiber and improves the hardness of the carbon fiber.

For example, on the 7th day and the 14th day of the elapsed days, the amount of hairiness in Examples 1 to 5 was smaller than that of the comparative example. In detail, the amount of hairiness increase in Examples 1 to 5 is smaller than that of Comparative Example. In addition, under the time-lapse test, the changes in the hardness of the carbon fibers in Examples 1 to 5 are also smaller than those in the comparative example.

For details, please refer to Table 2 below. In the comparative example, the hardness of the carbon fiber on the 0th day of the elapsed day was about 13 g, and the hardness of the carbon fiber on the 14th day of the elapsed day was about 39 g, and the hardness increased by about 200%. In Examples 2 to 5, the hardness of the carbon fiber on the 0th day of the elapsed time was about 13 g, and the hardness of the carbon fiber on the 14th day of the elapsed day was about 26 g, and the hardness increased by about 100%.

Table II

The sizing agent disclosed in this disclosure, because it contains hindered phenolic reagent (D), solves the problems of hygroscopicity and adhesiveness of the originally sized carbon fibers, thus suppressing the problem of hardening over time and prolonging the hardening time of carbon fiber bundles The effect. The sizing agent disclosed in the disclosure can strengthen the bonding force between the carbon fiber and the matrix resin, prevent hairiness or broken filaments of the carbon fiber during processing, and inhibit hardening over time, thereby preventing the decrease of machinability.

Although the content of this disclosure has been disclosed above in terms of implementation, it is not intended to limit the content of this disclosure. Any person who is skilled in this art can make various changes and modifications without departing from the spirit and scope of this disclosure. Therefore, this disclosure The scope of protection of the disclosed content shall be defined by the appended scope of patent application and its equivalent scheme.

100: Device for detecting carbon fiber hairiness 110: carbon fiber bundle 120: metal roller 130: sponge pad 200: A device for detecting the hardness of carbon fiber 210: source of force 220: platform 230: Gap

The detailed description of the present disclosure will be best understood when read in conjunction with the accompanying drawings. It should be noted that, in accordance with standard industry practice, features are not drawn to scale and are used for illustration purposes only. In fact, the dimensions of the various features may be arbitrarily increased or decreased for clarity of discussion. FIG. 1 is a schematic diagram of a device for detecting carbon fiber hairiness according to some embodiments of the present disclosure. FIG. 2A and FIG. 2B are schematic diagrams of an apparatus for detecting hardness of carbon fibers according to some embodiments of the present disclosure.

Domestic deposit information (please note in order of depositor, date, and number) none Overseas storage information (please note in order of storage country, institution, date, and number) none

100: Device for detecting carbon fiber hairiness

110: carbon fiber bundle

120: metal roller

130: sponge pad

Claims (10)

A sizing agent for carbon fiber, comprising: a resin main agent (A) of at least one epoxy-based compound, accounting for 2 to 30 parts by weight; a resin main agent (B) of at least one acrylate compound, accounting for 2 to 30 parts by weight; 30 parts by weight; A surfactant (C), accounting for 0.5 to 15 parts by weight; A hindered phenolic reagent (D), accounting for 0.01 to 0.5 parts by weight; and the remaining solvent, wherein the particle size of the sizing agent is between From 0.01 to 0.5

between. The sizing agent as described in Claim 1, wherein the resin main agent (A) of the at least one epoxy compound comprises bisphenol A epoxy compound, bisphenol F epoxy compound, bisphenol S epoxy compound , epoxy novolac resin or a combination thereof. The sizing agent according to claim 1, wherein the resin main agent (A) of the at least one epoxy compound accounts for 10 to 25 parts by weight. The sizing agent as described in claim 1, wherein the resin main agent (B) of the at least one acrylate compound comprises an acrylate with an oxyalkylene group in the molecule, a methacrylate with an oxyalkylene group in the molecule, Acrylate with oxyalkylene in the molecule, methacrylate with oxyalkylene in the molecule, acrylate without oxyalkylene in the molecule, methacrylate without oxyalkylene in the molecule, intramolecular An acrylate without an oxyalkyl group, a methacrylate without an oxyalkyl group in the molecule, or a combination thereof. The sizing agent according to claim 1, wherein the at least one acrylate compound resin main agent (B) accounts for 10 to 25 parts by weight. The sizing agent according to claim 1, wherein the surfactant (C) comprises a nonionic surfactant, an anionic surfactant, a cationic surfactant or a combination thereof. The sizing agent as described in Claim 1, wherein the surfactant (C) accounts for 5 to 12.5 parts by weight. The sizing agent according to claim 1, wherein the hindered phenolic agent (D) accounts for 0.05 to 0.1 parts by weight. A carbon fiber applied with a sizing agent according to claim 1, the sizing agent rate of the carbon fiber is between 0.1 and 5 weight percent. A carbon fiber applied with a sizing agent as claimed in claim 1, the hardness of the carbon fiber increases by less than 100% after 14 days of time-lapse detection.

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