JPH03206182A - Petroleum pitch-based carbon yarn - Google Patents

Abstract

PURPOSE:To obtain the title yarn having excellent collecting properties and smoothness and a few end breakage by blending a specific epoxy resin with a specific ether and esterified substance as essential components in a specific weight ratio to give a sizing agent and coating carbon yarn with the sizing agent. CONSTITUTION:Petroleum pitch-based carbon yarn is coated with an emulsion type sizing agent comprising (A) 55-84wt.% epoxy resin composition which is an epoxy resin having 550-1,600 number-average molecular weight and contains <=5mol% component having >=10,000 molecular weight in distribution of molecular weight calculated as polystyrene measured by gel permeation chromatography, (B) 15-35wt.% at least one selected from B1: polyoxyalkylene polycyclic phenyl ether compound and B2: polyoxyalkylene alkyl phenyl ether compound and (C) 1-25wt.% aliphatic monoalcohol ester of unsaturated fatty acid or monofatty acid ester of unsaturated fatty monoalcohol as essential components to give carbon yarn having excellent smoothness and improved handleability.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to carbon fiber coated with an emulsion-type sizing agent, and more specifically, it has excellent cohesiveness and smoothness, and is resistant to yarn breakage during processing steps such as weaving. This invention relates to carbon fiber coated with an emulsion type sizing agent, which prevents the occurrence of fuzz and significantly improves its handling properties. [Prior Art] In recent years, composite materials using carbon fibers have attracted attention due to their excellent strength, elasticity, and heat resistance.

This carbon fiber is generally used in filament form, but
Due to high elasticity, elongation is low and bending abrasion resistance is poor.
During the processing process, friction with guides and rollers and repeated bending can cause single yarn breakage, yarn damage, and fluffing, which can reduce the quality of the yarn, and cause the carbon fibers and matrix resin to not be sufficiently wetted due to the fluff, resulting in poor quality of the molded product. This causes various problems such as creating pores and deteriorating the mechanical properties of the composite material, and deteriorating the working environment due to the fuzz.

In order to solve these problems, conventional methods have been to apply a sizing agent to improve the cohesiveness and smoothness of carbon fibers.

This sizing agent for carbon fibers can be divided into two types. One is a solution type in which organic resins such as vinyl acetate polymer, acrylic polymer, polyurethane, epoxy resin, and polystyrene are dissolved in an organic solvent, and the other is a solution type in which these organic resins are dissolved in water using an emulsifier. It is a dispersed emulsion type. Solution-type products are economical because they use a large amount of organic solvent.
Recently, emulsion type products have been widely used due to safety and health issues. However, emulsion-type sizing agents use resins with a limited molecular weight from the standpoint of emulsion stability, so they are somewhat unsatisfactory in terms of carbon fiber cohesiveness and are insufficient in terms of smoothness. Ta.

[Problem to be solved by the invention]

The present invention has been made in view of the above-mentioned circumstances of the prior art, and provides excellent emulsion stability, as well as sufficient cohesiveness and smoothness to carbon fibers, and prevents thread breakage during processing processes such as weaving processes. The purpose of the present invention is to provide carbon fibers coated with an emulsion type sizing agent that can prevent the occurrence of fluff.

[Means to solve the problem]

As a result of intensive studies to achieve the above object, the inventors of the present invention have developed an epoxy resin composition having a number average molecular weight in a specific range and a specific molecular weight distribution, and a polyoxyalkylene polycyclic phenyl ether compound. and/or an emulsion-type sizing agent containing a polyoxyalkylene alkylphenyl ether compound and an aliphatic monoalcohol ester of an unsaturated fatty acid or a monofatty acid ester of an unsaturated aliphatic monoalcohol in a predetermined ratio. We have discovered that this is an excellent sizing agent and is an optimal sizing agent that can prevent yarn breakage and fuzzing of carbon fibers during processing processes such as weaving processes, and have completed the present invention. That is, according to the present invention, at least one selected from the following components (A), (B) and (C), and (D
) are essential components, and the blending ratio (weight ratio) of component (A), component (B) + component (C), and component (D) is (
^) Ingredients 55-84 weight calculation (B) component + (C) component 15-35 weight calculation (D) component
Carbon fibers coated with an emulsion-type sizing agent having a weight of 1 to 25% by weight are provided.

(A) l1ijE fractional average molecular weight is 550 to 1,600
An epoxy resin composition (B) component which is an epoxy resin in the range of , and in which the component having a molecular weight of 10,000 or more is less than 5 mol 2 in the polystyrene equivalent molecular weight distribution measured by gel permeation chromatography. Polyoxyalkylene polycyclic phenyl ether compound (C) component Polyoxyalkylene alkylphenyl ether compound (D) component aliphatic monoalcohol ester of unsaturated fatty acid or monofatty acid ester of unsaturated aliphatic monoalcohol ．． At least one selected from the following components (A), (B) and (C), and (D
) are essential components, and the blending ratio (weight ratio) of component (A), component (B), component (C), and component (D) is (
A) Component 55-84 weight 2 (B) component + (C) component 15-35 weight 2 (C)
A petroleum pitch-based carbon fiber obtained by coating with an emulsion-type sizing agent characterized by having a weight of 1 to 25 cm and then drying is provided. (A) An epoxy resin with a component number average molecular weight in the range of 550-1,600, and in the polystyrene equivalent molecular weight distribution measured by gel permeation chromatography, there are 5 moles of components with a molecular weight of 10,000 or more. % of the epoxy resin composition (B) component polyoxyalkylene polycyclic phenyl ether compound (C) component polyoxyalkylene alkylphenyl ether compound ([]) component aliphatic monoalcohol ester of unsaturated fatty acid or unsaturated fat Component (A), which is an essential component of the sizing agent used in the present invention, has a number average molecular weight of 550 to 1,600, preferably 60.
0 to 900, and the component having a molecular weight of 10,000 or more in the polystyrene (hereinafter abbreviated as PS) equivalent molecular weight distribution determined by gel permeation stomatography (hereinafter abbreviated as GPC) is less than 5 moles. It is made of resin and is an impressive item.

In this case, if the number average molecular weight is less than 550, it becomes sticky, increases frictional resistance with metals and/or fibers, etc., and tends to become fluffy on guides, etc. In addition, the effect of imparting convergence is insufficient, and especially in pitch-based carbon fibers with high elasticity and a large yarn diameter, the convergence deficiency becomes noticeable and the fibers tend to become fluffy. On the other hand, if the number average molecular weight exceeds 1,600, a stable emulsion cannot be obtained and it cannot withstand practical use. on the other hand. In the PS-equivalent molecular weight distribution by GPC, l
If the proportion of molecular weight components exceeding o, ooo is 5 mol 2 or more, the emulsion will become unstable even if the number average molecular weight is 1,600 or less, and will not be suitable for practical use.

To prepare the above-mentioned specific epoxy resin used in the present invention, for example, in the case of Yuka Shell's epoxy resin,
Epicote 828, 834, 1001, 1002, i0
It can be obtained by appropriately mixing 04, 1007, 152, 154, 604, etc. As a specific example, a desired epoxy resin can be obtained by mixing Ebikoat 828/1001 = 25/75 (weight ratio) or Ebikoat 82g/1004 = 50/50 (weight ratio). Component (B), which is an essential component of the sizing agent used in the present invention, is a polyoxyalkylene polycyclic phenyl ether compound. Representative examples of such compounds include the following. Styrenated phenols include polyoxyalkylene monostyrenated phenyl ether, polyoxyalkylene distyrenated phenyl ether, polyoxyalkylene tristyrenated phenyl ether, polyoxyalkylene polystyrenated phenyl ether, etc.; Oxyalkylene monobenzylated phenyl ether, polyoxyalkylene dibenzylated phenyl ether, polyoxyalkylene tribenzylated phenyl ether, polyoxyalkylene tetrabenzylated phenyl ether, polyoxyalkylene pentabenzylated phenyl ether, etc.; Among bisphenols, bisphenol A boroxyalkyl ether, bisphenol F
Borioxyalkyl ether, bisphenol S boryoxyalkyl ether, etc.; others include polyoxyalkylene naphthyl ether, etc.

Component (C), which is an essential component of the sizing agent used in the present invention, is a polyoxyalkylene alkylphenyl ether compound. Representative examples of such compounds include polyoxyalkylene ethyl phenyl ether, polyoxyalkylene butylphenyl ether, polyoxyalkylene butylphenyl ether, polyoxyalkylene benzyl phenyl ether, polyoxyalkylene hexylphenyl ether, polyoxy Alkylene heptyl phenyl ether, polyoxyalkylene octylphenyl ether, polyoxyalkylene nonylphenyl ether, polyoxyalkylene decylphenyl ether,
Examples include polyoxyalkylene dodecyl phenyl ether.

Component (D), which is an essential component of the sizing agent used in the present invention, is an aliphatic monoalcohol ester of an unsaturated fatty acid or a monofatty acid ester of an unsaturated aliphatic monoalcohol. Representative examples of such compounds include octyl oleate, lauryl oleate, stearyl oleate, isotridecyl oleate, oleyl oleate, oleyl stearate, oleyl laurate, oleyl isostearate, oleyl palmitate, oleyl octalate, and the like.

In the present invention, the sizing agent used includes an epoxy resin composition as component (A), a polyoxyalkylene polycyclic phenyl ether compound as component (B) and/or a polyoxyalkylene alkylphenyl ether compound as component CC), It is important to use component D), an aliphatic monoalcohol ester of an unsaturated fatty acid or a monofatty acid ester of an unsaturated aliphatic monoalcohol. Even if any of the components (A), (B) to (C), or (D) is missing, the desired effects of the present invention cannot be achieved.

That is, when component (A) is missing, sufficient cohesiveness cannot be obtained and yarn handling properties deteriorate. It also has a negative effect on the physical properties of composite materials. Moreover, if the components (B) to (C) are missing, the emulsion becomes unstable, and if the component (D) is missing, the smoothness is poor and some fluffing occurs. Therefore, in either case, the remarkable effects of the present invention cannot be achieved.

In addition, in the present invention, the blending ratio of the four components is (
55 to 84% by weight (preferably 60 to 75% by weight) of component A) and 15 to 35% by weight (preferably 20 to 30% by weight) of component (B) and component (C). (D) component 1
It is necessary to keep it at ~25% by weight (preferably 5-10% by weight). (^) If the ingredients exceed $84 by weight,
That is, if {(B) component 10 (C) component} is less than 15% by weight, the emulsion becomes unstable and cannot withstand practical use. On the other hand, if the amount of component (A) is less than 55% by weight, the cohesiveness will be insufficient and the yarn will tend to fluff, and the cohesiveness will also be insufficient, resulting in poor yarn handling properties. The same applies when {(B) component 10 (C) component} exceeds 35% by weight. Furthermore, (D)
If the amount of the component is less than 1% by weight, the smoothness will be insufficient and fluffing will occur, whereas if the amount is more than 25% by weight, the adhesion between the carbon fiber and the matrix resin will be adversely affected. (In other words, the adhesiveness (ILSS) decreases.) Therefore, in either case, the desired effect of the present invention is not expressed.

The sizing agent used in the present invention is particularly applicable to petroleum pitch-based carbon fibers, which have high elasticity and are difficult to aggregate, and require a focusing effect.

In general, petroleum pitch is a heavy substance obtained from petroleum refining equipment, including atmospheric distillation residue oil, vacuum distillation heavy distillate oil and residue oil, catalytic cracking heavy distillate oil (e.g. cycle oil, etc.), Residual Oils and Tars - Includes steam cracked heavy distillate oils, residual oils and tars, and other hydrocarbon oils obtained from petroleum refinery equipment. “Oil bitch” as used in the present invention
is mainly composed of these petroleum-derived pitches, but it also contains coal-based pitches (e.g., heavy oil, tar, pitch obtained by carbonization of coal, or heavy liquefied pitch produced from the coal liquefaction process). It also includes materials obtained by mixing synthetic pitch, etc. obtained by heat treatment using raw materials such as coal, aromatic compounds, and polycyclic condensed compounds, and if necessary, after pretreatment such as filtration and solvent extraction. used in

The amount of the sizing agent adhered to the petroleum pitch carbon fiber is 0.1 to 5.0% by weight2, preferably 0.5 to 3.0% by weight2.
0 weight 2, and conventionally known methods such as roller sizing method, roller dipping method, spray coating method, etc. are employed as the method of attachment.

〔Effect of the invention〕

Since the petroleum pitch-based carbon fiber of the present invention is coated with an emulsion-type sizing agent having the above structure, it has excellent cohesiveness and smoothness, prevents yarn breakage and fluffing during the processing process, and is extremely easy to handle. It is an improved
It has extremely high practical value.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A 1:3 (weight ratio) mixture of Ebikoat 828 (trade name; manufactured by Yuka Ciel Co., Ltd.) and Epicote 1001 (trade name; manufactured by Yuka Ciel Co., Ltd.) was used as component (A). there was.

The number average molecular weight of this epoxy component is 670, and the PS conversion molecular weight distribution measured by Gpc' is 10,00.
The proportion of molecular weight components exceeding 0 was 0.5 mol z or less. The obtained GPC chart is shown in Figure 1. Above (A
) component as 75 weight, (B) component polyoxyalkylene (PO/EO molar ratio 1/3; 3 mol) polyoxyethylene (20 mol) tristyrenated phenyl ether 14 weight 2, (C) component as component Polyoxyethylene (8 mol) nonylphenyl ether by weight, (D
) Lauryl oleate was mixed at a ratio of 5 parts by weight to form a sizing agent component, and the sizing agent component was emulsified in pure water so that the amount was 2 parts by weight.

The obtained emulsion was stable without emulsion sedimentation even after 5 hours.

Squeezing conditions were set so that Ig of the emulsion was attached to 1 g of carbon fibers, and after sizing treatment, hot air at 110° C. was blown to dry the emulsion. The carbon fiber used was petroleum pitch carbon fiber (3,000 tons) with an elastic modulus of 50 tons/11.
0 filament). As a result of measuring the running friction force 0* of the obtained carbon fiber, the fiber/fiber CF/F) friction force was 105g. The fiber/metal (F/M) friction force was 220g. In addition, the carbon fiber has good cohesiveness, and as expected from the extremely low F/F frictional force and sufficiently low F/M frictional force, it is resistant to rubbing between fibers and rubbing between fibers and metal. However, there was extremely little fluff.

In order to evaluate the adhesion of the carbon fiber to the epoxy resin, a unidirectionally reinforced CFRP with Vf=60% was prepared, and Q/h
The interlaminar shear strength (ILSS) was measured by a short beam three-point bending test at =4. The epoxy resin that became the matrix resin was Ebicoat 828 (trade name; manufactured by Yuka Ciel Co., Ltd.), acid anhydride curing agent FIN-550 (trade name; manufactured by Hitachi Chemical Co., Ltd.), and curing accelerator auxiliary agent ethyl. It is a mixture of methylimidazole in a weight ratio of 100/85/l, and the curing conditions are 120°C for 1 hour, then 180°C.
Post-curing was performed at ℃ for 1 hour.

ILSS showed good adhesion at 7.8 kg/am''.

*) GPC measurement conditions Model: Shimadzu LC-6A Column: HSG-40H+20H+15H: 30c
＋＋＋ Measure the increase in tension due to the frictional force between the threads during running. The twist angle is 540° (1.5 turns), the crossing angle is 30". The running speed is 2.0 + m/■ l The difference between tension meter 1 and tension meter 2 is the running friction force. The initial load is The weight was 20g.

(ii) Fiber/metal (F/M) friction force Using a running friction force measuring device consisting of two tension meters, a guide roller friction rod, and a yarn feeder, we measure the friction force between the yarn and metal during running. Measure tension increase. The running speed is 2.0 m/min. The difference between tension meter 1 and tension meter 2 is the running friction force. Examples 2 to 6 Epicoat 828/1001/1002/1004 (trade name manufactured by Dioilka Shell Co., Ltd.) was appropriately mixed to obtain a component ratio with a number average molecular weight of 550 to 1,600 and a GPC of 10,000 or more. Prepare an epoxy resin with a value of 5 moles or less, and (
A) It was used as a component.

The ratio of each epoxy component, the number average molecular weight, and the ratio of components with molecular weights of to, ooo or more in GPC of component (A) are as follows:
Each is as shown in Table-1. In the same manner as in Example 1, the components (B), (C), and (D) shown in Table 1 are mixed with the component (A) in a specific ratio to form a sizing component, and the sizing component is It was emulsified in pure water so that it was calculated by two weights. All of the obtained emulsions were stable without emulsion sedimentation even after 5 hours.

Squeezing conditions were set so that 1 g of the emulsion adhered to 1 g of carbon fibers, and after sizing treatment, hot air at 110° C. was blown to dry. The carbon fiber used was petroleum pitch carbon fiber (3.0
00 filament). The running frictional forces (CF/F frictional force and F/M frictional force) of the obtained carbon fibers were as shown in Table 1. The carbon fiber has good cohesiveness, extremely low F/F frictional force, and sufficiently low F/M frictional force, so it is resistant to fuzzing when fibers rub against each other or when fibers rub against metal. was extremely small.

Using the carbon fiber, ILSS was measured in the same manner as in Example 1, and as shown in Table 1, it was 7.5 to 7.5.
7.8 kg/mm", indicating good adhesion. Comparative Examples 1 to 2 Epicote 828/1001/1004 (trade name; manufactured by Yuka Ciel Co., Ltd.) was appropriately mixed and the number average Molecular weight is 55
An epoxy resin having a component ratio of 0 to 1,600 and 10,000 or more by GPC of 5 mol z or less was prepared and used as component (A). The ratio of each epoxy component, the number average molecular weight, and the ratio of components with a molecular weight of 10,000 or more by GPC of this component (^) are shown in Table 2.

The above (A) component was 80 wt. ) Polyoxyethylene (8 mol) nonylphenyl ether was mixed at a ratio of 6% by weight to form a sizing agent component, and the sizing agent component was emulsified in pure water to a weight of 2. The obtained emulsion was stable without emulsion sedimentation even after 5 hours.

Squeezing conditions were set so that 1 g of the emulsion adhered to 1 g of carbon fibers, and after sizing treatment, the fibers were dried by blowing hot air at 110°C. The carbon fiber used was petroleum pitch carbon fiber (3,
000 filament). The running frictional forces (F/Fl frictional force and F/M frictional force) of the obtained carbon fibers were as shown in Table-2.

Although the carbon fibers had good cohesiveness and were relatively less fluffy when the fibers rubbed against each other or when the fibers rubbed against metal, they fluffed somewhat more easily than the carbon fibers obtained in the examples. When ILSS was measured using the carbon fiber in the same manner as in Example 1, it showed good adhesion as shown in Table 2. Comparative Examples 3 to 4 Ebicoat 828/1004 (trade name: manufactured by Yuka Ciel Co., Ltd.) was used alone or in combination to prepare an epoxy resin having a number average molecular weight of less than 550 and used as component (A).

The ratio of each epoxy component, the number average molecular weight, and the ratio of components having a molecular weight of 10,000 or more by GPC of component (A) are shown in Table 2.

The above (▲) component was 75 wt. 6 parts by weight of polyoxyethylene (8 mol) nonylphenyl ether as component (D) and 5 parts by weight of lauryl elate as component (D) were mixed to form a sizing agent component, and the sizing agent component was 2 parts by weight.
It was emulsified in pure water to a weight of 2. The obtained emulsion was stable without emulsion sedimentation even after 5 hours.

Squeezing conditions were set so that 1 g of the emulsion adhered to 1 g of carbon fibers, and after sizing treatment, hot air at 110° C. was blown to dry. The carbon fiber used was petroleum pitch carbon fiber (3.0
00 filament).

Running friction force of the obtained carbon fiber (F/F friction force and F/F friction force
As shown in Table 2, the M friction force was a low value, but in actual use, fuzzing occurred due to lack of cohesiveness due to the rubbing between fibers and the rubbing between fibers and metal. ．． When LISS was measured using the carbon fiber in the same manner as in Example 1, it showed good adhesion as shown in Table 2.

Comparative Example 5 Epicoat 828/1004 (trade name; manufactured by Yuka Ciel Co., Ltd.) was mixed at a weight ratio of 50/50, and this was mixed with (A).
Used as an ingredient. The number average molecular weight of this epoxy component is 6l4. The ratio of molecular weight components exceeding 10,000 in the PS equivalent molecular weight distribution measured by GPC is approximately 2.5
It was a mole calculation.

The above (A) component is 50% by weight, (B) component is polyoxyalkylene (PO/EO molar ratio 1/3; 3 mol) polyoxyethylene (20 mol), tristyrenated phenyl ether is 14% by weight, (C ) polyoxyethylene (8 mol) nonylphenyl ether as component (6 by weight) and lauryl oleate as component (CD) in a ratio of 30 by weight to form a sizing agent component, so that the amount of the sizing agent component is 2 by weight. It was emulsified in pure water. The obtained emulsion is
Even after 5 hours, the emulsion remained stable with no sedimentation. Squeezing conditions were set so that 1 g of the emulsion adhered to 1 g of carbon fibers, and after sizing treatment, the fibers were dried by blowing hot air at 110°C. The carbon fiber used was petroleum pitch carbon fiber (3,000
0 filament).

The running friction force of the obtained carbon fiber is F/F friction force of 80g.
Although the F/M friction force was as low as 150 g, during actual use, fuzzing occurred due to lack of cohesiveness due to the rubbing between fibers and the rubbing between fibers and metal. Furthermore, ILSS was measured using the carbon fiber in the same manner as in Example 1, but the value was as low as 6.5 kg/am''.4.

[Brief explanation of drawings]

Figure 1 shows the GP composition of component (A) epoxy resin used in Example 1.
A C chart is shown.

Claims (4)

[Claims] (1) The following (A) component, at least one selected from (B) component and (C) component, and (D) component are essential components, and (A) component, (B) component + The mixing ratio (weight ratio) of component (C) and component (D) is 55 to 84% by weight of component (A) (component B) + 15 to 35% by weight of component (C) (1 to 25% by weight of component D) A petroleum pitch carbon fiber coated with an emulsion type sizing agent. (A) An epoxy resin with a component number average molecular weight in the range of 550 to 1,600, and in the polystyrene equivalent molecular weight distribution measured by gel permeation chromatography, there are no components with a molecular weight of 10,000 or more. Less than 5 mol% of the epoxy resin composition (B) component polyoxyalkylene polycyclic phenyl ether compound (C) component polyoxyalkylene alkylphenyl ether compound (D) component aliphatic monoalcohol ester of unsaturated fatty acid or unsaturated fat Monofatty acid esters of group monoalcohols (2) The following (A) component, at least one selected from (B) component and (C) component, and (D) component are essential components, and (A) component, (B) component + The mixing ratio (weight ratio) of component (C) and component (D) is 55 to 84% by weight of component (A), component (B) + 15 to 35% by weight of component (C), and 1 to 25% by weight of component (C). Petroleum pitch-based carbon fiber obtained by coating with an emulsion-type sizing agent and drying. (A) An epoxy resin with a component number average molecular weight in the range of 550 to 1,600, and in the polystyrene equivalent molecular weight distribution measured by gel permeation chromatography, there are no components with a molecular weight of 10,000 or more. Less than 5 mol% of the epoxy resin composition (B) component polyoxyalkylene polycyclic phenyl ether compound (C) component polyoxyalkylene alkylphenyl ether compound (D) component aliphatic monoalcohol ester of unsaturated fatty acid or unsaturated fat Monofatty acid esters of group monoalcohols (3) Petroleum pitch-based carbon coated with the emulsion-type sizing agent according to claim (1), wherein the (A) component, the (B) component, the (C) component, and the (D) component are essential components. fiber. (4) Petroleum pitch-based carbon fiber obtained by coating with the emulsion type sizing agent according to claim (3) and then drying.