RESIN COMPOSITION FOR CARBON FIBER COMPOSITE MATERIAL, TOWPREG

Abstract

A towpreg that is easy to unwind from a bobbin, has good width accuracy after unwinding and can produce a composite material with excellent heat resistance, and a resin composition that gives such a towpreg.

A towpreg is characterized by being impregnated with an epoxy resin that contains an epoxy resin which is solid at 23° C. in an amount of 30 parts or more in 100 parts by mass of total epoxy resin components, contains a polyfunctional amine type epoxy resin which is liquid at 23° C. in an amount of 20 parts or more in 100 parts by mass of total epoxy resin components, and further contains a clay mineral.

Claims

1. A towpreg comprising a reinforcing fiber bundle aligned in one direction and impregnated with an epoxy resin composition in that the epoxy resin composition contains the following components [A] to [C]: [A] an epoxy resin which is solid at 23° C. in an amount of 30 parts or more in 100 parts by mass of total epoxy resin components, [B] a polyfunctional amine type epoxy which is liquid at 23° C. in an amount of 20 parts or more in 100 parts by mass of total epoxy resin components, and [C] a clay mineral.)

2. The towpreg according to claim 1, characterized in that the epoxy resin composition contains an epoxy resin which has an epoxy equivalent of 300 g/eq or less in an amount of 20 parts or more among the solid epoxy resin.

3. The towpreg according to claim 1, characterized in that the epoxy resin composition has polyfunctional amine type epoxy in an amount of 20 parts or more in 100 parts by mass of total epoxy resin components.

4. The towpreg according to claim 1, characterized in that the towpreg satisfies at least conditions [T1] to [T3] below: [T1] a tension is 5.0 N or less required when a sample obtained by winding 1.2 m of the towpreg on a bobbin having an outer diameter of 8.25 cm under a load of 9.8 N over 30 seconds is stored in an environment of 23° C./50 RH% for 5 days, and then unwound at 1.0 m/min; [T2] an extension of width of the towpreg is 3.0% or less when a sample in which the towpreg cut into 7.6 cm length is inserted between two of 2.6 cm×7.6 cm glass plates is stored in an environment of 23° C./50 RH% for 2 days in a state where a pressure of 2.48×103 Pa is applied to the glass plates in thickness direction; and [T3] a cured product obtained by curing the towpreg at 180° C. for 2 hours has a glass transition temperature of 180° C. or more.

5. The towpreg according to claim 1, characterized in that the epoxy resin composition satisfies conditions [R1] to [R3] below: [R1] a thixotropy coefficient (η*.sub.0.1 Hz/η*.sub.10 Hz) at 60° C. is 3.0 or more; [R2] a storage modulus at 1 Hz at 23° C. is 2.0×10.sup.5 Pa or more; and [R3] a cured product obtained by curing the epoxy resin at 180° C. for 2 hours has a glass transition temperature of 180° C. or more.

6. The towpreg according to claim 4, wherein the cured product obtained by curing the towpreg at 180° C. for 2 hours has a glass transition temperature of 200° C. or more.

7. The towpreg according to claim 5, wherein the cured product obtained by curing the epoxy resin at 180° C. for 2 hours has a glass transition temperature of 200° C. or more.

8. The towpreg according to claim 1, characterized in that the epoxy resin composition contains an aromatic amine as a curing agent.

9. The towpreg according to claim 1, characterized in that the epoxy resin composition contains an epoxy resin which has at least one structure selected from the group consisting of a naphthalene skeleton, a dicyclopentadiene skeleton, a phenol aralkyl skeleton and a cresol novolac skeleton in an amount of 20 parts or more among the solid epoxy resin.

10. The towpreg according to claim 1, characterized in that the epoxy resin composition contains an epoxy resin which has an epoxy equivalent of 200 g/eq or less in an amount of 20 parts or more among the solid epoxy resin.

11. The towpreg according to claim 1 characterized in that the solid epoxy has a naphthalene skeleton.

12. The towpreg according to claim 1 characterized in that the solid epoxy has a dicyclopentadiene skeleton.

13. The towpreg according to claim 1, characterized in that the epoxy resin composition contains a thermoplastic resin.

14. The towpreg according to claim 1, characterized in that the thermoplastic resin is polyether sulfone.

15. The towpreg according to claim 1, characterized in that the polyether sulfone has a weight average molecular weight of 30,000 g/mol or less.

16. The towpreg according to claim 1, characterized in that the polyfunctional amine type epoxy resin is an aminophenol type.

17. A fiber-reinforced composite material prepared by obtained by heating and curing a towpreg according to claim 1.

18. A manufactured article comprising or made of one or more fiber-reinforced composite materials according to claim 17.

19. The manufactured article according to claim 18, characterized in that said manufactured article is a composite material for aerospace applications or the aeronautic industry such as for an aircraft, typically an aircraft fuselage.

Description

EXAMPLES

[0043] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the description of these examples. Unless otherwise specified, measurements of various physical properties were performed in an environment at a temperature of 23° C. and a relative humidity of 50%.

[0044] The materials used to prepare each towpreg are as follows.

Materials Used

Epoxy Resins Liquid at Room Temperature of 23° C.

[0045] “Araldite (registered trademark)” LY1556 (bisphenol type epoxy resin, epoxy equivalent: weight 187 g/eq, manufactured by Huntsman Corporation) [0046] “Araldite (registered trademark)” GY282 (bisphenol type epoxy resin, epoxy equivalent: weight 167 g/eq, manufactured by Huntsman Corporation) (Polyfunctional amine type epoxy resin which is liquid at 23° C.) [0047] “Araldite (registered trademark)” MY0510 (aminophenol type epoxy resin, epoxy equivalent weight: 96 g/eq, manufactured by Huntsman Corporation) [0048] “Araldite (registered trademark)” MY721 (glycidyl amine type epoxy resin, epoxy equivalent weight: 115 g/eq, manufactured by Huntsman Corporation) (Epoxy resins solid at room temperature of 23° C.) [0049] “Araldite (registered trademark)” GT7071 (bisphenol type epoxy resin, epoxy equivalent weight: 490 g/eq, manufactured by Huntsman Corporation) [0050] “Araldite (registered trademark)” GT6084-2 (bisphenol type epoxy resin, epoxy equivalent weight: 862 g/eq, manufactured by Huntsman Corporation) [0051] “EPICLON (registered trademark)” HP4710 (bisnaphthalene type epoxy resin, epoxy equivalent weight: 172 g/eq, manufactured by DIC Corporation) [0052] “EPICLON (registered trademark)” HP7200L (dicyclopentadiene type epoxy resin, epoxy equivalent weight: 247 g/eq, manufactured by DIC Corporation)

Curing Agent

[0053] “Aradur (registered trademark)” 9664-1 (4,4′-diaminodiphenylsulfone, manufactured by Huntsman Corporation) [0054] “Aradur (registered trademark)” 9771-1 (3,3′-diaminodiphenylsulfone, manufactured by Huntsman Corporation)

Inorganic Particles

[0055] “Garamite (registered trademark)”-7305 (organophilic phyllosilicates, manufactured by BYK Additives & Instruments) [0056] “Garamite (registered trademark)”-1958 (organophilic phyllosilicates, manufactured by BYK Additives & Instruments) [0057] “AEROSIL (registered trademark)”R 202 (Fumed silica, manufactured by Evonik)

[0058] Typically, the towpreg composition comprises between 1 and 10% of inorganic particles for 100 parts of epoxy resin composition.

Thermoplastic Resin

[0059] “SUMIKAEXCEL (registered trademark)” PES 2603MP, (polyether sulfone, weight average molecular weight of 16,000 g/mol, manufactured by Sumitomo Chemical Co., Ltd.)

[0060] Typically, the towpreg composition comprises between 1 and 20% of thermoplastic resin for 100 parts of epoxy resin composition.

Reinforcing Fiber

[0061] “Torayca (registered trademark)” T700G-12K (carbon fiber, manufactured by Toray Carbon Fibers Europe)

Method for Preparing Epoxy Resin Composition

[0062] Predetermined amounts of compositions except a curing agent and inorganic particles from the epoxy resin composition was placed in a kneader, and the mixture was heated and kneaded to obtain a transparent viscous liquid. After the temperature of the viscous liquid was lowered while kneading, the curing agent and the inorganic particles were added, and the mixture was kneaded to obtain an epoxy resin composition.

[0063] The compositions of the epoxy resin compositions of Examples and Comparative Examples are shown in Table 1.

Method for Measuring Properties of Epoxy Resin Composition

(1) Method for Measuring Storage Modulus of Epoxy Resin Composition at Room Temperature of 23° C.

[0064] Using a dynamic viscoelasticity measuring device (DISCOVERY HR-2: manufactured by TA Instruments) and a parallel plate with a diameter of 8 mm, an uncured resin composition was set so that the distance between upper and lower jigs was 500 μm, and storage modulus was measured in a torsional mode at a frequency of 1 Hz at a temperature of 23° C.

(2) Method for Measuring Thixotropy Coefficient of Epoxy Resin Composition at 60° C.

[0065] Using a dynamic viscoelasticity measuring device (DISCOVERY HR-2: manufactured by TA Instruments) and a parallel plate with a diameter of 25 mm, an uncured resin composition was set so that the distance between upper and lower jigs was 500 pm, and viscosity was measured in a torsional mode at frequencies of 0.1 Hz and 10 Hz at a temperature of 60° C. The thixotropy coefficient can be calculated from the obtained viscosity by the following formula (3).

Viscosity at 0.1 Hz (η*.sub.0.1 Hz)/Viscosity at 10 Hz (η*.sub.10 Hz)   Formula (3)

Method for Measuring Glass Transition Temperature of Epoxy Resin Cured Product

[0066] An uncured epoxy resin composition defoamed in vacuum was heated at 2.0° C./min using a dynamic viscoelasticity measuring device (ATD-3000: manufactured by Alpha Technologies) and cured at a temperature of 180° C. for 2 hours, then the temperature was raised at a temperature rising rate of 5° C./min, and storage modulus was measured in a torsional mode at a frequency of 1.64 Hz. The onset temperature of the storage modulus at this time was defined as a glass transition temperature.

Method for Preparing Towpreg

[0067] Various epoxy resin compositions prepared using the composition of Table 1 were impregnated into a reinforcing fiber bundle by a pultrusion molding method by the following method to prepare a towpreg.

[0068] Specifically, the reinforcing fiber bundle is passed through a tow prepreg manufacturing apparatus equipped with a creel for feeding reinforcing fibers, a resin bath for impregnating an epoxy resin, a slit die for shaping at a resin bath outlet, a drive station with a chiller and a winder, to make a yarn path. The epoxy resin composition was separately adjusted to a temperature of 80° C. in a hot air oven and supplied to a resin bath also adjusted to a temperature of 80° C. The reinforcing fiber is passed through the resin bath to supply the epoxy resin composition and then passed through the die to adjust the resin content. Finally, after passing through a drive station cooled to 20° C. or less, it was taken up by a winder to form a bobbin of towpreg. In addition, when winding up with a winder, in order to prevent adhesion between the towpreg, a back film was supplied together with the towpreg as necessary. Winding was carried out on the towpreg in both cases of with and without the back film.

[0069] The line speed at the time of making the towpreg was 1 m/min, the winding line tension was 12 N or less, and the resin content was adjusted so as to be 34% by weight.

Evaluation Method of Properties of Towpreg

(1) Evaluation of State After High-Speed Unwinding of Towpreg

[0070] The bobbin of the towpreg wound on the bobbin without back film, obtained in each example and comparative example, was allowed to stand for 30 minutes or more under an environment of a temperature of 23° C.±5° C. and a relative humidity of 60%±20%, and set on the creel, and the towpreg was unwound at 20 m/min using a winder, then the state of towpreg was evaluated. A case where unwinding performance were good, and fuzz and a fiber bridging did not occur after unwinding was determined as A, a case where fuzz occurred after unwinding was determined as B, and a case where a large amount of fuzz and fiber bridgings occurred after unwinding and unwinding was difficult was determined as C.

(2) Width Accuracy Evaluation After High-Speed Unwinding of Towpreg

[0071] The bobbin of the towpreg wound on the bobbin without back film, obtained in each example and comparative example, was allowed to stand for 30 minutes or more under an environment of a temperature of 23° C.±5° C. and a relative humidity of 60%±20%, and set on the creel, and the towpreg was unwound by 18 m at 2 m/min using a winder, then the width of the obtained towpreg after unwinding was measured at 481 points at 3.75 cm intervals with a microscope (VHX-500F: manufactured by KEYENCE CORPORATION), and the standard error was defined as a width accuracy.

(3) Winding Test of Towpreg

[0072] 1.2 m was separated from the towpreg wound on the bobbin with back film, obtained in each example and comparative example, and one end of the separated towpreg was fixed to the bobbin with an outside diameter of 8.25 cm with tape and a 1.0 kg weight was attached at the other end. Thereafter, the bobbin was attached to the creel so that the weight would float, and a towpreg without back film was wound on the bobbin over 30 seconds with the towpreg under a tension of 9.8 N to prepare a sample.

[0073] The sample was stored in an environment of a temperature 23° C.±5° C. and a relative humidity 50%±10% for 5 days, then set in the creel, and using an Instron universal testing machine (manufactured by Instron), a tension when unwound at a crosshead speed of 1.0 m/min was measured.

(4) Pressure Deformation Examination of Towpreg

[0074] 7.6 cm was separated from the towpreg wound on the bobbin with back film, obtained in each example and comparative example, and the separated towpreg was inserted between two of 2.6 cm×7.6 cm glass plates to prepare a sample. The width of the towpreg in the sample was measured at 7 points at 1.0 cm intervals using a microscope (VHX-500F: manufactured by KEYENCE CORPORATION) (the average value of the width at this time is defined as W.sub.b).

[0075] Next, a weight of 500 g were placed on the sample, and the glass plates were stored in a state that a pressure of 2.48×10.sup.3 Pa was applied to the glass plates in an environment of a temperature of 23° C.±5° C. and a relative humidity of 50%±10% for 2 days, then the width of the towpreg in the sample was again measured at 7 points using the microscope (the average value of the width at this time is defined as W.sub.a). Using the following formula (4), extendability of the width of the towpreg before and after applying pressure was calculated.

(Width W.sub.a of Towpreg after Storage/Width W.sub.b of Towpreg Before Storage−1)×100   Formula (4)

5) Measurement Method of Glass Transition Temperature of Towpreg

[0076] 25 cm was separated from the bobbin of the towpreg wound on the bobbin with back film, obtained in each example and comparative example, and the separated towpreg was laminated 8 plies on an aluminum plate and cured at a temperature of 180° C. for 2 hours to obtain a plate-like fiber-reinforced composite material with a thickness of 2 mm. From this fiber-reinforced composite material, a test piece with a width of 10 mm and a length of 35 mm was cut out, and storage modulus was measured using a dynamic viscoelasticity measuring device (for example, DISCOVERY HR-2: manufactured by TA Instruments), in a cantilever bending mode at a frequency of 1 Hz, by raising temperature at a temperature rising rate of 5° C./min. The onset temperature of the storage modulus at this time was defined as a glass transition temperature.

(6) Towpreg Surface Quality Observation

[0077] The bobbin of the towpreg just after production were used for towpreg surface quality observation. A case where surface quality were good, and fuzz and towpreg waving did not observed was determined as A, a case where small fuzz and small towpreg waving were observed was determined as B, and a case where a large amount of fuzz and large towpreg waving were observed was determined as C, and a case where a large amount of fuzz and carbon fiber breakage were observed was determined as D. So towpreg could not be produced in the D case.

Example 1

[0078] Using 50 parts by mass of “Araldite (registered trademark)” MY0510, and 50 parts by mass of “EPICLON (registered trademark)” HP4710 as epoxy resins, and using 45.9 parts of “Aradur (registered trademark)” 9664-1 as a curing agent, 10 parts by mass of “SUMIKAEXCEL (registered trademark)” PES 2603MP as a thermoplastic resin and 3 parts by mass of “Garamite (registered trademark)”-7305 as inorganic particles, an epoxy resin composition was prepared according to the above <Method for Preparing Epoxy Resin Composition>, then a towpreg with a resin content of 34% by weight was prepared according to the above <Method for Preparing Towpreg>.

[0079] A state and width accuracy after high-speed unwinding of the towpreg, a winding test, a pressure deformation examination, a glass transition temperature after curing at 180° C. for 2 hours, a thixotropy coefficient of the epoxy resin composition at 60° C., a storage modulus at 1 Hz at 23° C., and a glass transition temperature after curing at 180° C. for 2 hours were as shown in Table 1.

Examples 2 to 4

[0080] Epoxy resin compositions and towpreg with a resin content of 34% by weight were prepared in the same manner as in Example 1, except that the components and blending amounts of the epoxy resin compositions were changed as shown in Table 1, respectively.

[0081] With respect to the towpreg and epoxy resin composition of each example, a state and width accuracy after high-speed unwinding of the towpreg, a winding test, a pressure deformation examination, a glass transition temperature after curing at 180° C. for 2 hours, a thixotropy coefficient of the epoxy resin composition at 60° C., a storage modulus at 1 Hz at 23° C., and a glass transition temperature after curing at 180° C. for 2 hours were as shown in Table 1.

Comparative Example 1

[0082] Using the components shown in Comparative Example 1 of Table 1, an epoxy resin composition and a towpreg with a resin content of 34% by weight were prepared in the same manner as in Example 1. In Comparative Example 1, since the epoxy resin composition impregnated in the towpreg did not contain inorganic particles and the thixotropy coefficient at 60° C. was 1.3 that was 3.0 or less, the result of the winding test of towpreg was 5.8 N that was 5.0 N or more, resistance occurred when unwinding the towpreg at high speed, and a large amount of fuzz and fiber bridgings occurred. Therefore, the state after unwinding was poor, and the width accuracy after unwinding was also poor at 0.23.

Comparative Example 2

[0083] Using the components shown in Comparative Example 2 of Table 1, an epoxy resin composition and a towpreg with a resin content of 34% by weight were prepared in the same manner as in Example 1. In Comparative Example 2, no epoxy resin solid at room temperature was contained, the epoxy resin composition impregnated in the towpreg had storage modulus at 23° C. of 0.8×10.sup.5 Pa that was 2.0 x 10.sup.5 Pa or less, and the result of the pressure deformation examination of the towpreg was 6.0% that was 3.0% or more. Therefore, the width accuracy after unwinding the towpreg at high speed was poor.

Comparative Example 3

[0084] Using the components shown in Comparative Example 3 of Table 1, an epoxy resin composition and a towpreg with a resin content of 34% by weight were prepared in the same manner as in Example 1. In Comparative Example 3, since no epoxy resin solid at room temperature was contained, the epoxy resin could not achieve preferable level of both storage modulus at 23° C. and impregnation performance. Carbon fiber breakage happened during towpreg production due to high viscosity at impregnation temperature and towpreg could not be obtained.

Comparative Example 4

[0085] Using the components shown in Comparative Example 4 of Table 1, an epoxy resin composition and a towpreg with a resin content of 34% by weight were prepared in the same manner as in Example 1. In Comparative Example 4, since the epoxy resin did not contain polyfunctional amine type epoxy resin, the towpreg waving occurred during towpreg production, and the width accuracy after unwinding of the towpreg at high speed was poor.

Comparative Example 5

[0086] Using the components shown in Comparative Example 5 of Table 1, an epoxy resin composition and a towpreg with a resin content of 34% by weight were prepared in the same manner as in Example 1. In Comparative Example 5, since fused silica, not a clay mineral, was added as inorganic particles, the state when unwinding the towpreg at high speed was poor, and a large amount of fluff and fiber bridges occurred. Furthermore, the width accuracy after unwinding the towpreg at high speed was 0.24, which were also poor.

TABLE-US-00001 TABLE 1 Epoxy eq. Exam- Exam- Exam- Exam- Exam- Exam- Exam- [g/eq.] ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 Epoxy resin Bisphenol LY1556 (Bisphenol A type epoxy 187 — 20 20 30 50 — 20 which is type epoxy resin) liquid at GY282 (Bisphenol F type epoxy resin) 167 — — — — — 20 — room [B] MY0510 (Aminophenol type epoxy 96 50 40 40 30 — — 40 temperature Polyfunctional resin) amine type MY721 (Glycidyl amine type epoxy 115 — — — 10 — 30 — resin) MY9665T (Glycidyl amine type epoxy 120 — — — — 20 — — resin) [A] Epoxy EEW GT7071 (Bisphenol type epoxy resin) 490 — — — — — — 20 resin which >300[g/eq] GT6084-2 (Bisphenol type epoxy 862 — 20 — — — — 20 is solid at resin) room EEW HP4710 (Bisnaphthalene type epoxy 173 50 20 40 30 30 — — temperature ≤300[g/eq] resin) HP7200L (Dicyclopentadiene type 247 — — — — — 50 — epoxy resin) Thermoplastic resin PES 2603 MP (Polyether sulfone) — 10 10 10 10 3 14 10 Inorganic [C] Clay Garamite 7305 (Organophilic — 3 4 4 4 — — 4 particle mineral phyllosilicates) Garamite 1958 (Organophilic — — — — 4 4 — phyllosilicates) Fumed Aerosil RY200 (Fumed silica) — — — — — — — — silica Curing agent Aromatic Aradur 9664-1 — 45.9 37.5 42.7 41.5 34.4 — 33.3 amine ([[4-4′]]4,4′-diaminodiphenylsulfone) 0.9eq 0.9eq 0.9eq 0.9eq 0.9eq 0.9eq Aradur 9771--1 — — — — — — 33.1 — ([[4-4′]]3,3′-diaminodiphenylsulfone) 0.9eq High-speed unwinding Surface state after unwinding — B B A B B A B performance Width accuracy after unwinding — 0.15 0.10 0.09 0.17 0.19 0.08 0.10 (standard deviation of width [mm]) Towpreg properties Tension for winding test of towpreg — 4.1 3.1 3.0 4.8 4.8 3.1 3.2 [N] Spreadability for pressure deformation — 1.5 0.6 1.1 1.8 1.2 0.2 1.0 examination of towpreg [%] Grass transition temperature after — 216 200 212 212 202 182 163 cure180° C./2 h [° C.] Surface quality of towpre just after — A B A A A A C production Resin properties Thixotropy coefficient at 60° C. — 3.3 5.2 5.3 5.1 5.0 4.0 5.0 (η*.sub.0.1 Hz/η*.sub.10 Hz) 1 Hz storage modulus at 23° C. [Pa] — 3.1 6.0 4.0 2.7 2.9 23.6 5.6 Grass transition temperature after — 220 204 215 218 207 187 168 cure 180° C./2 h [° C.] Compar- Compar- Compar- Compar- Compar- ative ative ative ative ative Exam- Exam- exam- exam- exam- exam- exam- ple 8 ple 9 ple1 ple2 ple3 ple4 ple5 Epoxy resin Bisphenol LY1556 (Bisphenol A type epoxy — 20 10 60 — — — which is type epoxy resin) liquid at GY282 (Bisphenol F type epoxy resin) 20 — — — 60 50 — room [B] MY0510 (Aminophenol type epoxy — 30 40 40 — — 50 temperature Polyfunctional resin) amine type MY721 (Glycidyl amine type epoxy 40 — 10 — 40 — — resin) MY9665T (Glycidyl amine type epoxy — — — — — — — resin) [A] Epoxy EEW GT7071 (Bisphenol type epoxy resin) — — — — — — — resin which >300[g/eq] GT6084-2 (Bisphenol type epoxy — — — — — — — is solid at resin) room EEW HP4710 (Bisnaphthalene type epoxy 40 50 40 — — — 50 temperature ≤300[g/eq] resin) HP7200L (Dicyclopentadiene type — — — — — 50 — epoxy resin) Thermoplastic resin PES 2603 MP (Polyether sulfone) 4 10 10 22 22 15 10 Inorganic [C] Clay Garamite 7305 (Organophilic — 8 — 4 4 — — particle mineral phyllosilicates) Garamite 1958 (Organophilic 2 — — — — 4 — phyllosilicates) Fumed Aerosil RY200 (Fumed silica) — — — — — — 4 silica Curing agent Aromatic Aradur 9664-1 32.3 34.4 44.7 41.8 44.0 — 45.9 amine ([[4-4′]]4,4′-diaminodiphenylsulfone) 0.9eq 0.9eq 0.9eq 0.9eq 0.9eq 0.9eq Aradur 9771--1 — — — — — 31.6 — ([[4-4′]]3,3′-diaminodiphenylsulfone) 0.9eq High-speed unwinding Surface state after unwinding B B C C — B C performance Width accuracy after unwinding 0.16 0.12 0.23 0.32 — 0.22 0.24 (standard deviation of width [mm]) Towpreg properties Tension for winding test of towpreg 4.6 3 5.8 2.0 — 4.1 5.3 [N] Spreadability for pressure deformation 0.9 0.2 1.1 5.9 — 0.7 1.4 examination of towpreg [%] Grass transition temperature after 200 212 213 192 — 189 216 cure180° C./2 h [° C.] Surface quality of towpre just after A B A D D A A production Resin properties Thixotropy coefficient at 60° C. 3.0 6.5 1.3 6.3 5.8 4.3 5.1 (η*.sub.0.1 Hz/η*.sub.10 Hz) 1 Hz storage modulus at 23° C. [Pa] 4.0 59.3 3.5 1.0 3.3 6.0 3.3 Grass transition temperature after 209 214 218 197 190 195 220 cure 180° C./2 h [° C.]