PREPREG BASE MATERIAL, LAYERED BASE MATERIAL, FIBER-REINFORCED PLASTIC, PROCESS FOR PRODUCING PREPREG BASE MATERIAL, AND PROCESS FOR PRODUCING FIBER-REINFORCED PLASTIC

• US 20100028593A1
• Filed: 01/30/2008
• Published: 02/04/2010
• Est. Priority Date: 02/02/2007
• Status: Active Grant

• Current Assignee: Toray Industries Incorporated
• Original Assignee: Toray Industries Incorporated
• Inventors: Wadahara, Eisuke, Sato, Narumichi, Taketa, Ichiro
• Granted Patent: US 8,354,156 B2
• Time in Patent Office: Days
• US Class Current: 428/113
• CPC Class Codes: B29C 2043/463 corrugated, patterned or embossed surface
• CPC Class Codes: B29C 2793/0036 Slitting
• CPC Class Codes: B29C 2793/0054 partially cutting through the material
• CPC Class Codes: B29C 43/20 Making multilayered or multicoloured articles B29C43/14 takes precedence
• CPC Class Codes: B29C 43/222 characterised by the shape of the surface
• CPC Class Codes: B29C 43/34 Feeding the material to the mould or the compression means B29C43/085 takes precedence
• CPC Class Codes: B29C 70/14 oriented
• CPC Class Codes: B29C 70/20 oriented in a single direction, e.g. roofing or other parallel fibres B29C70/083, B29C70/226 take precedence
• CPC Class Codes: B29C 70/202 arranged in parallel planes or structures of fibres crossing at substantial angles, e.g. cross-moulding compound [XMC] B29C70/207 takes precedence
• CPC Class Codes: B29C 70/54 Component parts, details or accessories; Auxiliary operations , e.g. feeding or storage of prepregs or SMC after impregnation or during ageing
• CPC Class Codes: B29C 70/545 Perforating, cutting or machining during or after moulding
• CPC Class Codes: B29K 2105/06 containing reinforcements, fillers or inserts
• CPC Class Codes: B29K 2105/0809 Fabrics
• CPC Class Codes: B32B 2250/20 All layers being fibrous or filamentary
• CPC Class Codes: B32B 2260/023 Two or more layers
• CPC Class Codes: B32B 2260/046 Synthetic resin
• CPC Class Codes: B32B 2262/02 Synthetic macromolecular fibres
• CPC Class Codes: B32B 2262/0253 Polyolefin fibres vinyl or acrylic copolymers B32B2262/0223 or B32B2262/0246
• CPC Class Codes: B32B 2262/0269 Aromatic polyamide fibres
• CPC Class Codes: B32B 2262/06 Vegetal fibres
• CPC Class Codes: B32B 2262/08 : Animal fibres, e.g. hair, wool, silk
• CPC Class Codes: B32B 2262/10 : Inorganic fibres layered products comprising a layer of natural mineral fibres B32B19/00
• CPC Class Codes: B32B 2262/101 : Glass fibres
• CPC Class Codes: B32B 2262/103 : Metal fibres
• CPC Class Codes: B32B 2262/105 : Ceramic fibres
• CPC Class Codes: B32B 2262/106 : Carbon fibres, e.g. graphite fibres
• CPC Class Codes: B32B 2307/734 : Dimensional stability
• CPC Class Codes: B32B 2605/00 : Vehicles
• CPC Class Codes: B32B 3/266 : characterised by an apertured layer, the apertures going through the whole thickness of the layer, e.g. expanded metal, perforated layer, slit layer regular cells B32B3/12
• CPC Class Codes: B32B 5/12 : characterised by the relative arrangement of fibres or filaments of different layers, e.g. the fibres or filaments being parallel or perpendicular to each other
• CPC Class Codes: B32B 5/26 : another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12
• CPC Class Codes: Y10T 428/24124 : Fibers
• CPC Class Codes: Y10T 428/24132 : including grain, strips, or filamentary elements in different layers or components parallel
• CPC Class Codes: Y10T 428/24314 : Slit or elongated
• CPC Class Codes: Y10T 428/24322 : Composite web or sheet
• CPC Class Codes: Y10T 428/24488 : Differential nonuniformity at margin
• CPC Class Codes: Y10T 428/2457 : Parallel ribs and/or grooves
• CPC Class Codes: Y10T 428/249924 : Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
• CPC Class Codes: Y10T 428/249934 : Fibers are aligned substantially parallel
• CPC Class Codes: Y10T 428/2913 : Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/2931 : Fibers or filaments nonconcentric [e.g., side-by-side or eccentric, etc.]
• CPC Class Codes: Y10T 428/298 : Physical dimension
• CPC Class Codes: Y10T 442/20 : Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
• CPC Class Codes: Y10T 442/30 : Woven fabric [i.e., woven strand or strip material]
• CPC Class Codes: Y10T 442/3065 : Including strand which is of specific structural definition
• CPC Class Codes: Y10T 442/40 : Knit fabric [i.e., knit strand or strip material]
• CPC Class Codes: Y10T 442/425 : Including strand which is of specific structural definition

Abstract

A prepreg base material includes reinforcing fibers arranged substantially in one direction and a matrix resin between the reinforcing fibers, wherein the prepreg base material has substantially throughout its entire surface incisions, each incision extending in a direction substantially crossing the reinforcing fibers, wherein substantially all of the reinforcing fibers are divided by the incisions, a length (L) of each of reinforcing fiber segments formed by the incisions is in the range of 10 to 100 mm, a thickness H of the prepreg base material is in the range of 30 to 300 μm, and a fiber volume content by Vf of the reinforcing fibers is in the range of 45 to 65%.

Claims

1. A prepreg base material which comprises:

reinforcing fibers arranged substantially in one direction and a matrix resin between the reinforcing fibers, wherein the prepreg base material has substantially throughout its entire surface incisions, each incision extending in a direction substantially crossing the reinforcing fibers, wherein substantially all of the reinforcing fibers are divided by the incisions, a length L of each of reinforcing fiber segments formed by the incisions is in the range of 10 to 100 mm, a thickness H of the prepreg base material is in the range of 30 to 300 μ

m, and a fiber volume content Vf of the reinforcing fibers is in the range of 45 to 65%.

2. The prepreg base material according to claim 1, wherein each of said incisions is in the form of a slit segment having a selected length, and when said slit segment is projected in the arranging direction of said reinforcing fibers, a projected length Ws of said slit segment in the perpendicular direction to the arranging direction of said reinforcing fibers is in the range of 1 to 10 mm and said thickness H of said prepreg base material is in the range of 30 to 150 μ

m.

3. The prepreg base material according to claim 1, wherein each of said incisions is in the form of a slit segment having a selected length, and when said slit segment is projected in the arranging direction of said reinforcing fibers, a projected length Ws of said slit segment in the perpendicular direction to the arranging direction of said reinforcing fibers is in the range of 30 μ

m to 1.5 mm.

4. The prepreg base material according to claim 2, wherein said slit segments are aligned along at least three straight lines running in the same direction to form at least three slit rows and intervals between the adjacent said slit rows in the arranging direction of said reinforcing fibers are the same.

5. The prepreg base material according to claim 2, wherein said slit segments are arranged with an oblique angle to the perpendicular direction to the arranging direction of said reinforcing fibers.

6. The prepreg base material according to claim 2, wherein said slit segments are provided from top and bottom faces of said prepreg base material in the thickness direction thereof without penetrating said prepreg base material;

a cut depth Hs of each of said slit segments is in the range of 0.4 to 0.6 times the thickness H of said prepreg base material;

an interval La between any slit segment A in said top face and another slit segment B in said top face adjacent to said slit segment A in the orientation direction of said reinforcing fibers is in the range of 10 to 100 mm;

the geometrical center of a slit segment C provided in said bottom face is located at a position where its distance measured from said slit segment A toward said slit segment B in the orientation direction of said reinforcing fibers is 0.4 to 0.6 times La;

a part of said reinforcing fibers existing between said slit segment A and said slit segment B in said top face is cut by both said slit segment A in said top face and said slit segment C in said bottom face or both said slit segment B in said top face and said slit segment C in said bottom face; and

geometrical shapes of slit segments in said top face and/or geometrical shapes of slit segments in said bottom face are the same each other.

7. The prepreg base material according to claim 2, wherein said slit segments are provided in an inclined state having an inclination angle Θ

a in the thickness direction of said prepreg base material and having a distance S between a cut line of one of said slit segments in said reinforcing fibers in a top face of said prepreg base material and a cut line of the one of said slit segments in said reinforcing fibers in a bottom face of said prepreg base material in the arranging direction of said reinforcing fibers, and wherein the inclination angle Θ

a determined by the following equation (Formula I) from said distance S and said thickness H of said prepreg base material is in the range of 1 to 25°

;

$\begin{array}{cc}\mathrm{\Theta <br><br>}<br><br><br><br>a={\tan }^{-1}<br><br>\left(\frac{H}{S}\right).& \mathrm{Formula}<br><br><br><br>I\end{array}$

8. The prepreg base material according to claim 1, wherein the absolute value of an oblique angle Θ

b of each of said incisions in a face of said prepreg base material from the arranging direction of said reinforcing fibers is in the range of 2 to 25°

.

9. The prepreg base material according to claim 8, wherein each of said incisions is continuous over the total width of said prepreg base material.

10. The prepreg base material according to claim 8, wherein each of said incisions is formed with a slit segment having a certain length, and wherein when said slit segment is projected in the arranging direction of said reinforcing fibers, the projected length Ws of said slit segment in a perpendicular direction to an arranging direction of said reinforcing fibers is in the range of 30 μ

m to 100 mm and adjacent said slit segments in the arranging direction of said reinforcing fibers have the same geometrical shape each other.

11. The prepreg base material according to claim 9, wherein each of said incisions is linear and substantially all of said reinforcing fiber segments have substantially the same length L.

12. A laminated base material comprising a lamination and integration of prepreg base materials each of which comprises reinforcing fibers arranged substantially in one direction and a matrix resin adhered to said reinforcing fibers, wherein at least one of said laminated prepreg base materials is formed with a prepreg base material set forth in claim 1 and arranging directions of said reinforcing fibers between one and another laminated prepreg base materials have at least two directions different each other.

13. A laminated base material comprising a lamination and integration of prepreg base materials each of which comprises reinforcing fibers arranged substantially in one direction and a matrix resin adhered to said reinforcing fibers, wherein at least two of said laminated prepreg base materials are formed with prepreg base materials set forth in claim 2 adjacent to each other and arranging directions of said reinforcing fibers in said adjacent prepreg base materials have substantially the same direction, and wherein arranging intervals in an arranging direction of said reinforcing fibers of said slit segments in said two adjacent prepreg base materials are the same and positions of said slit segments in one of said two adjacent prepreg base material are shifted in the arranging direction of said reinforcing fibers relative to positions of said slit segments in the other prepreg base material.

15. A process for producing a prepreg base material set forth in claim 8, comprising preparing a preliminary prepreg by arranging reinforcing fibers in one direction and impregnating them with a matrix resin and incising said preliminary prepreg by pressing a rotary blade roller, which has a helical blade provided on the external surface of a roller, against said preliminary prepreg prepared.

16. A process for producing a fiber reinforced plastic which comprises placing said laminated base material set forth in claim 12 in a molding die, maintaining a charge rate of said laminated base material at 50 to 95%, and press-molding said laminated base material.

17. The prepreg base material according to claim 3, wherein said slit segments are aligned along at least three straight lines running in the same direction to form at least three slit rows and intervals between the adjacent said slit rows in the arranging direction of said reinforcing fibers are the same.

18. The prepreg base material according to claim 3, wherein said slit segments are arranged with an oblique angle to the perpendicular direction to the arranging direction of said reinforcing fibers.

19. The prepreg base material according to claim 10, wherein each of said incisions is linear and substantially all of said reinforcing fiber segments have substantially the same length L.

14. A fiber reinforced plastic comprising a laminate comprising a plurality of reinforcing fiber layers each of which comprises reinforcing fibers arranged substantially in one direction and a matrix resin, wherein at least two of said reinforcing fiber layers are laminated with their reinforcing fibers arranged in different directions, a fiber volume content Vf is in the range of 45 to 65%, and wherein at least one of the fiber-resin layers, each comprising one of said reinforcing fiber layers and said matrix resin accompanying thereto, has incised openings in substantially an entire surface of said fiber-resin layer, each of which comprises a region in which said matrix resin exists without said reinforcing fibers or said reinforcing fibers in the adjacent fiber-resin layer exist, said reinforcing fibers are cut by said incised openings, a length L of the reinforcing fiber segments of said cut reinforcing fibers is in the range of 10 to 100 mm, a surface area of said incised openings on the surface of said layer is in the range of 0.1 to 10% of the surface area of said layer, and an average thickness Hc of said layer is in the range of 15 to 300 μ

m.