JP6702414B2 - Prepreg, method for manufacturing resin-impregnated material, and apparatus for manufacturing resin-impregnated material - Google Patents

Description

The present invention relates to a prepreg, a method for producing a resin-impregnated product, and a device for producing a resin-impregnated product.
The present application claims priority based on Japanese Patent Application No. 2017-64313 filed in Japan on March 29, 2017, the contents of which are incorporated herein by reference.

As a method for producing a prepreg by impregnating a sheet of reinforcing fibers with a resin, a sheet of reinforcing fibers and a laminate obtained by stacking a resin sheet carrying a resin layer on the surface of a sheet-shaped carrier are pressed. There is known a method of impregnating a sheet-like material of reinforcing fibers with a resin by heating and pressurizing the material through a roll and a heating roll arranged opposite thereto.

In order to sufficiently impregnate the sheet-shaped material of the reinforcing fiber with the resin in a short time, the viscosity of the resin may be lowered, the linear pressure between the press roll and the heating roll may be increased, or the pressing time may be lengthened. There is a need. However, when the laminate is passed between the press roll and the heating roll under these conditions, the resin is squeezed from the laminate by the press roll and the heating roll, and the resin is on the upstream side in the moving direction of the laminate. The problem of flowing out (problem of resin flow) occurs.

As an impregnation method for suppressing the resin flow, a method using a press roll having a concave-convex pattern on the outer peripheral surface and having a convex portion area percentage of 20 to 90% of the outer peripheral surface is proposed. (Patent Documents 1 and 2).

Further, in a molding method such as vacuum bag molding, which has a long molding time, a method of using a prepreg in which a part of the fiber sheet is not impregnated is proposed. (Patent Document 3)

On the other hand, there are an autoclave method and a press molding for the molding of the prepreg. Among them, the press molding has high productivity because the molding time is short.
Further, there are a thin basis weight using a relatively thin base material and a thick basis weight using a comparatively thick base material as a raw material for forming a prepreg. When molding a member, it is more cost effective to use the thick basis weight. is there.

However, in order to form a prepreg using press forming, the matrix resin needs to be sufficiently impregnated in the base material. Conventionally, a lacquer method using a solvent has been used for producing a thick prepreg, but there is a problem (VOC) of using a volatile organic compound.
Therefore, it has been attempted to produce a thick prepreg by a hot melt method without using a solvent, but there is a problem such as void generation, it is desired to produce a thick prepreg with a high impregnation rate of the matrix resin. There is.

Japanese Patent Laid-Open No. 1-200914 JP-A-2-298519 JP, 2004-050574, A

However, even when the concavo-convex press rolls described in Patent Documents 1 and 2 are used, when the sheet of reinforcing fibers becomes thick and the amount of resin impregnated increases, the sheet of reinforcing fibers is suppressed while suppressing resin flow. It is difficult to sufficiently impregnate the resin.
Further, when the prepreg in which some of the unimpregnated parts remain in the fiber sheet described in the cited document 3 is applied to a method such as press molding in which the molding time is short, a defect called blisters on the appearance of the molded product, Interlayer voids and pinholes may appear.

The present invention provides a method for manufacturing a resin-impregnated product and a device for manufacturing a resin-impregnated product, which can sufficiently impregnate a sheet-shaped material to be impregnated with a resin while suppressing a resin flow.

The present invention has the following aspects.
[1] A prepreg including a sheet-shaped reinforcing fiber base material containing a fiber bundle of reinforcing fibers, and a matrix resin containing a resin composition,
The sheet-shaped reinforcing fiber base material has a basis weight of 400 g/m ² or more,
The content of the matrix resin in the prepreg is 33% by mass or more and 45% by mass or less,
The prepreg may contain a volatile component, and when the prepreg contains a volatile component, the content of the volatile component in the prepreg is more than 0% by mass and 0.50% by mass or less,
A prepreg having an impregnation ratio of the matrix resin of the fiber bundle constituting the sheet-shaped reinforcing fiber base material of 70% or more.
[2] the cross-sectional area of any in the vertical cross section of the direction of the prepreg perpendicular to the fiber direction of the fiber bundle, the cross-sectional area A _r of the matrix resin remaining in the periphery of the arbitrary fiber bundle, wherein any of the fiber bundle ratio expressed by _{(a r / a c) ×} 100 of the a _c is 10% or less, prepreg according to [1].
[3] The prepreg according to [1] or [2], wherein the basis weight of the sheet-shaped reinforcing fiber base material is 400 g/m ² or more and 1500 g/m ² or less.
[4] The prepreg according to any one of [1] to [3], which has an opening ratio of 0.5% or less.
[5] The prepreg according to any one of [1] to [4], having a cantilever value at 40° C. of 10 mm or more and 50 mm or less.
[6] The curing initiation temperature of the resin composition is 80 to 150° C., and the viscosity (minimum viscosity) at the curing initiation temperature is 0.1 to 10 Pa·S, [1] to [5] The prepreg described in any one.
[7] The prepreg according to any one of [1] to [6], wherein the resin composition is an epoxy resin composition.
[8] The prepreg according to any one of [1] to [7], wherein the reinforcing fibers are carbon fibers.
[9] A resin is applied to the impregnation target sheet-like material by passing a laminate obtained by stacking the impregnation target sheet-like material and the resin layer between a press roll and a counter roll arranged opposite to the press roll to apply pressure. Is a method for producing an impregnated resin impregnated product,
The laminate, after passing between the press roll and the counter roll, by passing between the press roll and the counter roll that is the same as or different from the preceding stage, between the press roll and the counter roll Pass m times in total (where m is an integer of 2 or more),
The press roll is a concavo-convex press roll having a plurality of convex portions on the outer peripheral surface and continuous concave portions formed between the convex portions, and which is a concavo-convex press roll satisfying the following condition (α). Method.
<Condition (α)>
Wherein the X _a determined from the following equation (1) uneven press roll for passing the laminate a time, and X _b obtained from the following equation for the irregularities press roll (1) passing said laminate b-th time , A and b satisfy the relationship of the following formula (2). However, a and b are integers of 1≦a<b≦m.
X _a >X _b (2)
X _i =A _i ×W _i (1)
However, i is an integer of 1 to m, A _i is the ratio of the area of the recess in the region where the projection and the recess are formed, and W _i is the width (mm) of the recess.
[10] The method for producing a resin-impregnated product according to [9], wherein X _i obtained from the above formula (1) is 0.5 to 6.
[11] The method for producing a resin-impregnated product according to [9] or [10], wherein the uneven press roll further satisfies the following condition (β).
<Condition (β)>
The depths D of the recesses obtained by measuring the depths of 20 recesses randomly selected from the region and averaging them and the width W of the recesses are expressed by the following equation (3). Be satisfied.
D≧W×0.35 (3)
[12] The sheet-shaped product to be impregnated is resin-molded by passing a laminate obtained by stacking the sheet-shaped product to be impregnated and a resin layer between a press roll and a counter roll arranged so as to face the press roll. Is a device for producing a resin impregnated product impregnated with
M (where m is an integer of 2 or more) press rolls arranged at intervals in the moving direction of the laminate, and counter rolls that are arranged to face the press rolls,
The press roll is a concavo-convex press roll having a plurality of convex portions on the outer peripheral surface and continuous concave portions formed between the convex portions, and which is a concavo-convex press roll satisfying the following condition (α). apparatus.
<Condition (α)>
X _a obtained from the following formula (1) for the _a-th unevenness press roll from the most upstream side in the moving direction of the laminate and the above-mentioned formula for the b-th unevenness press roll from the most upstream side in the moving direction of the laminate. There are a and b that satisfy the relationship of the following formula (2) with _Xb obtained from (1). However, a and b are integers of 1≦a<b≦m.
X _a >X _b (2)
X _i =A _i ×W _i (1)
However, i is an integer of 1 to m, A _i is the ratio of the area of the recess in the region where the protrusion and the recess are formed, and W _i is the width (mm) of the recess.
[13] The apparatus for producing a resin-impregnated product according to [12], wherein X _i obtained from the formula (1) is 0.5 to 6.
[14] The resin-impregnated product manufacturing apparatus according to [12] or [13], wherein the uneven press roll further satisfies the following condition (β).
<Condition (β)>
The depth D of the recesses obtained by measuring the depths of 20 recesses randomly selected from the region and averaging them, and the width W of the recesses are expressed by the following equation (3). Be satisfied.
D≧W×0.35 (3)

According to the method for producing a resin-impregnated material of the present invention, it is possible to sufficiently impregnate the sheet-shaped material to be impregnated with the resin while suppressing the resin flow.
By using the prepreg sheet produced by the method of the present invention for press molding having a short molding time, it is possible to produce a molded product having almost no visual defects.

It is a schematic block diagram which shows an example of the manufacturing apparatus of the resin impregnation thing of this invention. It is a figure which shows an example of the convex part and concave part in the outer peripheral surface of an uneven|corrugated press roll. FIG. 3 is an enlarged view in which a part of FIG. 2 is enlarged. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is a schematic block diagram which shows the other example of the manufacturing apparatus of the resin impregnation thing of this invention. It is a figure which shows the other example of the convex part and concave part in the outer peripheral surface of the uneven|corrugated press roll. It is a schematic block diagram which shows the mode of measurement of the surface side resin capture amount in an experimental example. It is a schematic block diagram which shows the mode of measurement of the back surface side resin capture amount in an experimental example. 6 is a graph showing the relationship between an index X represented by the product of the area ratio A of the recess and the width W of the recess and the amount of resin captured by the concavo-convex pattern plate. It is a schematic block diagram which shows the manufacturing apparatus of the prepreg used for the Example and the comparative example. A schematic cross-sectional view of a prepreg using a woven fabric (plain weave) as a sheet-like reinforcing base material, cut in a direction perpendicular to the warp, an impregnated portion A _{i of} the fiber bundle, and an unimpregnated portion A _{ui of the} fiber bundle. , An area defining the cross-sectional area A _r of the residual matrix resin around the fiber bundle and the cross-sectional area A _c of the fiber bundle. It is a schematic block diagram which shows the mode of preparation of the prepreg in an experiment example. It is the schematic which shows the measuring method of the cantilever value of a prepreg.

"-" showing a numerical range means including the numerical value described before and after that as a lower limit and an upper limit.
The dimensional ratios in the drawings are different from the actual ones for convenience of description.

<Resin impregnated product manufacturing equipment>
FIG. 1 is a schematic configuration diagram showing an example of an apparatus for producing a resin-impregnated material of the present invention.
The resin-impregnated material manufacturing apparatus 10 includes an impregnation target sheet-like material supply roll 11 that unwinds a long sheet of impregnation target sheet-shaped material 102;
A first resin that unwinds a long first resin sheet 104 in which a resin layer is carried on the surface of a long sheet-shaped carrier toward the lower surface of the impregnation target sheet-shaped object 102 so that the resin layer faces upward. Sheet supply roll 12;
A second resin that unwinds a long second resin sheet 106 in which a resin layer is carried on the surface of a long sheet-shaped carrier toward the upper surface of the impregnation target sheet-shaped object 102 so that the resin layer faces downward. Sheet supply roll 13;
A guide roll 14 for horizontally guiding the impregnation target sheet material 102 unwound from the impregnation target sheet material supply roll 11;
A guide roll 15 that horizontally guides the first resin sheet 104 unwound from the first resin sheet supply roll 12 along the lower surface of the impregnation target sheet 102 that moves horizontally;
A guide roll 16 that guides the second resin sheet 106 unwound from the second resin sheet supply roll 13 in the horizontal direction along the upper surface of the sheet material 102 to be impregnated that moves in the horizontal direction;
A peeling roll 17 for peeling the sheet-like carrier 107 from the second resin sheet 106 along the upper surface of the impregnation target sheet-like object 102;
A sheet-shaped carrier winding roll 18 for winding the peeled sheet-shaped carrier 107;
A top film supply roll 20 that unwinds the top film 112 toward the resin layer along the upper surface of the sheet material 102 to be impregnated;
A guide roll 22 that guides the top film 112 unwound from the top film supply roll 20 in the horizontal direction along the resin layer on the upper surface of the impregnation target sheet 102 that moves in the horizontal direction;
A heating plate 23 for heating the long laminate 108 in which the first resin sheet 104 is overlapped on the lower surface of the impregnation target sheet material 102 and the resin layer and the top film 112 are overlapped on the upper surface of the impregnation target sheet material 102. ;
N (where n is an integer of 2 or more) concave and convex press rolls 24 arranged so as to be in contact with the laminated body 108 at intervals in the moving direction of the laminated body 108;
N heating rolls 26 (opposite rolls) arranged to face each of the uneven press rolls 24 so as to be in contact with the laminated body 108;
The sheet material 102 to be impregnated is derived from the resin layer of the first resin sheet 104 and the second resin sheet 106 by being heated and pressed when passing between the uneven press roll 24 and the heating roll 26. A cooling plate 27 for cooling the resin impregnated material 110 impregnated with the resin layer;
A peeling roll 28 for peeling the top film 112 from the upper surface side of the resin-impregnated material 110;
A top film take-up roll 30 for taking up the peeled top film 112;
A top film supply roll 31 that unwinds the top film 113 toward the upper surface of the resin-impregnated material 110;
A guide roll 32 for guiding the top film 113 unwound from the top film supply roll 31 in the horizontal direction along the upper surface of the resin impregnated material 110 moving in the horizontal direction;
A guide roll 33 for guiding the resin-impregnated material 110, on which the top film 112 overlaps, downward.
And a resin-impregnated material winding roll 34 for winding the resin-impregnated material 110.

(Sheet-like material for impregnation)
The sheet material 102 to be impregnated is a sheet material to be impregnated with resin, and has a void for resin impregnation.
Examples of the sheet material to be impregnated include a reinforcing fiber sheet material (also referred to as “sheet-shaped reinforcing fiber base material”).

The sheet of reinforcing fibers is not particularly limited as long as it is a sheet-shaped reinforcing fiber substrate. As the sheet-shaped material of the reinforcing fibers, specifically, a sheet molding compound (SMC) in which the reinforcing fibers are randomly oriented, or a glass mat thermoplastic (GMT) can be used. A woven fabric can also be used, and examples of the woven fabric include a plain weave fabric, a twill weave fabric, a satin weave fabric, a blind weave fabric, and a non-crimp fabric.
The sheet of reinforcing fibers in the present invention is preferably a woven fabric, SMC or a non-crimp fabric, and particularly preferably a woven fabric, from the viewpoint of obtaining a prepreg with a thick basis weight of the reinforcing fibers.

Examples of the reinforcing fibers include inorganic fibers, organic fibers, metal fibers, and composite fibers thereof.
Examples of the inorganic fibers include carbon fibers, glass fibers, graphite fibers, silicon carbide fibers, silicon nitride fibers, alumina fibers, tungsten carbide fibers, boron fibers and the like.
Examples of the organic fiber include aramid fiber, high-density polyethylene fiber, nylon fiber, polyester fiber and the like.
Examples of the metal fiber include stainless fiber, iron fiber, titanium fiber, carbon fiber coated with metal, and the like.
As the reinforcing fiber, carbon fiber is preferable because a lightweight, highly rigid and high strength fiber reinforced plastic can be obtained.
The reinforcing fibers may be used alone or in combination of two or more.

The mass per unit area of the sheet material 102 to be impregnated may be appropriately set according to the characteristics required for the product (fiber reinforced plastic etc.) finally obtained, and is not particularly limited. INDUSTRIAL APPLICABILITY The present invention is suitable for impregnating a sheet-shaped material of thickened reinforcing fibers with a resin, and is preferably applied to the impregnated target sheet-shaped material 102 having a mass per unit area of 400 g/m ² or more, and 400 preferably ^{~1500g / m 2, 500~1000g / m} 2 is more preferable.

(Resin sheet)
The first resin sheet 104 and the second resin sheet 106 are sheet-shaped products in which a resin layer is carried on the surface of a sheet-shaped carrier.

As a sheet-shaped carrier, a release paper in which a release agent such as a silicone resin is coated on a wooden paper as needed, or a film using a soft or hard polymer is coated with a release agent such as a silicone resin as necessary. Examples of the release film include:

The resin layer contains a matrix resin containing the resin composition and, if necessary, an additive.
Examples of the resin contained in the resin composition include thermosetting resins and thermoplastic resins.

Examples of the thermosetting resin include epoxy resin, unsaturated polyester resin, acrylic resin, vinyl ester resin, phenol resin, urethane resin and benzoxazine resin. As the thermosetting resin, an epoxy resin is preferable because a fiber-reinforced plastic having high strength can be obtained.
An epoxy resin composition is preferable as the resin composition in the matrix resin.

Examples of the thermoplastic resin include polyamide (nylon 6, nylon 66, etc.), polyolefin (polyethylene, polypropylene, etc.), modified polyolefin, polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate, polyamide imide, polyphenylene oxide, polysulfone, polyether. Examples thereof include sulfone, polyether ether ketone, polyether imide, polystyrene, acrylonitrile-butadiene-styrene copolymer, polyphenylene sulfide, liquid crystal polyester, and acrylonitrile-styrene copolymer.

As additives, curing agents, mold release agents, defoaming agents, flame retardants, weather resistance improvers, antioxidants, heat stabilizers, UV absorbers, plasticizers, lubricants, colorants, compatibilizers, fillers. , Conductive fillers and the like.

The mass per unit area of the resin layer may be appropriately set according to the properties required of the product (fiber reinforced plastic etc.) finally obtained, and is not particularly limited. The present invention, because it is preferable to impregnate the resin into the sheet material thick reinforcing fibers, mass per unit area of the resin layer is preferably ^{200~1000g / m 2, 250~700g / m} 2 is More preferable.

The viscosity of the resin at the temperature of passing through the press roll is preferably 0.5 to 100 Pa·s, more preferably 1 to 20 Pa·s. If the viscosity of the resin at the temperature when passing through the press roll is equal to or higher than the lower limit value of the above range, the resin flow can be further suppressed. In particular, if the viscosity of the resin is not more than the upper limit value of the above range, the sheet material to be impregnated can be further sufficiently impregnated with the resin.
The viscosity of the resin at the temperature when passing through the press roll is obtained by measuring the viscoelasticity under the following conditions using a viscoelasticity measuring device.
Device: Rheometer ("MARS 40" manufactured by Thermo Fisher Scientific).
Plate used: 25φ parallel plate.
Plate gap: 0.5 mm.
Measurement frequency: 10 rad/sec.
Measurement start temperature: 30°C.
Temperature rising rate: 2°C/min.
Stress: 300 Pa.

(Top film)
If a highly rigid sheet-shaped carrier such as a release paper or a release film is present on the side in contact with the uneven press roll 24, the effect of trapping the resin by the uneven press roll 24 may be difficult to be exhibited.
Therefore, before passing the laminated body 108 between the uneven press roll 24 and the heating roll 26, the sheet-shaped carrier 107 is peeled off from the second resin sheet 106 supplied to the upper surface of the impregnation target sheet-shaped material 102, Instead of the carrier 107, the top film 112 is supplied on the upper surface of the resin layer derived from the second resin sheet 106.
As a material for the top film 112, a resin having low rigidity is preferable, and polyethylene or the like can be given.

(Resin impregnated material)
The resin-impregnated material 110 is obtained by impregnating a sheet-shaped material to be impregnated with a resin.
Examples of the resin-impregnated material 110 include a sheet molding compound (SMC) and a glass mat thermo-plastic (GMT), in addition to a prepreg containing a prepreg of the present invention, which will be described later, in which a sheet-shaped material of reinforcing fibers is impregnated with a resin.

(Concave and convex press roll)
The concavo-convex press roll 24 has a plurality of convex portions on the outer peripheral surface and continuous concave portions formed between the convex portions.
The shape of the convex portion of the concavo-convex roll is not particularly limited, but may be, for example, a rhombus as shown in FIG. 2, a circle as shown in FIG. 6, an ellipse or a rectangle. Alternatively, it may be a vertical groove, a lateral groove, a helical groove, a double helical groove, a worm groove, a threaded groove, etc., in which the convex portions are continuously connected in the circumferential direction or the width direction. From the viewpoint of uniformly impregnating the reinforcing fiber sheet with the resin, the shape of the convex portion is preferably a rhombus, a circle, an ellipse, a rectangle or the like, and particularly preferably a rhombus or a rectangle.
As the concavo-convex press roll 24, a concavo-convex press rubber roll obtained by winding a rubber sheet having a concavo-convex surface on the outer peripheral surface of a cylindrical roll base material, a concavo-convex press metal roll having concavo-convex formed on the surface of a metal roll, a resin roll An example is a concavo-convex press resin roll in which concavities and convexities are formed on the surface of the roll.

FIG. 2 is a diagram showing an example of a convex portion and a concave portion on the outer peripheral surface of the concavo-convex press roll, FIG. 3 is an enlarged view in which a part of FIG. 2 is enlarged, and FIG. 4 is a IV-IV of FIG. FIG.
On the outer peripheral surface of the concavo-convex press roll 24, the diamond-shaped plate-shaped convex portions 36 are arranged at equal intervals such that the same sides of the convex portions 36 are aligned on a straight line, and between the convex portions 36, Groove-shaped recesses 38 that are continuous in a grid pattern are formed.

The uneven press roll 24 satisfies the following condition (α).
<Condition (α)>
And X _a calculated for irregularities press roll 24 from the following equation (1) passing the laminate 108 in a time, the unevenness press roll for passing the laminate 108 in the b-th and X _b obtained from the following formula (1) However, there are a and b that satisfy the relationship of the following formula (2). However, a and b are integers of 1≦a<b≦n.
X _a >X _b (2)
X _i =A _i ×W _i (1)
However, i is an integer of 1 to n, A _i is the ratio of the area of the concave portion in the region where the convex portion and the concave portion are formed in the concave-convex press roll 24 that passes the laminate 108 for the i-th time, and W _i Is the width (mm) of the recess.

Further, W _i is a value at a portion where each convex portion 36 and the convex portion 36 adjacent thereto are closest to each other for 20 convex portions 36 randomly selected from the region where the convex portion 36 and the concave portion 38 are formed. The distance c between the convex portions 36 is measured, and these are averaged to obtain.
If the condition of the above formula (2) is satisfied, X _c obtained from the above formula (1) for the uneven press roll 24 that allows the laminate 108 to pass through the c-th time is laminated within a range that does not impair the effects of the present invention, and There may be c and d that satisfy the following equation (2′) with respect to X _d obtained from the above equation (1) for the uneven press roll that passes the body 108 d times. However, c and d are integers of 1≦c<d≦n.
X _c <X _d ...(2′)
As a certain aspect, there can be mentioned an aspect in which a and b satisfying the condition of the above formula (2) exist, and c and d do not satisfy the condition of the above formula (2′).

Satisfying the condition (α) means that the resin trapping amount of the concavo-convex press roll 24 decreases continuously or stepwise as it goes downstream. Since the amount of resin on the surface of the impregnation target sheet-like material 102 is large on the upstream side, the resin flow is suppressed by increasing the amount of resin captured by the concavo-convex press roll 24. On the downstream side, the amount of resin on the surface of the impregnation target sheet-like material 102 has decreased because the impregnation of the impregnation target sheet-like material 102 has progressed to some extent on the upstream side, so the amount of resin trapped by the concavo-convex press roll 24 is reduced. Then, the impregnation of the sheet-shaped object 102 to be impregnated with the resin is promoted.

In addition, from the viewpoint that the sheet material 102 to be impregnated is further sufficiently impregnated with the resin, it is preferable that the relationship of the following expression (2a) is satisfied, and it is more preferable that the relationship of the following expression (2b) is satisfied.
X ₁ >X _n ×1.5 (2a)
X ₁ >X _n ×2.5 (2b)

Further, X _i is preferably 0.5 to 6, and more preferably 0.8 to 5.
When X _i is at least the lower limit value of the above range, when the laminate 108 is passed between the uneven press roll 24 and the heating roll 26, the impregnation target sheet material 102 is provided on the upper surface of the impregnation target sheet material 102. Since the amount of the resin existing without being impregnated in the recess 38 is sufficiently captured in the recess 38, it is easy to suppress the resin flow.
When X _i is equal to or less than the upper limit value of the above range, the width of the concave portion 38 does not become too wide, the flow of resin from the concave portion 38 is easily suppressed, and the resin flow tends to be suppressed.

From the viewpoint of further sufficiently suppressing the resin flow on the upstream side, X ₁ in the _first concavo-convex press roll 24 is preferably 0.75 to 6, more preferably 1.25 to 6, and further preferably 1.5 to 6. preferable.

The number n of the concave-convex press rolls 24 is always 2 or more. If only one concavo-convex press roll 24 is used, the condition (α) cannot be satisfied, and it is not possible to sufficiently impregnate the impregnation target sheet-like material 102 with the resin while suppressing the resin flow.
The number n of the uneven press rolls 24 is preferably 4 to 20, and more preferably 6 to 16. When the number n of the concave-convex press rolls 24 is equal to or more than the lower limit value of the above range, it is possible to further sufficiently impregnate the sheet-shaped material 102 to be impregnated with the resin while further suppressing the resin flow. When the number n of the concave-convex press rolls 24 is equal to or less than the upper limit value of the above range, the resin-impregnated material manufacturing apparatus 10 can be made compact.

In order to suppress the resin flow when the laminated body 108 is passed between the uneven press roll 24 and the heating roll 26, if the resin on the upper surface of the sheet material 102 to be impregnated is captured by the uneven press roll 24 and held as it is. Good. For that purpose, the width of the recess 38 may be increased, but even if the width of the recess 38 is increased, if the total area of the recesses 38 is small, a sufficient amount of resin cannot be captured by the recesses 38. On the other hand, even if the width of the concave portions 38 or the total area of the concave portions 38 is made too large, the interval between the convex portions 36 becomes large, and it becomes difficult to uniformly impregnate the sheet-shaped material 102 to be impregnated with the resin.
Thus, in order to suppress the resin flow, it is important to balance the width of the concave portion 38 and the area of the concave portion 38 in the concavo-convex press roll 24. Therefore, the inventors of the present invention have diligently studied the relationship between the width of the concave portion 38 and the area of the concave portion 38 in the concavo-convex press roll 24, and the amount of resin captured by the concavo-convex press roll 24. It has been found that there is a correlation between the index X represented by the product of the area ratio A of the concave portion and the width W of the concave portion and the amount of resin trapped by the concave-convex pattern. Then, they found that the resin flow was suppressed when X was within the above range.

In addition, the uneven press roll 24 preferably satisfies the following condition (β).
Condition (β)
The depth d (mm) of the concave portion 38 obtained by measuring the depths d of 20 concave portions 38 randomly selected from the region where the convex portion 36 and the concave portion 38 are formed, and the concave portion The width W of 38 satisfies the relationship of the following expression (3).
D≧W×0.35 (3)

Even if the width of the recess 38 is increased, if the depth of the recess 38 is insufficient, the recess 38 may not be able to capture a sufficient amount of resin. Therefore, it is preferable to secure the depth of the recess 38 to some extent. If the concave portion 38 is made too deep, the mechanical strength of the convex portion 36 may be insufficient. Therefore, under the condition (δ), it is preferable to satisfy the relationship of the following expression (3a) from the viewpoint of securing the mechanical strength of the convex portion 36 while further suppressing the resin flow, and the following expression (3b) It is more preferable to satisfy the relationship.
W×1.0≧D≧W×0.35 (3a)
W×0.7≧D≧W×0.4 (3b)

(Heating roll)
The heating roll 26 is, for example, a metal roll having a flat outer peripheral surface, which incorporates a heating unit.

(Mechanism of action)
In the resin-impregnated product manufacturing apparatus 10 described above, a plurality of convex portions 36 are formed on the outer peripheral surface of the laminated body 108 at intervals, and continuous concave portions are formed between the convex portions 36. 38 (where n is an integer greater than or equal to 2) and the heating roll 26 arranged to face the uneven press roll 24, and the uneven press roll 24 satisfies the condition (α). Since (?) is satisfied, it is possible to sufficiently impregnate the impregnation target sheet-like material 102 with the resin while suppressing the resin flow.

Further, in such a resin-impregnated product manufacturing apparatus 10, the resin-impregnated product 110 can be manufactured without a resin flow even under the condition of promoting the impregnation of the impregnation target sheet-shaped material 102 with the resin, and therefore, the resin-impregnated product manufacturing The device 10 can be made compact, and the moving speed of the laminated body 108 can be increased. Further, even if the impregnation target sheet material 102 becomes thick and the amount of resin to be impregnated increases, the impregnation target sheet material 102 can be sufficiently impregnated with resin while suppressing the resin flow.

(Other embodiments)
The apparatus for producing a resin-impregnated material of the present invention includes m (where m is an integer of 2 or more) press rolls arranged at intervals in the moving direction of the laminate, and the press rolls are arranged to face each other. Counter rolls that are formed; up to n (where n is an integer of 2 to m) press rolls counted from the most upstream side in the moving direction of the laminate, and a plurality of convex portions and convex portions are formed on the outer peripheral surface. It is not limited to the resin impregnated material manufacturing apparatus 10 of the illustrated example, as long as it is a concavo-convex press roll having continuous recesses formed between the parts and satisfying the condition (α) described above.

For example, the resin-impregnated material manufacturing apparatus is provided with n concave and convex press rolls that satisfy the above condition (α), which is less than the total number m of press rolls, and the remaining (mn) press rolls are provided. The roll may be a flat press roll provided on the downstream side of the uneven press roll and having no unevenness on the outer peripheral surface.
Further, without providing the second resin sheet supply roll, only the top film having no resin layer may be supplied from the top film supply roll to the upper surface of the sheet material to be impregnated.
Further, the concavo-convex press roll and the heating roll may be switched up and down. However, in this case, if the resin sheet does not exist between the impregnation target sheet material and the heating roll, slippage easily occurs between the impregnation target sheet material and the heating roll, so that the resin sheet is applied to the heating roll. It is preferably supplied to the contact side.
Further, the facing roll is not limited to the heating roll, and instead of the heating roll, a metal roll having a flat outer peripheral surface is provided, and a heating means (a plate heater or the like) for heating the laminate is provided upstream of the press roll and the metal roll. May be.
Further, the resin-impregnated material manufacturing apparatus may be one in which a plurality of small-diameter uneven press rolls 24 are arranged along the outer peripheral surface of a large-diameter heating roll 26 as shown in FIG.
Further, the unevenness of the outer peripheral surface of the uneven press roll is not limited to the one having the diamond-shaped convex portion 36 in the illustrated example, and may have the elliptical convex portion 36 as shown in FIG. It may have convex portions of the shape (polygon, circle, etc.), or may have irregular irregularities.

<Method for producing resin-impregnated product>
A method for manufacturing a resin-impregnated product using the resin-impregnated product manufacturing apparatus 10 shown in FIG. 1 will be described.
The long first resin sheet 104 unwound from the first resin sheet supply roll 12 is provided on the lower surface of the long impregnation target sheet 102 unwound from the impregnation target sheet supply roll 11. Supply so that the resin layer faces upward. Further, the long second resin sheet 106 unwound from the second resin sheet supply roll 13 is supplied to the upper surface of the impregnation target sheet-shaped material 102 such that the resin layer faces downward.
After the sheet-shaped carrier 107 is peeled from the second resin sheet 106 along the upper surface of the impregnation target sheet-shaped object 102 by the peeling roll 17, the sheet-shaped carrier 107 is wound by the sheet-shaped carrier winding roll 18.
The top film 112 unwound from the top film supply roll 20 is supplied to the upper surface of the resin layer from which the sheet-shaped carrier 107 is peeled, along the upper surface of the impregnation target sheet-shaped material 102.

The first resin sheet 104 is superposed on the lower surface of the impregnation target sheet material 102, and the long laminated body 108 in which the resin layer and the top film 112 are superposed on the upper surface of the impregnation target sheet material 102 is moved. The sheet-like material 102 to be impregnated is heated and pressed by passing it between n concave and convex press rolls 24 arranged at intervals in the direction and a heating roll 26 opposed to the concave and convex press rolls 24. A resin impregnated product 110 impregnated with the resin layer of the first resin sheet 104 and the resin layer derived from the second resin sheet 106 is obtained.

After peeling the top film 112 from the upper surface side of the resin-impregnated material 110 by the peeling roll 28, the top film 112 is wound by the top film roll 30. Further, the resin impregnated material 110 from which the top film 112 has been peeled off is wound up by the resin impregnated material winding roll 34.

The linear pressure between the uneven press roll 24 and the heating roll 26 is preferably 0.1 to 40 N/mm, more preferably 2 to 20 N/mm. When the linear pressure is equal to or higher than the lower limit value of the above range, the sheet material 102 to be impregnated can be more sufficiently impregnated with the resin. If the linear pressure is not more than the upper limit of the above range, the resin flow can be further suppressed.

The moving speed of the laminated body 108 is preferably 0.5 to 25 m/min, more preferably 1 to 10 m/min. When the moving speed of the laminate 108 is equal to or higher than the lower limit value of the above range, the productivity of the resin-impregnated material 110 is improved. If the moving speed of the laminated body 108 is not more than the upper limit value of the above range, the resin impregnated material manufacturing apparatus 10 can be made compact.

(Mechanism of action)
In the resin impregnated material manufacturing method using the resin impregnated material manufacturing apparatus 10 described above, the laminated body 108 is n in total between the concavo-convex press roll 24 and the heating roll 26 (where n is 2 or more). It is an integer.), and since the uneven press roll 24 that satisfies the above condition (α) is used, the sheet material 102 to be impregnated can be sufficiently impregnated with the resin while suppressing the resin flow. You can

In such a method for producing a resin-impregnated product, the resin-impregnated product 110 can be produced without a resin flow even under the condition of promoting the impregnation of the sheet-shaped product 102 to be impregnated with the resin. 10 can be made compact, and the line speed for moving the laminate 108 can be increased. Further, even if the impregnation target sheet material 102 becomes thick and the amount of resin to be impregnated increases, the impregnation target sheet material 102 can be sufficiently impregnated with resin while suppressing the resin flow.

(Other embodiments)
The method for producing a resin-impregnated product of the present invention is one in which the laminate is passed between a press roll and a counter roll, and then passed between a press roll and a counter roll that are the same as or different from the preceding stage. , A total of m (where m is an integer of 2 or more) passes between the press roll and the facing roll; nth (where n is an integer of 2 to m) from the start of passage of the laminate. As a press roll to be passed up to, a method using a concavo-convex press roll having a plurality of convex portions on the outer peripheral surface and continuous concave portions formed between the convex portions and satisfying the above condition (α) However, the manufacturing method is not limited to the manufacturing method using the resin impregnated material manufacturing apparatus 10 of the illustrated example.

For example, you may use the manufacturing apparatus and uneven|corrugated press roll which were mentioned in other embodiment of the manufacturing apparatus of a resin impregnation thing.
Further, as shown in Examples, within a range satisfying the above-mentioned condition (α), after passing the laminate between the uneven press roll and the counter roll, the same uneven press roll and the counter roll as the previous stage It may be passed between the concave-convex press roll and the counter roll different from the first half, and then again passed between the concave-convex press roll and the counter roll same as the former stage.

<Prepreg>
The prepreg of the present invention is a resin impregnated product produced by using the apparatus for producing a resin impregnated product of the present invention, and a resin impregnated product obtained by the method for producing a resin impregnated product of the present invention, and the prepreg of the present invention is It was obtained for the first time using the resin impregnated product manufacturing apparatus of the present invention or by the resin impregnated product manufacturing method of the present invention.

The prepreg of the present invention is a prepreg containing a sheet-shaped reinforcing fiber base material containing a fiber bundle of reinforcing fibers and a matrix resin containing a resin composition, and the basis weight of the sheet-like reinforcing fiber base material is 400 g/m ² or more. The content of the matrix resin in the prepreg is 33% by mass or more and 45% by mass or less, and the impregnation rate of the matrix resin in the fiber bundle constituting the sheet-shaped reinforcing fiber base material is 70% or more.
The prepreg of the present invention may contain a volatile component. When the prepreg contains a volatile component, the content of the volatile component in the prepreg is more than 0% by mass and 0.50% by mass or less.

The prepreg of the present invention is a so-called thick prepreg. Basis weight of the sheet-like reinforcing fiber substrate is preferably ^{400~1500g / m 2, 500~1000g / m} 2 is more preferable.
When the basis weight of the sheet-shaped reinforcing fiber base material is equal to or more than the lower limit value of the above range, it is not necessary to stack many prepregs for one molding, and it is easy to suppress time and cost. When the basis weight of the sheet-shaped reinforcing fiber base material is equal to or less than the upper limit value of the above range, handling is easy.

The above-mentioned basis weight is the mass per unit area.
The basis weight of the sheet-shaped reinforcing fiber base material in the prepreg is, for example, before preparation of a prepreg sheet, a 100 mm square cutting die is placed on the sheet-like reinforcing fiber base material, and the weight of a sample of a predetermined size is cut out. Can be measured. Alternatively, in the case of a prepreg sheet, a 100 mm square cutting die is placed on the prepreg sheet, a sample of a predetermined size is cut out, boiled in an organic solvent such as methyl ethyl ketone (MEK) or tetrahydrofuran (THF), and the matrix resin It can be measured from the weight after the removal.

The sheet-shaped fiber-reinforced substrate in the present invention is the same as the impregnated target sheet-shaped material 102 described above.
Further, as the resin composition in the matrix resin in the present invention, the thermosetting resin or the thermoplastic resin mentioned in the description of the resin sheet or the resin composition containing them can be used.

The content of the matrix resin in the prepreg of the present invention is 33% by mass or more and 45% by mass or less, preferably 35% by mass or more and 43% by mass or less, and more preferably 37% by mass or more and 41% by mass or less.
When the content of the matrix resin is at least the lower limit value of the above range, it becomes easy to suppress the generation of pinholes or blisters due to the fact that the air in the fibers cannot be completely replaced. When the content of the matrix resin is less than or equal to the upper limit value of the above range, it becomes easy to suppress the generation of voids between the layers during lamination due to the resin remaining on the surface of the prepreg.

The content of the matrix resin in the prepreg can be measured from the weight of the prepreg and the sheet-shaped reinforcing fiber base material.

The prepreg of the present invention may contain a volatile component.
However, when the prepreg of the present invention contains a volatile component, the content of the volatile component in the prepreg of the present invention is more than 0% by mass and 0.50% by mass or less, and more than 0% by mass and 0.40% by mass. Is preferred, and more preferably more than 0 mass% and 0.35 mass% or less.
For example, when the prepreg is produced by the lacquer method, the volatile component used as a solvent remains in the prepreg, but if the content of the volatile component in the prepreg is not more than the upper limit value of the above range, the problem of VOC occurs. Hard to cause.

To measure the volatile components in the prepreg, specifically immerse the prepreg cut into a predetermined size in a solvent such as MEK or acetone, and put it in an ultrasonic cleaner to extract the residual solvent (volatile components). The solution after extraction can be transferred to a vial and the amount of residual solvent (volatile component) contained in the prepreg can be quantified using gas chromatography. When the type of solvent used is unknown, the amount of components can be quantified by changing the solvent and immersing it twice or more to analyze the extracted solution.

In the prepreg of the present invention, the impregnation rate of the matrix resin in the fiber bundle constituting the sheet-shaped reinforcing fiber base material is 70% or more, preferably 80% or more, more preferably 90% or more, and further preferably 95% or more. There is no particular upper limit, but it is 100% or less.
If the impregnation rate of the matrix resin of the fiber bundle constituting the sheet-like reinforcing fiber base material is equal to or more than the lower limit value, it seems that the tow on the surface of the molded product is swollen by the air remaining inside the fiber bundle during press molding. It is easy to suppress the generation of irregularities.

The "impregnation rate of the matrix resin of the fiber bundle constituting the sheet-shaped reinforcing fiber base material" in the present invention can be measured as follows.
The prepreg is cut into 20 mm×20 mm, and the sample is photographed under the following conditions by using an X-ray CT apparatus (TDM1000H-Sμ manufactured by Yamato Scientific Co., Ltd.).
Among the obtained images, the cross-sectional image of the fiber bundle is converted into a 16-bit gray scale using image processing software (ImagePro, manufactured by Media Cybernetics). After performing the edge extraction processing, the averaging processing is performed. As shown in FIG. 11, the cross-sectional area A _{ui of} the unimpregnated portion of the fiber bundle and the area per block (A _ui +A _i +A _r ) are measured. The area (A _ui +A _i ) of the fiber bundle is measured by measuring the tow bundle area before resin impregnation, and the cross-sectional area A _{r of} the matrix resin remaining around the fiber bundle and the cross-sectional area of the impregnated portion of the fiber bundle are measured. Calculate A _i . The impregnation rate is defined by the following equation (11), and the resin residual rate around the fiber bundle is defined by the following equation (12).

In the case of a woven fabric, the minimum unit between wefts is 1 block, and for non-crimp fabrics, SMC, and GMT, 1 block is a length of 20 to 100 mm, and an average value of 10 blocks.
A _i /(A _ui +A _i )×100 (11)
A _r /(A _ui +A _i )×100 (12)

The prepreg of the present invention, the direction perpendicular to the fiber direction of any of the fiber bundle in the vertical cross section of the prepreg sheet, the cross-sectional area A _r and the fiber bundles of the matrix resin remaining in the periphery of the arbitrary fiber bundle cross The ratio represented by (A _r /A _c )×100 of the area A _c is preferably 10% or less, and more preferably 6% or less.
When the ratio represented by (A _r /A _c )×100 is less than or equal to the upper limit value of the above range, inclusion of air between the sheet layers during lamination due to the smoothness of the prepreg is unlikely to occur, and interlayer voids are formed on the surface of the molded product. It is easy to suppress the occurrence of irregularities and pinholes called.

The prepreg of the present invention preferably has an aperture ratio of 0.5% or less, and more preferably 0.3% or less, from the viewpoint of suppressing pinholes due to voids contained in the fiber bundle of the prepreg.

The aperture ratio is calculated as follows.
An image processing device (CV-100V, manufactured by Keyence Corporation) and a backlight are used. Light is emitted from a backlight so that a predetermined illuminance (18000 lux) is obtained toward a camera light receiving unit of the image processing apparatus. Stainless steel plates having different opening areas per 100 mm square are placed on a backlight, the area of the white portion of the received image is measured, and a calibration curve of the opening area and the light receiving area is created. Then, the prepreg was placed on a backlight, and an image of the transmitted light was photographed using CV-100 to calculate the total area S2 (mm ² ) of the openings per 100 mm ² of the prepreg, and the following formula was calculated. The aperture ratio X (%) is calculated from (13).
X(%)=(S2(mm ² )/100(mm ² ))×100...(13)

The cantilever value at 40° C. of the prepreg of the present invention is preferably 10 mm or more and 50 mm or less, and more preferably 20 mm or more and 40 mm or less.
When the cantilever value is equal to or higher than the lower limit value of the above range, the prepreg sheet can easily follow the molding die. If the cantilever value is less than or equal to the upper limit value of the above range, wrinkles are less likely to occur when the sheet is laminated on the mold.

The cantilever value is calculated as follows.
Three 20 mm×140 mm test pieces are taken. As shown in FIG. 13, a 50 mm edge portion of the test piece is suppressed by a metal block 13A in which the position where the test piece is sandwiched is 100 mm from the ground. The jig sandwiching the test piece 13B is provided with a wind shield so as not to be exposed to wind, and then heating is started in the oven, and waits for 30 minutes after the furnace temperature reaches the target temperature. After heating, cooling is performed, the distance between the center point at one end of the test piece 13B and the ground is read on a scale, and the cantilever value (CL) can be obtained by subtracting from the initial height of 100 mm.

The curing start temperature of the resin composition in the matrix resin contained in the prepreg of the present invention is preferably 80 to 150° C., and the viscosity (minimum viscosity) of the resin composition at the curing start temperature is 0.1 to 10 Pa. -It is preferable that it is in the range of S.
When the minimum viscosity of the resin composition in the matrix resin is within the above range, the sheet-shaped reinforcing fiber base material can be impregnated with the matrix resin in a short time.

The minimum viscosity of the resin composition and the curing start temperature of the resin composition are measured using a viscoelasticity measuring device (rheometer, "MARS 40" manufactured by Thermo Fisher Scientific Co., Ltd.) at a temperature of 2°C/min. While increasing the temperature at a speed, the plate diameter φ25 mm, the frequency 10 rad/sec, the plate interval 0.5 mm, the stress 300 Pa, the curing start temperature is the temperature when the minimum viscosity is reached. It is defined as.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

<Measurement of basis weight of sheet-shaped reinforcing fiber substrate>
A 100 mm square cutting die is placed on the reinforcing fiber sheet, a sample of a predetermined size is cut out with a cutter, and the weight is measured.

<Measurement of matrix resin impregnation rate in prepreg and content of matrix resin around fiber bundles>
The prepreg is cut into 20 mm×20 mm, and the sample is photographed under the following conditions by using an X-ray CT apparatus (TDM1000H-Sμ manufactured by Yamato Scientific Co., Ltd.).
-Tube voltage 20 kV.
-Tube current 90 μA.
・Integrated time 1 s.
・Number of views 1500 divisions/360 degrees.
-Average number of frames 4 views.

Among the obtained images, the cross-sectional image of the fiber bundle is converted into a 16-bit gray scale using image processing software (ImagePro, manufactured by Media Cybernetics). After performing the edge extraction processing, the averaging processing is performed. As shown in FIG. 11, the cross-sectional area A _{ui of} the unimpregnated portion of the fiber bundle and the area per block (A _ui +A _i +A _r ) are measured. The area (A _ui +A _i ) of the fiber bundle is measured by measuring the tow bundle area before resin impregnation, and the cross-sectional area A _{r of} the matrix resin remaining around the fiber bundle and the cross-sectional area of the impregnated portion of the fiber bundle are measured. Calculate A _i . The impregnation rate is defined by the following equation (11), and the resin residual rate around the fiber bundle is defined by the following equation (12).
In the case of a woven fabric, the minimum unit between wefts is 1 block, and for non-crimp fabrics, SMC, and GMT, 1 block is a length of 20 to 100 mm, and an average value of 10 blocks.
A _i /(A _ui +A _i )×100 (11)
A _r /(A _ui +A _i )×100 (12)

<Measurement of content of volatile components in prepreg>
The prepreg cut into a size of 15×30 mm is immersed in methyl ethyl ketone as a solvent, put in an ultrasonic cleaner to extract the residual solvent (volatile components), and the extracted solution is transferred to a vial and subjected to gas chromatography. Is used to quantify the amount of residual solvent (volatile components) contained in the prepreg. The amount of methyl ethyl ketone component is also quantified by changing the solvent to acetone and performing the same operation.

<Viscosity>
The viscosity of the matrix resin was obtained by measuring the viscoelasticity under the following conditions using a viscoelasticity measuring device (rheometer, "MARS 40" manufactured by Thermo Fisher Scientific Co., Ltd.).
Plate used: 25φ parallel plate.
Plate gap: 0.5 mm.
Measurement frequency: 10 rad/sec.
Measurement start temperature: 30°C.
Temperature rising rate: 2°C/min.
Stress: 300 Pa.

<Aperture ratio>
An image processing device (CV-100V, manufactured by Keyence Corporation) and a backlight are used. Light is emitted from a backlight so that a predetermined illuminance (18000 lux) is obtained toward a camera light receiving unit of the image processing apparatus. Stainless steel plates having different opening areas per 100 mm square are placed on a backlight, the area of the white portion of the received image is measured, and a calibration curve of the opening area and the light receiving area is created. Then, the prepreg is placed on a backlight, and an image transmitted through the prepreg is photographed using CV-100 to calculate the total area S2 (mm ² ) of the openings per 100 mm ² of the prepreg. The aperture ratio X (%) is calculated from the equation (13).
X(%)=(S2(mm ² )/100(mm ² ))×100 (13)

<Cantilever value>
Three 20 mm×140 mm test pieces are taken. As shown in FIG. 13, a 50 mm edge portion of the test piece is suppressed by a metal block 13A in which the position where the test piece is sandwiched is 100 mm from the ground. The jig sandwiching the test piece 13B is provided with a wind shield so as not to be exposed to wind, and then heating is started in the oven, and waits for 30 minutes after the furnace temperature reaches the target temperature. After heating, cooling is performed, the distance between the center point at one end of the test piece 13B and the ground is read on a scale, and the initial height of 100 mm is subtracted to obtain the cantilever value (CL).

<Judgment of resin flow, weight of residual resin>
The resin flow was judged by visually observing whether the resin was flowing out from the end of the sample when passing through the press roll.
Further, the test laminate is cut into 10 cm×10 cm, the mass per unit area of the test laminate 126 is determined, and the release paper and the reinforcing fiber sheet are calculated from the mass per unit area of the test laminate 126 after pressing. The residual resin areal weight of the test laminate was measured after pressing with a press roll by subtracting the total mass of the polyethylene film per unit area.

<Creation of matrix resin 1>
The resin composition shown below was uniformly mixed and used as the matrix resin 1.
A: 25 parts by mass of bisphenol A type epoxy resin (epoxy equivalent 189 g/eq, manufactured by Mitsubishi Chemical Corporation, trade name: jER828).
B: 2-phenyl-4-methyl-5-hydroxymethylimidazole (manufactured by Shikoku Chemicals Co., Ltd., trade name: 2P4MHZ-PW) 1 part by mass.
-C: 2-phenyl-4,5-dihydroxymethyl imidazole (Shikoku Chemicals Co., Ltd. make, brand name: 2PHZ-PW) 8.7 parts by mass.
D: A and a reaction product of 4,4'-diaminodiphenyl sulfone [A and 4,4'-diaminodiphenyl sulfone (Wakayama Seikagyo Co., Ltd., trade name: Seika Cure S) /4,4'-Diaminodiphenylsulfone = 100/9 in a mass ratio, and then mixed and heated at 150°C to obtain a reaction product. It is a mixture whose main component is a reaction product of an epoxy resin and an amine compound having at least one sulfur atom in the molecule (epoxy equivalent of 266 g/eq). ] 75 parts by mass.

The matrix resin 1 was uniformly applied to a release paper with a predetermined resin weight to prepare a resin film. A test laminate in which the resin film was attached to a reinforcing fiber sheet base material was prepared as follows.

(Example A1)
As an experimental device, as shown in FIG. 12, a rubber roll 12A (material: ethylene-propylene-diene rubber, hardness: 80 degrees, diameter: 200 mm) and a metal roll 12B (material: stainless steel, diameter) disposed opposite to the rubber roll 12A. : 200 mm) and a plate heater 12C provided on the upstream side of the rubber roll 12A and the metal roll 12B. As the rubber roll 12A, a pattern roll in which a rhombus pattern was engraved was used.

As a sheet-shaped material to be impregnated, a release paper 12D, a lower resin layer 12E, a sheet-shaped reinforcing fiber base 12F, an upper resin layer 12G, and a polyethylene film 12H were stacked in this order from the bottom to obtain a test laminate 12I.
Carbon fiber cloth TRK510 (fiber basis weight 646 g/m ² , 2/2 twill) manufactured by Mitsubishi Chemical Corporation was used for the sheet-shaped reinforcing fiber base material 12F. As the resin film, both of the lower resin layer 12E and the upper resin layer 12G used were those obtained by coating the matrix resin 1 with a resin areal weight of 216 g/m ² (total resin areal weight: 432 g/m ² ).

After heating the laminated body 12I to a predetermined temperature on the plate heater 12C, the moving speed is 2.5 m/min, the matrix resin viscosity is 3 Pa·s, and the linear pressure per convex portion of the concavo-convex pattern is 20 N/mm. Then, the rubber roll 12A and the metal roll 12B were repeatedly passed until a predetermined number of times was reached.

The obtained prepreg is cut into 300 mm×300 mm, put into a 300 mm square flat plate mold, and the film laminate (F) is subjected to a surface pressure of 7.2 MPa, a mold temperature of 140° C., and a molding time of 5 minutes. Was press-molded to obtain a fiber-reinforced plastic molded body (also referred to as “molded plate”).

Each rubber roll shown in Table 1 was used as the rubber roll for passing the laminated body 12I a predetermined number of times, and the laminated body 12I was passed through the combination of the numbers of times shown in Table 2.

(Examples A2 to A4)
Using each rubber roll shown in Table 1, a prepreg was produced in the same manner as in Example A1 except that the laminate 12I was passed through the combination of the numbers of times shown in Table 2 to give a fiber-reinforced plastic molded body. Obtained.

(Example A5)
The same as Example A1 except that carbon fiber cloth TRK501 (fiber basis weight 400 g/m ² , 2/2 twill) manufactured by Mitsubishi Chemical was used as the sheet-like reinforcing fiber base material and the resin basis weight was changed as shown in Table 2. A prepreg was produced by the method to obtain a fiber-reinforced plastic molded body.

(Example A6)
Mitsubishi Chemical's carbon fiber bundle TR50S15L is cut with a cutting machine to make a chopped fiber bundle with an average fiber length of 25.4 mm, which is sprinkled on a resin film so that the average fiber basis weight is 646 g/m ² and is a sheet. A prepreg was produced in the same manner as in Example A1 except that the fiber-reinforced plastic base material was used to obtain a fiber-reinforced plastic molded body.

(Example A7)
A method similar to that of Example A1 except that two unidirectional woven fabrics TRK976PQRW (fiber basis weight 317 g/m ² ) manufactured by Mitsubishi Chemical Corporation were stacked to form a sheet-like reinforcing fiber base material and the resin basis weight was changed as shown in Table 2. Then, a prepreg was produced to obtain a fiber-reinforced plastic molded body.

(Comparative Example A1)
As a rubber roll, a prepreg was prepared in the same manner as in Example A1 except that only one type of pattern roll (roll 45A) having a rhombic pattern engraved and an area ratio of convex portions of 45% was used, and a fiber was prepared. A reinforced plastic molding was obtained.

(Comparative Example A2)
A prepreg was produced in the same manner as in Example A1 except that a flat rubber roll (roll 100) without a pattern was used as the rubber roll to obtain a fiber-reinforced plastic molded body.

(Comparative Example A3)
A matrix resin was prepared by uniformly mixing the resin components shown below, and the resin viscosity at each temperature was measured to be 16 Pa·s at 60° C. and 5 Pa·s at 70° C.
-A: 40 parts by mass of jER828 (manufactured by Mitsubishi Chemical Corporation).
B: 40 parts by mass of jER1001 (manufactured by Mitsubishi Chemical Corporation).
C: 20 parts by mass of Epicron N740 (manufactured by DIC Corporation).
-D: DICY7 (manufactured by Mitsubishi Chemical Corporation) 5 parts by mass.
E: 5 parts by mass of DCMU99 (manufactured by Hodogaya Chemical Co., Ltd.).

A prepreg was produced in the same manner as in Example A1 except that the temperature was changed so that the resin viscosity of the matrix resin 1 was 5 Pa·s and the flat rubber roll was used to obtain a fiber-reinforced plastic molded body. ..

(Comparative Example A4)
A prepreg was produced in the same manner as in Comparative Example A3, except that the temperature was changed so that the resin viscosity of the matrix resin 1 was 16 Pa·s, to obtain a fiber-reinforced plastic molded body.

(Comparative Example A5)
A prepreg was produced in the same manner as in Comparative Example A1 except that the temperature was changed so that the resin viscosity of the matrix resin 1 was 66 Pa·s, to obtain a fiber-reinforced plastic molded body.

(Comparative Example A6)
A carbon fiber cloth TRK501 (fiber basis weight 400 g/m ² , 2/2 twill weave) manufactured by Mitsubishi Chemical Corporation was used as the fiber reinforced sheet, and the resin basis weight was changed as shown in Table 2, except that the resin basis weight was changed as in Comparative Example A1. Then, a prepreg was produced to obtain a fiber-reinforced plastic molded body.

Table 3 shows the evaluation results of the obtained prepreg and molded plate.
In all cases, no volatile component was detected in the obtained prepreg.

The symbols and the like in the table have the following meanings.
Matrix resin impregnation ratio: impregnation rate of the matrix resin of the fiber bundles constituting the sheet-like reinforcing fiber substrate _{(A i / (A ui +} A i) × 100).
-Residual resin amount: residual resin ratio around the fiber bundle (A _r /(A _ui +A _i )×100).
Resin flow: Presence or absence of resin flow by visual inspection. ◯ indicates that the resin did not flow out from the prepreg end after pressing, and x indicates that the resin flowed out from the prepreg end after pressing.
-Pinhole: Presence or absence of a pinhole visually. ◯ indicates that the molded product with choking was visually observed and no pinhole was observed, and Δ indicates that the molded product with choking was visually observed and that there were 1 to 5 pinholes.
・Interlayer voids: Presence or absence of visual interlayer voids. ◯ indicates visually that there is no bulge larger than the fiber bundle on the surface of the molded product, and × indicates that there is one or more bulge larger than the fiber bundle on the surface of the molded product visually.
-Tofu-kure: Presence or absence of visual tofu-kure. ∘ indicates visually that there is no bulge along the fiber bundle on the surface of the molded product, and × indicates visually that there is one or more bulge along the fiber bundle on the surface of the molded product.
-Resin death: Presence or absence of resin death by visual inspection. ◯ indicates that the resin on the fiber bundle existing on the surface of the molded product is not thinned and the hue is not different from the surroundings, and × indicates that the resin on the fiber bundle existing on the surface of the molded product becomes thin visually, Indicates that the shade is different from the surroundings.
The blank column indicates that the evaluation is not performed.

<Measurement of resin capture amount>
The relationship between the width of the concave portion and the area of the concave portion in the concave-convex press roll and the amount of resin captured by the concave-convex press roll was examined.

(Experimental Examples 1-10)
Front-side resin capture amount:
As an experimental apparatus, as shown in FIG. 7, a flat press roll 40 (material: ethylene-propylene-diene rubber, hardness: 80 degrees, diameter: 200 mm), and a flat metal roll 42 (opposed to the flat press roll 40 ( (Material: stainless steel, diameter: 200 mm), and a plate heater 44 provided on the upstream side of the flat press roll 40 and the flat metal roll 42 were used.

As shown in FIG. 7, in order from the bottom, release paper 114 (mass per unit area: 105 g/m ² ); lower resin layer 116 (epoxy resin, viscosity at 90° C.: 3 Pa·s, mass per unit area) : 216 g/m ² ); carbon fiber woven fabric 118 (twill weave, mass per unit area: 646 g/m ² ); polyethylene film 120 (mass per unit area: 16 g/m ² ); upper resin layer 122 (epoxy resin, Viscosity at 90° C.: 3 Pa·s, mass per unit area: 432 g/m ² ); and polyethylene film 124 (mass per unit area: 16 g/m ² ) were stacked to form a test laminate 126.
An uneven pattern plate 46 (material: acrylonitrile-butadiene-styrene resin, total thickness: 4 mm, concave depth: 3 mm) having the uneven pattern shown in FIG. 2 formed on the lower surface was placed on the test laminate 126. Layered further.

After heating the test laminate 126 to 90° C. on the plate heater 44, the flat press roll 40 and the flat metal roll 42 are moved together with the uneven pattern plate 46 at a moving speed of 2.5 m/min and a linear pressure of 9.4 N/mm. I passed between
At this time, the resin does not flow out from the lower resin layer 116 in contact with the carbon fiber woven fabric 118, but cannot be captured by the uneven pattern plate 46 from the upper resin layer 122 sandwiched between the polyethylene film 120 and the polyethylene film 124. Resin flows out.

The uneven pattern plate 46 was removed from the test laminate 126, the test laminate 126 was cut into 10 cm×10 cm, and the mass per unit area of the test laminate 126 was determined. From the mass per unit area of the test laminate 126 after pressing, the total mass per unit area of the release paper 114, the lower resin layer 116, the carbon fiber woven fabric 118, the polyethylene film 120 and the polyethylene film 124 (999 g/m 2). ² ) was subtracted to obtain the mass per unit area of the upper resin layer 122 remaining in the test laminate 126 without the resin flowing, and this was taken as the front surface side resin capture amount.

The same experiment was repeated while changing the area ratio A of the concave portions and the width W of the concave portions in the concave/convex pattern of the concave/convex pattern plate 46 as shown in Table 4.
The relationship between the index X, which is represented by the product of the area A of the recessed portion and the width W of the recessed portion, and the amount of resin trapped on the front surface side by the uneven pattern plate 46 is plotted. As shown in FIG. A correlation was found between 0 and 4.

(Experimental examples 11 to 20)
Backside resin capture amount:
As an experimental apparatus, as shown in FIG. 8, a flat press roll 40 (material: ethylene-propylene-diene rubber, hardness: 80 degrees, diameter: 200 mm), and a flat metal roll 42 (opposite to the flat press roll 40 ( (Material: stainless steel, diameter: 200 mm), and a plate heater 44 provided on the upstream side of the flat press roll 40 and the flat metal roll 42 were used.

As shown in FIG. 8, in order from the bottom, the release paper 114 (mass per unit area: 105 g/m ² ); the lower resin layer 116 (epoxy resin, viscosity at 90° C.: 3 Pa·s, mass per unit area) : 432 g/m ² ); polyethylene film 120 (mass per unit area: 16 g/m ² ); carbon fiber woven fabric 118 (twill weave, mass per unit area: 646 g/m ² ); upper resin layer 122 (epoxy resin, Viscosity at 90° C.: 3 Pa·s, mass per unit area: 216 g/m ² ); and polyethylene film 124 (mass per unit area: 16 g/m ² ) were stacked to form a test laminate 128.
An uneven pattern plate 46 (material: acrylonitrile-butadiene-styrene resin, total thickness: 4 mm, recess depth: 3 mm) having the uneven pattern shown in FIG. Layered further.

After heating the test laminate 128 to 90° C. on the plate heater 44, the flat press roll 40 and the flat metal roll 42 are moved together with the uneven pattern plate 46 at a moving speed of 2.5 m/min and a linear pressure of 9.4 N/mm. I passed between
At this time, the resin does not flow out from the upper resin layer 122 in contact with the carbon fiber woven fabric 118, but cannot be captured by the uneven pattern plate 46 from the lower resin layer 116 sandwiched between the release paper 114 and the polyethylene film 120. Resin flows out.

The uneven pattern plate 46 was removed from the test laminate 128, the test laminate 128 was cut into 10 cm×10 cm, and the mass per unit area of the test laminate 128 was determined. From the mass per unit area of the test laminate 126 after pressing, the total mass per unit area of the release paper 114, the polyethylene film 120, the carbon fiber woven fabric 118, the upper resin layer 122, and the polyethylene film 124 (999 g/m ² ), the mass per unit area of the lower resin layer 116 remaining in the test laminate 128 without flowing the resin was determined, and this was taken as the backside resin trapped amount.

The same experiment was repeated while changing the ratio A of the area of the concave portion and the width W of the concave portion in the concave-convex pattern of the concave-convex pattern plate 46 as shown in Table 5.
A graph showing the relationship between the index X represented by the product of the area ratio A of the recessed portion and the width W of the recessed portion and the amount of resin trapped on the back surface side by the concavo-convex pattern plate 46 shows that X is as shown in FIG. A correlation was found between 0 and 6.

<Manufacture of prepreg>
(Example 1)
As an apparatus for manufacturing a prepreg, as shown in FIG. 10, a concavo-convex press roll 24 (material: ethylene-propylene-diene rubber, hardness: 80 degrees, diameter: 200 mm) and a flat metal roll arranged opposite to the concavo-convex press roll 24. 42 (material: stainless steel, diameter: 200 mm) and a plate heater 44 provided on the upstream side of the uneven press roll 24 and the flat metal roll 42 were used. In the concavo-convex pattern of the concavo-convex press roll 24, the ratio A of the concave area, the concave width W, the index X, the convex minor axis length a, the convex major axis length b, the concave depth D, and D/W are shown. 6 shows.

As shown in FIG. 10, in order from the bottom, release paper 114; lower resin layer 116 (epoxy resin, viscosity at 90° C.: 3 Pa·s, mass per unit area: 216 g/m ² ); carbon fiber fabric 118 ( Twill weave, mass per unit area: 646 g/m ² ); upper resin layer 122 (epoxy resin, viscosity at 90° C.: 3 Pa·s, mass per unit area: 216 g/m ² ); polyethylene film 124 stacked and laminated Body 108.

The laminate 108 was heated to 90° C. on the plate heater 44, and then passed between the uneven press roll 24 and the flat metal roll 42 at a moving speed of 2.5 m/min and a linear pressure of 9.4 N/mm. After passing the laminated body 108 a total of three times between the same concavo-convex press roll 24 and the flat metal roll 42, the concavo-convex press roll 24 was replaced with the latter concavo-convex press roll 24 shown in Table 3 to form the laminated body 108. The prepreg was obtained by passing the rugged press roll 24 and the flat metal roll 42 a total of three times.

(Examples 2 to 4, Comparative Examples 1 to 4)
The concavo-convex pattern of the concavo-convex press roll 24 was changed to those shown in Tables 6 and 7, and the number of presses when using the concavo-convex press rolls 24 in the first half and the second half (or the initial stage, the middle stage, and the final stage) is shown in Table 6 and Table. A prepreg was obtained in the same manner as in Example 1 except that the number of times shown in 7 was changed.

<Evaluation>
(Resin flow)
The prepreg was cut into 10 cm×10 cm, and the mass per unit area of the prepreg was determined. If the amount of decrease in mass per unit area of the prepreg from the mass per unit area of the laminated body 108 before pressing was 5 g/m ² or less, it was evaluated as ◯, and if the amount of decrease was more than 5 g/m ² , it was evaluated as ×. .. The results are shown in Tables 6 and 7.

(Impregnating property)
The prepreg was cut into 3 cm×3 cm with a razor blade, and the cross section of the prepreg was observed at a magnification of 200 times using a microscope (VHX-5000 manufactured by Keyence Corporation). Ten carbon fiber warps and ten wefts of the prepreg were observed and evaluated as ◯ if there was no resin-impregnated portion and as × if there was no resin-impregnated portion. The results are shown in Tables 6 and 7.

In Comparative Example 1, since the same concavo-convex press roll 24 was used in all the presses, resin flow occurred.
In Comparative Example 2, since the concavo-convex press roll 24 having a larger X in the second half than in the first half was used, impregnation of the carbon fiber woven fabric with the resin was insufficient.
In Comparative Example 3, X of the uneven press roll 24 in the latter half was too small, so that resin flow occurred.
In Comparative Example 4, the X of the uneven press roll 24 in the first half was too large, the carbon fiber woven fabric was not uniformly impregnated with the resin, and resin flow occurred.

INDUSTRIAL APPLICABILITY The method for producing a resin-impregnated product and the apparatus for producing a resin-impregnated product according to the present invention are useful for producing a resin-impregnated product such as a prepreg.

10 Resin impregnated product manufacturing equipment,
11 Sheet-like material supply roll for impregnation,
11A fabric,
11B resin,
12 first resin sheet supply roll,
12A rubber roll,
12B metal roll,
12C plate heater,
12D release paper,
12E lower resin layer,
12F sheet-shaped reinforcing fiber base material,
12G upper resin layer,
12H polyethylene film,
12I test stack,
13 second resin sheet supply roll,
13A block 13B test piece 14 guide roll,
15 guide rolls,
16 guide rolls,
17 peeling roll,
18 sheet-shaped carrier winding roll,
20 Top film supply roll,
22 guide rolls,
23 heating plate,
24 uneven press roll,
26 heating rolls,
27 cooling plate,
28 peeling rolls,
30 Top film winding roll,
31 Top film supply roll,
32 guide rolls,
33 guide rolls,
34 resin impregnated material winding roll,
36 convex part,
38 recess,
40 flat press rolls,
42 flat metal roll,
44 plate heater,
46 uneven pattern board,
102 sheet material to be impregnated,
104 first resin sheet,
106 second resin sheet,
107 sheet carrier,
108 laminated body,
110 resin impregnation,
112 top film,
113 top film,
114 release paper,
116 lower resin layer,
118 carbon fiber fabric,
120 polyethylene film,
122 upper resin layer,
124 polyethylene film,
126 test laminate,
128 test laminate,
a short axis length of convex part,
b Long axis length of convex part,
c Distance between convex parts,
d the depth of the recess,
A Area ratio of the recess,
D depth of recess,
W recess width,
X index.

Claims (14)

A prepreg containing a sheet-like reinforcing fiber base material containing a fiber bundle of reinforcing fibers, and a matrix resin containing a resin composition,
The sheet-shaped reinforcing fiber substrate is a woven fabric, a sheet molding compound, or a non-crimp fabric,
The sheet-shaped reinforcing fiber base material has a basis weight of 400 g/m ² or more,
The content of the matrix resin in the prepreg is 33% by mass or more and 45% by mass or less,
The prepreg may contain a volatile component, and when the prepreg contains a volatile component, the content of the volatile component in the prepreg is more than 0% by mass and 0.50% by mass or less,
A prepreg having an impregnation ratio of the matrix resin of the fiber bundle constituting the sheet-shaped reinforcing fiber base material of 70% or more. In the vertical cross section of the prepreg in the direction orthogonal to the fiber direction of the arbitrary fiber bundle, the cross-sectional area A _{r of the} matrix resin remaining around the arbitrary fiber bundle and the cross-sectional area A _c of the arbitrary fiber bundle are The prepreg according to claim 1, wherein the ratio represented by (A _r /A _c )×100 is 10% or less. The prepreg according to claim 1 or 2, wherein the basis weight of the sheet-shaped reinforcing fiber base material is 400 g/m ² or more and 1500 g/m ² or less. The prepreg according to any one of claims 1 to 3, which has an opening ratio of 0.5% or less. The prepreg according to any one of claims 1 to 4, which has a cantilever value at 40°C of 10 mm or more and 50 mm or less. The curing start temperature of the resin composition is 80 to 150° C., and the viscosity (minimum viscosity) at the curing start temperature is 0.1 to 10 Pa·S. Prepreg. The prepreg according to claim 1, wherein the resin composition is an epoxy resin composition. The prepreg according to claim 1, wherein the reinforcing fibers are carbon fibers. The laminate in which the sheet material to be impregnated and the resin layer are stacked, is impregnated with the resin by impregnating the sheet material to be impregnated by passing it between a press roll and an opposing roll arranged to face the press roll. A method for producing a resin impregnated product,
The laminate, after passing between the press roll and the counter roll, by passing between the press roll and the counter roll that is the same as or different from the preceding stage, between the press roll and the counter roll Pass m times in total (where m is an integer of 2 or more),
The press roll is a concavo-convex press roll having a plurality of convex portions on the outer peripheral surface and continuous concave portions formed between the convex portions, and which is a concavo-convex press roll satisfying the following condition (α). Method.
<Condition (α)>
Wherein the X _a determined from the following equation (1) uneven press roll for passing the laminate a time, and X _b obtained from the following equation for the irregularities press roll (1) passing said laminate b-th time , A and b satisfy the relationship of the following formula (2). However, a and b are integers of 1≦a<b≦m.
X _a >X _b (2)
X _i =A _i ×W _i (1)
However, i is an integer of 1 to m, A _i is the ratio of the area of the recess in the region where the projection and the recess are formed, and W _i is the width (mm) of the recess. The method for producing a resin-impregnated product according to claim 9, wherein X _i obtained from the formula (1) is 0.5 to 6. The method for producing a resin-impregnated product according to claim 9 or 10, wherein the uneven press roll further satisfies the following condition (β).
<Condition (β)>
The depths D of the recesses obtained by measuring the depths of 20 recesses randomly selected from the region and averaging them and the width W of the recesses are expressed by the following equation (3). Be satisfied.
D≧W×0.35 (3) The laminate in which the sheet material to be impregnated and the resin layer are stacked, is impregnated with the resin by impregnating the sheet material to be impregnated by passing it between a press roll and an opposing roll arranged to face the press roll. A device for manufacturing resin impregnated products,
M (where m is an integer of 2 or more) press rolls arranged at intervals in the moving direction of the laminate, and counter rolls that are arranged to face the press rolls,
The press roll is a concavo-convex press roll having a plurality of convex portions on the outer peripheral surface and continuous concave portions formed between the convex portions, and which is a concavo-convex press roll satisfying the following condition (α). apparatus.
<Condition (α)>
X _a obtained from the following formula (1) for the _a-th unevenness press roll from the most upstream side in the moving direction of the laminate and the above-mentioned formula for the b-th unevenness press roll from the most upstream side in the moving direction of the laminate. There are a and b that satisfy the relationship of the following formula (2) with _Xb obtained from (1). However, a and b are integers of 1≦a<b≦m.
X _a >X _b (2)
X _i =A _i ×W _i (1)
However, i is an integer of 1 to m, A _i is the ratio of the area of the recess in the region where the projection and the recess are formed, and W _i is the width (mm) of the recess. The apparatus for producing a resin-impregnated product according to claim 12, wherein X _i obtained from the formula (1) is 0.5 to 6. The resin-impregnated material manufacturing apparatus according to claim 12 or 13, wherein the uneven press roll further satisfies the following condition (β).
<Condition (β)>
The depths D of the recesses obtained by measuring the depths of 20 recesses randomly selected from the region and averaging them and the width W of the recesses are expressed by the following equation (3). Be satisfied.
D≧W×0.35 (3)

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