JP3535779B2 - Sheet molding compound - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet molding compound (hereinafter referred to as SMC) in which a molded product has high strength and excellent strength uniformity.

[0002]

2. Description of the Related Art Generally, SMC is a thermosetting resin composition, which is a relatively short glass fiber cut product having a length of usually 80 mm or less, most often around 25 mm, that is, a glass chopped strand. (Hereinafter referred to as CS)
Is a sheet-shaped molding material that contains as a reinforcing material and is thickened, and a molded product can be obtained simply by cutting it into a desired size, placing it in the mold of a press molding machine, and applying pressure and heat. is there.

However, the SMC containing the above CS
In the case of a molded product obtained by molding, the strength of the molded product is insufficient to be applied particularly as a structural member typified by water tank panels, casings, automobile parts, housings, etc. In order to obtain a molded product having a sufficient strength applicable even in, SMC (hereinafter, referred to as L-SMC) using a long glass fiber or a continuous glass fiber as a reinforcing material is known. There is.

For example, Japanese Unexamined Patent Publication No. 9-155861 discloses an L-SMC in which glass fibers having a length of 500 to 4000 mm as a reinforcing material are dispersed in a spiral non-direction. In the publication, L-SMC in which continuous glass fibers as a reinforcing material are non-directionally dispersed is disclosed.
Is disclosed.

Also known is L-SMC, which is a combination of CS as a reinforcing material and a long glass fiber or a continuous glass fiber having a relatively long length.
In Japanese Patent No. 24726, relatively long glass fibers having a length of 80 mm or more (preferably 120 to 2000 mm) and CS having a length of 10 to 50 mm are used as a reinforcing material in L-.
SMC is disclosed, and JP-A-5-301220 discloses L-SMC in which continuous glass fibers and CS having a length of 12 to 50 mm are used together as a reinforcing material.

[0006]

SM including L-SMC
C is generally continuously produced by the following method (see FIG. 1). That is, the thermosetting resin composition is applied to one of the two thermoplastic resin films to form a resin layer, and glass fibers serving as a reinforcing material are dispersed on the resin layer to form a reinforcing material layer. . Further, the thermosetting resin composition is applied to the other thermoplastic resin film to form a resin layer, and then the two resin layers are laminated so that the reinforcing material layer is sandwiched. Subsequently, the thermosetting resin composition is impregnated into the reinforcing material by narrowing the pressure using a roll pressing device or a belt pressing device, and after winding a predetermined amount or folding and then packaging, a predetermined time After aging, the thermosetting resin composition is thickened to obtain SMC.

In the above manufacturing method, in the case of SMC using CS as a reinforcing material, since the length of the glass fiber is relatively short, the amount of CS dispersed on the resin layer is SMC. Easy to control so that it is uniform over the entire width. However, in the case of L-SMC, since the length of the glass fiber is long, the edges of the resin layer and the edges of the reinforcing material layer are made to coincide with each other at both end portions in the width direction so that the content of the reinforcing material is increased. It is difficult to control so as to match with the central portion in the width direction. Therefore, the reinforcing material may protrude from the edge of the resin layer, or conversely, the amount of the reinforcing material sprayed may decrease and the L-SMC may be reduced.
In many cases, a portion having a high ratio of the thermosetting resin composition (having a low content of the reinforcing material) was formed at both end portions of the. In the latter case, specifically, as shown in FIG. 4, when the width of the L-SMC is 1000 mm, the width of the width of the L-SMC is 2 from the both ends to the inside.
In the width in the range up to around 00 mm, the content of the reinforcing material tended to gradually decrease from the normal value in the central portion in the width direction from the center side to both ends.

In the L-SMC in which the reinforcing material protrudes from the edge of the resin layer as described above, it is necessary to cut off the portion where the reinforcing material protrudes during molding, and therefore the work is complicated. At the same time, there has been a problem that the yield of products is lowered. On the other hand, in L-SMC in which both end portions have a low content of the reinforcing material, minute cracks (hair cracks) occur at the ends (peripheral portions) of the molded product obtained by molding, and the strength of the molded product is increased. There was a problem that the appearance was damaged.

Further, if the weight (thickness) per unit area of the L-SMC is reduced, the difference in the reinforcing material content between the central portion and both end portions in the width direction is also reduced (the degree of decrease in the content rate is (Becomes smaller), it is possible to suppress the occurrence of hair racks in the molded product. However, if the unit area weight of the L-SMC is reduced, a larger number of L-SMCs must be loaded into the mold at the time of molding, which significantly impairs workability and productivity during molding. Will occur.

Further, even in the case of L-SMC in which both CS as a reinforcing material and long glass fiber or continuous glass fiber having a relatively long length are used in combination, the same problem as described above cannot be avoided. In addition, if the content of the reinforcing material (glass fiber) that is low at both ends is made to be the same value as the content of the regular reinforcing material in the central part, and the amount of CS is spread over the entire width of the L-SMC, In the central portion, the content of the reinforcing material becomes too high, and it becomes difficult to impregnate the glass fiber with the resin composition, and there is a problem that the strength of the obtained molded article is lowered or the appearance is deteriorated. .

L-SM in which CS and long glass fibers are used in combination
In C, it may be possible to reduce the content of the reinforcing material (glass fiber) as a whole in order to increase the degree of impregnation of the resin composition into the glass fiber. Since the strength is reduced, it cannot be a practical countermeasure. Therefore, it is an object of the present invention that, in the SMC, there is no protrusion of the reinforcing material in the width direction, and the content ratio of the reinforcing material is substantially the same in the width direction of the SMC, and defects such as cracks occur. It is an object of the present invention to provide an SMC that gives molded articles having excellent strength and strength uniformity.

[0012]

The present invention is an SMC obtained by blending a thermosetting resin composition with glass fiber as a reinforcing material and increasing the viscosity, and the length is 50 over the entire width of the SMC.
When long glass fibers or continuous glass fibers of 0 to 4000 mm are dispersed in a non-directional manner and the total width of the SMC is X mm, the widthwise end portions have 0.0 mm inward from the edges.
The width is in the range of 5 × Xmm to 0.3 × Xmm, and the length is
Provided is an SMC characterized in that short glass fibers of 5 to 100 mm are dispersed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to preferred embodiments. The SMC of the present invention is shown in FIG.
As shown in FIG. 2, which is an enlarged cross-sectional view in the width direction of the portion,
Between the upper and lower resin layers, glass long fibers or continuous glass fibers 22 and glass short fibers 21 which are reinforcing materials are contained in a sandwich structure. Further, as shown in FIG. 3 which is an enlarged plan view of the B part in FIG. 1, the glass long fibers or continuous glass fibers 32 are dispersed in the non-direction over the entire width of the SMC, and the glass is provided at both ends in the width direction. Short fiber 31
Are dispersed so that the glass fiber content is substantially the same over the entire width of the SMC.

It should be noted that FIGS. 2 and 3 are drawn so that long glass fibers or continuous glass fibers do not exist at both ends in the width direction of the SMC for easy understanding, but in reality, , Long glass fiber or continuous glass fiber,
Since these fibers are dispersed so as not to protrude from the both edges of the SMC, long glass fibers or continuous glass fibers are present at both ends of the SMC at a certain content ratio.

Further, in the above description, "substantially the same" means that even if there is a difference in the glass fiber content, it is acceptable as long as the SMC is molded and the object of the present invention is achieved. It means that specifically, the total content of glass fibers at both ends is "content of glass fiber in the central part ± 15% by weight,
The range is preferably ± 10% by weight. For example, SM
The glass fiber content in the center portion of the width direction of C is 40% by weight.
If so, the total content of the glass fibers at both ends of the SMC may be 25 to 55% by weight, preferably 30 to 50% by weight. Here, the "total content rate" of the glass fibers at both ends means the content rate of both the glass long fibers or continuous glass fibers and the glass short fibers.

The present invention will be described in more detail below with reference to the materials used and the manufacturing method. The thermosetting resin composition used in the present invention is a thermosetting resin in which a filler and other additives are blended as necessary, and the thermosetting resin used in the conventionally known SMC is used. It is similar to the resin composition. For example, as the thermosetting resin, unsaturated polyester resin, vinyl ester resin, phenol resin, epoxy resin and the like are used, but unsaturated polyester resin and vinyl ester resin are preferably used. Monomer components such as styrene are usually added to these thermosetting resins, and if necessary, non-reactive thermoplastic resins such as polystyrene are added, and the final composition becomes a paste. ing.

As the filler, various fillers are mixed and used in various proportions depending on the intended use, but the usual mixing proportion is 200 parts by weight or less relative to 100 parts by weight of the thermosetting resin.
As the filler, for example, calcium carbonate, aluminum hydroxide, glass fine powder, glass balloon, etc. are used, but usually calcium carbonate, aluminum hydroxide are used. Furthermore, in the thermosetting resin composition, if necessary, a polymerization initiator, a release agent, a colorant, a low-shrinking agent, a thickener and other known additives can be appropriately contained. Are mixed and used according to a conventional method.

In the present invention, the glass fiber used as the reinforcing material is obtained by bundling a large number of filaments having a filament diameter of 6 to 16 μm and has a count of 500 to 5
A glass fiber having a weight of 000 g / km (Tex) is preferably used. That is, when the filament diameter is less than 6 μm, the productivity of the glass fiber itself is low and the cost becomes high, which is not realistic. On the other hand, when it exceeds 16 μm, the specific surface area of the filament is reduced, the contact area with the thermosetting resin is reduced, and the strength of the molded product may be reduced.

The glass fiber count is 500 g / km.
If less than the above, a large number of glass fibers are required to obtain the glass fiber content required for SMC, and the layer of the reinforcing material dispersed with glass fibers becomes bulky, resulting in a thermosetting resin composition. Impregnation of the product becomes difficult, and an unimpregnated portion is generated, and this portion may cause internal peeling after pressure molding, so that the strength of the molded product is likely to be adversely affected. On the other hand, when the count is more than 5000 g / km, the glass fibers are too thick and the distribution of the glass fibers in the SMC tends to be non-uniform, and in this case also, the strength of the molded product tends to be non-uniform.

In the present invention, as shown schematically in FIGS. 2 and 3, the glass fibers having different lengths as described above are used.
Seed glass fibers 21 and 31, and 22 and 3
2 is used. The glass fibers to be dispersed over the entire width of the SMC 23, 33 are long glass fibers of 500 to 4000 mm or continuous glass fibers (glass fibers that are continuous, not cut). The length of this long glass fiber is 50
When it is less than 0 mm, it is difficult to uniformly disperse the glass long fibers in the SMC in a non-directional manner, and 4000
If it exceeds mm, the cutting device becomes large in size, which is not realistic. If it is continuous glass fiber,
Continuous glass fibers can be uniformly dispersed in a non-directional manner without using a cutting device.

The glass short fibers used in the present invention have a length of 5 to 5.
It is 100 mm, preferably 25 to 50 mm.
When the length is less than 5 mm, the strength of the parts of the molded product corresponding to both ends of the SMC locally becomes weak. On the other hand, 1
When it exceeds 00 mm, it becomes difficult to control the spraying state so that the edge of the resin layer and the edge of the reinforcing material layer are aligned with each other.

The content ratio of the long glass fiber or continuous glass fiber (A) and short glass fiber (B) to SMC is preferably 20 to 60% by weight based on the weight of the entire SMC as the whole glass fiber, It is more preferably 25 to 40% by weight. The glass fiber content is S
If it is less than 20% by weight with respect to the MC, a molded product having a desired strength cannot be obtained, and if it exceeds 60% by weight, it is difficult to impregnate the glass fiber with the thermosetting resin composition during the production of SMC. After pressure molding at the impregnated portion, the molded product may be peeled off internally, which may adversely affect the strength of the molded product, which is not practical.

The weight ratio of the glass long fibers or continuous glass fibers A to the glass short fibers B is A: B = 60 to 95:40, where 100 parts by weight of the entire glass fibers at both widthwise ends of the SMC are used. ~ 5, preferably 50-8
It is 0:50 to 20 and, as described above, it is preferable that the content ratio of the glass fiber is made to be substantially the same over the entire width of the SMC. Depending on the width to be sprayed, if the ratio of the long glass fibers or the continuous glass fibers A is too high, the long glass fibers or the continuous glass fibers A may protrude from the edge of the obtained SMC in the width direction, or the long glass fibers in the center part. Alternatively, the content rate of the continuous glass fiber A becomes too high, and the subsequent processing is complicated, or the glass fiber content rate at the width direction end portion is relatively decreased, and the content rate of the glass fiber is averaged over the entire width. Difficult to do. On the other hand, when the ratio of the long glass fibers or the continuous glass fibers A is too low, the strength of the molded product is not improved so much.

As shown in FIGS. 2 and 3, the SM
When the total width of C is X mm (for example, 1000 mm),
The width Y of both ends in the width direction in which the glass short fibers B are mixed is
Inward from the edge Y = 0.05 × Xmm to 0.3 × Xm
a width in the range of m (for example, 50 to 300 mm),
The width is preferably in the range of Y = 0.15 × X mm to 0.25 × X mm. When the width Y is too wide, a portion having an excessively high glass fiber content is formed around the center portion in the width direction of the SMC, resulting in an unimpregnated portion of the resin composition,
If the strength of the finally obtained molded product is insufficient or the appearance is deteriorated, and if the width Y is too narrow, a portion having a low glass fiber content is formed at both end portions, and the effect of the present invention can be sufficiently obtained. I can't.

The width of the SMC of the present invention as described above is usually 75.
0 to 1200 mm, the weight per unit area is 2
It is preferably 8 kg / m ² . With such a weight per unit area, the yield of the material is improved, the flexibility of charging the SMC to the molding apparatus at the time of molding is improved, and the workability is improved .

The SMC manufacturing method of the present invention can be carried out by partially modifying a conventionally known SMC manufacturing apparatus except that the two types of glass fibers A and B having different lengths are used as described above. . FIG. 1 is a schematic diagram showing an example of an SMC manufacturing apparatus used in the present invention. In this apparatus, the resin tanks 1 and 3 are charged with the above-mentioned thermosetting resin compositions 2 and 4, and the resin compositions 2 and 4 supplied from the resin tanks 1 and 3 are made into a thermoplastic resin film by a doctor knife 5 and 7. A resin layer is formed on the film by coating on the inner surface of 6, 8 (for example, polyethylene film).

The continuous glass fiber 10 drawn from the cake 9 is placed on the resin layer applied on the inner surface of the one thermoplastic resin film 8 by the glass fiber supply device 11 consisting of two rolls rotating in opposite directions. The continuous glass fibers 12 are sprayed as uniformly as possible in a non-directional manner so that the continuous glass fibers 12 do not protrude from the both edges of the resin layer. At this time, when the continuous glass fiber 12 is replaced with a continuous glass fiber, the glass fiber supply device 11 is changed to a roving cutter (see the enlarged view of the C portion), and a cutter roll 13 having a cutting blade 13a and a pinch. The continuous glass fibers 10 may be cut into a predetermined length by combination with the rolls 14, and the continuous glass fibers may be uniformly dispersed in the same direction as in the case of the continuous glass fibers 12.

Further, short glass fibers 18 obtained by cutting the roving 15 with a roving cutter 17 in a glass fiber supply device 16 are spread on both end portions on the resin layer of the thermoplastic resin film 8 with a predetermined width. Then, the inner surfaces of the two thermoplastic resin films 6 and 8 on which the resin layers are formed are overlapped with each other, and the glass fiber reinforced material is impregnated and mixed with the resin composition by the defoaming / impregnating roll 19. The SMC of the present invention can be obtained by winding, aging and thickening with the winding roll 20. The glass long fibers or continuous glass fibers and the glass short fibers may be dispersed and dispersed in the order described above, or vice versa, or two or more layers may be dispersed simultaneously or alternately.

As a method of forming a resin layer of the thermosetting resin compositions 2 and 4 on the inner surfaces of the thermoplastic resin films 6 and 8, in addition to the method of using the doctor knives 5 and 7, curtain coating, Shower coat and spray coat can be used. In the production of the SMC of the present invention, the pair of rolls used for the glass fiber supply devices 11 and 16 may be ordinary rubber rolls, but at least one is made of metal or hard plastic,
It is preferable for pulling out the glass fiber without slipping, and it is more preferable to use a metal or hard plastic roll having grooves or protrusions in the longitudinal direction.

In addition to the above, the following method can be considered as a method for supplying the continuous glass fiber or the continuous glass fiber. That is, while supplying glass fiber by a pair of small rolls rotating in opposite directions, the supply device is reciprocated in the width direction of the SMC manufacturing device, or the supply device is moved in the width direction of the SMC manufacturing device. It is a method of dispersing glass fibers on the resin layer by arranging a plurality of them on the resin layer. Also in this case, it is preferable that at least one of the rolls is made of metal or hard plastic in order to pull out the glass fiber without slipping.

Still another method is to reciprocate the nozzle in the width direction of the SMC manufacturing apparatus while blowing long glass fibers or continuous glass fibers from the nozzle together with the high-speed air flow, or in the width direction of the SMC manufacturing apparatus. A plurality of nozzles may be provided to spray long glass fibers or continuous glass fibers on the resin composition.

[0032]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. Using the materials and methods described below, the manufacturing conditions were changed as shown in Table 1 to obtain SMCs of Examples and Comparative Examples.

1. Thermosetting Resin Composition As the thermosetting resin composition (paste), a composition obtained by mixing the following components in the following quantitative ratios was used. 78 parts by weight of unsaturated polyester resin (resin solid content of about 60% by weight, styrene monomer of about 40% by weight) 12 parts by weight of polystyrene solution (about 30% by weight of polystyrene, about 70% by weight of styrene monomer) 5 parts by weight of pigment Hardener (catalyst, TBPB) 1 part by weight Release agent (zinc stearate) 3 parts by weight Filler (calcium carbonate) 100 parts by weight Thickener (magnesium oxide) 0.6 parts by weight

2. Glass fiber as a reinforcing material As the long glass fiber as a reinforcing material, a continuous glass fiber having a filament diameter of 11 μm and a count of 1084 g / km cut into a length of 1000 mm is used, and it is protruded from both ends of the resin layer. It was sprinkled over the entire width of the resin layer without doing so. As the glass short fibers, a glass roving having a filament diameter of 13 μm and a count of 4800 g / kg cut into a length of 25 mm is used, and is sprayed inward from the end edges of the resin layer to a width of 200 mm. did.

3. Production of SMC (Example 1) Using the apparatus shown in FIG. 1, a width of 1200 mm
While forming a resin layer having a width of 1000 mm and a thickness of about 1 mm by the thermosetting resin compositions 2 and 4 on the inner surfaces of the polyethylene films 6 and 8, the glass long fibers are dispersed over the entire width of the resin layer formed on the film 8. Then, the glass short fibers were sprayed inward from the edges of both end portions of the resin layer to a width of 200 mm. Thereafter, as shown in FIG. 1, the SMC of the present invention having the weight per unit area and the glass fiber content shown in Table 1 was manufactured according to a conventional method.

(Example 2) Table 1 was carried out in the same manner as in Example 1 except that the amount of short glass fibers was changed.
The SMC of the present invention having the weight per unit area and the glass fiber content shown in FIG.

Comparative Example 1 The weight per unit area and the glass fiber content shown in Table 1 were the same as in Example 1 except that the short glass fibers were sprayed over the entire width of the resin layer. The SMC of the comparative example was manufactured.

(Comparative Example 2) Table 1 is the same as Example 1 except that the amount of long glass fibers was changed and the short glass fibers were applied over the entire width of the resin layer. A comparative example SMC of weight per unit area and glass fiber content was produced. (Comparative Example 3) In the same manner as in Example 1 except that the weight per unit area of SMC and the amount of long glass fibers were changed and the short glass fibers were not applied in Example 1, the results are shown in Table 1. Comparative SMCs of the indicated weight per unit area and glass fiber content were prepared.

(Comparative Example 4) In the same manner as in Example 1 except that the short glass fibers were not sprayed, the weight per unit area and the glass fiber content of Comparative Example 4 shown in Table 1 were compared. SMC was manufactured.

4. SMC molding In order to examine the performance of the SMC obtained above, each SMC cut into 1000 × 1000 mm was
Four sheets were piled up in Examples 1 and 2 and Comparative Examples 1, 2 and 4, and seven sheets were piled up in Comparative Example 3, and the resultant was placed in a mold having an upper mold = 135 ° C. and a lower mold = 145 ° C. A sample for evaluation was prepared by heating and pressurizing at 100 kg / cm ² . The shape of the molded product was a rectangular shallow box shape, and the thickness of the molded product was 4 mm.

5. Evaluation method Impregnation of glass fiber with SMC (degree of impregnation of resin into glass fiber) Using a cutter knife, each SMC was peeled from the center in the thickness direction, and the surface (the surface that was the inside before peeling) Is visually observed to evaluate the degree of impregnation of the glass fiber with the resin. The part where the glass fiber is white is not impregnated with resin, so if there is such a part, it is "X (bad)", and if there is no such part, it is "○".
(Good) "was evaluated. The state of the end portion of the SMC It was confirmed whether the glass fiber was protruding from the end portion of the SMC, and when it was not protruding, it was determined to be "proper".

Appearance of Molded Product If the molded product is obtained in the shape of the mold and there is no defect in the appearance, it is evaluated as “◯”, and there are defects (swelling, cracks, warpage, waviness, etc.) in the appearance. Or, when the surface of the molded product was not glossy, it was evaluated as "x". Cracks on the edge of the molded product Visually observe the edge of the molded product (around the edge of the outer peripheral part of the box-shaped opening), which is a shallow rectangular box, and check for the presence of fine cracks (hair cracks). did. Bending strength of the molded product was measured by a method according to JIS K 7055. The evaluation results are shown in Table 1 below.

[0043]

[Table 1]

As is apparent from Table 1 above, in Examples 1 and 2, SMCs having a glass content of 30 to 40% by weight and no impregnation failure were obtained, but the glass fiber content was appropriate at both ends. However, in Comparative Example 1 in which the center portion is high, SMC had impregnation failure and swelling occurred in the molded product. Further, in Comparative Example 2 in which the glass content rate was lowered as a whole, although there was no impregnation defect, the strength of the molded product was lower than that of the Examples due to the low glass content rate, and the intended strength could not be obtained. In addition, although good SMC was obtained in Example 2, in Comparative Example 3, since the unit area weight of SMC is low, a good SMC can be obtained with less decrease in the glass content at the edges, but the unit area is Since the weight is low, the number of SMC charges (the number of plies) must be increased in the molding work, and the workability is poor. Further, in Examples 1 and 2, no hair crack was generated at the end of the molded product,
In Comparative Examples 1 and 4, hair cracks were generated at the ends of the molded products, and good molded products could not be obtained.

[0045]

As described above, according to the present invention, in the SMC, there is no protrusion of the reinforcing material in the width direction, and the content ratio of the reinforcing material is substantially the same in the width direction of the SMC.
It is possible to provide an SMC that gives a molded article having excellent strength and strength uniformity without causing defects such as cracks. Further, since the weight per unit area of the glass fiber in the SMC can be improved, hair-like hair cracks do not occur at the end of the molded product, and excellent strength can be imparted to the molded product. .

[Brief description of drawings]

FIG. 1 is a diagram for explaining the production of SMC of the present invention.

FIG. 2 is a diagram schematically illustrating a cross section in the width direction of the SMC of the present invention.

FIG. 3 is a diagram schematically illustrating a dispersion form of glass fibers of the SMC of the present invention.

FIG. 4 is a diagram illustrating the distribution of long glass fibers in a conventional L-SMC.

[Explanation of symbols]

1,3: Resin tank 2,4: Thermosetting resin composition 5,7: Doctor knife 6, 8: Thermoplastic resin film 9: Cake 10: Continuous glass fiber 11, 16: Glass fiber supply device 12: Continuous glass fiber 13: Cutter roll 14: Pinch roll 15: Roving 17: Roving cutter 18: Glass short fiber 19: Defoaming / impregnating roll 20: Winding roll 21, 31: Short glass fiber 22, 32: long glass fiber or continuous glass fiber 23, 33: SMC

Continuation of front page (51) Int.Cl. ⁷ identification code FI B29K 105: 08 B29K 105: 08 309: 08 309: 08 (56) References JP-A-63-268604 (JP, A) JP-A-8- 192424 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08J 5/04-5 / 10,5 / 24 B29B 11 / 16,15 / 08-15/14

Claims (4)

(57) [Claims] 1. A sheet molding compound (SMC) obtained by blending a thermosetting resin composition with glass fiber as a reinforcing material and increasing the viscosity, to obtain the entire width of the SMC.
Glass long fibers or continuous glass fibers having a length of 500 to 4000 mm are dispersed in a non-directional manner, and the entire width of the SMC is X.
When the length is 5 mm, short glass fibers having a width of 0.05 × X mm to 0.3 × X mm and a length of 5 to 100 mm are dispersed inward from the edges at both end portions in the width direction. SMC which is characterized by. 2. Glass long fibers or continuous glass fibers (A) and glass short fibers (B) at both ends in the width direction.
Is a weight ratio of A: B = 60 to 95:40 to 5 , SMC according to claim 1 . 3. The weight per unit area of SMC is 2 to 8.
The SMC according to claim 1 or 2 , which has a kg / m ² . 4. SMC according to any one of claims 1 to 3 substantially identical content of the glass fibers over the entire width of the SMC.