JPH09131825A - Fiber-reinforced resin molding and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber-reinforced resin molding having the structure that defoaming operation after a laminated resin layer is sprayed is eliminated or alleviated without a shrink at a gel coating layer and crack at the time of mold releasing and a method for manufacturing the molding. SOLUTION: The fiber-reinforced resin molding comprises a structure having a first laminated resin layer 2 mixed with relatively short fiber 2a as the next layer of a surface gel coating layer 1 and a curable resin layer mixed with fiber powder 3a as the next second laminated resin layer 3, wherein the layer 3 is formed in the state that the layer 2 is uncured by using a spraying-up method in the case of manufacturing the structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber reinforced resin molded product suitable for use as, for example, a bathtub or a waterproof pan, and a method for producing the same.

[0002]

2. Description of the Related Art In a fiber-reinforced resin molded article such as a bath, generally, a layer called a laminate layer or an intermediate layer is laminated after a gel coat layer on the surface of the product. A spray-up method is often used as a method for producing such a fiber-reinforced resin molded product, but in a molded product having this type of laminated structure, bubbles are generated in the laminate layer or between the gel coat layer and the laminate layer. When used for a long time, the gel coat layer is easily broken, which not only deteriorates the appearance but also causes water leakage. Therefore, when manufacturing a molded article of this type, so-called defoaming work is required to remove such harmful bubbles.

For the purpose of simplifying or eliminating the above-described defoaming work, conventionally, a molded article having the following structure or a manufacturing method thereof has been proposed. In JP-A-5-301295, a first laminate layer is formed by spraying a relatively short fiber of about 2 to 10 mm and a thermosetting resin next to the gel coat layer by using a spray-up method. 25-5 before the laminate layer is cured
It discloses a method of obtaining a fiber-reinforced resin molded product by spraying a relatively long fiber of about 0 mm and a thermosetting resin to form a second laminate layer, followed by curing after defoaming.

In Japanese Patent Laid-Open No. 6-64053, a resin layer containing no fiber is formed between the gel coat layer and the intermediate layer (laminate layer) by the spray-up method.
A technique is disclosed in which two intermediate layers are sprayed before the resin layer is cured, and after the defoaming work, the resin layer is cured to obtain a fiber-reinforced resin molded article.

[0005]

By the way, among the above-mentioned conventional proposals, Japanese Patent Laid-Open No. 5-301295 discloses
Since the first laminate layer contains relatively short fibers, defoaming work is unnecessary, but since the second laminate layer contains relatively long fibers, bubble removal after spraying becomes worse. , The defoaming work is still required, and the mixed fiber of the second laminate layer is 25-50m.
Since it is long m, the entrainment of air bubbles during spraying is large,
Aggregation of bubbles called "Foam" occurs between the first laminate layer and the second laminate layer, and the bubbles are difficult to be removed by defoaming work, so thorough thorough bubble inspection and repair work are required. It becomes a cause of lowering productivity and quality. Further, air bubbles in the molded product may cause swelling on the gel coat surface due to repeated use of hot water, which may cause a complaint.

On the other hand, in JP-A-6-64053, defoaming work is still required after spraying the intermediate layer, and workability is not improved. Further, since only the resin is sprayed on the flat gel-coated surface after curing, if the viscosity of the resin is low, resin dripping becomes a problem. If the viscosity of the resin is increased in order to prevent such resin dripping, a new problem that bubbles will be removed and bubbles will remain in the molded product will be extremely difficult to adjust the viscosity of the resin. Become. Furthermore, if the thickness of the resin layer provided between the gel coat layer and the intermediate layer varies during spraying (1 mm
When the thickness exceeds the above value), the gel coat layer in the thick resin portion shrinks due to the shrinkage of the resin, and since the resin layer does not contain reinforcing fibers, the strength is low and cracks may occur during demolding.

The present invention has been made in view of the above circumstances, and the defoaming work after spraying the laminate layer can be eliminated or greatly simplified, and "foam" between the layers can be achieved.
And a fiber-reinforced resin molded product having a structure that does not cause sink marks in the gel coat layer or cracks at the time of mold release, and a method capable of efficiently manufacturing such molded product. To do.

[0008]

In order to achieve the above object, the fiber-reinforced resin molded article of the first invention is provided with a gel coat layer 1 on the surface of the product, as schematically shown in FIG. The first laminated resin layer 2 in which the relatively short fibers 2a are mixed, and the second laminated resin layer 3 subsequent thereto is a curable resin layer in which the fiber powder 3a is mixed. Characterized by

The first method of the present invention, which is a method for producing the molded article of the first invention, comprises spraying the gel coat layer 1 on the surface of the mold and then spraying a mixture of relatively short fibers and a curable resin. To form the first laminated resin layer 2 and to improve the adhesiveness and adhesion with the next layer, the first laminated resin layer 2 is in an uncured state and is mixed with the fiber powder 3a in advance. Is sprayed to form the second laminate resin layer 3.

In order to achieve the above object, the fiber-reinforced resin molded article of the second invention is provided with a gel coat layer 1 on the surface of the product as shown in FIG. The first laminate resin layer 2 in which the relatively short fibers 2a are mixed is provided, the curable resin layer is further provided as the second laminate layer 4 next to the first laminate resin layer 2, and the relatively long fibers 5a are further mixed as the next layer. It is characterized by having the third laminated resin layer 5.

The second method of the present invention, which is a method for producing the molded article of the second invention, comprises spraying the gel coat layer 1 on the surface of the molding die and then mixing a relatively short fiber 2a and a curable resin. To form the first laminate layer 2, and in the uncured state of the first laminate layer 2, a curable resin is blown to form the second laminate resin layer 4, and the second laminate resin It is characterized by spraying a mixture of relatively long fibers 5a and a curable resin in the uncured state of the layer to form the third laminate resin layer 5.

Here, in the first and second inventions and the first and second methods for producing them, after forming all the laminate layers, a backing layer 10 usually containing a reinforcing material.
In the case of a molded article in which is laminated and a heat-retaining property such as a bath is required, it is preferable to form a foam layer such as a urethane layer as a heat insulating layer 11 by spraying after the backing layer 10.

In the first laminate resin layer 2 of the first invention and the second invention, the length of the reinforcing fiber 2a contained therein is usually 2.0 to 10.0 mm.
And more preferably 3.0 to 6.0 mm. The reinforcing fiber 2a contained in the first laminated resin layer 2 has a slight decrease in mechanical strength as compared with the length of the reinforcing fiber contained in the conventional laminated layer of 25 to 50 mm, but is compatible with the resin. And the voids or bubbles caused by the entanglement of bridges between fibers are small and small.

When the length of the reinforcing fiber 2a is less than 2 mm, cracking due to curing shrinkage of the resin can be prevented, but the reinforcing effect due to the incorporation of the fiber is hardly exhibited, and the reinforcing fiber produced by the spray molding machine is It is not preferable because cutting becomes difficult and roving slipping occurs and the workability deteriorates. In addition, the length of the reinforcing fiber 2a is 10 m
If it exceeds m, bubbles having a diameter of about 2.0 to 3.0 mm are generated, and defoaming work is required, which lowers workability, which is not preferable.

In the first invention, the thickness of the second laminate resin layer 3 made of a curable resin and fiber powder is 0.2 to
It is preferably 2.0 mm. It has a thickness of 0.
If it is less than 2 mm, it is difficult to spray the resin uniformly, and it is difficult to exert the effect of reducing bubbles, and the thickness is 2.
If it exceeds 0 mm, cracks may occur due to curing shrinkage of the resin, and if the curing temperature is lowered to suppress the occurrence of such cracks, the productivity will decrease. However, when a resin-only layer is provided in place of the second laminate resin layer 3, the occurrence of cracks due to curing shrinkage was noticeable at a thickness of 1.0 mm or more, but fiber powder was mixed in. Further, the occurrence of cracks due to curing shrinkage is suppressed, and the thickness can be set to 2.0 mm. The mixing ratio of the fiber powder to the resin in the second laminate resin layer 3 is not particularly limited, but considering viscosity and workability, it is about 5 to 50%,
It is preferably 10 to 30%.

On the other hand, in the second invention, the thickness of the second laminate resin layer 4 made of a curable resin layer is 0.2 to 0.
It is preferably 8 mm. It has a thickness of 0.2m
If it is less than m, it is difficult to spray the resin uniformly, and it is difficult to exert the effect of reducing bubbles, and the thickness is 0.
This is because if it exceeds 8 mm, cracks may occur due to curing shrinkage of the resin, and if the curing temperature is lowered in order to suppress the occurrence of cracks, productivity will decrease.

Further, the length of the reinforcing fiber 5a of the third laminate resin layer 5 in the second invention is determined from the viewpoint of the reinforcing effect.
Usually, it is set to 25 to 50 mm. The first laminated resin layer 2 and the second laminated resin layer 3 of the first invention, and the second
As the curable resin used for the first laminate resin layer 2, the second laminate resin layer 4, and the third laminate resin layer of the invention, a thermosetting resin such as unsaturated polyester resin, vinyl ester resin, phenol resin, or epoxy resin is used. It is possible to use a mixture of a suitable curing agent.
Further, instead of the thermosetting resin as described above, a photocurable resin which is cured by irradiation with ultraviolet rays can be used.

The materials for the fibers used in the first laminate resin layer 2 of the first invention and the first laminate resin layer 2 and the third laminate resin layer 5 of the second invention include glass fiber and carbon fiber. Examples thereof include inorganic fibers, or organic fibers such as aramid fibers and polyethylene terephthalate (PET) fibers, but glass fibers are preferably used in terms of performance and cost. The fiber form is not limited, but roving fibers are generally used.

Further, the second laminate resin layer 3 of the first invention
As the material of the fiber powder 3a used in the above, the same kind as described above can be used, but it is preferable to use the glass fiber powder in terms of performance and cost.

[0020]

In the structure of the first invention, the gel coat layer 1 is followed by the first laminate resin layer 2 containing the relatively short fibers 2a and the second laminate resin layer 3 containing the fiber powder 3a.
Since these are laminated in order, the voids and bubbles generated by the entanglement between the fibers at the time of spraying each of the laminate resin layers 2 and 3 are small and small, and even if defoaming work is substantially unnecessary, No harmful bubbles remain.

In the constitution of the second invention, the gel coat layer 1
Followed by laminating a first laminate resin layer 2 containing relatively short fibers 2a, and curability between the first laminate resin layer 2 and a third laminate resin layer 5 containing relatively long fibers 5a. A second laminate resin layer 4 made of a resin is interposed, and in particular, the second and third laminate layers 4 and 5 are sprayed in a state where the previous layer is uncured, whereby the respective laminate resin layers are formed. Bubbles are less likely to remain inside and between layers, and the defoaming work can be simplified. Further, the second laminate resin layer 4 containing no reinforcing fiber is not in contact with the gel coat layer 1 unlike the conventional proposal, and the first and third fibers are reinforced on both sides thereof.
Since it is sandwiched between the laminated resin layers 2 and 5, resin sag does not easily occur during spraying, and
Generation of cracks at the time of demolding and sinking of the gel coat layer 1 due to resin shrinkage do not occur.

[0022]

EXAMPLES Some examples to which the first invention and the second invention are applied will be described below together with comparative examples. In addition,
In the following examples, Examples 1-1 and 1-2 are examples of the first invention, and Examples 2-1 and 2-2 are examples of the second invention.

The manufacturing apparatus used in each of the examples and comparative examples is as schematically shown in FIG.
A spray-up machine 31 (manufactured by Togiken Co., Ltd.) was sprayed onto the molding die 30 while cutting the resin, the curing agent, and the glass roving as necessary.
In FIG. 3, 32 is a glass roving, 33 is a hardening agent tank, 34 is a resin tank, and 35 is a supply hose.

[Example 1-1] -Manufacture of fiber-reinforced resin bath-In the laminated structure shown in FIG. 1, the materials used for each layer, such as the resin, the curing agent, and the glass fiber, are as follows.

A vinyl ester resin was used for the gel coat layer 1, and methyl ethyl ketone peroxide was used as a curing agent. Further, as the resins 2b and 3b in the first and second laminate resin layers 2 and 3, a bis-based unsaturated polyester resin (containing about 40% styrene and 6% cobalt naphthenate) was used, and 100 parts by weight thereof was used.
The same methyl ethyl ketone peroxide as described above was used as a curing agent at a ratio of 1.2 parts by weight.

The fibers contained in the first laminate resin layer 2 are glass fiber (roving) = count 2350, second fiber
Glass fiber powder was used for the laminate resin layer 3. Now, using a mold for a bath as the FRP mold 30 schematically shown in FIG. 3, first, a gel coat resin and a curing agent are sprayed with a spray gun, and then a curing furnace at 50 ° C. is used.
It was cured for 0 minutes to form a gel coat layer 1. Next, with the spray-up machine 31, as the first laminate resin layer 2, while cutting the above glass fibers into a length of 3 mm, the thermosetting resin and the above curing agent are sprayed to a thickness of 0.6 mm. It was Then, in the uncured state of the first laminate resin layer 2, the thermosetting resin and the curing agent, which are mixed with glass powder in advance, are sprayed up as a second laminate resin layer 3 from above onto the spray up machine 6.
Was sprayed with a thickness of 2.0 mm. Then, without performing the defoaming work, curing was performed for 20 minutes in a curing furnace at 50 ° C.

Next, the unsaturated polyester resin and the glass fiber are used as the backing layer 1 so that the glass content is about 30%.
No. 0 was sprayed, and after curing, a heat insulating layer 11 was formed from urethane resin, trimming and demolding were performed to obtain a fiber reinforced resin bath.

Twenty baths were molded in this manner, but no bubbles were found and no cracks were found in the work of inspecting the residual bubbles of the molded product with a hammer. In addition, two of these molded products were randomly drawn out at 98 ° C.
The boiling test was conducted at × 500 hours, but no defective appearance such as swelling, chipping or cracking was observed after the boiling test was completed. When the boiling test was conducted for an additional 500 hours, no abnormalities were found in the appearance.

[Example 1-2] -Production of waterproof pan made of fiber reinforced resin-In the structure of FIG. 1, the gel coat layer 1, the first and the second
The resin, curing agent and fiber used for each of the laminated resin layers 2 and 3 were exactly the same as in Example 1-1.

A mold for a waterproof pan was used as the FRP mold 30. First, a gel coat resin and a curing agent were sprayed with a spray gun and then cured in a curing oven at 50 ° C. for 30 minutes. Next, with the spray-up machine 31, as the first laminate resin layer 2, glass fibers having a length of 3 mm, a thermosetting resin, and a curing agent were sprayed to a thickness of 1.5 mm. Then, in a state where the first laminated resin layer 2 is uncured, a thermosetting resin and a curing agent mixed with glass fiber powder in advance are used as the second laminated resin layer 3 from above on the sprayed machine 31 for 2.0 mm. And was cured for 20 minutes in a curing oven at 50 ° C. without defoaming work.

Next, the unsaturated polyester resin and the glass fiber are used as the backing layer 1 so that the glass content is about 30%.
No. 0 was sprayed, and after curing, a heat insulating layer 11 was formed from urethane resin, trimming and demolding were performed, and a fiber-reinforced resin waterproof pan was obtained.

In this way, 20 waterproof pans were molded, but in the work of inspecting the residual air bubbles of the molded product with a hammer,
No bubbles were found and no cracks were seen. Also,
Of this molded product, 2 units are randomly extracted and 98 °
A boiling test was carried out at C × 500 hours, but after the boiling test was completed, no defective appearance such as swelling, chipping or cracking was observed. When the boiling test was conducted for an additional 500 hours, no abnormalities were found in the appearance.

[Example 2-1] -Manufacture of fiber-reinforced resin bath-In the laminated structure shown in FIG. 2, the materials used for each layer, such as the resin, the curing agent, and the glass fiber, are as follows.

For the gel coat layer 1, a vinyl ester resin was used as in each of the above examples, and as a curing agent, methyl ethyl ketone peroxide was also used. As the resins 2b, 4b and 5b in the first, second and third laminate resin layers 2, 4 and 5, the bis type unsaturated polyester resin (styrene content of about 40% and 6%) is used as in the above examples.
Cobalt naphthenate was used), and 1.2 parts by weight of methyl ethyl ketone peroxide was also used as a curing agent with respect to 100 parts by weight thereof.

The fibers contained in the first laminate resin layer 2 are glass fiber (roving) = count 2350, third fiber
For the laminated resin layer 4, glass fiber (roving) = count 3460 was used.

A FRP molding die 30 schematically shown in FIG. 3 was used for a bath. First, a gel coat resin and a curing agent were sprayed with a spray gun, and then in a curing furnace at 50 ° C. for 30 minutes. It was cured to form a gel coat layer 1. Next, the above-mentioned glass fiber is used as the first laminate resin layer 2 with a spray-up machine 31 to have a length of 2 m.
While cutting to m, this and the above-mentioned thermosetting resin and curing agent were sprayed with a spray up machine 31 to a thickness of 0.6 mm. Then, in the uncured state of the first laminate resin layer 2, a thermosetting resin and a curing agent are sprayed as a second laminate resin layer 4 from above onto the spray-up machine 31 to a thickness of 0.2 mm. Further, in the uncured state, the machine 31 blows glass fibers having a length of 25 mm as a third laminate resin layer 5 together with the thermosetting resin and the curing agent to a thickness of 1.5 mm, and the roller is rotated once. After performing the hanging defoaming work, it was cured in a curing oven at 50 ° C. for 20 minutes.

Next, the unsaturated polyester resin and the glass fiber are used as the backing layer 1 so that the glass content is about 30%.
No. 0 was sprayed, and after curing, a heat insulating layer 11 was formed from urethane resin, and trimming and demolding operations were performed to obtain a fiber reinforced resin bath.

Twenty baths were molded in this manner, but no bubbles were found and no cracks were found in the work of inspecting the residual bubbles of the molded product with a hammer. In addition, two of these molded products were randomly drawn out at 98 ° C.
The boiling test was conducted at × 500 hours, but after the boiling test was completed, no defective appearance such as swelling, hanging, or cracking was observed in the bath. The boiling test was conducted for an additional 500 hours,
No abnormal appearance was observed.

[Example 2-2] -Production of waterproof pan made of fiber reinforced resin-In the laminated structure of FIG. 2, the gel coat layer 1, the first and the second
The resin, the curing agent and the fibers used for each layer of the third laminated resin layers 2, 4 and 5 were the same as in Example 2-1.

A FRP molding die 30 for a waterproof pan was used. First, a gel coat resin and a curing agent were sprayed with a spray gun and then cured in a curing oven at 50 ° C. for 30 minutes. Next, with the spray-up machine 31, as the first laminate resin layer 2, glass fibers having a length of 3 mm, a thermosetting resin, and a curing agent were sprayed to a thickness of 1.5 mm. Then, in the uncured state of the first laminate resin layer 2, a thermosetting resin and a curing agent are sprayed as a second laminate resin layer 4 from above onto the spray-up machine 31 to a thickness of 0.2 mm. Further, in the uncured state, the machine 31 blows glass fibers having a length of 25 mm as a third laminate resin layer 5 together with the thermosetting resin and the curing agent to a thickness of 1.5 mm, and the roller is rotated once. After performing the hanging defoaming work, it was cured in a curing oven at 50 ° C. for 20 minutes.

Next, the unsaturated polyester resin and the glass fiber are used as the backing layer 1 so that the glass content is about 30%.
No. 0 was sprayed, and after curing, a heat insulating layer 11 was formed from urethane resin, and trimming and demolding operations were performed to obtain a fiber reinforced resin bath.

Twenty waterproof pans were molded in this way, but in the work of inspecting the remaining bubbles of the molded product with a hammer,
No bubbles were found and no cracks were seen. Also,
Of this molded product, 2 units are randomly extracted and 98 °
A boiling test was conducted at C × 500 hours, but after the boiling test was completed, no defective appearance such as swelling, hanging, or cracking was observed on the waterproof pan. When the boiling test was conducted for an additional 500 hours, no abnormal appearance was observed.

[Comparative Example 1] -Manufacture of fiber-reinforced resin bath-In Comparative Example 1, the first laminated resin layer 101 is provided next to the gel coat layer 1 as schematically shown in its laminated structure in FIG. Further, the second laminated resin layer 102 is further formed next to the first laminated resin layer 101 in Comparative Example 1. And also contains the second laminated resin layer 102 in Comparative Example 1.
Is a layer containing relatively long fibers 102a as in the case of the third laminate resin layer 5 in Examples 2-1 and 2-2 described above.

In the laminated structure of FIG. 4, the resin and the curing agent used for the gel coat layer 1 are the same as those in the above-mentioned respective embodiments, and the first laminate resin layer 101 and the second laminate resin layer
Resins 101b and 102 used for the laminated resin layer 102
The b and the curing agent are the same as those used for the respective laminated resin layers of the above-mentioned respective examples, and the glass fiber used for the first laminated resin layer 101 is the same as the first laminated resin layer 2 of the respective examples. The glass fiber used for the second laminate resin layer 102 was the same as that used for the third laminate resin layer 5 of Examples 2-1 and 2-2.

A FRP mold 30 for a bath was used. First, a gel coat resin and a curing agent were sprayed with a spray gun and then cured in a curing furnace at 50 ° C. for 30 minutes. Next, the spray up machine 31
As the laminated resin layer 101, a glass fiber having a length of 3 mm, a thermosetting resin, and a curing agent were sprayed to a thickness of 0.6 mm. Then, the first laminate resin layer 101
In the uncured state, the same machine 31 was used to spray glass fibers having a length of 25 mm, a thermosetting resin and a curing agent as a second laminate resin layer 102 to a thickness of 2.0 mm, and the roller was rotated once. After the defoaming work, the resin was cured in a curing oven at 50 ° C for 20 minutes.

Next, the unsaturated polyester resin and the glass fiber are used as the backing layer 2 so that the glass content is about 30%.
No. 0 was sprayed, and after curing, a heat insulating layer 11 was formed from urethane resin, and trimming and demolding operations were performed to obtain a fiber reinforced resin bath.

In this way, 20 waterproof pans were molded, but bubbles were found in 4 of the 20 waterproof pans by the inspection work of residual bubbles in the molded product with a hammer. In addition, out of the 16 units in which no bubbles were found, two units were randomly extracted and a boiling test was performed at 98 ° C x 500 hours. After the boiling test was completed, bubbles were formed on the gel coat surface of one bath. The blisters that were thought to be due to the innate nature of the were seen.

[Comparative Example 2] -Manufacture of waterproof pan made of fiber reinforced resin-In Comparative Example 2, as shown schematically in FIG. 201, then the second laminate resin layer 202, and then the third laminate resin layer 203. The first laminate resin layer 201 in this Comparative Example 2 is a layer containing no fibers similar to the second laminate resin layer 4 in the above-mentioned Examples 2-1 and 2-2, and the first laminate resin layer 201 in this Comparative Example 2 is the same. The second laminate resin layer 202 is a layer containing relatively short fibers 202a as in the case of the first laminate resin layer 2 in each of the above-mentioned examples, and the third laminate resin layer 203 in this comparative example 2 is the same as that of the above-mentioned example 2. −
Similar to the third laminate resin layer 5 in Nos. 1 and 2, it is a layer containing relatively long fibers 203a.

In the laminated structure of FIG. 5, the gel coat layer 1
The resin and the curing agent used for the same are the same as those in the above-mentioned respective embodiments, and the resin of the first laminate resin layer 201 and the second,
Resin 20 used for the third laminate resin layers 202 and 203
2b, 203b, and the curing agent were the same as those of the laminated resin layers of the above-mentioned respective examples. Furthermore, the second
The glass fiber used for the laminate resin layer 202 is the same as that of the first laminate resin layer 2 of each example,
The glass fiber used for the third laminate resin layer 203 was the same as that used for the third laminate resin layer 5 of Examples 2-1 and 2-2.

A FRP molding die 30 for a waterproof pan was used. First, a gel coat resin and a curing agent were sprayed with a spray gun and then cured in a curing oven at 50 ° C. for 30 minutes. Next, with the spray up machine 31,
As the first laminated resin layer 201, a thermosetting resin and a curing agent are sprayed to a thickness of 1.0 mm, and the first laminated resin layer 201 is in an uncured state. As 202
A glass fiber having a length of 3 mm, a thermosetting resin and a curing agent were sprayed at a thickness of 1.0 mm. Further, in the uncured state of the second laminate resin layer 202, the same laminate 31 having a length of 2
A glass fiber of 5 mm was blown together with a thermosetting resin and a curing agent at a thickness of 1.0 mm, and after performing a defoaming work with a roller once, it was cured in a curing oven at 50 ° C. for 20 minutes.

Next, the unsaturated polyester resin and the glass fiber are used as the backing layer 1 so that the glass content is about 30%.
No. 0 was sprayed, and after curing, a heat insulating layer 11 was formed from urethane resin, and trimming and demolding operations were performed to obtain a fiber reinforced resin bath.

Twenty waterproof pans were molded in this manner, but air bubbles were found in two of the twenty pans by the work of inspecting the residual air bubbles of the molded product with a hammer, and it is thought that the impact during demolding was the cause. There were three sink marks.

There were no defects in this molded product.
Randomly pick 2 out of the table, 98 ° C x 50
A boiling test was carried out for 0 hours, but after the boiling test was completed, no defective appearance such as swelling, chipping or cracking was observed on the waterproof pan. However, when the boiling time was further extended by 500 hours, swelling was observed on the gel-coated surface of the molded product for both of them.

[Table 1] is a summary of the structure of the laminate resin layer in each of the above Examples and Comparative Examples and various test results. It was confirmed that a reduction in foaming work could be achieved.

[0055]

[Table 1]

[0056]

According to the structure and manufacturing method of the present invention,
Harmful bubbles are less likely to occur after spraying each laminate resin layer, and by eliminating the defoaming work or performing a simple defoaming work, there is no residual bubbles or blistering and excellent adhesion between laminated layers. A fiber-reinforced resin molded product having excellent boiling performance and mechanical strength can be obtained.

Further, even after demolding, the gel coat layer is not cracked or chipped, or sink marks are not generated, and the defoaming work is not required or reduced, and high quality is achieved with high productivity and high yield. It is now possible to obtain the fiber-reinforced resin molded product of.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a laminated structure of the first invention.

FIG. 2 is a schematic cross-sectional view showing a laminated structure example of a second invention.

FIG. 3 is a schematic explanatory view of an apparatus for manufacturing Examples and Comparative Examples of the first and second inventions.

FIG. 4 is a schematic cross-sectional view showing a laminated structure of Comparative Example 1.

FIG. 5 is a schematic cross-sectional view showing a laminated structure of Comparative Example 2.

[Explanation of symbols]

 1 Gel coat layer 2 1st laminated layer 2a Relatively short fiber 2b Curable resin 3 2nd laminated layer (1st invention) 3a Fiber powder 3b Curable resin 4 2nd laminated layer (2nd invention) 5 3rd laminated layer ( Second invention 5a Relatively long fiber 5b Curable resin 30 FRP mold 31 Spray-up machine

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B29K 105: 08

Claims (4)

[Claims] 1. A gel coat layer is provided on the surface of a product, a first laminate resin layer mixed with relatively short fibers is provided as the next layer, and a fiber powder is provided as the second laminate resin layer next. A fiber-reinforced resin molded product having a curable resin layer mixed therein. 2. A method for producing the fiber-reinforced resin molded article according to claim 1 by a spray-up method, which comprises spraying a gel coat layer on the surface of a molding die and then forming a relatively short fiber and curable resin. The mixture is sprayed to form the first laminate resin layer, and in the uncured state of the first laminate resin layer, a curable resin premixed with fiber powder is sprayed to form the second laminate resin layer. A method for producing a characteristic fiber-reinforced resin molded product. 3. A gel coat layer is provided on the surface of the product, a first laminate resin layer mixed with relatively short fibers is provided as the next layer, and a curable resin layer is provided as the next second laminate layer. A fiber-reinforced resin molded article, which further comprises a third laminate resin layer in which relatively long fibers are mixed as the next layer. 4. A method for producing the fiber-reinforced resin molded product according to claim 3 by a spray-up method, which comprises spraying a gel coat layer on the surface of a molding die and then forming a relatively short fiber and curable resin. The mixture is sprayed to form a first laminate resin layer, and in the uncured state of the first laminate resin layer, a curable resin is sprayed to form a second laminate resin layer. A method for producing a fiber-reinforced resin molded article, which comprises spraying a mixture of relatively long fibers and a curable resin in a uncured state to form a third laminated resin layer.