JP3294809B2 - Lightweight laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light-weight laminated plate used for a sewage purifying tank or a chemical liquid tank lid, a container, a storage box for transporting various parts, or an aircraft or a vehicle.

[0002]

2. Description of the Related Art As a plate material used for a lid or a container of the above-mentioned sewage treatment tank, it is light in weight, high in strength and hardly corroded.
A material having excellent durability is desired, and a material having a heat insulating property adapted to each application is often required.

[0003] Conventionally, as such a plate material, a light-weight plate-like core material made of a foamed resin is coated on both sides with an unsaturated polyester-based material.
Non-foamed resin protective layer such as RP board (hereinafter referred to as FR
A lightweight laminate sandwiched between P-plates may be used as an example). FIG. 1 is a cross-sectional view showing the lightweight laminate, in which protective layers 1 and 3 are provided on both surfaces of a lightweight plate-like core material 2.

Examples of the lightweight plate-shaped core material include resins such as urethane resin foam, vinyl chloride resin foam, polypropylene resin foam, polyester resin foam, polyethylene resin foam, and phenol resin foam. A foamed product, a balsa material, or the like is used, and a resin obtained by mixing a silica balloon with a resin and solidifying the resin is also used. These lightweight laminates achieve high strength, corrosion resistance, and durability by the FRP plate, and exhibit light weight and heat insulation by the resin foam or the like.

[0005] In addition, there has been proposed a hollow lightweight laminate in which an FRP thin-walled honeycomb is used as a lightweight plate-like core material and FRP plates are further joined to both surfaces thereof. By making the core material into a honeycomb shape, the weight of the laminated plate is reduced, and the strength in the compression direction is also excellent.

[0006] As the FRP plate, a material obtained by impregnating an unsaturated polyester resin with glass fiber is mainly used in view of strength and cost.

[0007] As a method of manufacturing the lightweight laminate,
A method in which the lightweight plate-shaped core material and the FRP board are separately manufactured in advance, and these are bonded with an adhesive (hereinafter, sometimes referred to as a bonding method), or a foamed resin composition is placed between two FRP boards. Injection and foaming to form a lightweight laminate (hereinafter sometimes referred to as an intermediate injection method) (Japanese Patent Application Laid-Open No. 7-259111). Laminated so as to cover the fiber aggregate on both sides of the material, placed in the mold, filled in the mold so as to impregnate the thermoset resin material into the fiber aggregate, and cured. Method (RTM method [resin transfer molding method]) and the like.

[0008]

However, the above-mentioned conventional lightweight laminate has poor weather resistance, and has a problem that the FRP plate on the surface becomes brittle and white when exposed to sunlight for a long period of time.

Therefore, in order to improve the weather resistance of the unsaturated polyester-based FRP plate, a layer of a gel coat agent obtained by adding a pigment and an ultraviolet absorber to an unsaturated polyester resin is provided.
Although a product formed on the surface of the unsaturated polyester-based FRP plate (hereinafter sometimes referred to as gel coat FRP) is provided, it is not yet satisfactory.

As the FRP plate, one using a (meth) acrylic resin having relatively good weather resistance as a resin component of the FRP can be considered. There is a problem that it is difficult to obtain a lightweight laminate having good surface properties, such as poor smoothness, pinholes and cracks.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a lightweight laminate having better weather resistance, and a smooth and good surface property.

[0012]

According to the present invention, there is provided a light-weight laminate having a protective layer disposed on both sides of a lightweight plate-like core material including a number of voids, wherein at least one of the protective layers is provided. Is a (meth) acrylic FRP layer, and the (meth) acrylic FRP layer is made of a (meth) acrylic resin 5
Cured product of a molding material containing from 70 to 70% by weight, from 5 to 50% by weight of a fiber, and from 0.01 to 10 parts by weight of a succinic acid derivative per 100 parts by weight of a (meth) acrylic resin as a thickening control agent Wherein the (meth) acrylic resin is
The gist of the invention is to include a (meth) acrylic polymer having a carboxyl group of 0.05 to 1.5 mol / 1000 g.

As described above, the lightweight laminate of the present invention has good weather resistance because at least one of the protective layers is a (meth) acrylic FRP layer, and hardly changes even when exposed to sunlight for a long time. And a good surface can be maintained. In addition, among the (meth) acrylic FRPs, since the (meth) acrylic polymer having a carboxyl group of 0.05 to 1.5 mol / 1000 g is contained as a resin component, the protective layer exhibits smooth and good surface properties.

As described above, it is necessary that the (meth) acrylic polymer has a carboxyl group content of 0.05 to 1.5 mol / 1000 g. Pinholes and cracks are liable to occur, and the viscosity of the (meth) acrylic resin composition is too small when SMC is used. Therefore, the viscosity of SMC is too low and the SMC becomes sticky. This is because the handleability of the device becomes poor. Meanwhile 1.
In the case of more than 5 moles, in the impregnation step in the production of SMC, the viscosity becomes too high, so that the impregnation of the fibers (chopped roving, mat, cloth, etc.) with the (meth) acrylic resin composition becomes poor. As a result, the fibers and the (meth) acrylic resin composition separate during press molding, resulting in poor fluid dispersion, resulting in poor smoothness of the surface of the molded FRP plate, and inconvenience such as generation of cracks. is there.

Further, as described above, (meth) acrylic FRP
Since the fiber content of the layer is 5 to 50% by weight, a lightweight laminate having excellent bending strength can be obtained. If the amount is less than 5% by weight, the bending strength of the lightweight laminate becomes low, while the weight is 50% by weight.
In the case of exceeding, the impregnation of the fiber in the FRP layer with the (meth) acrylic resin composition is cured in a poor state, and the cured product of the resin composition and the fiber are easily peeled off, and the resistance to bending of the lightweight laminated board is obtained. This is because the property becomes low.

Further, in the present invention, the (meth) acrylic polymer is obtained by polymerizing a monomer component essentially containing a vinyl monomer having a carboxyl group and an alkyl (meth) acrylate monomer.
It is preferably an acrylic polymer. This is because a lightweight laminate having even better weather resistance and water resistance can be obtained.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION As described above, at least one of the protective layers of the lightweight laminate according to the present invention is a (meth) acrylic FRP layer. It is obtained by curing a molding material impregnated with an object.

The (meth) acrylic resin composition comprises:
(Meth) acrylic resin is an essential component and refers to the mixture of filler and various additives. The above (meth) acrylic resin is a mixture of (meth) acrylic polymer and polymerizable monomer. Point to. The (meth) acrylic polymer is obtained by polymerizing a monomer component essentially containing a vinyl monomer having a carboxyl group and an alkyl (meth) acrylate monomer.

Examples of the vinyl monomer having a carboxyl group include unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid; One or more ester compounds can be used.

The vinyl monomer having a carboxyl group is an essential component for constituting the (meth) acrylic polymer. As described above, the amount of the carboxyl group in 1000 g of the (meth) acrylic polymer obtained from the monomer component is reduced. It is necessary that the amount be between 0.05 and 1.5 mol.

The above (meth) acrylic acid alkyl ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, propyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and lauryl (meth) acrylate. ) Acrylate, cyclohexyl (meth) acrylate, (meth) acrylamide, hydroxy (meth) acrylate, glycidyl (meth) acrylate and the like. It is preferable to use one or a mixture of two or more of these. Particularly, when methyl methacrylate is mainly used, a high-performance molded article can be obtained.

As a monomer constituting the (meth) acrylic polymer, another vinyl monomer can be used in combination, if necessary. However, the amount of the other vinyl monomer is preferably an amount not exceeding the total amount of the above-mentioned vinyl monomer having a carboxyl group and the alkyl (meth) acrylate monomer. Examples of the other vinyl monomers include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, vinyl acetate, allyl alcohol, ethylene glycol monoallyl ether, and propylene glycol monoallyl ether.

The (meth) acrylic polymer can be synthesized by polymerizing the above monomer components by a known method such as solution polymerization, bulk polymerization, emulsion polymerization, suspension polymerization and the like. Among them, when synthesized by the bulk polymerization method,
The viscosity of the obtained molding material is improved, and the bulk polymerization method has the advantage that a (meth) acrylic resin can be produced without a complicated process.

After the known solution polymerization, emulsion polymerization, suspension polymerization, etc., the purified polymer may be dissolved in a polymerizable monomer to produce a (meth) acrylic resin.

The polymer has a polymerization average molecular weight of 30,000-1.
It is recommended that the number be 100,000 and the number average molecular weight be 10,000 to 200,000. This is because viscosity control is easy, molding workability is good, and physical properties of a molded product are good.

The polymerizable monomer constituting the (meth) acrylic resin together with the (meth) acrylic polymer is
It is used to form a liquid (meth) acrylic resin by mixing with the produced polymer. As the polymerizable monomer, any of the monomers exemplified as the monomer constituting the polymer may be used. it can. The most preferred of these is methyl methacrylate.

If necessary, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene pyrene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate (Meth) acrylates such as trimethylolpropane tri (meth) acrylate and pentaerythritol tetra (meth) acrylate; and polyfunctional (meth) acrylates such as divinylbenzene, diallyl phthalate, diallyl isophthalate, triallyl cyanurate and triallyl isocyanurate. A functional crosslinking monomer may be used.

It should be noted that unsaturated polyester resins, vinyl ster resins, and (meth) acrylates having hydroxyl groups and polyisocyanate compounds which can be copolymerized with vinyl monomers having carboxyl groups and alkyl (meth) acrylate monomers. An oligomer having a vinyl group such as a reactant may be used as a part of the polymerizable monomer.

The mixing ratio of the polymer and the polymerizable monomer in the (meth) acrylic resin is preferably from 7 to 45 parts by weight of the polymer and from 93 to 55 parts by weight of the polymerizable monomer. The (meth) acrylic resin before thickening preferably has a viscosity range of 0.5 to 400 poise at 25 ° C., more preferably 1 to 200 poise. Since the viscosity of the (meth) acrylic resin changes depending on the molecular weight and carboxyl group content of the polymer, it is desirable to adjust the above-mentioned viscosity range by appropriately increasing or decreasing the amount of the polymerizable monomer.

The (meth) acrylic resin composition may contain various known fillers and additives, if necessary, in addition to the (meth) acrylic resin.

Hereinafter, the filler and the additive will be described. The fillers and additives are not limited to those exemplified below,
Needless to say, it may be used for purposes other than the examples.

<Filler> The (meth) acrylic resin composition includes aluminum hydroxide, calcium carbonate, barium sulfate, alumina, clay, talc, milled fiber, quartz sand, river sand, diatomaceous earth,
It is desirable to add an inorganic or organic filler such as mica powder, gypsum, gypsum, asbestos powder, glass powder, glass spheres, or polymer beads. By adding such a filler, it is possible to obtain a (meth) acrylic FRP layer having excellent strength properties and excellent surface smoothness.

These fillers are preferably used in an amount of 250 parts by weight or less, more preferably 100 to 200 parts by weight, based on 100 parts by weight of the (meth) acrylic resin.

<Polymerization Initiator> In order to polymerize the polymerizable monomer in the (meth) acrylic resin to obtain a protective layer, it is preferable to add a polymerization initiator. As the polymerization initiator, t-amyl peroxy-
2-ethylhexanate, benzoyl peroxide,
Lauryl peroxide, methyl ethyl ketone peroxide, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy octoate, t-butyl peroxy benzoate, cumene hydroperoxide, cyclohexanone peroxide, dicumyl peroxide, etc. Organic peroxide, 2-2'-azobisisobutyronitrile, 2-phenylazo-2,4-dimethyl-4-
An azo compound such as methoxyvaleronitrile can be used.

These polymerization initiators are preferably used in an amount of 0.1 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic resin. Further, a polymerization inhibitor generally used for SMC or the like may be used in combination.

<Release Agent> A release agent may be used for the purpose of improving the mold release during the formation of the protective layer of the lightweight laminated board. Examples of the release agent include stearic acid, zinc stearate, and aluminum stearate. And known release agents such as calcium stearate, barium stearate, stearic acid amide, alkyl phosphate and silicone oil.

<Colorant> Colorants such as known inorganic pigments and organic pigments may be added according to the use of the lightweight laminate.

<Low-shrinking agent> When high-precision dimensional stability is required for the protective layer of the lightweight laminate, it is preferable to add a low-shrinking agent. Examples of the low-shrinkage agent include polyethylene, polypropylene, polystyrene, polyethylene glycol, polypropylene glycol, cellulose butyrate, acetate, polyvinyl chloride, polyvinyl acetate,
Examples include thermoplastic polymers such as polycaprolactone, saturated polyester, and copolymers thereof.

<Thickener> When a (meth) acrylic FRP layer serving as a protective layer is formed by a press molding method,
It is preferable to use the SMC thickener in an amount of 5 parts by weight or less based on 100 parts by weight of the (meth) acrylic resin.
Examples of the thickener include magnesium oxide, magnesium hydroxide, calcium oxide, calcium hydroxide and the like.

<Thickening Control Agent> When a (meth) acrylic FRP layer serving as a protective layer is formed by press molding, it is desirable to use a succinic acid derivative as the thickening controlling agent. The succinic acid derivative has a function of controlling excessive thickening of the (meth) acrylic resin. In a system that does not contain a succinic acid derivative, the viscosity sharply increases during the preparation of the resin composition, which makes it difficult to prepare a molding material thereafter, and even if it can be made, insufficient impregnation with fibers and defoaming. This is because problems such as shortage and insufficient fluidity occur in the molding material.

The succinic acid derivative is a compound having a succinic acid skeleton or a succinic anhydride skeleton and having a substituent such as an alkyl group, an alicyclic group, an alkenyl group, or an aromatic ring group in the ethylene group. . As the succinic acid derivative, a mixture of several isomers may be used and is not limited to a single compound. Among the succinic acid derivatives, the total carbon number is 8 to
Thirty succinic acid derivatives can be particularly preferably used in the present invention. If the total number of carbon atoms is less than 8, (meth)
This is because solubility in an acrylic resin tends to be inferior, while those having more than 30 carbon atoms have a reduced effect of suppressing thickening.

Specific examples of the succinic acid derivative include succinic acids having an alkyl group of butyl or more (heptylsuccinic acid, octylsuccinic acid, nonylsuccinic acid, decylsuccinic acid, dodecylsuccinic acid, tetradecylsuccinic acid, hexadecylsuccinic acid). , Heptadecyl succinic acid, octadecyl succinic acid, pentadecyl succinic acid, pentadodecyl succinic acid, eicosyl succinic acid, etc.) and succinic acid having an alkenyl group (hexenyl succinic acid, heptenyl succinic acid, octenyl succinic acid, nonenyl succinic acid, decenyl succinic acid, decenyl succinic acid) , Dodecenylsuccinic acid, tetradecenylsuccinic acid, cyclododecylsuccinic acid, cyclododecenylsuccinic acid, hexadecenylsuccinic acid, heptadecenylsuccinic acid, octadecenylsuccinic acid, pentadecenylsuccinic acid Acid, pentadodecenyl Haq acid, eicosyl succinic acid) or, diphenyl butenyl succinic acid, etc., and can be exemplified these anhydrides may be used alone or in combination.

The succinic acid derivative is preferably contained in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the (meth) acrylic resin. When the amount of the succinic acid derivative is less than 0.01 part by weight, the effect of controlling the thickening is not exerted, and a problem arises due to the rapid thickening of the (meth) acrylic resin composition. On the other hand, if the amount of the succinic acid derivative exceeds 10 parts by weight, the water resistance of the obtained (meth) acrylic FRP layer may deteriorate, which is not preferable. The preferred range of the amount of the succinic acid derivative used is as described above, but it is recommended to appropriately change the amount of the succinic acid derivative according to the method of producing the molding material and the use of the lightweight laminate.

<Other Additives> The polymer having a carboxyl group is an essential component constituting the (meth) acrylic resin, but another polymer having no carboxyl group can be used as an additive. However, it is preferable that the amount does not exceed the amount of the polymer constituting the (meth) acrylic resin.

Next, the fibers contained in the molding material will be described. The fibers are used for the purpose of increasing the strength physical properties of the (meth) acrylic FRP layer, and the content in the FRP layer is 5 to 50% by weight as described above. It is recommended to mainly use glass fibers as the fibers. In addition to the glass fibers, inorganic fibers such as carbon fibers, metal fibers, and ceramics, various organic fibers including aramid, polyester, and natural fibers are also used. Available.

Examples of the form of the fiber include roving, cloth, mat, woven fabric, chopped roving, chopped strand and the like, and the type may be determined according to the use.

The fiber content is preferably 10 to 40% by weight when the fiber form is chopped roving, 15 to 50% by weight when the fiber form is cloth or mat, and 5 to 30% by weight when the fiber form is chopped strand. preferable.

Although it is generally required that the lightweight laminate be floated on water, the specific gravity of the lightweight laminate according to the present invention varies depending on the thickness and specific gravity of the lightweight plate-like core material and the protective layer. It is recommended to select and adjust appropriately from the range described below according to the use and specifications.

The specific gravity of the lightweight laminate of the present invention is from 0.3 to 1.
It is preferably less than 0, and floats on water even when a handle fitting or the like is attached.
-0.8 is more preferable.

To improve the handleability, a handle or the like may be attached to the lightweight laminate, or an opening may be provided in the lightweight laminate. Alternatively, the above (meth) acrylic resin or the like may be applied to a portion of the lightweight plate-shaped core material that is not covered with the protective layer.

As the lightweight plate-shaped core material, a known plate-shaped foam or a plate having a honeycomb structure can be used, and these plate-shaped core materials exhibit weight reduction and heat insulation. In addition, as the lightweight plate-shaped core material, a plate-shaped core material having excellent solvent resistance is preferable.

The thickness of the lightweight plate-shaped core material is 5 to 150 mm
And more preferably 20 to 90 mm. The specific gravity of the foam used for the lightweight plate-shaped core material is 0.3 to
0.05 is preferable, and 0.2 or less is more preferable.
1 or more.

The thickness of the protective layer is 0.5 to 1
It is preferably 0 mm, more preferably 2 mm or more and 6 mm or less.

The manufacturing method of the lightweight laminate according to the present invention includes:
(1) The bonding method, (2) A method in which an FRP plate and a lightweight plate-shaped core material which are protective layers are preliminarily formed, and the FRP plate and the lightweight plate-shaped core material are heated and heat-fused (hereinafter, referred to as “the fusion bonding”). , Sometimes referred to as a fusion method), (3) a lightweight plate-shaped core material is formed in advance, the lightweight plate-shaped core material and the molding material are simultaneously supplied into a press mold, and the molding material is cured. And forming the FRP layer at the same time as joining with the lightweight plate-shaped core material (integral molding method);
(4) The RTM method and the like are available.

In manufacturing the lightweight laminate of the present invention,
Since the step of providing a gel coat layer as in the conventional case is unnecessary, the productivity is superior to that of the gel coat FRP.

In the above methods (1) and (2), the protective layer is manufactured in advance. As the method for manufacturing the protective layer, press molding is preferable from the viewpoint of productivity, more preferably SMC press molding. The reason is that the strength physical property value of the (meth) acrylic FRP layer is increased.

When the FRP plate is formed in advance, a mold having an uneven shape on the inner surface may be used as the mold, and the uneven surface may be formed on the outer surface of the FRP plate.

Further, in the present invention, it is preferable that a foam is used as the lightweight plate-like core material, and a part of the (meth) acrylic FRP layer penetrates a part of the surface of the foam.

In the case where a lightweight laminate is manufactured by the above-mentioned (1) bonding method or (2) fusion method, the convex portion penetrates into the foam by forming an uneven shape on the inner surface of the FRP plate. Looks like This demonstrates the anchor effect,
The plate-shaped core material and the protective layer are strongly bonded. When the lightweight laminated board is manufactured by the above-mentioned (3) integral molding method or the above-mentioned (4) RTM method, the (meth) acrylic molding material used for the (meth) acrylic FRP layer is a foam of the above plate-shaped core material. And then hardens.

[0060]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a lightweight laminated board according to the present invention will be described in detail with reference to embodiments, but the present invention is not limited to the embodiments, but may be adapted to the above and following points. The present invention can be implemented with appropriate modifications within the scope, and all of them are included in the technical scope of the present invention.

The lightweight laminate according to Examples 1 to 3 of the present invention,
And about the lightweight laminated board which concerns on Comparative Examples 1-4, the manufacturing method is shown below. The lightweight laminates of Comparative Examples 1 to 4 used a (meth) acrylic FRP plate as the protective layer.

First, a method for producing a (meth) acrylic resin used for an FRP plate as a protective layer will be described below.

After charging methyl methacrylate (first time) and methacrylic acid into a reactor equipped with a thermometer, a cooler, a nitrogen gas inlet tube, and a stirrer, the inside of the reactor is replaced with nitrogen gas. Next, the mixture of methyl methacrylate and methacrylic acid was heated to 80 ° C. while stirring, and then azobisisobutyronitrile as a polymerization initiator and n-dodecyl mercaptan as a chain transfer agent were added, followed by polymerization. Perform the reaction. The viscosity of the polymer is 36-4 at 25 ° C.
When the poise reaches 0 poise, methyl methacrylate (second time) and hydroquinone are added, and the mixture is rapidly cooled to 40 ° C. Next, maleic anhydride and triethylamine are added to the obtained reaction mixture, and the mixture is stirred for 15 minutes to treat n-dodecyl mercaptan contained in the reaction mixture. In this way, the (meth) acrylic FRP board is used for (meth)
Manufacture acrylic resin. Table 1 shows the amounts of the above components. Further, the above-mentioned polymer (meth) acrylic resin 100
Table 1 also shows the amount of carboxyl group in 0 g.

[0064]

[Table 1]

Next, a method of manufacturing an FRP plate using the obtained acrylic resin will be described.

100 parts by weight of the above (meth) acrylic resin, 1.5 parts by weight of pentadodecylsuccinic acid, t-amyl peroxy 2-ethylhexanate as a polymerization initiator (trade name: Trigonox 121LS-50 Yakuzo Akzo Co., Ltd.])
2 parts by weight, 4 parts by weight of zinc stearate as a release agent, 130 parts by weight of aluminum hydroxide (trade name: B-308 [manufactured by Alcoa Chemical Co., Ltd.]), and 0.9 parts of magnesium oxide.
Mix by weight. This mixture (compound) is applied to a polyethylene film at a constant thickness, and a 2 inch glass fiber chopped roving is evenly spread thereon. Further, the above-mentioned compound applied to a certain thickness on another polyethylene film was layered on the above-mentioned glass fiber, and the glass fiber was sandwiched by the compound.
An SMC in which the glass fiber is impregnated with the compound is obtained. Table 2 shows the glass fiber content after FRP curing.

The obtained SMC is wrapped with a cellophane film and aged at normal temperature (about 23 ° C.). Examples 1 to
3. In Comparative Examples 2 to 4, stickiness was not observed in the aged SMC. On the other hand, in Comparative Example 1, stickiness was observed.

Using a mold, the aged SMC was filled with a material filling amount of 1.5 kg, an upper mold temperature of 115 ° C., and a lower mold temperature of 105 ° C.
The molded product was heated and pressed under the molding conditions of 6 ° C., a molding pressure of 6 MPa, and a pressing time of 7 minutes to obtain a flat plate having a thickness of 3 mm.

The FRP plates ((meth) acrylic FRP plates) of Examples 1 to 3 had excellent surface smoothness.
Further, in Examples 1 to 3, when the aged SMC was allowed to stand at room temperature for 3 weeks and molded in the same manner, an excellent FRP plate comparable to the FRP plate molded immediately after aging was obtained.

The light-weight plate-like core material of the light-weight laminate has a thickness of
Using a 25 mm styrene foam (trade name: BSC Styrol Board-7 [manufactured by Tatsuno Cork Industry Co., Ltd.]), the FRP plate ((meth) acrylic FRP plate) was bonded to the front and back surfaces of the styrene foam with an adhesive ( Bonding with a urethane-based adhesive and a primer) to obtain lightweight laminates (Examples 1 to 3 and Comparative Examples 1 to 4).

As Comparative Example 5, a lightweight laminate using an unsaturated polyester-based FRP plate for the protective layer was manufactured. As a method for producing the unsaturated polyester-based FRP board of Comparative Example 5, an unsaturated polyester-based resin (trade name: EPORAC N-21B) was used as a resin component for forming the FRP board.
Example 1 except that [Nippon Shokubai] was used.
-3 and Comparative Examples 1-4. Comparative Example 5
The fiber content of the unsaturated polyester-based FRP board in the lightweight laminated board was 25% by weight, the same as in Examples 1 to 3,
As in the case of Examples 1 to 3, styrene foam (thickness: 25 mm) is also used as the plate-shaped core material, and a light-weight laminate is obtained by bonding with an adhesive (urethane-based adhesive and primer).

In addition, as Comparative Example 6, a light-weight laminate using an unsaturated polyester-based FRP plate having a gel coat layer formed on the surface as the protective layer was manufactured.

The manufacturing method of the lightweight laminate in Comparative Example 6 was as follows: First, a gel coat resin composition (Gelcoat I Gray #
1108: Mokutoku Shigyo Co., Ltd.) was sprayed into a mold to cure it to a semi-cured state, and a lightweight plate-shaped core material (styrene foam with a thickness of 27 mm) covered with a glass mat and glass cloth on both sides Place in the mold. Next, an unsaturated polyester resin composition (containing various polymerization initiators and the like) is filled in the mold so as to impregnate the glass mat and the glass cloth. Thereafter, the gel coat resin composition and the unsaturated polyester resin composition are cured to obtain a lightweight laminate having a protective layer having a thickness of 3 mm.

The fiber content of the protective layer (FRP layer) is 25% by weight, which is the same as in Examples 1 to 3 and Comparative Example 5.

Next, these Examples 1 to 3 and Comparative Examples 1 to 6
The following tests were performed on the lightweight laminated board or FRP board, and various characteristics were evaluated.

<FRP Plate Surface Properties> The surfaces of the FRP plates of Examples 1 to 3 and Comparative Examples 1 to 6 were evaluated by visual observation.

<Bending test of lightweight laminate>
Each of the lightweight laminates of Comparative Example 3 and Comparative Examples 3, 5, and 6 has a width of 50 mm.
Into a strip-shaped test piece, and the distance between the fulcrum points is 924 mm.
A four-point bending test (method B) was performed according to SK7055. The bending test was performed on the FRP plate surface properties having good test results.

<Weather Resistance Test of FRP Plate> Accelerated weather resistance tester (trade name: I-Super UV tester SUV-W13)
[Manufactured by Iwasaki Electric Co., Ltd.] under an environment of humidity of 50%, UV illuminance 90 ± 5 mW / cm ² , UV wavelength 295 to 450
nm of ultraviolet light from Examples 1 to 3 and Comparative Examples 5 and 6
After continuously irradiating the RP plate for 50 hours, the appearance of the FRP plate was visually observed. Further, the weather resistance test was performed on those having good results of the bending test. Table 2 shows the results of these tests.

[0079]

[Table 2]

In the case of using a (meth) acrylic resin in which the amount of carboxyl groups per 1000 g of the (meth) acrylic polymer used in the FRP plate was as small as 0.03 mol (Comparative Example 1), There is a pinhole,
The appearance was unfavorable. Further, the amount of carboxyl groups in 1000 g of the (meth) acryl-based polymer is 2.0
In the case of using a (meth) acrylic resin as much as 0 mol (Comparative Example 2), the FRP surface had no gloss and had poor surface smoothness. In Comparative Example 2, the glass fiber was poorly dispersed in the cured product of the (meth) acrylic resin composition because the glass was poor in the fluid dispersion state during FRP plate pressing.
It is considered that the surface smoothness deteriorated due to this.

In the case where the fiber content of the FRP plate is as large as 55% by weight (Comparative Example 4), the impregnation of the (meth) acrylic resin composition into the glass fiber is cured in a poor state,
The surface was whitened and the appearance was poor. In addition, the fiber content of the FRP board was as low as 3% by weight (Comparative Example 3).
The bending strength was weak. This is because in Comparative Example 3, the amount of fibers was too small, and the reinforcing effect by the compounding was not exhibited.

As can be seen from the results of Examples 1 to 3 and Comparative Examples 5 and 6, both the unsaturated polyester-based FRP board (Comparative Example 5) and the gel-coated unsaturated polyester-based FRP board (Comparative Example 6) were used. The weather resistance was not so good, and the surface was whitened after long-term use.

In contrast to these comparative examples, the FRPs of Examples 1 to 3
The board has a glossy surface, is excellent in smoothness, shows a good appearance, and is different from a conventional product (corresponding to Comparative Example 6) in a bending test when a FRP board and a foam are joined to form a lightweight laminate. It exhibited excellent bending strength comparable to that. The flexural strength of the lightweight laminate of Example 1 was 60 MPa, and the flexural modulus was 5 GPa.

The weather resistance of Examples 1 to 3
The RP plate showed almost no change even after irradiation with ultraviolet rays for 50 hours and showed excellent weather resistance.

In the first to third embodiments, a polystyrene foam is used as the plate-shaped core material. However, the present invention is not limited to this, and a honeycomb-shaped core material may be used.

[0086]

The lightweight laminate according to the present invention has excellent weather resistance and good surface smoothness. In addition, since the step of forming the gel coat layer is not required unlike the conventional gel coat FRP, the productivity is as good as the conventional one.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a lightweight laminate.

[Explanation of symbols]

 1,3 protective layer 2 plate core material

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Noguchi 5-8 Nishiburi-cho, Suita-shi, Osaka Nippon Shokubai Co., Ltd. (72) Inventor Tetsuya Fujiwara 8-1 Techno Park, Mita-shi, Hyogo Japan Polyester Stock Company Mita Plant (72) Inventor Kazuki Sugihara 8-1 Techno Park, Mita City, Hyogo Japan Polyester Co., Ltd. Mita Plant (56) References JP-A-7-259111 (JP, A) JP-A-7-60848 ( JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 B29B 11/16 B29B 15/08-15/14 C08J 5/04-5/10 C08J 5 /twenty four

Claims (2)

(57) [Claims] 1. A light-weight laminated board comprising a light-weight plate-like core material including a number of voids and protective layers disposed on both sides, wherein at least one of the protective layers is a (meth) acrylic F
The (meth) acrylic FRP layer is composed of 5 to 70% by weight of the (meth) acrylic resin, 5 to 50% by weight of fiber and
100% by weight of (meth) acrylic resin as viscosity control agent
It is a cured product of a molding material containing 0.01 to 10 parts by weight of a succinic acid derivative , and the (meth) acrylic resin has a carboxyl group of 0.1 to 10 parts by weight .
A lightweight laminate comprising a (meth) acrylic polymer having a content of from 0.5 to 1.5 mol / 1000 g. 2. The (meth) acrylic polymer is a (meth) acrylic polymer obtained by polymerizing a monomer component essentially containing a vinyl monomer having a carboxyl group and an alkyl (meth) acrylate monomer. The lightweight laminate according to claim 1.