JPH1158534A - Manufacture of fiber reinforced urethane resin multi-layer foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a fiber reinforced urethane resin multi- layer foam, which has a fiber reinforced urethane resin low density foamed layer and a high density foamed layer, both the densities of which are different from each other, and high strength, high rigidity and high heat insulating properties, in one process. SOLUTION: In a method for producing a fiber reinforced urethane resin multi-layer foam, in which a matlike reinforcing fiber-containing fiber reinforced high density urethane resin foamed layer 1 and a low density urethane resin foamed layer 2 containing small solidlike piece materials 4 are made into an integral body, a series of processes, in which a polyurethane resin stock containing a very small amount of water as foaming agent is poured in a casting mold 5 and then at least one sheet of a matlike reinforcing fiber 3 is placed in the mold 5 and the small solidlike piece materials, to or into which water adheres or infiltrates as foaming agent, are charged on the matlike reinforcing fibers 3 and finally a mold is clamped, completes before the finish of the foaming of a polyurethane resin stock 6. The number of the layers in the fiber reinforced urethane resin multi-layer foam is two or three as the case may be.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a high strength, high rigidity,
The present invention relates to a method for producing a fiber-reinforced urethane resin multilayer foam having high heat insulating properties.

Here, the fiber-reinforced urethane resin multilayer foam refers to a fiber-reinforced urethane resin double-layer foam having a low-density urethane resin foam layer and a high-density fiber-reinforced urethane resin foam layer having different densities, and a surface. It means a foam including at least a three-layer fiber-reinforced urethane resin sandwich-type foam having a high-density fiber-reinforced urethane resin foam layer as a layer and a low-density urethane resin foam layer as a core layer.

[0003]

2. Description of the Related Art Conventionally, as a method for producing a fiber-reinforced urethane resin multilayer foam having a low-density urethane resin foam layer and a fiber-reinforced high-density urethane resin foam layer having different densities in one step, for example, the following method is used. It has been known.

[0004] First, the foaming process is performed in a single casting foaming process. At this time, by adjusting the molding temperature and the foaming pressure of the reactive resin stock solution to the mold, a continuous foam core (core) made of the same material is used. ) And a solid surface portion to obtain a urethane resin integral skin form.

[0005] In the production of this type of reaction injection foam molded article, the molding die is usually heated and maintained at 30 to 60 ° C in order to improve the flowability of the reactive composition stock solution in the mold. . On the other hand, the reactive composition stock solution generates heat during reaction curing and becomes higher than the mold temperature (about 100 ° C. in the case of urethane resin). After casting, the reactive composition stock solution containing the foaming agent foams with reaction curing and is cooled from the part in contact with the mold, whereby the gas in the bubble film formed in the part in contact with the mold is cooled and condensed, The foam film in this portion shrinks to form a skin layer having a higher density than the inside, and then the foamed molded product is cooled to a temperature at which it can be released, and then released.

Second, as disclosed in JP-A-8-291209, in order to make up for the poor surface hardness of the conventional foam, the polyurethane resin stock solution is immediately injected into the mold. The atmospheric pressure is reduced, and before the reaction is completed, the atmospheric pressure of the mold is changed to a normal pressure state or a pressurized state, so that a high-density and high-hardness outer layer portion and a low-density and low-hardness inner layer portion are formed. It is a method of forming.

Third, as disclosed in Japanese Patent Publication No. 3-60280, a plurality of different upper dies can be opened and closed by hinge joints around the lower die, respectively.
The foaming compounding liquids of foams of different hardness are automatically injected by the casting head, and when the foam of each layer to be laminated is sequentially molded, immediately before or after the end of the tack-free time of the foam to be laminated, the next layer is formed. Is obtained by injecting a foamable compounding liquid for the foam of Example 1 to obtain a laminated sheet having a different hardness.

[0008]

However, in the above-mentioned conventional first integral skin form, the skin layer is at most about 1 mm, and the density ratio of the skin layer to the core is limited to about 3. . That is, when the density of the core portion is set to be low, the heat insulating property is obtained, but the density of the skin layer is also low and the strength is not sufficient because the thickness is thin. Conversely, if the density of the skin layer is set high with emphasis on the strength, the strength and rigidity are obtained, but the density of the core layer also increases, and the heat insulating property rapidly decreases. In short, strength
It is difficult to achieve both rigidity and heat insulation.

According to the second conventional method, since the density is made different by adjusting the pressure in the mold, the density difference between the outer layer portion and the inner layer portion is set to be large similarly to the case of the integral skin form. It was impossible to achieve both strength and rigidity and heat insulation.

In order to supplement the strength of a low-density molded product as a whole, a method of attaching a reinforcing fiber or FRP to the surface of the molded product can be considered. Given the workability,
There was a problem of cost and environmental pollution due to evaporation of the solvent of the adhesive.

Further, according to the third conventional method, since a plurality of upper dies are used for forming a foam of different hardness, a complicated die structure is required, and the cost of each die is increased. Requires a large capital investment. Further, the upper mold cannot be replaced and the next layer cannot be cast until the foam of each layer is immediately before or after the tack-free time has elapsed, so that there has been a problem that the molding time becomes extremely long.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to form a fiber-reinforced high-density urethane resin foam layer and a low-density urethane resin foam layer having a high expansion ratio (contrast) in one step. It is possible to obtain a molded product with good balance of heat insulation and bending strength / rigidity with high productivity, and it is necessary to attach a reinforcing surface material to a preformed foam with an adhesive. Since there is no workability, workability is excellent, and the strength design of the fiber-reinforced urethane resin multilayer foam can be freely performed by appropriately selecting the number and the number of mat-like reinforcing fibers on the surface portion. An object of the present invention is to provide a method for producing a fiber-reinforced urethane resin multilayer foam.

[0013]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, there is provided a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber, A method for producing a fiber-reinforced urethane resin multi-layer foam in which a low-density urethane resin foam layer containing a flake-like material is integrated, comprising a polyurethane containing a small amount of water as a foaming agent in a casting mold. After injecting the resin solution,
Place at least one mat-like reinforcing fiber in the same mold,
Next, a series of steps of filling the mold-shaped reinforcing fiber with a solid particle material adhering or impregnated with water as a foaming agent and closing the mold are completed before the foaming of the polyurethane resin stock solution is completed. Features.

According to a second aspect of the present invention, a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber is integrated with a low-density urethane resin foam layer containing solid small-piece material. A method for producing a fiber-reinforced urethane resin multi-layer foam, which is a casting mold, after filling a solid piece material impregnated or impregnated with water as a foaming agent, at least in the same mold A series of steps of placing one sheet of mat-like reinforcing fiber, then injecting a polyurethane resin stock solution containing a small amount of water as a foaming agent onto the mat-like reinforcing fiber and clamping the mold is performed by foaming of the polyurethane resin stock solution. It is characterized in that it is completed before finishing.

According to a third aspect of the present invention, there is provided a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber and a low-density urethane resin foam layer containing a solid piece material. A method for producing a multi-layered fiber reinforced urethane resin foam, comprising: injecting a polyurethane resin stock solution containing a small amount of water as a foaming agent into a casting mold, and then adding at least one mat to the same mold. The solid reinforcing fibers are placed, and then the mat-like reinforcing fibers are filled with a solid piece of material adhering or impregnated with water as a foaming agent, and at least one mat is placed on the solid piece of material. A series of steps of placing the fiber-shaped reinforcing fibers and finally injecting a polyurethane resin stock solution containing a trace amount of water as a foaming agent onto the mat-shaped reinforcing fibers and clamping the mold is completed. It is characterized in that to complete.

[0016]

Next, an embodiment of the present invention will be described.
This will be described with reference to the drawings.

First, referring to FIG. 1, the fiber-reinforced urethane resin multi-layer foam produced by the method according to the first aspect of the present invention has a two-layer structure, and the lower layer is a mat. High-density urethane resin foam layer (1) almost impregnated in fiber-reinforced fibers (3), and the upper layer is a low-density urethane resin foam containing solid small piece material (4) that has lost water due to the formation of urea bonds during curing. Consists of layer (2).

Although the high-density urethane resin foam layer (1) has a different appearance from that of the mat-like reinforcing fiber (3), the mat-like reinforcing fiber (3) is slightly exposed on the surface. ) It has penetrated quite a bit inside.

Here, the formation of a bond in the linear reaction of the isocyanate will be described. The isocyanate reacts with a polyether or polyester polyol having a terminal hydrogen group to form a urethane bond. Isocyanate reacts with water or an amine to generate a urea bond. When the urea bond is formed, water in the mold is consumed.

Although not shown in the drawings, the fiber-reinforced urethane resin multilayer foam produced by the method according to the second aspect of the present invention is characterized in that the upper layer and the lower layer after demolding are different from those described above. Is reversed, and the configuration is almost the same as that shown in FIG.

Referring now to FIG. 4, the fiber-reinforced urethane resin multilayer foam produced by the method of the third aspect of the present invention is the foam produced by the method of the first aspect. Matte reinforcing fibers on the front and back layers
(3) has a high-density urethane resin foam layer (1) impregnated in
The central part is a low-density urethane resin foam layer containing solid small piece material (4) that has lost water due to the formation of urea bonds during curing.
(2) It has a three-layer sandwich structure.

Next, a method for producing a fiber-reinforced urethane resin multilayer foam according to the first aspect of the present invention will be described with reference to FIG.

That is, in order to produce a fiber-reinforced urethane resin multilayer foam, first, a solid piece material (4) impregnated or impregnated with water is filled in a casting mold (5) ( Then, a predetermined number of mat-like reinforcing fibers (3) are placed, and finally, a polyurethane resin stock solution containing a small amount of water.
(6) is poured almost uniformly into the flat or curved surface of the casting mold (5) (see FIG. 2b) to obtain a molded article of the desired fiber-reinforced urethane resin multilayer foam after mold clamping and curing (see FIG. 2B). See FIG. 2c).

The manufacturing method according to the second aspect of the present invention is the same as that of the first aspect except that the order of placing the materials in the casting mold (5) is opposite to that of the first aspect. Because there is no
The description is omitted.

Next, with respect to the principle of the two-layer structure using the same urethane resin material of the present invention, an example of the method for producing a fiber-reinforced urethane resin multi-layer foam according to the present invention will be described with reference to FIG. I will explain.

First, in a state where all the materials are set in the casting mold (5) and the mold is clamped, a polyurethane resin stock solution containing a trace amount of water present on the bottom surface in the casting mold (5) is used as a catalyst. Due to the action of (1), foaming starts gradually, and one side is bound by the mold (5) and impregnated with the mat-like reinforcing fibers toward the upper surface of the mold (5) (see FIG. 3A).

A certain amount of resin that has passed through the mat starts to foam rapidly under the influence of a large amount of water from the moment it comes into contact with the solid particle material (4) that has adhered or impregnated water (FIG. 3).
b), a desired fiber-reinforced urethane resin two-layer foam is formed.

The method for producing the fiber-reinforced urethane resin multi-layer foam according to the second aspect of the present invention comprises a mold (5)
There is no special description except that the order of placing the materials therein is the reverse of the case of manufacturing the fiber-reinforced urethane resin multilayer foam according to the first aspect of the present invention.

[0029] In the above, after the fiber-reinforced high-density urethane resin foam layer is formed, the water contained in the solid small piece material that is adhered to or impregnated with the filled water with respect to the remaining foam area inside the mold. If the ratio of the amount of urethane resin permeated from between the mat-like reinforcing fibers is poor (when there is a lot of water),
Since there is a problem that the number of urea bonds increases and becomes brittle, it is necessary to optimize the amount (volume) of urethane resin passing through the mat-like reinforcing fiber and the amount of water present in the foaming area with respect to the remaining foaming area. is there.

Here, the amount of the urethane resin passing through the mat-like reinforcing fibers is determined by the number and the number of the mat-like reinforcing fibers, and the amount of a very small amount of water to be initially mixed with the polyurethane resin stock solution. This is because the passable area (porosity) for the supplied urethane resin differs depending on the number and the number of the mat-like reinforcing fibers. That is, the amount of resin penetrating into the inside is determined by the balance between the total foaming pressure generated in the supplied urethane resin and the resistance of the mat-like reinforcing fiber layer to the foaming pressure. As a result, it is possible to freely set the density ratio between the fiber-reinforced high-density urethane resin foam layer and the low-density urethane resin foam layer.

The number and the number of the mat-like reinforcing fibers can be freely set according to the required quality.

Further, the amount of the urethane resin to be supplied into the mold is naturally determined by the required heat insulating properties and the like. That is, if the required density (expansion ratio) of each layer is known, the amount of resin that passes through the mat-like reinforcing fibers with respect to the internal foaming area may be adjusted as described above.

The mat-like reinforcing fiber has another role. The urethane resin which passes through the mat-like reinforcing fiber and goes inward reversely penetrates due to a sudden increase in foaming pressure, and the molded product has a high fiber-reinforced strength. It plays the role of a barrier layer for preventing the mixed density urethane resin foam layer and the low density urethane resin foam layer from being mixed.

The basis weight of the mat-like reinforcing fiber (3) and the amount of the solid small piece material (4) adhering or impregnated with water are not particularly limited, but the mat-like reinforcing fiber is a barrier material. Since it is necessary to function as a layer, it is preferable that the eyes are clogged (having a large basis weight), and the filling amount of the solid small particle material (4) to which water is attached or impregnated Since it is preferable to increase the area as much as possible, it is preferable that the gap is large (the basis weight is small). Further, the thickness of each layer can be freely set depending on the thickness and the number of the mat-like reinforcing fibers.

The solid piece material (4) may be in the form of, for example, granules, blocks, short fibers, or needles.

Next, the amount of water will be described.

With respect to the amount of water to be added, the purpose of the present invention is to form a urethane resin foamed layer into a multi-layered structure with a difference in density. First, water contained in a polyurethane resin stock solution passes through a mat-like reinforcing fiber. Since it is added in order to generate a sufficient foaming pressure, the amount of water may be considerably smaller than the amount of water to be carried on the solid small particle material to which water is attached or impregnated. Therefore, the expression “trace amount” is used in the claims.

The ratio of the weight of water to be added is not particularly defined because it depends on the resin density ratio of the multilayer foam to be produced.

Further, when the isocyanate itself absorbs water after being left after opening, it may not be necessary to add water to the polyurethane resin stock solution.

Here, the urethane resin comprises an isocyanate, a polyol, a foaming catalyst, a gelling catalyst and a foaming agent.

Examples of the isocyanate include diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate, toluene diisocyanate (TDI), cyclohexyl isocyanate, and meta-xylene diisocyanate, and modified products thereof may be used.

Examples of the polyol include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, mannitol, pentaerythritol, diethylene triamine and the like.

Examples of the foaming catalyst include tertiary amines such as trimethylenediamine, dimethylbenzylamine and tetramethylhexamethylenediamine, and alkanolamines such as diethanolamine and dimethylaminomethanol.

As the gelling catalyst, organometallic compounds such as dibutyltin dilaurate, tin octoate, and dibutyltin diacetate are used. By changing the mixing ratio and amount of the two catalysts, the rise time and gradient of foaming can be set freely.

In the present invention, water is used as the foaming agent. However, distilled water does not need to be distilled water, and the level of domestic water such as tap water is sufficient.

Further, the solid small piece material to which water is attached or impregnated is used to secure a space for forming a low-density urethane resin foam layer between the mold and the mat-like reinforcing fiber. Therefore, there is a problem with liquids, and liquids having shape retention properties are required. Accordingly, solid particle material is meant to include both solid and semi-solid particle materials.

Here, examples of the solid small piece material include waste materials such as wood powder, paper waste, waste plastic, and rubber powder. Further, a reinforcing material such as chopped fiber or milled fiber may be used. Examples of the material of the reinforcing material include glass fiber, carbon fiber, and aramid fiber. Further, fillers such as glass balloons, calcium carbonate, clay, and mica may be used. Examples of the semi-solid small piece material include a water-absorbent resin, agar, and the like.

However, since the low-density urethane resin foam layer needs to contain as many urethane resin foam cells as small as possible from the viewpoint of heat insulation, the solid small particle material which is attached or impregnated with water is powdery. If it is, it is preferable that the material has a large particle size, and if it is a fibrous material, it is bulky with respect to the internal space such as a fiber having a long fiber length. That is, it is preferable that the volume of the solid particle material to which water is attached or impregnated is 10 to 50% of the total low foaming space volume. The reason is that if it is more than 50%, the space for forming the low-density urethane resin foam layer inside is densely packed and the low-density urethane resin foam layer cannot be sufficiently formed, so that the heat insulating property is reduced and On the other hand, if it is less than 10%, a space for forming a sufficient low-density urethane resin foam layer cannot be formed.

It is to be noted that the above-mentioned solid or semi-solid piece material may be used by being rubbed and adhered to a mat-like body or a net-like body.

The mat-like reinforcing fibers include, for example, chopped strand mats, continuous mats, cloths, and the like, and the materials thereof include glass fibers, carbon fibers, and aramid fibers.

In addition, if necessary, an internal release agent, a foam stabilizer, a stabilizer, a weather resistance improver, a coloring agent, and the like can be added.

The urethane resin multi-layer foams having different expansion ratios obtained by the present invention have high strength on the fiber reinforced low foam layer side.
Because it is high hardness and the high foam layer side has heat insulation,
No need to attach surface materials for reinforcement.
It is suitably used for flooring and the like.

Although not shown in the drawings, the method for producing a fiber-reinforced urethane resin multilayer foam according to the second aspect of the present invention differs only in that the upper layer and the lower layer after demolding are opposite to each other. This is almost the same as the method for producing a fiber-reinforced urethane resin multilayer foam according to the first aspect of the present invention.

Next, a method for producing the sandwich-type fiber-reinforced urethane resin multilayer foam according to the third aspect of the present invention will be described with reference to FIGS.

First, referring to FIG. 5, an undiluted polyurethane resin solution (6) containing a small amount of water was poured into a casting mold (5).
(5) Pour almost uniformly to the plane or curved surface,
Then, a predetermined number of mat-like reinforcing fibers (3) are placed (FIG. 5).
a), a solid small piece material (4) adhering or impregnated with water is arranged horizontally on the inner surface of the mold so as to be almost free of irregularities. Further, mat-like reinforcing fibers (3) and polyurethane resin stock solution (6) ) In order (FIG. 5b) to obtain a desired molded product after clamping and curing (FIG. 5c). At this time, the water carried on the solid small piece material (4) is consumed while forming a urea bond when a rapid low-foaming layer is formed.

Next, the principle of sandwiching the same urethane resin material of the present invention will be described with reference to FIG.

In a state where all the materials are set in the casting mold (5) and the mold is clamped, first, a polyurethane resin stock solution containing a small amount of water existing on both front and back sides gradually starts foaming by the action of the catalyst. Since both the front and back surfaces are constrained by the mold surface, they are impregnated with the mat-like reinforcing fiber and head toward the inside of the mold from both front and back surfaces (FIG. 6a).

A certain amount of resin that has passed through the mat-like reinforcing fiber starts to foam rapidly under the influence of a large amount of water from the moment it comes into contact with the water-adhering or impregnated solid particle material (FIG. 6b). The core is filled with a low-density urethane resin foam layer to form a sandwich molded product.

After the front and back layers are formed, if the ratio of the amount of water existing between the mat-like reinforcing fibers and the amount of resin permeated from the mat-like reinforcing fibers to the foaming area inside the mold is poor, that is, the amount of water is large. Therefore, the amount (volume) of the urethane resin passing through the mat-like reinforcing fibers and the amount of water existing between the mat-like reinforcing fibers need to be optimized with respect to the internal foaming area. is there.

Here, the amount of the urethane resin passing through the mat-like reinforcing fibers is determined by the number and the number of the mat-like reinforcing fibers and the amount of a small amount of water to be initially mixed with the polyurethane resin stock solution. This is because the passable area (porosity) for the urethane resin supplied to the front and back layers differs depending on the number and the number of the mat-like reinforcing fibers.

That is, the amount of resin penetrating into the inside is determined by the balance between the total foaming pressure generated in the urethane resin supplied to the front and back layers and the resistance to the foaming pressure of the mat-like reinforcing fiber layer. As a result, the density ratio between the front and back layers and the intermediate layer can be freely set.

The number and the number of the mat-like reinforcing fibers used on the front and back surfaces can be freely set according to the required quality, and need not always be the same. Further, the amount of the urethane resin to be supplied to the front and back surfaces is naturally determined by the required heat insulating property. That is, if the necessary internal density (expansion ratio) is known, the amount of resin that passes through the mat-like reinforcing fibers with respect to the internal foaming area may be adjusted as described above.

Further, the mat-like reinforcing fibers on the front and back sides serve as a barrier layer, and the resin that has passed through the mat-like reinforcing fibers toward the inside is pushed up to the surface due to a sudden increase in foaming pressure, and the surface of the molded article is raised. The point that the high-density urethane resin foam layer and the low-density urethane resin foam layer are not mixed is the same as the above case.

In the method for producing a sandwich-type fiber-reinforced urethane resin multilayer foam according to the third aspect of the present invention, an object is to form a urethane resin foam layer in which the core is higher in foam than the surface. The other points are almost the same as those of the method for producing a fiber-reinforced urethane resin multilayer foam according to the first aspect of the present invention.

(Function) The invention of claim 1 of the present invention
Method for producing a fiber-reinforced urethane resin multi-layer foam in which a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber and a low-density urethane resin foam layer containing solid piece material are integrated After pouring a polyurethane resin stock solution containing a small amount of water as a foaming agent into a casting mold, at least one mat-like reinforcing fiber is placed in the same mold, and then the mat-like reinforcing fiber is placed. A series of steps of filling a solid small piece material on which water as a foaming agent is adhered or impregnated and closing the mold is completed before foaming of the polyurethane resin stock solution is completed. .

Further, according to the invention of claim 2 of the present invention, almost the same method is used, except that the upper layer and the lower layer after demolding are reversed from those of the invention of claim 1 described above. It is a feature.

Further, the invention according to claim 3 of the present invention provides:
A method for producing a three-layer sandwich-structured fiber-reinforced urethane resin foam in which a fiber-reinforced high-density urethane resin foam layer on the front and back surfaces and a low-density urethane resin foam layer on a core are integrated, After injecting a polyurethane resin stock solution containing a trace amount of water as a foaming agent into a mold, at least one mat-like reinforcing fiber is placed in the mold, and then the foaming agent is placed on the mat-like reinforcing fiber. Is filled with a solid particle material adhering or impregnated with water, and at least one mat-like reinforcing fiber is placed on the solid particle material, and finally, a foaming agent is placed on the mat-like reinforcing fiber. A series of steps of injecting a polyurethane resin stock solution containing a trace amount of water and closing the mold are completed before the foaming of the polyurethane resin stock solution is completed.

According to the method of the present invention, in each case,
Since the fiber-reinforced high-density urethane resin foam layer and the low-density urethane resin foam layer having a large expansion ratio (contrast) can be formed in one step, a multilayer panel can be manufactured with low equipment cost and high productivity. . In addition, the layers are essentially made of the same urethane resin, and the layers are firmly adhered to each other for simultaneous molding, and have excellent temporal stability.

Further, since it is not necessary to attach a reinforcing surface material or the like to the foam molded in advance with an adhesive, the workability and workability are excellent, and the number and the number of mat-like reinforcing fibers on the surface portion are improved. The strength of the fiber-reinforced urethane resin multilayer foam can be freely designed by appropriately selecting.

In any of the above-mentioned methods for producing a fiber-reinforced urethane resin multilayer foam, a high-density urethane resin foam layer is formed in a mold by filling a solid piece of material adhering or impregnated with water. To secure space for
Further, rapid foaming is excited by water present in the portion, and a fiber-reinforced urethane resin multilayer foam can be obtained.

[0071]

Next, examples of the present invention will be described together with comparative examples.

Example 1 Using the mold (5) shown in FIG. 2, a flat fiber-reinforced urethane resin multilayer foam of the present invention shown in FIG. 1 was produced.

The working conditions in this example were as follows.

Mold size: height 300 mm x width 400 m
mx20 (thickness) mm Isocyanate; SBU isocyanate 0581 (manufactured by Sumitomo Bayer Urethane Resin Co., Ltd.) Polyol; SBU Tpolyol-6FT03 (manufactured by the company) Weight mixing ratio; isocyanate: polyol = 144: 1
00 Density of cured resin; 1.2 g / cm ³ (non-foamed) Note that all units of density described below are g / cm ³ . The parts by weight of the water and the amine catalyst described below are based on 100 parts by weight of the polyol.

The density of the fiber-reinforced high-density urethane resin foam layer and the low-density urethane resin foam layer were measured according to JISK
The measurement of the resin densities of the surface layer and the inner layer was performed based on the volume of each layer before firing and the weight change after firing (635 ° C.).

First, isocyanate, polyol, water (0.2 parts by weight of polyol) and amine catalyst (0.3 parts by weight of polyol) were blended so as to have a total weight of 820 g and mixed by a stirrer. , And uniformly injected into the mold.

Next, the same size (30 mm) as the flat portion of the molding die is used.
Chopped strand mat cut to 0x400mm (Product name: Graspace, # 450, Product number: GP4
50RA186SS, manufactured by Nitto Boseki Co., Ltd.), and about 100 g of 25 mm glass short fibers (Nitto Boseki Co., Ltd.) as a solid small piece material on which water as a foaming agent is adhered or impregnated. 2.0 parts by weight of water with respect to the above-mentioned polyol was placed.

After the mold was clamped and cured, the mold was released to obtain a two-layer fiber-reinforced urethane resin foam.

As a result of the density measurement, the density of the fiber-reinforced high-density urethane resin foam layer was 0.70, and the density of the low-density urethane resin foam layer was 0.19. The total time required for molding was 5 minutes.

Example 2 First, wood chips (average particle size: 750 μm) were used as a solid small piece material to which water as a foaming agent was adhered or impregnated.
A mixture of 50 g of water and 1.6 parts by weight of a spray applied to the above polyol was spread almost uniformly in the mold.

Next, the same size (3
00 × 400 m), two chopped strand mats (# 600 A type surface treatment, manufactured by Nitto Boseki Co., Ltd.) are placed one on top of the other, and finally isocyanate, polyol, water (0.2 parts by weight of polyol) and An amine catalyst (0.3 parts by weight of polyol) was used in a total weight of 110
After mixing with a stirrer so as to be 0 g, the mixture was uniformly poured into a mold.

After the mold was closed and cured, the mold was released to obtain a fiber-reinforced urethane resin two-layer foam.

As a result of the density measurement, the density of the fiber-reinforced high-density urethane resin foam layer was 0.80, and the density of the low-density urethane resin foam layer was 0.24. The total time required for molding was 5 minutes.

Comparative Example 1 The compounding of the urethane resin for forming the high-density urethane resin foam layer and the low-density urethane resin foam layer was set as follows.

[0085]

[Table 1] Prepare two upper molds, first place two chopped strand mats (same as in Example 1) in the lower mold,
Clamp the upper mold to form a clearance of 10mm,
700 g of urethane resin was injected.

After 4 minutes, it was confirmed that the urethane resin for forming the high-density foamed layer was before and after the tack-free time.
The upper mold was replaced with an upper mold having a clearance of 0 mm, and after clamping, 140 g of resin was injected and cured to obtain a fiber-reinforced urethane resin two-layer foam.

As a result of the density measurement, the density of the fiber-reinforced high-density urethane resin foam layer was 0.6, and the density of the low-density urethane resin foam layer was 0.12. The total time required for molding was 10 minutes.

From the above, it was confirmed that Examples 1 and 2 according to the present invention can form a urethane resin two-layer foam with higher production than Comparative Example 1 according to the description of Japanese Patent Publication No. 60280/1991.

Example 3 Using the mold (5) shown in FIG. 5, a flat sandwich type fiber-reinforced urethane resin multilayer foam of the present invention shown in FIG. 4 was produced.

The working conditions in this embodiment are as follows, and are almost the same as those in the first embodiment.

The measurement of the total density was carried out according to JIS K7112.
According to the measurement of the resin density of the surface layer and the inner layer,
It was determined from the volume of each layer before firing and the weight change after firing (635 ° C.).

First, isocyanate, polyol, water (0.2 parts by weight of polyol) and amine catalyst (0.3 parts by weight of polyol), whose amounts were adjusted so that the overall density after molding was about 0.4, were added. The mixture was mixed with a stirrer, and then the mixture was divided into two equal parts.

Then, one of the divided blends was poured into a mold, and then the same size (300 × 4) as the flat part of the mold.
00mm) chopped strand mat (# 600, A type surface treatment, manufactured by Nitto Boseki Co., Ltd.)
Are stacked on top of each other, and the wood chips (average size: 7
50 μm) 150 g of water with respect to the above polyol.
What was applied by spraying so as to be 0 parts by weight was spread almost uniformly in the mold.

Further, two chopped strand mats (same as above) were stacked from the top, and the remaining polyurethane resin stock solution finally divided into two equal parts was poured uniformly on the surface of the chopped strand mats, and after 7 minutes from the mold clamping, demolded, A reinforced urethane resin multilayer foam was obtained.

Since the density of the molded article itself changes relatively gradually from the front and back to the center, the distribution of the density and thickness classified roughly into the inside and outside of the chopped strand mat is rough. It was as follows.

[0096]

[Table 2] Here, the overall density refers to the density of the entire sandwich foam.

Comparative Example 2 First, two chopped strand mats (same as in Example 1) were placed in a mold and wood chips (average size: 750 μm)
m) 150 g (one that does not carry water) is uniformly supplied to the mold surface, two chopped strand mats (the same as in Example 1) are placed, the mold is clamped, and then a urethane resin (however,
1.5 parts by weight of water and 0.3 parts by weight of catalyst are added to the mold so that the overall density becomes about 0.5, and the mixture is cured and cooled for 10 minutes to form an integral skin. Got the form. (The heat generation temperature of the urethane resin at the center of the mold was about 100 ° C.) The density and thickness of this molded product were as follows.

[0098]

[Table 3] Comparative Example 3 First, two chopped strand mats (same as in Example 1) were placed in a mold and wood chips (average size: 750 μm)
m) 150 g (one that does not carry water) is evenly supplied to the mold surface, two chopped strand mats (same as above) are placed, the mold is clamped, and then a urethane resin (provided that water is 1.4 with respect to the polyol). Parts by weight of the catalyst and 0.3 parts by weight of the catalyst) were added to the mold so that the overall density was about 0.30, the atmospheric pressure was reduced to 550 Torr, and after 2 minutes, the atmospheric pressure was changed to 760 Torr. Hold for 5 minutes. Thus, a foam of different hardness was obtained. The density and thickness configuration of this molded product were as follows.

[0099]

[Table 4] Next, the results of evaluating the physical properties of the above three molded products are shown below.

[0100]

[Table 5] Test method The bending strength was measured according to JIS K7055. The thermal conductivity (5 ° C.) was measured in accordance with the JIS A1412 two-flow method.

As described above, according to the present invention, as compared with the integral skin foam of Comparative Example 2, the density was almost the same, the bending strength was almost the same, and the thermal conductivity (heat insulation) was significantly improved. Was done. Further, in Example 3, the results were excellent in bending strength and thermal conductivity at a density similar to that of Comparative Example 3.

[0102]

According to the present invention, as described above, first, claim 1 is described.
The described invention is directed to a fiber-reinforced urethane resin multi-layer foam in which a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber and a low-density urethane resin foam layer containing a solid piece material are integrated. A method for producing a body, comprising: injecting a polyurethane resin stock solution containing a small amount of water as a foaming agent into a casting mold, and then adding at least one liquid to the same mold.
A series of steps of placing a sheet of mat-like reinforcing fiber, filling the mat-like reinforcing fiber with a solid small piece of material adhering or impregnated with water as a foaming agent, and clamping the mold. Is completed before foaming is completed.

According to a second aspect of the present invention, there is provided a method for producing a fiber-reinforced urethane resin multi-layer foam in which the upper layer and the lower layer after demolding are reversed from those of the first aspect. It is.

Further, according to the third aspect of the present invention,
A method for producing a three-layer sandwich-structured fiber-reinforced urethane resin foam in which a fiber-reinforced high-density urethane resin foam layer on the front and back surfaces and a low-density urethane resin foam layer on a core are integrated, After injecting a polyurethane resin stock solution containing a trace amount of water as a foaming agent into a mold, at least one mat-like reinforcing fiber is placed in the mold, and then the foaming agent is placed on the mat-like reinforcing fiber. Is filled with a solid particle material adhering or impregnated with water, and at least one mat-like reinforcing fiber is placed on the solid particle material, and finally, a foaming agent is placed on the mat-like reinforcing fiber. A series of steps of injecting a polyurethane resin stock solution containing a trace amount of water and closing the mold are completed before the foaming of the polyurethane resin stock solution is completed.

According to the method of the present invention, in each case,
Since the fiber-reinforced high-density urethane resin foam layer and the low-density urethane resin foam layer having a large expansion ratio (contrast) can be formed in one step, a multilayer panel can be manufactured with low equipment cost and high productivity. . In addition, the layers are essentially made of the same urethane resin, and the layers are firmly adhered to each other for simultaneous molding, and have excellent temporal stability.

Further, since it is not necessary to attach a reinforcing surface material or the like to the preformed foam with an adhesive, the workability and workability are excellent, and the number and the number of mat-like reinforcing fibers on the surface portion are improved. The strength of the fiber-reinforced urethane resin multilayer foam can be freely designed by appropriately selecting.

In any of the above-mentioned methods for producing a fiber-reinforced urethane resin multi-layer foam, a high-density urethane resin foam layer is formed in a mold by filling a solid small piece of material which is adhered or impregnated with water. To secure space for
Further, there is an effect that rapid foaming is excited by water present in the portion and a fiber-reinforced urethane resin multilayer foam can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a fiber-reinforced urethane resin multilayer foam produced according to the first embodiment of the present invention.

FIG. 2 is an explanatory view showing one embodiment of a manufacturing process according to claim 1 of the present invention.

FIG. 3 is a conceptual diagram showing the principle of two layers in urethane resin molding according to the present invention.

FIG. 4 is a cross-sectional view of a fiber-reinforced urethane resin multilayer foam produced according to the third aspect of the present invention.

FIG. 5 is an explanatory view showing one embodiment of a manufacturing process according to claim 5 of the present invention.

FIG. 6 is a conceptual diagram showing the principle of forming a sandwich in urethane resin molding according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 high-density urethane resin foam layer 2 low-density urethane resin foam layer 3 mat-like reinforcing fiber 4 solid small piece material 5 casting mold 6 polyurethane resin stock solution

Continuation of the front page (51) Int.Cl. ⁶ Identification code FI B32B 5/32 B32B 5/32 // B29K 75:00 105: 04 105: 08 B29L 9:00

Claims (3)

[Claims] 1. A fiber-reinforced urethane resin multi-layer foam in which a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber and a low-density urethane resin foam layer containing a solid piece material are integrated. A method for producing a body, comprising: injecting a polyurethane resin stock solution containing a small amount of water as a foaming agent into a casting mold, and then adding at least one liquid to the same mold.
A series of steps of placing a sheet of mat-like reinforcing fiber, filling the mat-like reinforcing fiber with a solid small piece of material adhering or impregnated with water as a foaming agent, and clamping the mold. A method for producing a fiber-reinforced urethane resin multilayer foam, which is completed before foaming is completed. 2. A fiber-reinforced urethane resin multi-layer foam in which a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber and a low-density urethane resin foam layer containing a solid piece material are integrated. A method for producing a body, comprising: filling a casting mold with a solid small piece material adhering or impregnated with water as a foaming agent, and placing at least one mat-like reinforcing fiber in the mold. Then, a series of steps of injecting a polyurethane resin stock solution containing a small amount of water as a foaming agent onto the mat-like reinforcing fiber and closing the mold are completed before foaming of the polyurethane resin stock solution is completed. A method for producing a fiber-reinforced urethane resin multilayer foam. 3. A fiber-reinforced urethane resin multi-layer foam in which a fiber-reinforced high-density urethane resin foam layer containing at least one mat-like reinforcing fiber and a low-density urethane resin foam layer containing a solid piece material are integrated. A method for producing a body, comprising: injecting a polyurethane resin stock solution containing a small amount of water as a foaming agent into a casting mold, and then adding at least one liquid to the same mold.
One sheet of the mat-like reinforcing fiber is placed, and then the mat-like reinforcing fiber is filled with a solid particle material that has been adhering or impregnated with water as a foaming agent. A series of steps of placing a sheet of mat-like reinforcing fiber and finally injecting a polyurethane resin stock solution containing a trace amount of water as a foaming agent onto the mat-like reinforcing fiber and clamping the mold, foaming of the polyurethane resin stock solution. A method for producing a fiber-reinforced urethane resin multilayer foam, which is completed before finishing.