JP2019119790A - Fiber reinforced composite and manufacturing method therefor - Google Patents

Abstract

To provide a composite of a cement-based inorganic material and expandable polyurethane, having right weight and high flexure strength needed in JIS A 5908.SOLUTION: There is provided a fiber reinforced composite having a fiber mat and a polyurethane-based foam layer, in which the polyurethane-based foam layer is a foam body of a mixture containing a cement-based inorganic filler consisting of cement, cement and sand or cement, sand and gravel, polyisocyanate, polyol, a foam stabilizer, a catalyst and water, the fiber mat is arranged on at least one single surface area of the fiber reinforced composite, density of the fiber reinforced composite is 800 kg/mor less and flexure strength measured according to JIS A 5908 is 18 MPa or more.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a fiber reinforced composite and a method of manufacturing the same. More particularly, the present invention relates to a fiber-reinforced composite comprising a fiber mat and a polyurethane foam layer, which has excellent lightness and flexural strength, and a method of producing the same.

  Cement, mortar and concrete (hereinafter, also referred to as “cement-based inorganic material”) are basic structural materials in the field of architecture and civil engineering, and are relatively inexpensive and versatile materials. From the viewpoint of weight reduction and strength development, it has been studied to create a composite of cement-based inorganic material and foamable polyurethane.

  In Patent Document 1, a raw material composition comprising 100 parts by weight of cement, 6 parts by weight of polyisocyanate, 0.6 parts by weight of polyol, 120 parts by weight of sand, 180 parts by weight of gravel, 60 parts by weight of water is put into a molding machine and condensed. It is disclosed that after 72 hours, it was removed from the mold and further cured for 28 days to obtain a composite concrete material having a compressive strength of 160 to 300 kg / cm 2 (16 to 30 MPa).

  In Patent Document 2, 250 parts by weight of Portland cement, 290 parts by weight of water, and 100 parts by weight of a urethane raw material composition (equimolar mixture of diphenylmethane diisocyanate and polypropylene glycol) are mixed and filled in a mold, and then It is disclosed that the mixture was cured and completely cured to obtain a cement-based polyurethane composite having a compressive strength of 10 kgf / cm 2 (1 MPa) or more (the same document, Example 3).

In Patent Documents 3 and 4, 300 g of a urethane-based curing agent main agent (polyisocyanate-based prepolymer), 15 g of a urethane-based curing agent auxiliary (polyol and catalyst), and a blast furnace cement B type (silica blast furnace slag 30 to 60% or less It is disclosed that a composition containing 600 g of Portland cement and gypsum and mixed and pulverized and mixed and mixed with 600 g of water and 240 to 360 g of water is mixed to form a slurry, which is then hardened to form a foamable solid. . The curing start time is 1 to 3 minutes, and heat generation during curing reaches 76 to 78 ° C., and the compressive strength of the foamable solid after one-day aging is 69.4 to 29.0 kgf / cm ² (6.9 to A high strength of 2.9 MPa) is realized (Example 1, Nos. 11 to 13 of documents 3 and 4).

  Patent Document 5 discloses that, by selecting a specific polyether polyol, a cement-based polyurethane foam composite having both short mold removability, low specific gravity and high compression hardness is obtained. And the compressive strength of the cement-type polyurethane foam composite after curing for one week has shown 1.2-1.7 Mpa by density 409-618 kg / m <3>.

  On the other hand, Letizia Verdolotti et al (Non-patent document 1) mix cement powder with a polyol, a catalyst, a silicone surfactant, a crosslinking agent and water as a foaming agent at room temperature, and after stirring for 2 minutes, an isocyanate (diphenylmethane diisocyanate (MDI) It is reported that a polyurethane-cement foam composition (polymer cement) is obtained, with the ratio of urethane to cement being constant at 2/3 by adding. In particular, the composition is stirred for 40 seconds, filled in a 50 × 50 × 5 cm 3 tree mold and solidified at normal temperature for 20 minutes, and the obtained molded product is hydrated in water at 60 ° C. for 72 hours for polymer cement ( Disclosed are the results of obtaining "HIRP-C") and comparing the compressive strength with unhydrated polymer cement ("PC"). According to the test results, the compressive strengths of HIRP-C and PC show high strengths of 4.31 MPa and 3.4 Mpa, respectively.

However, according to JIS A 5908: 2015, a structural particle board is required to have a bending strength (density of 0.4 to 0.9 g / cm ³ ) of 18 MPa or more. It has not been reported at all that such strengths have been achieved in composites of conventional cement-based inorganic materials and foamable polyurethanes. On the other hand, structural materials are also required to have low density (light weight) in consideration of workability. Furthermore, in view of the rapidity of the material production, it can be said that the composite material is also required to be obtained in a short demolding time.

Japanese Patent Publication No. 50-6213 JP 2002-38619 A Japanese Patent Application Laid-Open No. 06-80483 Japanese Patent Application Laid-Open No. 06-80966 JP, 2016-56077, A

Letizia Verdolotti et al. "J. Mater. Sci. (2012) 47: 6948-6957"

  The present invention aims to solve the problems of the prior art. That is, according to the present invention, in the composite material of cement-based inorganic material and foamable polyurethane, low density (light weight) and high flexural strength required by JIS A 5908: 2015 (hereinafter referred to as "flexural strength") One goal is to simultaneously achieve Furthermore, another object of the present invention is to obtain such a composite in a short demolding time.

The present invention includes the following.
(1) A fiber-reinforced composite comprising a fiber mat and a polyurethane foam layer,
Foaming of a mixture comprising the above-mentioned polyurethane-based foam layer, cement-based inorganic filler consisting of cement, sand with sand or cement and sand with gravel, polyisocyanate, polyol, foam stabilizer, catalyst and water Is the body,
The fiber mat is disposed in at least one side area of the fiber reinforced composite,
A fiber-reinforced composite, wherein the density of the fiber-reinforced composite is 800 kg / m ³ or less and the flexural strength measured by JIS A 5908 is 18 MPa or more.
(2) The fiber mat is selected from at least one of glass fiber mat, carbon fiber mat, aramid fiber mat, unsaturated polyester fiber mat, vinyl ester fiber mat, epoxy fiber mat, amide fiber mat, vegetable fiber mat, The fiber reinforced composite as described in (1).
(3) The fiber reinforced composite according to (1) or (2), wherein the fiber mat is a chopped strand mat or a roving cross.
(4) The fiber reinforced composite according to any one of (1) to (3), wherein the fiber mat is a glass chopped strand mat defined by JIS R 3411.
(5) The fiber reinforced composite according to any one of (1) to (4), wherein a unit weight of the fiber mat is 200 g / m ² or more.
(6) The fiber reinforced composite according to any one of (1) to (5), wherein the weight ratio of the cement-based inorganic filler to the total of polyisocyanate and polyol is 50:50 to 90:10.
(7) The fiber reinforced composite according to any one of (1) to (6), wherein the weight ratio of the polyurethane foam layer to the fiber mat is 100: 0.5 to 100: 10.
(8) The fiber-reinforced composite according to any one of (1) to (7), wherein the single-sided region is a region within 5 mm inward from the single-sided surface of the fiber-reinforced composite.
(9) The fiber reinforced composite according to any one of (1) to (8), wherein the cement-based inorganic filler is cement and sand, or cement and sand and gravel.
(10) The fiber reinforced composite according to any one of (1) to (9), wherein the weight ratio of the cement to the total of sand and gravel is 1: 1 to 1: 3.
(11) The fiber reinforced composite according to any one of (1) to (10), wherein the weight ratio of the polyisocyanate to the polyol is 70:30 to 90:10.
(12) The fiber reinforced composite according to any one of (1) to (11), wherein the mixture has at least one of the following (A) to (C):
(A) The cream time of the above mixture at a liquid temperature of 25 ° C is 10 to 30 seconds (B) The gel time of the above mixture at a liquid temperature of 25 ° C is 40 to 70 seconds (C) The above mixture of the above mixture at a liquid temperature of 25 ° C The tack time is 70 to 110 seconds.
(13) A method for producing a fiber-reinforced composite according to any one of (1) to (12),
The manufacturing method which comprises at least the steps of pouring the above mixture into a mold and demolding.
(14) The production method according to (13), which is within 5 minutes from injecting the mixture into a mold to releasing the mold.
(15) The method according to (13) or (14), wherein the fiber mat is arranged in advance in the mold such that the polyurethane foam layer obtained by foaming the mixture adheres to the fiber mat. Manufacturing method.

  According to the present invention, it is possible to provide a fiber reinforced composite having low density (light weight) and high flexural strength required by JIS A5908. Also, according to the present invention, such a fiber reinforced composite can be manufactured in a remarkably short demolding time. Such a fiber-reinforced composite can be manufactured in a short time, and can reduce the amount of use of an expensive material such as polyurethane while providing weight reduction and strength improvement, and thus it is a foundation in the construction and civil engineering fields. Can be used advantageously as structural structural materials.

It is a schematic diagram which shows one embodiment of the fiber reinforced composite body of this invention. The frame line indicates a fiber reinforced composite and the dotted line indicates a fiber mat. FIG. 5 is a schematic view showing another embodiment of the fiber-reinforced composite of the present invention. It is a schematic diagram of the comparative example which arrange | positioned the fiber mat in the middle of the polyurethane-type foam layer. It is a cross-sectional photograph of one embodiment of the fiber reinforced composite of the present invention.

The fiber-reinforced composite of the present invention comprises a fiber mat and a polyurethane foam layer, and the polyurethane foam layer is a cement-based inorganic filler comprising any of cement, cement and sand, or cement and sand and gravel. Fiber reinforced composite, wherein the fiber mat is disposed on at least one side region of a polyurethane foam layer, wherein the fiber mat is disposed on at least one side of the polyurethane foam layer. It has a density of 800 kg / m ³ or less and a flexural strength of 18 MPa or more measured in accordance with JIS A 5908: 2015.
Hereinafter, each component of the present invention will be described.

Fiber Mat The "fiber mat" used in the present invention is a mat-like molded article having reinforcing fibers and a binder such as a thermoplastic resin as its components, and various materials may be used unless the effects of the present invention are impaired. it can.

The unit density (area weight), thickness and the like of the fiber mat are not particularly limited as long as the effects of the present invention are not impaired, and may be various depending on the type and blending ratio of the reinforcing fibers. The unit density of the fiber mat, from the viewpoint of sufficiently securing the reinforcement strength, preferably 200 g / ^{m 2} or more, more preferably 200 to 1000 g / ^{m 2,} more preferably at 200 to 600 g / ^{m 2} And more preferably 200 to 500 g / m ² .

  The thickness of the fiber mat is not particularly limited as long as the effects of the present invention are not impaired, but is preferably 5 mm or less, more preferably 0.5 to 5 mm, still more preferably 1 to 5 mm more preferably 1 ~ 2 mm.

  As long as the effects of the present invention can be exhibited, the fiber mat may be used as a single sheet or a plurality of sheets may be overlapped. When the fiber mats are used in layers, the preferable ranges of the total thickness and the total weight of the plurality of fiber mats are respectively the same as the preferable ranges when using a single fiber mat.

  The “reinforcing fiber” is a fiber material that functions as a reinforcing material in the obtained fiber composite. The strength of the entire fiber composite can be secured by having a structure in which the reinforcing fibers are bound by a binder such as a thermoplastic resin. The material of the reinforcing fiber is not particularly limited, and includes synthetic resin, vegetable fiber and inorganic fiber, preferably inorganic fiber.

Various materials can be used for the above-mentioned "synthetic resin" without specifying the type in particular. For example, aramid fibers, unsaturated polyester fibers, vinyl ester fibers, epoxy fibers, amide fibers and the like.
The "plant fiber" is a fiber derived from a plant. It includes fibers obtained from plants and fibers obtained by treating fibers obtained from plants.
As this vegetable fiber, kenaf, jute hemp, manila hemp, sisal hemp, cocoon, mulberry, persimmon, banana, pineapple, coconut, coconut, corn, sugar cane, bagasse, palm, papyrus, persimmon, esparto, savigrass, wheat, rice, bamboo And vegetable fibers obtained from various plants such as various conifers (eg, cedar and cypress), broadleaf trees and cotton flowers. This vegetable fiber may use only 1 type and may use 2 or more types together. Among these, kenaf (ie, kenaf fiber as vegetable fiber) is preferred. Kenaf is an extremely fast-growing annual grass and has excellent carbon dioxide absorbability, so it can contribute to the reduction of the amount of carbon dioxide in the atmosphere and the effective use of forest resources.

  Moreover, the site | part of the plant body used as said vegetable fiber is not specifically limited, It may be any site | part which comprises plant bodies, such as a wood part, a non-wood part, a leaf part, a stem part, and a root part. Furthermore, only a specific site may be used, or two or more different sites may be used in combination.

The above-mentioned kenaf is a plant having woody stems and classified into mallow. The kenaf includes hibiscus cannabinus and hibiscus sabdariffa in scientific names, etc., and includes commonly known names such as red hemp, cuban kenaf, hemp, taikenafu, mesta, bimuri, ambari hemp and bombay hemp. The jute is a fiber obtained from jute hemp. The jute hemp includes hemp and linnaceous plants including jute (Couma, Corchorus capsularis L.), and Tunishes (Tunaso), Shimatsunaso and Morohiya.
The vegetable fibers may be used singly or in combination.

  Examples of the above-mentioned "inorganic fibers" include glass fibers (including glass wool and the like) and carbon fibers and the like, with preference given to glass fibers. These inorganic fibers may be used singly or in combination.

  Furthermore, any one of synthetic fibers, vegetable fibers and inorganic fibers may be used alone, or synthetic fibers, vegetable fibers and inorganic fibers may be used in combination.

  The shape and size of the reinforcing fiber are not particularly limited, but the fiber length is preferably 1 to 150 mm. High strength (bending strength etc.) can be imparted to the fiber composite obtained thereby. The fiber length is more preferably 1 to 100 mm, more preferably 1 to 20 mm, and particularly preferably 1 to 10 mm.

  The fiber diameter is not particularly limited, but is preferably 1 mm or less, more preferably 0.01 to 1 mm, still more preferably 0.02 to 0.7 mm, and particularly preferably 0.03 to 0.5 mm. When the fiber diameter is in the above range, a fiber composite having particularly high strength can be obtained. The content of the fiber is not particularly limited, but is preferably 0.5 to 10% by mass (particularly 0.5 to 3% by mass) based on the whole of the reinforcing fiber.

  In addition, the said fiber length means an average fiber length (it is the same as that of the following), According to JISL1015, a single fiber is taken out at a time at random at a direct method at a direct method, A fiber length is measured on a scale, and a total It is the average value measured about 200 pieces. Further, the above fiber diameter means an average fiber diameter (the same applies hereinafter), randomly take out one single fiber at a time, and measure the fiber diameter at the center in the longitudinal direction of the fiber using an optical microscope. It is an average value measured for the book.

In order to bond the reinforcing fibers together, thermoplastic resin fibers are suitably used as a binder. The “thermoplastic resin fiber” is a component which is contained as a thermoplastic resin fiber in the above-mentioned fiber mat and is melted in a molding step or the like to bond reinforcing fibers together.
Examples of the thermoplastic resin constituting the thermoplastic resin fiber include polyolefin, polyester resin, polystyrene, acrylic resin, polyamide resin, polycarbonate resin, polyacetal resin, and ABS resin. Among these, as polyolefin, polypropylene, polyethylene, an ethylene propylene random copolymer, etc. are mentioned. Examples of polyester resins include aliphatic polyester resins such as polylactic acid, polycaprolactone and polybutylene succinate, and aromatic polyester resins such as polyethylene terephthalate, polytrimethylene terephthalate and polybutylene terephthalate. The acrylic resin is a resin obtained by using methacrylate and / or acrylate and the like. These thermoplastic resins may be resins which have been modified to enhance the affinity to the reinforcing fibers (in particular, the surface of the reinforcing fibers). Moreover, the said thermoplastic resin may be used individually by 1 type, and may be used combining 2 or more types.

  As said modified resin, the polyolefin which improved the affinity with respect to a reinforcement fiber (material which comprises a reinforcement fiber) is mentioned, for example. More specifically, when the reinforcing fiber is a vegetable fiber, it is preferable to use a polyolefin acid-modified with a compound having a carboxyl group or a derivative thereof (such as an anhydride group). Furthermore, it is more preferable to use an unmodified polyolefin and a maleic anhydride modified polyolefin in combination, and it is particularly preferable to use an unmodified polypropylene and a maleic anhydride modified polypropylene in combination.

  Moreover, as this maleic anhydride modified polypropylene, a low molecular weight type is preferable. Specifically, for example, the weight average molecular weight (by GPC method) is preferably 25,000 to 45,000. The acid value (according to JIS K 0070) is preferably 20 to 60. In the present invention, it is particularly preferable to use a maleic anhydride-modified polypropylene having a weight average molecular weight of 25,000 to 45,000 and an acid value of 20 to 60, and it is particularly preferable to use this maleic anhydride-modified polypropylene in combination with an unmodified polypropylene. In this combined use, when the total of the modified polypropylene and the unmodified polypropylene is 100% by mass, the modified polypropylene is preferably 1 to 10% by mass, and more preferably 2 to 6% by mass. In this range, particularly high mechanical properties can be obtained.

Among these thermoplastic resins, polyolefins and polyester resins are preferred. Among the above-mentioned polyolefins, polypropylene is preferred.
The polyester resin is preferably a biodegradable polyester resin (hereinafter, also simply referred to as "biodegradable resin"). This biodegradable resin is exemplified below.
(1) Homopolymers of hydroxycarboxylic acids such as lactic acid, malic acid, glucose acid and 3-hydroxybutyric acid; Hydroxycarboxylic acid based aliphatics such as copolymers using at least one of these hydroxycarboxylic acids polyester.
(2) Polycaprolactone, a caprolactone based aliphatic polyester such as a copolymer of caprolactone with at least one of the above-mentioned hydroxycarboxylic acids.
(3) Dibasic acid polyester such as polybutylene succinate, polyethylene succinate, polybutylene adipate and the like.
Among these, polylactic acid, a copolymer of lactic acid and the above-mentioned hydroxycarboxylic acid other than lactic acid, polycaprolactone, and a copolymer of at least one of the above hydroxycarboxylic acids and caprolactone are preferable. And polylactic acid are particularly preferred. These biodegradable resins may be used alone or in combination of two or more. The above-mentioned lactic acid includes L-lactic acid and D-lactic acid, and these lactic acids may be used alone or in combination.

  The shape and size of the thermoplastic resin fiber are not particularly limited, but the fiber length is preferably 10 mm or more. It is possible to impart high strength (flexural strength and flexural modulus, etc. hereinafter) to the fiber composite obtained thereby. As for this fiber length, 10-150 mm is more preferable, 20-100 mm is still more preferable, 30-80 mm is especially preferable.

  The fiber diameter is preferably 0.001 to 1.5 mm, more preferably 0.005 to 0.7 mm, still more preferably 0.008 to 0.5 mm, and particularly preferably 0.01 to 0.3 mm. When the fiber diameter is in the above range, the thermoplastic resin fiber is not cut, and the fiber can be entangled with the reinforcing fiber with good dispersibility. Particularly suitable when the reinforcing fiber is a vegetable fiber.

  Although the ratio of the reinforcing fiber and the thermoplastic resin fiber constituting the fiber mat is not particularly limited, when the total of the reinforcing fiber and the thermoplastic resin fiber is 100% by mass, the reinforcing fiber is 10 to 95% by mass (preferably Is preferably 20 to 90% by mass, more preferably 30 to 80% by mass. Within this range, it is easy to achieve both the excellent lightness and high strength according to the present invention.

  In addition to the reinforcing fibers and the thermoplastic resin fibers, the fiber mat contains additives such as an antioxidant, a plasticizer, an antistatic agent, a flame retardant, an antibacterial agent, an antifungal agent, and a coloring agent. It is also good.

  The fiber mat used in the present invention is required to have a certain degree of strength from the viewpoint of setting the bending strength of the fiber reinforced composite to a target value. Therefore, preferable specific examples of the fiber mat include glass fiber mat, carbon fiber mat, aramid fiber mat, polyester fiber mat, unsaturated polyester fiber mat, vinyl ester fiber mat, epoxy fiber mat, amide fiber mat, plant fiber mat There may be mentioned (palms, kenafs, etc.), but a glass fiber mat is particularly preferable in terms of availability and expression of strength.

  In addition to glass fiber mats, examples of glass fibers include short glass fibers. For example, chopped strands (for example, 1 to 10 mm in length and 1 to 20 μm in fiber diameter) and milled fibers (for example, 10 to 500 μm in length and 1 to 20 μm in fiber diameter) are known as short glass fibers. As shown in the experiment, the effect of reinforcement as in the present invention was hardly confirmed. It is surprising to those skilled in the art that, given the general use of short glass fibers for reinforcing cement and resin, it is possible to impart remarkable strength to the use of the glass fiber mat as compared to short glass fibers. It is a true fact.

  Also, according to a more preferred embodiment of the present invention, the glass fiber mat is preferably a chopped strand mat (nonwoven fabric) or a roving cloth (woven fabric). Here, in the chopped strand mat, glass fiber strands may be cut to about 50 mm, dispersed uniformly in a nondirectional direction, and formed into a sheet (non-woven fabric) using a binder. Also, the roving cloth can be a woven fabric woven using roving glass long fibers in the warp and weft.

  As a type of glass in the glass fiber mat used in the present invention, it is preferable to use an alkali resistant grade from the viewpoint of using cement and obtaining long-term stability of physical properties.

  As glass fiber mats, according to the classification of JIS R 3411: 2014 (Central Glass Fiber Co., Ltd., Nittobo Co., Ltd., Asahi Fiber Glass Co., Ltd., Nippon Electric Glass Co., Ltd., Owens Corning Co., Ltd. etc.) ) May be used.

Polyurethane-Based Foam Layer The polyurethane-based foam layer used in the present invention is, as described above, a cement-based inorganic filler consisting of cement, cement and sand, or cement and sand and gravel, polyisocyanate, polyol, foam control It is a foam of a mixture comprising an agent, a catalyst and water.

  The cement-based inorganic filler used in the present invention comprises either cement, cement and sand, or cement and sand and gravel. The cement is not particularly limited, but most commonly used Portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, moderate heat Portland cement, sulfate resistant Portland cement, white cement, etc. Other than the above, mixed cements such as blast furnace cement, silica cement and fly ash cement, alumina cement, super rapid-hardening cement, colloidal cement, special cement such as oil well cement, hydraulic lime, roman cement, natural cement and the like can be mentioned. Among these, for example, portland cements are preferable.

  Sand as an aggregate used in the present invention is not particularly limited, but sand which passes all 10 mm sieves usually classified as fine aggregate and which has a particle diameter of 6 mm or less is contained 85% or more by weight Point to Among them, mortar sand having a particle diameter of 0.3 to 6 mm is preferable. The above-mentioned mixture of cement and sand with water is the main component of the so-called mortar. In the fiber-reinforced composite of the present invention, a fiber-reinforced composite having good physical properties according to the present invention can be obtained regardless of the occurrence of hydration reaction of cement.

  The ratio of cement to sand, that is, the weight ratio of the two in the mortar component, may vary depending on the application used, but may be in the range generally used for mortar products, for example, cement: sand = 1: 1.5. It may be in the range of 1: 5, preferably 1: 2 to 1: 4, for example 1: 3 weight ratio.

  In addition to the above, admixtures (powders such as fly ash, slag powder, silica fume and the like) which are usually added to mortar components can be appropriately added according to the application.

  Although the gravel as an aggregate used by this invention is not specifically limited, The gravel in which the particle diameter of 5 mm or more normally classified as a coarse aggregate is contained 85% or more by weight is preferable. A mixture of cement, sand and gravel with water is the main component of so-called concrete. In the fiber-reinforced composite of the present invention, a good fiber-reinforced composite according to the present invention can be obtained regardless of the occurrence of hydration of cement.

  The ratio by weight of cement to the sum of sand and gravel may vary depending on the application used, but for example, the sum of cement: sand and gravel = 1: 0.5-3: 0.5-4, preferably May be in a weight ratio of 1: 1 to 1: 3.

  Also, the ratio of cement to sand to gravel, that is, the weight ratio of these three components in the concrete component may vary depending on the application used, for example, cement: sand: gravel = 1: 0.5-3: The weight ratio may be in the range of 0.5 to 4, preferably 1: 1 to 2: 1.5 to 3.5, such as 1: 2: 3.

  In addition to the above, admixtures (powders such as fly ash, slag powder, silica fume and the like) which are usually added to concrete components can be appropriately added according to the application.

  The polyisocyanate used in the present invention is not particularly limited, and may be aromatic, alicyclic or aliphatic polyisocyanate having two or more isocyanate groups, a mixture of two or more of them, and There are modified polyisocyanates obtained by modification. Specifically, for example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate (generally called: polymeric MDI or crude MDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI) Polyisocyanates such as hexamethylene diisocyanate (HMDI) and their modified products such as isocyanurate modified products, urethane modified products, urethane modified products, urea modified products, adduct modified products, biuret modified products, allophanate modified products, carbodiimide modified products etc. Be Among them, polymeric MDI and urethane-modified MDI and / or urethane-modified polymeric MDI obtained by urethanizing MDI and / or polymeric MDI are particularly preferable.

  The polyol used in the present invention reacts with an isocyanate to form a polyurethane, and at the same time, acts as a crosslinking agent according to the functionality of the polyol, and is preferably added from the viewpoint of imparting strength to the obtained glass fiber reinforced composite .

  The polyol used in the present invention is not particularly limited as long as the effects of the present invention are not impaired, but is preferably a polyether polyol having a hydroxyl value of 5 to 300 mg KOH / g and a functional group number of 2 to 6, and more preferably The above polyether polyols do not dissolve in the water solubility test. Furthermore, preferably, the Davis method HLB value of the polyether polyol is 11 or less.

  Here, in the water solubility test, a polyol and water are mixed and stirred in a test tube under the condition of water / polyol = 6/1 weight ratio, and a test method for visually confirming the state after standing for 1 day It is. As a result of visual observation, the case of "white turbidity or layer separation" is evaluated as "not dissolved". On the other hand, dissolution in the water dissolution test is evaluated as "dissolving" when the state after standing for one day is "transparent or slightly cloudy".

  In addition, with the Davis Method HLB value, the number of groups determined by the type of functional group is determined (for example, the number of methyl groups of the lipophilic group and the number of methylene chains are both -0.475, and ethyleneoxy groups of the hydrophilic group and hydroxyl groups The radix is 0.33 and 1.9, respectively (see Table 1), which is the value calculated by equation 1 (Xiaowen Guo, Zongming Rong, Xugen Ying, “Calculation of hydrophile-lipophile balance for polyethoxylated surfactants by group” contribution method "Journal of Colloid and Interface Science 298 (2006) 441-450).

    HLB value = 7 + sum of base numbers of hydrophilic groups−sum of base numbers of lipophilic groups (Formula 1).

  The Davis's HLB value indicates the relative degree of hydrophilicity-lipophilicity; the larger the value, the stronger the degree of hydrophilicity, and the smaller the value, the stronger the degree of lipophilicity. In the present invention, the HLB value may be 11 or less, preferably 0 to 11, more preferably 5 to 11, and further preferably 7 to 11.

  In the present invention, the use of a polyol having the characteristics as described above is particularly advantageous for imparting high compressive strength to a glass fiber reinforced composite in a short demolding time. While not being bound by theory, the present inventors consider the reasons as follows. That is, when the water solubility of the polyol is high, the polyol dissolves in a large amount of water, and the reaction between the polyol and the isocyanate is inhibited, so that the moldability in a short time (removal property) is defective. It may occur. On the other hand, if the water solubility of the polyol is low, the reaction between the polyol and the isocyanate proceeds smoothly, and it is considered that the moldability (removalability) in a short time becomes good. In addition, under the condition in which no polyol is present (Comparative Example 5 described later), it is considered that it is important that the polyol effectively participates in this reaction because the moldability (removal property) is also poor.

  Among the polyols used in the present invention, particularly preferred polyether polyols are, for example, polyethers having a functionality of 3 and a hydroxyl value of about 28 mg KOH / g, obtained by ring-opening addition polymerization of alkylene oxides using glycerin as a starting material. Polyol (for example, "SBU Polyol 0248" manufactured by Sumika Kobe Soro Urethane Co., Ltd., HLB value of Davis method = 10), propylene glycol as a starting material, and ring opening addition polymerization of the alkylene oxide thereto, the number of functional groups 2. Polyether polyol having a hydroxyl value of about 110 mg KOH / g (for example, "Sumiphen 1600 U" manufactured by Sumika Kobe Soro Urethane Co., Ltd., Davis method HLB value = 9.5), and functional group number about 2.7, hydroxyl value Castor that is about 160 mg KOH / g polyester-based polyol (Davis method HLB value = 7.6) and others as mentioned, but not limited thereto.

  In the present invention, the weight ratio of cement-based inorganic filler (cement, cement and sand, or either cement and sand or gravel) to polyurethane resin (that is, polyisocyanate + polyol) is lightness, strength, The ratio can be suitably adjusted in consideration of the cost etc., and usually, the ratio of cement-based inorganic filler: polyurethane (weight ratio) is 40:60 to 95: 5, preferably 50:50 to 90:10, in particular Preferably, 55: 45 to 85: 15, for example 80: 20 or 60: 40.

  The foam stabilizer used in the present invention is an auxiliary agent for forming good air bubbles. The air bubbles become communication holes, prevent the reduction of the obtained glass fiber reinforced composite, and contribute to weight reduction and strength development. The foam stabilizer is not particularly limited. For example, silicone foam stabilizers (eg, SH-193, L-5420A, SZ1325, SF2937F from Toray Dow Corning, L-580 from Momentive, Inc.) Examples thereof include B8462) manufactured by Evonik Degussa Co., Ltd. and fluorine-containing compound type foam stabilizers. The amount of foam stabilizer may be up to 20 parts by weight, in particular 1 to 10 parts by weight, for example 0.5 parts by weight, based on 100 parts by weight of polyether polyol.

  The density of the fiber-reinforced composite of the present invention can be controlled by the ratio of polyurethane and cement-based inorganic filler (comement, cement and sand, or either cement and sand and gravel) and the foaming ratio.

  The catalyst used in the present invention promotes the urethane formation reaction of polyisocyanate and polyol. The catalyst is not particularly limited as long as it promotes urethane formation reaction, but triethylenediamine, triethylamine, bis (2-dimethylaminoethyl) ether, imidazole compound, 1,8-diazabicyclo [5 4.0] undecene-7 and its organic acid salts, and N, N, N-tris (dimethylaminopropyl) hexahydro-S-triazine. Among these, for example, tertiary amines such as Aircat's Polycat 8 are preferred as catalysts.

  The amount of catalyst may be 0.01 to 5% equivalents, preferably 0.1 to 1% equivalents, such as 0.5% equivalents, based on 1 equivalent of isocyanate groups.

  The water used in the present invention is preferably used as a medium for dispersing the raw material to form a slurry, and at the same time, a part of the water reacts with an isocyanate group to generate carbon dioxide gas to form a foam.

  The amount of water is not particularly limited as long as it is sufficient to stir and mix water and the cement-based inorganic filler and disperse it into a slurry. The amount of water is required to include the amount necessary to react and foam with the hydration reaction of the cement and the polyisocyanate groups used, but usually the amount of water required to make a good slurry state The amount is a large excess compared to the amount of water required for the reaction.

  In order to reduce the density of the fiber-reinforced composite of the present invention, it is preferable to use carbon dioxide gas generated by the reaction of polyisocyanate with water as a foaming source.

  Further, the ratio of polyol: polyisocyanate is not particularly limited as long as the effect of the present invention is not impaired, but, for example, 60:40 to 100: 1, preferably 65:35 to 95: 5, more preferably 70:30 to It can be 90:10.

Method of Producing Fiber-Reinforced Composite Next, a method of producing the fiber-reinforced composite of the present invention will be described.
The method for producing a fiber-reinforced foam composite according to the present invention comprises either of a mold (also referred to as "mold" or "mold type") cement-based inorganic filler (cement, cement and sand, or cement and sand and gravel) And at least the step of injecting a mixture comprising polyisocyanate, polyol, foam stabilizer, catalyst and water into a mold and demolding.

  In the manufacturing method of the present invention, it is preferable to place the fiber mat in a suitable place in the mold, foam the above mixture to form a polyurethane foam layer, and integrate it with the fiber mat. Therefore, according to a preferred embodiment of the present invention, the fiber mat is arranged in advance in the mold so that the polyurethane foam layer obtained by foaming the mixture adheres to the fiber mat.

  There is no particular limitation on the order of mixing the components in the above mixture, but when the polyisocyanate comes in contact with a polyol, a urethane forming reaction (including a urethanization reaction, a urea formation reaction, a biuret binding reaction, etc.) starts. In general, it is preferable to use a mixing order such that the contact between the two takes place in the final stage of mixing. It is a so-called "two-component reaction type composition".

  More specifically, in the mold of fiber reinforced composite, cement based inorganic filler consisting of cement, sand with sand, or cement and sand with sand, gravel, polyol, foam stabilizer, catalyst and water are mixed. Agitation forms a slurry, and polyisocyanate (and / or a prepolymer type modified product thereof) is added and mixed in the slurry to generate carbon dioxide gas generated by the reaction of the polyisocyanate and water in the slurry. Polymerize the polyisocyanate and the polyol, and form a cement-based inorganic filler powder composed of cement in the slurry, cement and sand, or cement and sand and gravel in the polyurethane formed by the polymerization; A dispersed polyurethane foam layer can be formed.

  In addition, mixing and stirring of the above components (polyisocyanate, cement-based inorganic filler, polyol, foam stabilizer, catalyst and water) may be carried out directly in the mold, but the mold is usually a rectangular solid. If the mixing efficiency is taken into consideration, the ingredients are added to a circular cup (for example, a polycup for small scale experiments, a polymer liner circular stirring tank for large scale production, etc.) in consideration of mixing efficiency. In a scale experiment, it is preferable to immediately transfer to the mold after stirring and mixing with a hand mixer, and in a large scale production, a motorized stirring device etc.). Since the urethanization reaction starts immediately with the addition of the polyisocyanate or the catalyst, it is preferable to previously add other components and sufficiently stir and mix them into a slurry prior to their addition. Since the reaction starts immediately after the addition of the polyisocyanate or the catalyst starts stirring, the stirring in the circular cup is stopped for a short time (for example, several seconds) and immediately transferred to the mold. At this time, in order to obtain sufficient mixing efficiency by short-time stirring, stirring at high speed rotation is preferable.

Then, after mixing for a short time (several seconds) in a cup, the resulting mixture can be transferred into a mold to start the formation of the fiber-reinforced composite of the present invention. The initial temperature setting of the mold may be about normal temperature (about 20 ° C. to 30 ° C.). The formation of the fiber-reinforced composite involves the generation of heat of polymerization of polyurethane formation along with foaming, and the temperature in the mold rises. Although depending on the shape and size of the mold, the temperature in the mold usually rises to about 30 to 40 ° C. The pressure in the mold slightly increases with the foaming, but may be about 0.5 MPa.
Further, the shape of the mold is generally a rectangular parallelepiped, but may be another shape as needed.

  In addition, visual observation and finger corrosion observation of the surface state in the state in the above-mentioned cup can be used as an index of the progress of curing (polymerization and crosslinking) reaction using cream time, gel time and tack time as indexes. In the present invention, the cream time of the mixture of the above components at a liquid temperature of 25 ° C. is preferably 10 to 30 seconds, more preferably 10 to 20 seconds. The gel time of the mixture of the above components at a liquid temperature of 25 ° C. is preferably 40 to 70 seconds, more preferably 50 to 65 seconds. The tack time of the mixture of the above components at a liquid temperature of 25 ° C. is preferably 70 to 110 seconds, and 80 to 100 seconds.

In the present invention, it is preferable to place the fiber mat in advance in the mold so as to be disposed within 5 mm of the inner surface of the fiber reinforced composite. Specifically, the place of placement of the fiber mat is designed so that at least one fiber mat is included within 5 mm inside from the surface on at least one side where the flexural strength of the fiber reinforced composite is required, and It is preferable to arrange in. With respect to at least one side where bending strength is required, as shown in FIG. 1, one side where load is assumed to be applied from one direction is suitably selected. In FIG. 1, the frame line indicates a fiber reinforced composite and the dotted line indicates a fiber mat. In addition, as shown in FIG. 2, it may be disposed on both side regions (preferably within 5 mm from each surface) of the molded article (fiber-reinforced composite).
In the present invention, as long as the fiber mat is disposed in at least one side region of the fiber reinforced composite, another fiber mat is disposed in a portion (in the polyurethane foam layer) other than the one side region. Such embodiments are also included in the present invention.

  In addition, as shown in the below-mentioned experiment example, even if it arrange | positions a fiber mat in the place (For example, arrangement | positioning in the middle of a fiber reinforced composite: FIG. 3) other than the above, the effect is limited. While not being bound by theory, in the fiber-reinforced composite of the present invention, as shown in the photograph of FIG. 4, a layer having a low degree of foaming and a relatively high density on the surface of the polyurethane foam layer (so-called skin layer Because the layer is formed and this layer affects the mechanical properties, it is considered that placing a fiber mat in the vicinity of the skin layer is effective for improving the strength.

  Also, as the impregnation of the polyurethane-based foam into the fiber mat proceeds smoothly, the fiber mat is pre-wetted (applied) with a small amount of a mixture of each component except polyisocyanate, and the polyisocyanate is made into a fiber mat May be added to Performing such treatment is advantageous in obtaining a fiber-reinforced composite in which the resin component sufficiently penetrates the fiber mat.

  In the production method of the present invention, the fiber-reinforced composite in which the polyurethane foam layer and the fiber mat are integrated can be obtained by demolding in a short time. In addition, even immediately after demolding, the fiber reinforced composite can exhibit sufficiently high hardness. That is, the demolding time can be usually about 5 minutes, and the compressive strength immediately after the demolding can also give a high value of 1 MPa or more. Therefore, according to the production method of the present invention, a production time cycle can be established in a short time, and a fiber-reinforced composite having good cured physical properties can be obtained in a process with high production efficiency. The compressive strength, for example, reaches a substantially constant value immediately after demolding after 5 minutes, and is a similar compressive strength even after 1 day to 1 week. That is, according to the production method of the present invention, good initial physical property values can be stably obtained in a remarkably short time.

Fiber-Reinforced Composite / Functional Application The fiber-reinforced composite of the present invention can be obtained by bonding or integrating a polyurethane foam layer and a fiber mat by the manufacturing method as described above. In the fiber-reinforced composite of the present invention, the weight ratio of the polyurethane foam layer to the fiber mat is not particularly limited as long as the effects of the present invention are not impaired, and preferably 100: 0.5 to 100: 10, preferably Can range from 100: 1 to 100: 10.

  In the fiber-reinforced composite of the present invention, the thickness ratio of the polyurethane foam layer to the fiber mat is not particularly limited as long as the effects of the present invention are not impaired, and preferably 10: 0.01 to 10 It can be in the range of 2.0, preferably 10: 0.1 to 10: 2.0, and more preferably 10: 0.3 to 10: 1.0.

  Further, since the fiber-reinforced composite of the present invention is a structure provided with the lightness as described above and the high bending strength required in JIS A 5908, construction materials (heat insulation materials, wall materials, etc.), etc. It can be suitably used as The flexural strength of the fiber-reinforced composite of the present invention is preferably 18 MPa or more, preferably 18 to 30 MPa, more preferably 18 to 25 MPa, and still more preferably 20 to 25 MPa.

Further, in the fiber reinforced structure of the present invention, the density is set to 800 kg / m ³ or less from the viewpoint of securing the lightness. The density of the fiber-reinforced composite of the present invention is preferably 500 to 800 kg / m ³ , more preferably 550 to 700 kg / m ³ , still more preferably 580 to 680 kg / m ³ , still more preferably 600. It is ̃650 kg / m ³ .

  Moreover, it is preferable that the fiber reinforced structure of this invention has a suitable compressive strength from a viewpoint of use as a construction material. The compressive strength of the fiber-reinforced composite of the present invention can be 1 MPa or more, as described above, preferably 5.0 to 7.0 MPa, more preferably 5.1 to 6.2 MPa.

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples. In addition, although the measurement of the unit and each parameter of this invention is performed according to the Example mentioned later, if there is no notice in particular, according to the prescription | regulation of JIS (Japanese Industrial Standard).

Raw Materials The following experiments were conducted using the following raw materials.
Glass fiber mat A: ECM 300-501 (made by Central Glass Fiber Co., Ltd.)
(Chopped strand mat; unit weight 300 g / m ^2, thickness about 1 mm)
Glass staple fiber A: ECS 03-615 (made by Central Glass Fiber Co., Ltd.)
(Glass chopped strand, average fiber length 3 mm, fiber diameter 9 μm)
Glass staple fiber B: EFH 100-31 (made by Central Glass Fiber Co., Ltd.)
(Glass milled fiber, average fiber length 30 μm, fiber diameter 11 μm)

Cement: Portland cement Sand: Mortar sand (average particle size about 1 mm)
Polyol: Polyol A (Sumiphen 1600 U; functional group number 2, hydroxyl value 110 mg KOH / g) (manufactured by Sumika Kobe Soro Urethane Co., Ltd.)
Foam control agent: silicone type foam control agent (Silicone SH-193, Toray Dow Corning Co., Ltd.)
Catalyst: Polycat 8 (tertiary amine) (manufactured by Air Products)
Polyisocyanate: Polyisocyanate A (Polymeric MDI (Diphenylmethane Diisocyanate; about 31.5% of Isocyanate Group Content: Sumidur 44 V 20 L (manufactured by Sumika Kobe Soro Urethane Co., Ltd.)

Measurement Method Each parameter was measured by the following measurement method.
Foamed product density (kg / m ³ ): Determined by the following equation.
[Weight of foam ÷ mold capacity]

Reactivity (cream time, gel time, tack free time):
The reactivity was observed as it is in the polycup (25 ° C.) without transferring the same slurry mixture in the polycup to the mold. The index of reactivity is as follows.
(A) Cream time: time (seconds) until the mixture foams and starts rising after slurry mixing
(B) Gel time: time (seconds) until the mixture starts to gel after slurry mixing
(C) Tack free time: The time (seconds) required to stop sticking to the fingertip when the rising foam surface is touched with a fingertip after slurry mixing.

Bending strength (bending strength): The bending strength was measured in accordance with JIS A 5908: 2015 (particle board).
Compressive strength: The compressive strength was measured in accordance with JIS K 7220: 2006 (hard foamed plastic-how to determine the compression characteristics).

Example 1 <Production Example of Glass Fiber Mat Reinforced Composite>
1. Placement of Glass Fiber Mat in Mold 13.8 g of glass fiber mat A, cut to 210 × 210 mm, was placed on the bottom of the mold.
2. Charge the reaction mixture into a mold Add 1000g of Portland cement, 300g of sand, 30g of Polyol A, 90g of water, 3.7g of a foam stabilizer and 3.7g of a catalyst into a hand mixer in a 1000ml polycup. The mixture was stirred at 4,000 rpm for 4 seconds to form a uniform slurry. Then, 270 g of Isocyanate A was added, and the resulting slurry was stirred at 4,000 rpm for 4 seconds with a hand mixer (equipment homomixer: T.K. Robotics F Model; manufactured by Primix Inc .; stirring blade: diameter 50 mm) for 4 seconds. The mixture was immediately filled into a mold in which the above glass fiber mat A was placed and sealed. The mold initial temperature (initial mold temperature) was 30 ° C. After 5 minutes, the mold temperature (also referred to as "mold temperature") had reached 40.degree. Immediately after demolding, each sample obtained after 5 minutes was subjected to appearance evaluation, curing evaluation and strength expression evaluation according to the following criteria by trained panelists (n = 10).

Appearance evaluation (visual)
○: The surface is uniform and smooth ×: The surface is uneven and not smooth

Cure evaluation (Feeling of the finger when the hardened surface is pressed and released for 1 second with the index finger)
○: no stickiness ×: with stickiness

Evaluation of strength development (evaluation of whether or not a mark remains on the hardened surface when the hardened surface is pressed and released for 1 second with a finger tip of a forefinger)
○: There is no trace left ×: There is a trace left

The evaluation results of Example 1 are as shown in Table 2.
Specifically, the appearance evaluation, the cure evaluation and the strength expression evaluation were all good (o).
As a result of measuring the density of the fiber reinforced composite 3 days after demolding, it was 620 kg / m ³ .
As a result of measuring the bending strength of the fiber reinforced composite 3 days after demolding, it was 20.3 MPa.
As a result of measuring the compressive strength 3 days after demolding, it was 5.6 MPa.

In this Example 1, the reactivity was observed in the polycup as it was (liquid temperature 25 ° C.) without transferring the same slurry mixture in the polycup separately to the mold.
As a result of observation, the cream time of the slurry was 20 seconds, the gel time was 60 seconds, and the tack free time was 92 seconds.

Example 2
1. Placement of Glass Fiber Mat in Mold Two glass fiber mats A (27.6 g in total) cut to 210 × 210 mm were placed on the top and bottom of the mold. For the upper surface of the glass fiber mat A, the four corners of the mat were attached to the upper surface of the mold with a double-sided tape.
2. Loading of reaction mixture into mold The reaction mixture was used as in Example 1 to obtain a fiber reinforced composite. The evaluation results are as shown in Table 2. In addition, when a cross section of the glass fiber reinforced composite obtained in Example 2 was photographed, it was as shown in FIG. In FIG. 4, the thickness of the glass fiber reinforced composite was 25 mm, and the glass fiber mat A was disposed in an area within 5 mm from the upper surface and the lower surface of the glass fiber reinforced composite. Further, as shown in FIG. 4, in the cross-sectional photograph of the glass fiber reinforced composite, it was confirmed that the skin layer was formed on the surface of the polyurethane foam layer and was integrated with the glass fiber mat.

Comparative Example 1
The reaction mixture was used as in Example 1 except that no glass fiber mat was used to obtain a foam. The evaluation results are as shown in Table 2.

Comparative Example 2
A fiber reinforced body was obtained using the reaction mixture in the same manner as in Example 1 except that the arrangement of the glass fiber mat in the mold was at an intermediate position of the mold height. The evaluation results are as shown in Table 2.

Comparative Example 3
The reaction mixture was used in the same manner as in Example 1 except that a glass fiber mat was not used and 22.5 g of glass short fibers A were added to obtain a slurry, to obtain a fiber reinforced composite. The evaluation results are as shown in Table 2.
In addition, although 30 g of short glass fibers A was added to obtain a slurry, it was also considered that the slurry could not be stirred because of its high viscosity, and finally a fiber-reinforced composite could not be obtained.

Comparative Example 4
A fiber reinforced composite was obtained using the reaction mixture in the same manner as in Example 1, except that a glass fiber mat was not used and 22.5 g of glass short fibers B were added to obtain a slurry. The evaluation results are as shown in Table 2.
In addition, although 30 g of short glass fibers B was added to obtain a slurry, it was also studied that the slurry could not be stirred because of the high viscosity, and finally a fiber-reinforced composite could not be obtained.

When the glass fiber mat was placed at a predetermined position as in Example 1 and Example 2, the bending strength was significantly improved and became 20 MPa or more at a density of 610 to 620 kg / m ³ . In addition, in Example 1 and Example 2, the reactivity was also high, and it was sufficiently possible to demold in 5 minutes.
On the other hand, in Comparative Example 1 in which no reinforcing material was used, the bending strength was about 8 MPa.
In addition, when the arrangement position of the glass fiber mat was not appropriate, as shown in Comparative Example 2, the bending strength was hardly improved.
Moreover, in Comparative Example 3 and Comparative Example 4 in which short glass fibers were used instead of the glass fiber mat, the bending strength was hardly improved.

According to the fiber-reinforced composite of the present invention, high flexural strength (18 MPa or more) and lightness (density 800 kg / m ³ or less) can be achieved. In addition, the glass fiber reinforced composite of the present invention can be obtained in a very short demolding time, and can be advantageously used as a construction material.

Claims (15)

A fiber reinforced composite comprising a fiber mat and a polyurethane foam layer,
Foaming of a mixture comprising the cement-based inorganic filler, which is composed of cement, cement and sand, or cement and sand and gravel, the polyurethane foam layer, polyisocyanate, polyol, foam stabilizer, catalyst and water Is the body,
Said fiber mat is arranged in at least one side area of the fiber reinforced composite,
A fiber reinforced composite, wherein the density of the fiber reinforced composite is 800 kg / m ³ or less and the flexural strength measured according to JIS A 5908 is 18 MPa or more.   The fiber mat is selected from at least one of glass fiber mat, carbon fiber mat, aramid fiber mat, unsaturated polyester fiber mat, vinyl ester fiber mat, epoxy fiber mat, amide fiber mat, vegetable fiber mat. Fiber-reinforced composite as described in   The fiber reinforced composite according to claim 1 or 2, wherein the fiber mat is a chopped strand mat or a roving cloth.   The fiber reinforced composite according to any one of claims 1 to 3, wherein the fiber mat is a glass chopped strand mat defined by JIS R 3411. The fiber reinforced composite as described in any one of Claims 1-4 whose unit weight of the said fiber mat is 200 g / m < ² > or more.   The fiber reinforced composite according to any one of claims 1 to 5, wherein the weight ratio of the cementitious inorganic filler to the total of polyisocyanate and polyol is 50: 50 to 90: 10.   The fiber reinforced composite according to any one of claims 1 to 6, wherein a weight ratio of the polyurethane foam layer to the fiber mat is 100: 0.5 to 100: 10.   The fiber reinforced composite according to any one of claims 1 to 7, wherein the single sided area is an area within 5 mm inside from the single sided surface of the fiber reinforced composite.   The fiber-reinforced composite according to any one of claims 1 to 8, wherein the cementitious inorganic filler is cement and sand, or cement and sand and gravel.   The fiber reinforced composite according to any one of claims 1 to 9, wherein the weight ratio of the cement to the sum of sand and gravel is 1: 1 to 1: 3.   The fiber reinforced composite according to any one of claims 1 to 8, wherein the weight ratio of the polyisocyanate to the polyol is 70:30 to 90:10. The fiber reinforced composite according to any one of claims 1 to 9, wherein the mixture has at least one feature of the following (A) to (C).
(A) cream time of the mixture at a liquid temperature of 25 ° C is 10 to 30 seconds (B) gel time of the mixture at a liquid temperature of 25 ° C is 40 to 70 seconds (C) the mixture of the mixture at a liquid temperature of 25 ° C The tack time is 70 to 110 seconds. A method of producing a fiber reinforced composite according to any one of claims 1 to 12,
The method of manufacturing, comprising at least the steps of injecting the mixture into a mold and demolding.   14. The method according to claim 13, wherein the mixture is poured into a mold and within 5 minutes of demolding.   The method according to claim 13 or 14, wherein the fiber mat is arranged in advance in the mold so that the polyurethane foam layer obtained by foaming the mixture adheres to the fiber mat.