JP2013056473A - Low density resin laminated sheet and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a low density resin laminated sheet that enables further low specific gravity without spoiling other characteristics such as the appearance, electrical characteristics, mechanical strength, and thermal conductivity.SOLUTION: A method for manufacturing the low density resin laminated sheet in that the thermosetting resin powder has putting on temporary to the reinforcement material made of the fiber particle size 20-40 μm, includes: (i) a step of forming the powder composition by uniformly mixing (a) thermosetting resin powders (b) organic balloons, inorganic balloons, and the filler selected from a group comprising those mixtures; (ii) a step of making the powder composition uniformly contact the surface of the reinforcement material made of the fiber; (iii) a step of heating the powder composition under pressurization and perform tack welding of the fiber made reinforcement material to make the sheet-like material; and (iv) a step of performing fusion integration by laminating, heating and pressing a plurality of sheets.

Description

  The present invention relates to a low specific gravity resin laminate used as an electrical insulating plate, a plate-like heat insulating material and other lightweight plate-like materials, and a method for producing the same.

  In general, in order to produce a synthetic resin laminate, first, a woven or non-woven fabric made of glass fiber, carbon fiber, other synthetic fiber or natural fiber is used as a reinforcing material, and a solution or emulsion of the required concentration is used for this. Impregnate with resin. Then, a plurality of the obtained web pieces are stacked, accommodated in a hot press provided with a pair of upper and lower hot plates, and heated and cured by a required pressure.

  The synthetic resin laminate formed in this way is adjusted to the required specific gravity mainly in combination with a reinforcing material. For example, the specific gravity when glass fiber is used as a reinforcing material is about 1.8 to 2.0. There is a specific gravity of about 1.35 to 1.4 when a cotton cloth is used as a reinforcing material. In addition, in order to further reduce the weight of such synthetic resin laminates, the filler of low specific gravity is uniformly dispersed in the thermosetting resin, which is the main binder component, or the amount and concentration of the binder impregnated in the reinforcing material are adjusted. A technique to do this is also possible.

  However, if a fine particle balloon containing foamy air is used as a filler for reducing the weight of the synthetic resin laminate described above, it will float in the liquid phase and will not be uniformly dispersed in the synthetic resin. However, there is a problem in that the impregnation is not efficiently held by the reinforcing material.

  In addition, as another method for adjusting the specific gravity of the laminate to be molded, there is a method for controlling the amount of binder impregnated or the concentration of the web-like fiber reinforcing material continuously supplied from the roll body. However, many factors such as the fluidity and viscosity of the binder are involved, and there is a problem that such control is complicated and there is no other appropriate method.

  In order to uniformly disperse the low specific gravity filler in the binder and to adjust the holding amount of the binder to the reinforcing material, that is, to adjust the specific gravity of the laminate, in a simple manner, As the low specific gravity filler, the organic balloon and the inorganic balloon are used alone or in combination of both, and the mixture with the thermosetting resin powder is adhered to the surface of the fiber reinforcing material, and then heated and under pressure. A method for producing a low specific gravity resin laminate was proposed in which the mixture was temporarily attached to the reinforcing material to form a sheet-like material, and a plurality of the obtained sheet-like materials were laminated and fused and integrated under heat and pressure ( Patent Document 1).

  By using the above manufacturing method, the balloon can be uniformly dispersed in the thermosetting resin powder at a required ratio and held by the reinforcing material as a low specific gravity filler. In addition, since it is easy to adjust the adhesion amount of the binder, it is possible to easily adjust the specific gravity, the efficiency of the manufacturing process is high, and the manufacturing cost can be reduced by the ease of blending of the binder. .

  However, with a view to environmental issues, there is an increasing demand to reduce fuel and electric energy consumption in order to lower the fuel ratio of automobiles, shift to the use of electric energy, and further increase the speed of railway vehicles. Increasingly, materials used for automobiles, railway vehicles, and the like are required to be further reduced in weight without impairing other properties such as strength.

JP-A-5-476

  The present invention solves the problems of the conventional low specific gravity resin laminate as described above, and further lowers the specific gravity without impairing other characteristics such as appearance, electrical characteristics, mechanical strength, and thermal conductivity. An object of the present invention is to provide a low specific gravity resin laminate and a method for producing the same.

  As a result of intensive studies to solve the above-mentioned object, the present inventors can disperse both uniformly by making the particle size of the thermosetting resin powder mixed with the low specific gravity filler very small. The present inventors have found that it is possible to provide a low specific gravity resin laminate capable of further reducing the specific gravity without impairing other characteristics and a method for producing the same, and have completed the present invention.

That is, the present invention
(I) (a) thermosetting resin powder;
(B) a step of uniformly mixing a filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof to form a powder composition;
(Ii) a step of bringing the powder composition into uniform contact with the surface of the fiber reinforcing material;
(Iii) a step of heating the powder composition under pressure to temporarily attach the fiber composition to the fiber reinforcing material to form a sheet-like material; and (iv) laminating a plurality of the sheet-like materials, and heating press And including the step of fusing and integrating,
The thermosetting resin powder has a particle size of 1 to 100 μm, and relates to a method for producing a low specific gravity resin laminate.

Furthermore, in order to implement this invention suitably,
In the step (iv), a plurality of the sheet-like materials are laminated, and at least one layer selected from the uppermost layer, the lowermost layer and an intermediate layer thereof is impregnated with a thermosetting resin in a fiber reinforcing material. Laminate sheets, heat press and fuse and integrate;
The thermosetting resin is a mixture of a bisphenol A type epoxy resin and a novolac type epoxy resin;
The bisphenol A type epoxy resin has a softening point of 60 to 120 ° C. and an epoxy equivalent of 450 to 2000, the novolac type epoxy resin has a softening point of 60 to 120 ° C., and the bisphenol A type epoxy resin / novolac type epoxy resin The blending ratio of 8/1 to 1/1;
It is desirable.

As another aspect of the present invention,
(A) a thermosetting resin powder;
(B) a filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof;
(C) There is a low specific gravity resin laminate comprising a fiber reinforcing material, having a specific gravity of 0.6 to 1.1, a bending strength of 100 MPa or more and a compressive strength of 150 MPa or more.

As still another aspect of the present invention,
(I) (a) a thermosetting resin powder having a particle size of 1 to 100 μm;
(B) uniformly mixing a filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof to form a powder composition;
(Ii) contacting the powder composition uniformly with the surface of the fiber reinforcement;
(Iii) heating the powder composition under pressure to temporarily attach the fiber composition to the fiber reinforcing material to form a sheet-like material;
(Iv) It is manufactured by laminating a plurality of the sheet-like materials, heat-pressing, and fusing and integrating them,
There is a low specific gravity resin laminate having a specific gravity of 0.6 to 1.1, a bending strength of 100 MPa or more, and a compressive strength of 150 MPa or more.

  In order to suitably carry out the present invention, the thermosetting resin is a mixture of a bisphenol type epoxy resin and a novolac type epoxy resin, and the blending ratio of the bisphenol A type epoxy resin / novolac type epoxy resin is 8 / It is desirable that it is 1-1 / 1.

  The method for producing a low specific gravity resin laminate of the present invention comprises a powder composition in which a low specific gravity filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof is uniformly dispersed in a thermosetting resin powder at a required ratio. As a product, it can be held by a fiber reinforcing material, so that a significant weight reduction can be achieved, and the adjustment of the specific amount of the binder can be easily performed because the amount of the binder attached can be easily adjusted. Therefore, the efficiency of the manufacturing process is good, and the manufacturing cost can be reduced by the ease of blending of the binder, and it can be said that the industrial utility value of the present invention is extremely high. In addition, in the method for producing a low specific gravity resin laminate of the present invention, by making the particle size of the thermosetting resin powder very small, the appearance, electrical characteristics, mechanical strength, thermal conductivity, etc. A resin laminate having a lower specific gravity can be provided without impairing the above characteristics.

It is a schematic explanatory drawing of the manufacturing process explaining one aspect of the manufacturing method of the low specific gravity resin laminated board of this invention. FIG. 2 is a schematic explanatory diagram of a main part of the hot press machine of FIG. 1. It is a schematic explanatory drawing which shows the lamination | stacking state of the sheet-like material of FIG. It is a schematic explanatory drawing which shows the other lamination | stacking state of the sheet-like material in the manufacturing method of the low specific gravity resin laminated board of this invention. It is a schematic explanatory drawing which shows the other laminated state of the sheet-like material in the manufacturing method of the low specific gravity resin laminated board of this invention.

As mentioned above, the present invention
(I) (a) thermosetting resin powder;
(B) a step of uniformly mixing a filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof to form a powder composition;
(Ii) a step of bringing the powder composition into uniform contact with the surface of the fiber reinforcing material;
(Iii) a step of heating the powder composition under pressure to temporarily attach the fiber composition to the fiber reinforcing material to form a sheet-like material; and (iv) laminating a plurality of the sheet-like materials, and heating press And including the step of fusing and integrating,
The thermosetting resin powder has a particle size of 1 to 100 μm, and relates to a method for producing a low specific gravity resin laminate.

  Hereinafter, the manufacturing method of the low specific gravity resin laminated board of this invention is demonstrated in detail with reference to drawings in order of process (i)-(iv).

Step (i)
First, in step (i), (a) thermosetting resin powder and (b) a filler selected from the group consisting of organic balloons, inorganic balloons, and mixtures thereof are uniformly mixed to form a powder composition. Form things. The mixing method is not particularly limited as long as the balloon can be uniformly mixed with the thermosetting resin powder without cracking at the time of mixing, and a mixer known to those skilled in the art such as a rotary mixer may be used. it can.

(A) Thermosetting resin powder The thermosetting resin used in the production method of the present invention is not particularly limited in its type. For example, phenol resin, epoxy resin, silicone resin, polyester resin, melamine resin, Examples thereof include resin powders, each of which is a thermosetting polyimide resin or other thermosetting resin, or a mixture of two or more of them. Among the above-mentioned thermosetting resins, an epoxy resin excellent in a good balance of moldability and workability as a laminate, adhesion to a fiber reinforcing material, and electrical insulation of the resulting laminate is preferable.

  The epoxy resin is not particularly limited as long as it is solid at room temperature and can be pulverized, but bifunctional bisphenol types such as bisphenol A type, bisphenol F type, bisphenol S type, and bisphenol AD type epoxy resin. Examples include epoxy resins, and polyfunctional novolac type epoxy resins such as phenol novolak, o-cresol novolak, m-cresol novolak, and p-cresol novolak, and biphenyl type epoxy resins. Two or more kinds can be mixed and used. The bisphenol type epoxy resin is preferably a bisphenol A type epoxy resin, and the novolak type epoxy resin is preferably an o-cresol novolac epoxy resin.

  The thermosetting resin powder used in the present invention is required to have a particle size of 1 to 100 μm, preferably 10 to 60 μm, more preferably 20 to 40 μm. If the particle size of the thermosetting resin powder is less than 1 μm, the difference in particle size from the low specific gravity filler is large, making uniform mixing difficult, and pulverization to less than 1 μm is caused by melting of the resin due to heat generated during pulverization. For prevention, special equipment is required, and the grinding process takes time and cost. Moreover, since the bulk specific gravity of the resin exceeds 100 μm, the amount of resin necessary for uniform mixing with the low specific gravity filler cannot be reduced, and as a result, the blending ratio of the low specific gravity filler is increased. This makes it impossible to produce a low specific gravity resin laminate. The particle size of the thermosetting resin powder used in the present specification is an average measured by a dry method using a laser diffraction / scattering particle size distribution measuring device “Partica LA-950V2” manufactured by Horiba, Ltd. Means particle size.

  As described above, the thermosetting resin powder used in the present invention is required to have a specific particle size, but usually, by pulverizing the thermosetting resin supplied in the form of flakes or beads, the above-mentioned Adjust to a specific particle size. Therefore, it is desirable that the softening point of the thermosetting resin is 60 to 120 ° C., preferably 70 to 110 ° C., more preferably 80 to 105 ° C. from the viewpoint of ease of pulverization. If the softening point of the thermosetting resin is lower than 60 ° C., the resin melts due to heat generated during pulverization and pulverization becomes difficult, and if it is higher than 120 ° C., temporary attachment to the fiber reinforcing material may be insufficient. There is sex.

  In addition, when an epoxy resin is used as the thermosetting resin, it has a softening point equivalent to that of a bisphenol-type epoxy resin having excellent moldability in a heating process or a heating press process under pressure at the time of producing a prepreg. However, it is preferable to mix and use a novolac type epoxy resin which has less stickiness at the time of pulverization and is excellent in ease of pulverization and heat resistance. The blending ratio (c / d) of the bisphenol type epoxy resin (c) and the novolak type epoxy resin (d) is 8/1 to 1/1, preferably 6/1 to 2/1, more preferably 5/1. It is desirable to be ˜3 / 1. Based on the mass of all epoxy resins, the heat resistance of the low specific gravity resin laminate obtained when the above novolac type epoxy resin (d) is less than 11.1% by mass is low, and when it exceeds 50% by mass, the melt viscosity of the resin is low. It becomes too high and the impregnation of the resin into the fiber reinforcement becomes insufficient.

  When using the epoxy resin as described above, the thermosetting resin powder (a) used in the method for producing the low specific gravity resin laminate of the present invention contains a curing agent and a curing accelerator. Examples of the curing agent include dicyandiamide, amines such as m-phenylenediamine and diaminodiphenylmethane, and acid anhydrides such as phthalic anhydride and trimellitic anhydride. Among these, solid (powder) at room temperature. Are preferred. As known to those skilled in the art, the blending amount of the curing agent is calculated from the epoxy equivalent of the epoxy resin used and the amount of active hydrogen in the curing agent. These may be used alone or in combination.

  In addition, when using the mixture of two types of epoxy resins as a thermosetting resin as mentioned above, both are melt-mixed or kneaded to make a uniform mixture, and the cooled one is pulverized to obtain a thermosetting resin powder. . Such a method is not particularly limited, and methods known to those skilled in the art such as a mixer, a kneading roll, and an extruder can be used.

(B) Low specific gravity filler The organic balloon or inorganic balloon as the filler used in the present invention is not particularly limited as long as the specific gravity is in the range of 0.05 to 0.70. Balloons made of resin, cellulose and other organic materials, shirasu, glass, alumina and other inorganic materials that contain microbubbles during granulation, such as plastic balloons, glass balloons, shirasu balloons, alumina balloons, etc. Depending on the conditions, heat resistance, acid resistance, rigidity and durability are selected and used. Among these, the particle size of the glass balloon is preferably 10 to 120 μm, for example, and “Glass Bubbles” manufactured by Sumitomo 3M Limited is mentioned as a commercially available product. The particle size of the organic balloon made of a copolymer of vinylidene chloride and acrylonitrile can be 10 to 100 μm (center value 40 to 60 μm). It goes without saying that the particle size of such organic balloons or inorganic balloons is more uniform and preferable as the particle size distribution range is narrower.

  The blending ratio (a / b) of the thermosetting resin powder (a) and the glass balloon (b) described above is 2/1 to 0.8 / 1, preferably 1.8 / 1 to 1/1 / by mass ratio. 1, more preferably 1.5 / 1 to 1/1. When the blending ratio (a / b) is greater than 2/1 (when the glass balloon is less than 33.3% by mass), the weight of the low specific gravity resin laminate obtained by reducing the glass balloon can be sufficiently reduced. However, if it is smaller than 0.8 / 1 (if the glass balloon is more than 55.6% by mass), there is insufficient resin to sufficiently bond the glass balloon and the fiber reinforcing material, and the mechanical strength is lowered. Therefore, sufficient physical properties cannot be obtained.

Step (ii)
In step (ii), the powder composition obtained in step (i) is uniformly contacted with the surface of the fiber reinforcing material. As such a method, for example, the powder composition is placed on the surface of the fiber reinforcing material, and an excess powder composition is used so that the powder composition layer has a certain thickness using a squeegee plate or the like. This can be done by scraping an object or passing through a gap adjusted to a uniform height. The thickness of the powder composition layer is appropriately adjusted depending on the desired thickness of the sheet-like material obtained in the next step (iii).

  The fiber reinforcing material used in the present invention is a sheet-like knitted fabric made of inorganic fibers such as glass fibers, carbon fibers, rock wool, metal fibers, or whiskers, or organic fibers made of cotton, hemp or other natural fibers or synthetic fibers. A cloth or non-woven fabric having a required mechanical strength after molding is preferable. Further, the fiber reinforcing material is preferably a glass fiber woven fabric, that is, a glass cloth, in view of the strength, electrical characteristics, thermal characteristics, and the like of the resulting laminate.

Step (iii)
In the step (iii), the powder composition is heated under pressure and temporarily attached to the fiber reinforcing material to form a sheet-like material. By passing the fiber reinforcement obtained by uniformly contacting the surface of the powder composition obtained in the step (ii), for example, between heating and pressing rolls, the powder composition is made to be the fiber reinforcement. Temporarily wear. The temperature range of the heating and pressing roll is 60 to 160 ° C, preferably 80 to 150 ° C, more preferably 100 to 150 ° C, and the linear pressure is 2 to 40 N / cm, preferably 5 to 30 N / cm, more preferably. Is 10 to 25 N / cm. When the temperature of the heating and pressing roll is less than 60 ° C., the thermosetting resin powder does not melt, so it cannot be temporarily attached to the fiber reinforcing material. When the temperature exceeds 160 ° C., the curing reaction proceeds while passing through the heating and pressing roll. Too much. For example, when an epoxy resin is selected as the thermosetting resin, an appropriate temperature is about 140 ° C. If the linear pressure of the heating and pressing roll is less than 2 N / cm, heat cannot be sufficiently transferred to the powder composition, so that it cannot be temporarily attached to the fiber reinforcement, and if it exceeds 40 N / cm, the surface of the fiber reinforcement The powder composition brought into contact with the material collapses, and the thickness is not uniform.

Step (iv)
In step (iv), a plurality of the sheet-like materials obtained in the above step (iii) are laminated, heat-pressed, and fused and integrated to produce the low specific gravity resin laminate of the present invention. As an apparatus for performing heat pressing as described above, for example, a hot press machine as shown in FIG. 1 is used. The hot press 12 has a structure in which stacked plurality of heating the pressing plates 13, between each, arranged stacking a plurality sheet material P ₂ as shown in FIGS. 2 and 3, 2 to 8 MPa The mixture is heated to 130 to 180 ° C, preferably 150 to 180 ° C, more preferably 160 to 175 ° C under a pressure of 3 to 7 MPa, more preferably 4 to 6 MPa, and these are fused and integrated.

  If the pressure is less than 2 MPa, the sheet-like materials do not sufficiently adhere to each other, so that desired physical properties cannot be obtained. If the pressure exceeds 8 MPa, the low specific gravity filler is likely to break. If the heating temperature is lower than 130 ° C., sufficient heat is not transmitted to the sheet-like material, which may result in insufficient curing. Also, the molding time becomes longer, resulting in poor productivity. The melt viscosity becomes too low, making it difficult to control the molding conditions. For example, if an epoxy resin is selectively used, 175 ° C. is an appropriate temperature.

In the molding of the laminate obtained by laminating plural sheets of the sheet-like material P ₂ shown in FIG. 3, the sheet material P ₂ is the weight converted into the desired shaped article, the number of sheet to be equivalent to the equivalent amount overlapping material P ₂ accommodated between heated press plate 13. At this time, when it is necessary to improve the planar precision of the molded article may be clamped via a mirror plate 14 between the heating platen 13 and the sheet-like material P ₂ shown in FIG. Thus the sheet material P ₂ of a laminate subjected to heat forming by a hot press 12 is then cut into a predetermined size by the cutting machine 15 shown in FIG. 1, a low specific gravity resin laminate which is the final product Plate A can be obtained.

  In the step (iv), a plurality of the sheet-like materials are laminated, and one or more layers selected from the uppermost layer, the lowermost layer, and an intermediate layer thereof are coated with a thermosetting resin on the fiber reinforcement. It is preferable to laminate the impregnated prepreg sheets, heat-press them, and fuse and integrate them. Unlike the sheet-like material of the present invention, the prepreg sheet in which the fiber reinforcement is impregnated with a thermosetting resin does not contain a low specific gravity filler, and the fiber reinforcement is not a powder composition. It is a prepreg obtained by impregnating a thermosetting resin solution, and is applied to a laminate that can obtain higher mechanical strength than the sheet-like material.

For example, as shown in FIG. 4, when the sheet material P ₂ are arranged plurally stacked, laminated prepreg sheets P ₃ impregnated with a thermosetting resin to textile reinforcement in the top layer and bottom layer, obtained the mechanical strength of the laminated plate a ₁ may be enhanced. Further, as shown in FIG. 5, further laminating a prepreg sheet P ₃ to the intermediate layer of the sheet material P ₂ in which a plurality of sheets laminated, the mechanical strength of the laminated plate A ₂ obtained may further enhance.

  As described above, the specific gravity of the synthetic resin laminate using glass fiber as a reinforcing material is about 1.8 to 2.0, whereas the above-mentioned obtained by the method for producing a low specific gravity resin laminate of the present invention. The laminate has a specific gravity of 0.6 to 1.1, preferably 0.7 to 1.05.

  Moreover, the said laminated board obtained by the manufacturing method of the low specific gravity resin laminated board of this invention has bending strength of 100 MPa or more, Preferably it is 110 MPa or more, More preferably, it is 120 MPa or more. If the bending strength is less than 100 MPa, it is not suitable as a material used for the automobiles and railway vehicles as described above. The higher the upper limit of the bending strength, the better for the above application, but it is 250 MPa or less from the blending amount and ratio of the material of the laminate. The bending strength was measured in accordance with JIS K 6911.

  Furthermore, the laminate obtained by the method for producing a low specific gravity resin laminate of the present invention has a compressive strength of 150 MPa or more, preferably 160 MPa or more, more preferably 180 MPa or more. When the compressive strength is less than 150 MPa, it is not suitable as a material used for the automobiles and railway vehicles as described above. Moreover, although the said compressive strength is so preferable that it is the said use, it is 300 Mpa or less from the compounding quantity of the material of the said laminated board, a ratio, etc. The compressive strength was measured according to JIS K 6911.

  In the method for producing a low specific gravity resin laminate of the present invention, a binder comprising (a) a thermosetting resin powder and (b) a low specific gravity filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof. Is a powder composition, so that the low specific gravity fillers do not float in the resin solution and become non-uniform, regardless of the mixing ratio, they are uniformly dispersed with good compatibility, and the fiber sheet reinforcement Easy to hold on the material. Further, when performing such holding, after the binder is attached to the surface of the reinforcing material, the binder is temporarily attached under heating and pressurization, and the thickness of the binder is changed at the time of the attachment, and then molded. The specific gravity of the resin laminate can be adjusted. Furthermore, in the method for producing a low specific gravity resin laminate of the present invention, by defining the particle size of the thermosetting resin powder used in the powder composition within a specific range much smaller than the conventional one, In addition, a resin laminate having a lower specific gravity can be provided without impairing other characteristics such as electrical characteristics, mechanical strength, and thermal conductivity.

(I) Preparation of thermosetting resin powder (a) Epoxy resins A and B shown in Tables 1 and 2 below and a curing agent were twin-screw extruder (“TITAN-45” manufactured by Cincinnati Extrusion Co., Ltd.) Kneaded and cooled to form a pellet-shaped thermosetting resin composition, and pulverized using a pulverizer (“Milstar Dam” manufactured by Tokyo Atomizer Manufacturing Co., Ltd.) to produce a thermosetting resin powder. Obtained. The particle size of the obtained thermosetting resin powder is shown in the same table.

（注１）新日鐵化学株式会社から商品名「ＹＤ−０１２」で市販されているビスフェノールＡ型エポキシ樹脂（エポキシ当量７５０ｇ／ｅｑ、軟化点８０℃）
（注２）新日鐵化学株式会社から商品名「ＹＤＣＮ−７００−１０」で市販されているｏ−クレゾールノボラック型エポキシ樹脂（エポキシ当量２０６ｇ／ｅｑ、軟化点８０℃）
（注３）エアープロダクツジャパン株式会社から商品名「アミキュアＣＧ−３２５」で市販されているジシアンジアミド硬化剤
（注４）住友スリーエム株式会社から商品名「グラスバブルズ」で市販されているガラスバルーン（粒径４０μｍ、比重０．３８）
（注６）樹脂含有率（Ｒ.Ｃ.）：積層板の全重量（熱硬化性樹脂粉末＋充填材＋繊維製補強材）に対する上記熱硬化性樹脂粉末（ａ）の配合割合

(Note 1) Bisphenol A type epoxy resin marketed by Nippon Steel Chemical Co., Ltd. under the trade name “YD-012” (epoxy equivalent 750 g / eq, softening point 80 ° C.)
(Note 2) o-cresol novolac type epoxy resin marketed by Nippon Steel Chemical Co., Ltd. under the trade name “YDCN-700-10” (epoxy equivalent 206 g / eq, softening point 80 ° C.)
(Note 3) Dicyandiamide curing agent marketed by Air Products Japan Co., Ltd. under the trade name “Amicure CG-325” (Note 4) Glass balloon marketed by Sumitomo 3M Co., Ltd. under the trade name “Glass Bubbles” Particle size 40μm, specific gravity 0.38)
(Note 6) Resin content (RC): blending ratio of the thermosetting resin powder (a) with respect to the total weight of the laminate (thermosetting resin powder + filler + fiber reinforcing material)

(Ii) Production of Low Specific Density Resin Laminate Using the production apparatus shown in FIG. 1, first, a fiber reinforcing material P made of a web-like glass fiber woven fabric (commercially available from Nitto Boseki Co., Ltd. under the trade name “WEA26”) The glass cloth is fed out from the roll body 1 at a constant speed of 3 to 4 m / min, and is advanced in a tensioned state along the lower surface of the frame-type container 2 having an opening on the upper and lower surfaces. the polyester release sheet S ₁ pulled out from the roll body 3 was also closely tension in such a state, above the said reinforcing material was transferred at the same rate as P. frame type container 2, a hopper 4, and more upward A rotary mixer 5 is installed, and the thermosetting resin powder (a) and the low specific gravity filler (b) prepared in (i) above are put into the rotary mixer 5 and mixed uniformly. Thus, a powder composition M was produced. The obtained powder composition M was continuously supplied into the frame container 2 through the hopper 4.

A thickness control gap 6 adjusted to a uniform height (1.4 mm) over the width direction of the reinforcing material P is formed at the downstream end of the frame container 2, and the thickness of the reinforcing material P is thick on the surface of the reinforcing material P. A powder composition layer having a thickness of about 1.13 mm was uniformly formed. The thickness control gap 6 is configured such that the powder composition layer can be appropriately adjusted to a desired thickness by changing the height so that the downstream side surface of the container 2 can slide in the vertical direction. Also, pull separately release sheet S ₂ from the roll body 7 was affixed to the powder composition layer top surface.

The web-shaped reinforcing material P having a uniform powder composition layer thus obtained is a pair of heated to 140 ° C. with the upper and lower surfaces sandwiched between release sheets S ₁ and S ₂ . It passed through the peripheral surfaces of the heating rolls 8 and 9 and heated under a pressure of 20 N / cm of linear pressure by the pressure roll 10. At this time, the epoxy resin in the powder composition is partially melted and fixed to the web-like reinforcing material P while being partly impregnated with the glass balloon, so that a semi-cured prepreg P ₁ is obtained. Been formed.

The prepreg P ₁ is cut into a rectangular shape with a predetermined size (1000 mm × 1000 mm) by a cutting device 11 in which two blades face each other, and is formed into a sheet-like material P _2, and release sheets S ₁ , S ₂ from peeled off, was fused molded accommodated in hot press 12 by laminating a ₂ plurality said sheet material P.

Hot press, as shown in FIG. 1 12 has a structure in which stacked plurality of heating the pressing plates 13, heating the sheet material P ₂ 7 sheets stacked to the 175 ° C. under a pressure of 5MPa between each These were fused and integrated.

Thus the sheet material P ₂ of a laminate subjected to heat forming by a hot press 12 is then by cutting machine 15 is cut into a predetermined size to obtain a resin laminated plate A is the final product.

Further, as shown in FIG. 1, when the release sheets S ₁ and S ₂ are endless annular and are circulated through the peripheral surface of the pressure roll 10 or the heating roll 9, respectively, the upper and lower surfaces of the prepreg P ₁ are provided. Can be automatically peeled off, and the production cost is reduced by reusing the release sheets S ₁ and S ₂ . The release sheet S _1, S ₂ described above showed a made of polyester, the may be other synthetic resin or paper, as a matter of course.

  The specific gravity, insulation resistance (normal state and after boiling), bending strength, compressive strength, water absorption and thermal conductivity of the obtained resin laminate were measured, and the results are shown in Tables 3 to 4 below. . The thermal conductivity was measured according to ASTM D4351 and the Shibayama method (acetone-benzene method), and the other measurement methods were performed according to JIS K 6911.

(Test results)

  The resin laminate of the present invention of Example 1 has the same specific gravity and the same bending strength as the conventional resin laminate of Comparative Example 1 except that the particle size of the thermosetting resin powder is large. , Other physical properties such as compressive strength, insulation resistance (normal and after boiling), water absorption, etc. were very excellent.

  In addition, the resin laminates of the present invention in Examples 2 to 4 have other insulation resistance (normal state and after boiling), bending strength, compressive strength, water absorption rate, and the like than the conventional resin laminates of Comparative Examples. It can be seen that the thermal conductivity is small and the specific gravity is very low without impairing the characteristics.

  Furthermore, the resin laminate of the invention of Example 5 produced in the same manner as Example 4 except that the coating amount of the powder composition was increased, the insulation resistance, bending strength and water absorption after boiling were slightly reduced. However, the thermal conductivity is further low, the thermal insulation is excellent, the specific gravity is 0.83, which is a very low value, and a large weight reduction is possible. Also, the resin laminates of the present inventions of Examples 6 to 7 produced in the same manner as Example 5 except that the particle size of the thermosetting resin powder was changed were also the insulation resistance after boiling, bending strength and water absorption rate. However, the thermal conductivity was low and the heat insulation was excellent, the specific gravity was 0.83, which was a very low value, and a large weight reduction was possible.

Since the comparative example 1 has a large particle size of the thermosetting resin powder, the specific gravity value is equivalent when compared with the resin laminate of Example 1 prepared in the same manner except that the particle size of the thermosetting resin powder is small. There are other physical properties that are very inferior,
In Comparative Example 2, the particle size of the thermosetting resin powder is large compared to the resin laminate of Example 5 prepared in the same manner except that the particle size of the thermosetting resin powder is small. The amount of the binder temporarily attached to the fiber reinforcing material was insufficient, and a sheet-like material could not be produced and molded (thus, the characteristic evaluation could not be performed).

  Comparative Example 3 has a specific gravity value as compared with the resin laminates of Examples 5 to 7 prepared in the same manner except that the particle size of the thermosetting resin powder is as large as 110 μm and the particle size of the thermosetting resin powder is small. And the thermal conductivity values are equivalent, but other properties are very inferior, and because the temporary attachment to the fiber reinforcement of the powder composition is insufficient, the handling properties are poor, Productivity was inferior.

  Further, as a result of trying to grind the particle size of the thermosetting resin powder to 0.5 μm, the resin was melted by the heat generated at the time of pulverization and could not be pulverized.

  That is, by using the method for producing a low specific gravity resin laminate of the present invention, it became possible to produce a laminate having a specific gravity of 0.83 in Examples 5 to 7 that could not be produced by the conventional laminate production method. It is.

P ... Fiber reinforcing material P ₁ ... Prepreg P ₂ ... Sheet-like material P ₃ ... Prepreg obtained by impregnating a thermosetting resin solution with a fiber reinforcing material not containing a low specific gravity filler M ... Powder composition A, A ₁ , A ₂ ... low specific gravity resin laminate S ₁ , S ₂ ... release sheet 1 ... fiber reinforcing material roll body 2 ... frame-type container 3, 7 ... release sheet roll body 4 ... hopper 5 ... rotary mixing Machine 6 ... Thickness control gap 8, 9 ... Heating roll 10 ... Pressure roll 11 ... Cutting device 12 ... Hot press machine 13 ... Heating and pressing panel 14 ... Mirror plate 15 ... Cutting machine

Claims (8)

(I) (a) thermosetting resin powder;
(B) a step of uniformly mixing a filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof to form a powder composition;
(Ii) a step of bringing the powder composition into uniform contact with the surface of the fiber reinforcing material;
(Iii) a step of heating the powder composition under pressure to temporarily attach the fiber composition to the fiber reinforcing material to form a sheet-like material; and (iv) laminating a plurality of the sheet-like materials, and heating press And including the step of fusing and integrating,
The method for producing a low specific gravity resin laminate, wherein the thermosetting resin powder has a particle size of 1 to 100 μm.   In the step (iv), a plurality of the sheet-like materials are laminated, and at least one layer selected from the uppermost layer, the lowermost layer and an intermediate layer thereof is impregnated with a thermosetting resin in a fiber reinforcing material. The manufacturing method according to claim 1, wherein the sheets are laminated, heat-pressed, and fused and integrated.   The method according to claim 1, wherein the thermosetting resin is a mixture of a bisphenol type epoxy resin and a novolac type epoxy resin.   The bisphenol type epoxy resin has a softening point of 60 to 120 ° C. and an epoxy equivalent of 450 to 2000), the novolac type epoxy resin has a softening point of 60 to 120 ° C., and the bisphenol A type epoxy resin / novolac type epoxy resin The manufacturing method of Claim 3 whose compounding ratio of is 8/1-1/1.   The low specific gravity resin laminated board manufactured by the manufacturing method of any one of Claims 1-4. (A) a thermosetting resin powder;
(B) a filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof;
(C) A low specific gravity resin laminate comprising a fiber reinforcing material and having a specific gravity of 0.6 to 1.1, a bending strength of 100 MPa or more, and a compressive strength of 150 MPa or more. (I) (a) a thermosetting resin powder having a particle size of 1 to 100 μm;
(B) uniformly mixing a filler selected from the group consisting of organic balloons, inorganic balloons and mixtures thereof to form a powder composition;
(Ii) contacting the powder composition uniformly with the surface of the fiber reinforcement;
(Iii) heating the powder composition under pressure to temporarily attach the fiber composition to the fiber reinforcing material to form a sheet-like material;
(Iv) It is manufactured by laminating a plurality of the sheet-like materials, heat-pressing, and fusing and integrating them,
A low specific gravity resin laminate having a specific gravity of 0.6 to 1.1, a bending strength of 100 MPa or more, and a compressive strength of 150 MPa or more.   The thermosetting resin is a mixture of a bisphenol type epoxy resin and a novolac type epoxy resin, and a blending ratio of the bisphenol A type epoxy resin / novolak type epoxy resin is 8/1 to 1/1. Low specific gravity resin laminate.

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