JP2009006494A - Method for producing fiber-reinforced resin composite structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a fiber-reinforced resin composite structure preventing occurrence of peeling in molding. <P>SOLUTION: The method for producing a fiber-reinforced resin composite structure where, into a fiber-reinforced resin layer using a thermosetting resin as a matrix, an insert material having a linear expansion coefficient higher than that of the fiber-reinforced resin layer is inserted, comprises: a stage where the insert material is arranged at the inside of a prepreg material forming the fiber-reinforced resin layer; a pre-warming stage where the fiber-reinforced resin composite structure is warmed to a temperature less than a temperature at which the thermosetting resin in the prepreg material is perfectly cured; and a main warming stage where, after the warming by the pre-warming stage, the fiber-reinforced resin composite structure is warmed to a temperature at which the thermosetting resin is perfectly cured. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a fiber reinforced resin composite structure, and more particularly to a method for producing a composite structure comprising a carbon fiber reinforced plastic and a glass fiber reinforced plastic.

  Patent Document 1 relates to a method for connecting a fiber reinforced plastic composite structure. A fiber reinforced plastic composite structure in which an outer layer portion is made of a high-strength fiber reinforced plastic layer and an inner layer portion is made of a low-strength resin or lightweight material. When connecting to another structure, a sleeve made of a tough material such as metal, composite material, plastic or the like and provided with a fastening hole in the connection portion with the other structure in the composite structure A fiber reinforced plastic composite structure is disclosed, in which one or two or more are inserted, a fastener is inserted into a hole in the sleeve, and is connected to another structure via the fastener.

  Patent Document 2 relates to an invention of an FRP structure, and discloses an FRP structure in which an FRP skin layer, a core material, and an insert fitting interposed therebetween are integrally formed.

  Patent Document 3 discloses a CFRP laminate in which FRP inserts are installed between CFRP layers at predetermined portions when a CFRP laminate is molded.

In order to increase the strength of the laminate structure as described above, when molding is performed by inserting a block such as GFRP or aluminum into the CFRP laminate, the molding temperature is usually 130 to 150 ° C. When removing from the product, cool the product to near room temperature. During this cooling, peeling occurs at the interface between the two materials, which causes a problem that the fastening temperature is lowered.
The cause of this peeling is that there is a large difference in the linear expansion coefficients of both materials. Normally, the linear expansion coefficient of CFRP is 1-2 × 10 ⁻⁶ / ° C., whereas the linear expansion coefficient of GFRP is 20-50 × 10 ⁻⁶ / ° C. The linear expansion coefficient of the lamination method becomes a problem, but due to the insert structure, the linear expansion coefficient of the GFRP lamination method is several hundred times that of CFRP. When cooling from the molding temperature to room temperature, peeling occurs on the weaker side between the boundary between GFRP and CFRP and the CFRP layer.

Japanese Patent Laid-Open No. 4-1029 JP 2002-59498 A JP 2006-175606 A

  This invention is made | formed in view of such a situation, and it aims at providing the manufacturing method of the fiber reinforced resin composite structure which peeling does not generate | occur | produce at the time of shaping | molding.

  In order to solve the above problems, the method for producing a fiber-reinforced resin composite structure according to the present invention has a linear expansion coefficient larger than that of the fiber-reinforced resin layer inside the fiber-reinforced resin layer using a thermosetting resin as a matrix. A method for producing a fiber-reinforced resin composite structure formed by inserting an insert material comprising: a step of arranging an insert material inside a prepreg material forming the fiber-reinforced resin layer; and thermosetting in the prepreg material A preliminary heating step of heating the fiber-reinforced resin composite structure to a temperature less than a temperature at which the thermosetting resin is completely cured, and a temperature at which the thermosetting resin is completely cured after the heating by the preliminary heating step And a main heating step for heating the fiber-reinforced resin composite structure.

  In addition to the above characteristics, in the method for producing a fiber-reinforced resin composite structure of the present invention, the insert member is a fiber-reinforced resin having a larger linear expansion coefficient than the fiber-reinforced resin layer of the matrix. It is characterized by.

  In addition to the above features, the method for producing a fiber reinforced resin composite structure of the present invention may further include adding the fiber reinforced resin composite structure to a temperature near the glass transition temperature of the insert material in the preliminary heating step. It is a process of heating.

  In addition to the above features, the method for producing a fiber-reinforced resin composite structure of the present invention is characterized in that the fiber-reinforced resin layer of the matrix is a layer made of carbon fiber-reinforced plastic, and the insert material is glass fiber-reinforced plastic. It is characterized by comprising.

  The present invention uses a thermosetting resin, and has an excellent effect that peeling does not occur at an interface between layers or between members when molding a fiber reinforced resin composite including an insert material inside. is there.

  In addition, when molding a composite having a sandwich structure of two members having different thermal expansion coefficients such as CFRP and GFRP, there is an excellent effect that peeling does not occur at the CFRP layer or at the interface between CFRP and GFRP.

  The best mode for carrying out the present invention is a composite structure in which a prepreg material containing a thermosetting resin is used as a matrix and an insert material is incorporated therein. The resin is cured to a degree of curing of about 80 to 95% at a temperature as low as about 10 to 50 ° C., and then completely cured at the original curing temperature in the second stage. Since it is cured, when it is heated to the original curing temperature in the second stage, the insert material tends to thermally expand, but since the surrounding matrix material has been cured to a considerable extent, the insert material Therefore, when the composite structure is cooled to room temperature after the end of the second stage, the amount of shrinkage of the insert material is reduced, and as a result, To prevent the occurrence of peeling between layers and the matrix and the boundary of the insert box material.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a view showing a cross section of a fastening portion of a composite structure including a matrix 1 of CFRP (carbon fiber reinforced plastic), an insert material 2 of GFRP (glass fiber reinforced plastic), and a core material 3. As a first step, the composite structure is heated at 120 ° C. for 120 minutes, and then as a second step, a heat treatment is performed at 150 ° C. for 60 minutes.

  FIG. 2 is a graph showing the measurement results of temperature and strain with respect to time of the GFRP insert material during the first stage process and the second stage process. According to FIG. 2, the strain when the temperature reaches 120 ° C. is about 2000 με, but the strain gradually decreases as the resin cures. Even when the temperature rises to 150 ° C., the strain is about 2050 με, and the strain can be suppressed to a considerably low level of increase compared to the strain of about 2000 με at 120 ° C. It is shown.

  FIG. 3 shows the TMA (Thermo-mechanical Analyzer) measurement result of the GFRP block material. The horizontal axis represents the cell temperature, the vertical axis represents the TMA measurement result, and the slope of the graph represents the linear expansion coefficient. The inflection point in the graph in FIG. 3 indicates the dislocation point of GFRP, which means that dislocation occurs in the material near 100 ° C., and that the linear expansion coefficient of the material greatly changes before and after this dislocation. ing. In the first stage, by setting the heating temperature to the vicinity of the glass transition temperature, curing of CFRP around the GFRP proceeds while avoiding a rapid increase in the linear expansion coefficient.

FIG. 1 is a view showing a cross section of a fastening portion of a composite structure including a CFRP matrix, a GFRP insert material, and a core material. FIG. 2 shows measurement results of temperature and strain with respect to time of the GFRP insert material when two-stage molding is performed using a CFRP matrix and a GFRP insert material. FIG. 3 shows the TMA (Thermo-mechanical Analyzer) measurement result of the GFRP block material.

Explanation of symbols

1 CFRP (carbon fiber reinforced plastic) matrix 2 GFRP (glass fiber reinforced plastic) insert material 3 Core material

Claims (4)

A method for producing a fiber reinforced resin composite structure, wherein an insert material having a linear expansion coefficient larger than that of the fiber reinforced resin layer is inserted into a fiber reinforced resin layer having a thermosetting resin as a matrix,
A step of arranging an insert material inside the prepreg material forming the fiber reinforced resin layer;
A preliminary heating step of heating the fiber reinforced resin composite structure to a temperature less than a temperature at which the thermosetting resin in the prepreg material is completely cured;
A main heating step of heating the fiber reinforced resin composite structure to a temperature at which the thermosetting resin is completely cured after the heating by the preliminary heating step;
The manufacturing method of the fiber reinforced resin composite structure characterized by including this. The manufacturing method according to claim 1,
The method for producing a fiber-reinforced resin composite structure, wherein the insert member is a fiber-reinforced resin having a larger linear expansion coefficient than the fiber-reinforced resin layer of the matrix. In the manufacturing method described in Claim 1 or 2,
The method for producing a fiber reinforced resin composite structure, wherein the preliminary heating step is a step of heating the fiber reinforced resin composite structure to a temperature near a glass transition temperature of the insert material. In the manufacturing method according to any one of claims 1 to 3,
The method for producing a fiber reinforced resin composite structure, wherein the fiber reinforced resin layer of the matrix is a layer made of carbon fiber reinforced plastic, and the insert material is made of glass fiber reinforced plastic.

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