JP2015226986A - Fiber-reinforced thermoplastic resin molding body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fiber-reinforced thermoplastic resin molding body excellent in mechanical characteristics, and molding fluidity to complicated shape parts such as a rib and boss.SOLUTION: A molding body is a fiber-reinforced thermoplastic resin molding body and comprises a substrate part 1 and a projection part 2 whose thickness 6 on a bottom is 2-30 mm, and whose height 7 is 5-150 mm. The molding body is formed of a member A formed of a continuous reinforcement fiber 3 and thermoplastic resin, and a member B formed of a non-continuous reinforcement fiber 4 and thermoplastic resin, in which the member B is filled in a tip end part of the projection part 2, and influx depth 5 of the member A into the projection part 2 is equal to or more than 0.5 mm.

Description

  Fiber reinforced thermoplastic resin molded article composed of continuous fiber reinforced thermoplastic composite material and discontinuous fiber reinforced thermoplastic composite material with excellent mechanical properties and moldability of complex shaped members having protrusions (ribs, bosses, etc.) About.

In recent years, it has been studied to change the material of parts from metal to resin in various fields. In particular, attempts have been made to replace the fiber reinforced resin reinforced with reinforcing fibers with metal in terms of rigidity, impact resistance, and the like.
The fiber reinforced resin includes a fiber reinforced thermoplastic resin in which a thermoplastic resin is used as a matrix resin. For example, in a vehicle field such as an automobile, application to a frame material used around an engine, a bumper beam, or the like. (For example, refer patent documents 1-5.).

  In the case of a member with a simple sheet shape, it can be formed with a woven fabric with reinforced fibers linearly arranged and a unidirectional (UD) material, and high mechanical strength can be secured, but it is arranged in a limited space according to the application. In the case of molding a fiber reinforced thermoplastic resin molded body having a complicated shape, the woven fabric and the UD material alone have poor fluidity and cannot follow the complicated shape. In order to solve this problem, it is attempted to integrate by filling the protrusions such as ribs and bosses with a short reinforcing fiber length and good fluidity, etc. It has been. However, the interfacial adhesion between the low fluidity woven fabric, UD material layer and the high fluidity short fiber reinforced resin layer is low, the fiber reinforced resin molded body has a sufficient mechanical strength and easily causes peeling failure due to deformation. Was not obtained.

JP-A-5-9301 JP-A-6-313292 JP-A-7-88840 JP-A-9-216225 International Publication No. 09/142291 Pamphlet

  The present invention solves the above-mentioned problems and provides a fiber-reinforced thermoplastic resin molded article comprising a continuous fiber-reinforced thermoplastic composite material and a discontinuous fiber-reinforced thermoplastic composite material, which are excellent in mechanical properties and moldability. To do.

In order to obtain high mechanical strength while ensuring molding fluidity capable of filling a material in a complicated shape, the present invention takes the following means.
That is, the present invention is as follows.
[1] A molded body having a base portion and a protrusion having a base thickness of 2 mm to 30 mm and a height of 5 mm to 150 mm, and the molded body is a member A composed of continuous reinforcing fibers and a thermoplastic resin. And a member B made of discontinuous reinforcing fibers and a thermoplastic resin, the member B is filled in the tip of the protrusion, and the depth of flow of the member A into the protrusion is 0.5 mm or more. A fiber-reinforced thermoplastic resin molded article characterized by
[2] The mass of the reinforcing fiber and the thermoplastic resin contained in the member B is composed of a thin film piece of tape having a length of 5 mm to 100 mm, a width of 4 mm to 60 mm, and a thickness of 0.05 mm to 0.4 mm. The fiber reinforced thermoplastic resin molded article according to [1], wherein the ratio is 85/15 to 30/70.
[3] The fiber reinforced thermoplastic resin molded article according to [1] or [2], wherein the continuous reinforcing fiber of the member A is a cloth material, and the member A is a laminate including 2 to 10 layers of the cloth material.

  According to the present invention, a fiber reinforced thermoplastic comprising a continuous fiber reinforced thermoplastic composite material and a discontinuous fiber reinforced thermoplastic composite material having excellent mechanical properties and fluidity in forming a complicated shape such as a rib and a boss. A resin molded body can be provided. Further, the fiber-reinforced thermoplastic resin molded article of the present invention also has a feature that peeling failure at the interface between the continuous fiber-reinforced thermoplastic composite material and the discontinuous fiber-reinforced thermoplastic composite material hardly occurs.

It is the schematic of the cross section of the fiber reinforced thermoplastic resin molding of this invention.

The fiber-reinforced thermoplastic resin molded body of the present invention is a molded body having a base material portion and a protrusion.
Moreover, the fiber reinforced thermoplastic resin molding of the present invention is composed of a member A containing continuous reinforcing fibers and a member B containing discontinuous reinforcing fibers. While ensuring high rigidity and mechanical properties with continuous fibers, the protrusions arranged for dimensional stability etc. are filled with member B containing discontinuous fibers with good molding fluidity, improving total mechanical properties It becomes possible to make it.
In the mold having the protruding portion shape, the member A is disposed on the base portion side and the member B is disposed on the protruding portion side and integrally molded, and the fiber-reinforced thermoplastic resin molded body of the present invention is obtained. In the case of a molded body having protrusions on both sides of the base material, the member B is disposed on both sides of the member A and is integrally molded. It is preferable that both the member A and the member B arranged in the mold have a sheet shape.

  The magnitude | size of a base material part is not specifically limited. From the configuration of the member A described below, it is preferably a flat plate having a thickness of 0.4 mm to 6 mm. In the case of a flat plate shape, the end of the flat plate is preferably within 30 cm from the protrusion.

The shape of the protrusion is not particularly limited. It may be a prismatic shape, a cylindrical shape, or a tapered shape that decreases as it goes to the tip.
The thickness of the base of the protrusion is 2 mm to 30 mm, and the height is 5 mm to 150 mm. When the protrusion is a polygonal prism, the thickness of the root refers to the length of the smallest side of the polygon, and when the protrusion is a cylinder, the thickness of the root refers to the diameter of the circle.

When the thickness of the base of the protrusion is 2 mm to 30 mm, the member A can be easily integrated with the member B by flowing into the protrusion, and the mechanical strength of the fiber-reinforced thermoplastic resin molded body can be increased. It becomes possible. When it is less than 2 mm, the integration with the member B due to the flow of the member A into the protrusion is not sufficiently performed, which is not preferable. Conversely, if it exceeds 30 mm, the weight becomes unnecessarily heavy, which is not preferable. Therefore, a more preferable range is 3 mm to 20 mm.
Further, when the height of the protrusion is less than 5 mm, the mechanical properties are hardly improved, and when it exceeds 150 mm, the weight is unnecessarily heavy, and the filling property of the member B itself is impaired. A more preferable range is 10 mm to 80 mm.

  One or a plurality of protrusions may be provided. In the case of a plurality, it is preferable that the distance between adjacent protrusions is 15 mm or more at the shortest distance.

Further, the fiber reinforced thermoplastic resin molded article of the present invention has a configuration in which the member A containing continuous reinforcing fibers enters the protrusion from the base material (tangent line connecting the base of the protrusion) to a depth of 0.5 mm or more. Is made. The depth at which the member A enters the protrusion is referred to as the flow depth in this specification. The measurement method is described in the section of the following example, but the inflow depth of the member A substantially refers to the inflow depth of the continuous fibers of the member A. Moreover, the schematic of the cross section (part which can understand the thickness of the base of a projection part) of the fiber reinforced thermoplastic resin molding of this invention in FIG. 1 is shown.
This is the point of the present invention. Normally, the member A containing continuous fibers that are difficult to flow is fitted into the depressions of the protrusions, so that the resin impregnation into the reinforcing fibers by the abrasion of the interface is continuous and continuous. A sense of unity accompanying the crimp shape of the reinforcing fiber is born, and it becomes difficult to cause delamination failure, and it is possible to exhibit excellent mechanical properties.
The means is not particularly limited, and the projection A can be filled by appropriately selecting the fabric size, fabric structure, and molding pressure at which the member A including the continuous reinforcing fibers facing the projection can flow during molding. It is possible to make it.
The larger the depth of flow into the protrusions of the member A containing continuous reinforcing fibers, the greater the integration and the less likely the delamination will occur, but there is also a limit to the amount of indentation (flow depth) of materials with low fluidity There is. Therefore, the preferable range of the inflow depth is in the range of 0.8 mm to 30 mm.

  The reinforcing fibers used for the member A and the member B are not particularly limited, but representative examples include inorganic fibers such as carbon fibers, silicon carbide fibers, and glass fibers, metal fibers such as boron fibers, and organic fibers such as aramid fibers. It is done. Glass fiber, carbon fiber and the like are particularly preferable from the viewpoints of cost and the elastic modulus and mechanical strength of the obtained molded product.

  The thermoplastic resin constituting the fiber reinforced thermoplastic resin used for the member A and the member B is not particularly limited, but representative examples include polyamide resins such as polyamide 6, polyamide 12, polyamide 66, and polyamide 46, polyethylene Examples thereof include polyester resins such as terephthalate and polybutylene terephthalate, polyolefin resins such as polyethylene and polypropylene, polyether ketone resins, polyphenylene sulfide resins, polyether imide resins, and polycarbonate resins. Moreover, the modified body of these each resin may be used, and multiple types of resin may be blended and used. Further, the thermoplastic resin may contain various additives, fillers, colorants and the like. These components are preferably 5% by mass or less in the total amount of the thermoplastic resin.

The member B containing discontinuous reinforcing fibers used for the fiber reinforced thermoplastic resin molded body melts a tape-like resin of a thin film piece having a length of 5 mm to 100 mm, a width of 4 mm to 60 mm, and a thickness of 0.05 mm to 0.4 mm. It is preferable that the mass ratio of the reinforcing fiber and the thermoplastic resin (reinforcing fiber / thermoplastic resin) to be contained is 85/15 to 30/70. The tape-like material obtained as described above is randomly dispersed in a mold, and in a laminated state, a heat press is performed to melt the resin, and then a cooling press is performed to obtain a sheet having a predetermined thickness. It is preferable to obtain the member B and use it for the fiber-reinforced thermoplastic resin molded article of the present invention.
The tape-like material constituting the member B can be obtained by continuously impregnating a continuous fiber with a resin, crushing with a shaping roller, solidifying by cooling, and cutting the tape.

When the thickness of the tape is less than 0.05 mm, the production efficiency is poor, and when it exceeds 0.4 mm, the resin impregnation property tends to be insufficient. More preferably, it exists in the range of 0.07 mm-0.2 mm. On the other hand, when the width is less than 4 mm or exceeds 60 mm, the production efficiency is deteriorated. More preferably, it is the range of 10 mm-50 mm. When the length is less than 5 mm or more than 100 mm, the productivity deteriorates, which is not preferable. More preferably, it exists in the range of 10 mm-50 mm. Further, it is more preferable that the width and the length are close to the same size, since the anisotropy is lost and randomization is easily performed. If the mass ratio of the reinforcing fibers contained exceeds 85%, the resin impregnation property becomes insufficient and tends to be a starting point of breakage, and if it is less than 30%, it is difficult to obtain a reinforcing fiber reinforcing effect. A more preferable range of the mass ratio between the reinforcing fiber and the thermoplastic resin is 80/20 to 50/50. With the above configuration, high molding fluidity and mechanical properties are ensured.
The mass ratio between the reinforcing fiber and the thermoplastic resin is the same for the member A described below.

The member A is composed of continuous reinforcing fiber and thermoplastic resin. As the continuous reinforcing fiber, a cloth material is preferably used. Examples of the weaving method include plain weave, twill weave, satin weave and triaxial weave. Etc. are exemplified. In order to ensure high rigidity, it is necessary to reduce the crimp amount of continuous fibers as much as possible. For this purpose, a UD material (unidirectional material) that does not have a woven structure may be used as appropriate.
The member A is obtained from such a cloth material or UD material and the above thermoplastic resin.

  Moreover, it is preferable that the member A containing a continuous fiber is comprised from the laminated body containing a 2-10 layer cloth material and UD material. A layer close to the protrusion flows into the protrusion and forms a crimp, so that the member A of the layer far from the protrusion can maintain the straightness of the fiber and ensure rigidity while maintaining a sense of unity. The number of laminated members A varies depending on the structure and thickness of the target member, but 3 to 7 layers are preferable. At this time, the thermoplastic resin is preferably in the form of a film or powder, and a member A is preferably obtained by sandwiching a cloth material or a UD material and heating and melting it. That is, a configuration in which a film-like or powder-like thermoplastic resin layer and a cloth material or UD material layer are alternately laminated is preferable.

  Such fiber reinforced thermoplastic resin moldings are used for, for example, automotive parts such as front subframes, rear subframes, front pillars, center pillars, side members, cross members, side sills, roof rails, propeller shafts, and subsea oil fields. It is preferably used for pipes, electric cable cores, rolls and pipes for printing presses, robot forks, aircraft primary structural materials, secondary structural materials, and the like.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, it is not restrict | limited by these Examples.
In addition, the inflow depth of the protrusion part (rib part) of the sheet | seat member B containing the continuous reinforcement fiber described in an Example was calculated | required by observing the cross section after cut | disconnecting a molded article with a jigsaw. Specifically, a ruler was applied to the line connecting the tangent lines of the protrusions, a right-angle ruler was applied thereto, and the flow depth was determined by measuring the length of the continuous reinforcing fiber flowing into the protrusions.

Example 1
After opening continuous glass fiber (Nippon Electric Glass Co., Ltd., ER2310-431N, 2310Tex, 4000f), polyamide 6 (Toyobo Co., Ltd., A2500, melting point 220 ° C.) was used as the thermoplastic resin at 270 ° C. The resin is continuously impregnated through a resin tank, then crushed with a shaping roller and cooled and solidified, and then cut, and 70 parts by mass of glass fiber is impregnated with 30 parts by mass of polyamide resin. A tape-shaped preform (tape) having a thickness of 35 mm and a thickness of 0.1 mm was produced.
While this preformed body was randomly dispersed and laminated in the mold, heat pressing was performed at a temperature of 260 ° C. to melt the resin, and then cooling pressing was performed in a mold at 150 ° C. A thick sheet member B was obtained.
Also, after producing a plain weave fabric using the same continuous glass fiber (manufactured by Nippon Electric Glass Co., Ltd., ER2310-431N, 2310Tex, 4000f), 5 layers of polyamide 6 film alternately with polyamide 6 film in the mold. 2 mm thick sheet in which 4 layers of glass fiber fabric are laminated, and the resin is melted with a heating press at 260 ° C., and then 75 parts by weight of glass fiber is impregnated with 25 parts by weight of polyamide resin with a cooling press at 150 ° C. Member A was obtained.
Thereafter, the sheet member B containing non-continuous reinforcing fibers and the sheet member A containing continuous reinforcing fibers are each cut out to a size of 240 mm square, and heated with a far infrared heater until the material temperature becomes 260 ° C., After charging so that the sheet member B including the discontinuous reinforcing fibers is on the rib side, the outer shape having a rib shape of 4 mm at the base, 30 mm in height, and 80 mm in width and having an outer shape of 250 mm square is 150 ° C. A fiber reinforced thermoplastic resin molded article was obtained with a cooling press. The flow depth of the sheet member A containing continuous reinforcing fibers into the rib portion was 1.5 mm.
After that, the specimen was cut out with a width of 35 mm so that the rib part was just in the center of the measurement of bending properties, and the bending strength was measured by applying a load from the back side of the rib part. The bending strength was very good at 610 MPa and the bending elastic modulus was 20 GPa.

(Example 2)
The member B containing discontinuous reinforcing fibers and the member A containing continuous reinforcing fibers obtained in Example 1 were cut into 480 mm square sizes, and the surface temperature was 260 ° C. with an infrared heater as in Example 1. After heating until the bottom is 4 mm, the height is 30 mm, and the width is 200 mm, the outer shape of the mold is 500 mm square and charged so that the sheet member B containing discontinuous reinforcing fibers is on the rib side. After molding with a cooling press at 150 ° C., a fiber-reinforced thermoplastic resin molded body was obtained. The inflow depth of the rib portion of the sheet member A containing continuous reinforcing fibers was 1.2 mm.
In addition, the flow amount of the rib part of the sheet member A containing the continuous reinforcing fiber was controlled by the flow characteristic difference by changing the sheet size.
After that, the specimen was cut out with a width of 35 mm so that the rib part was just in the center of the measurement of bending properties, and the bending strength was measured by applying a load from the back side of the rib part. The bending strength was very good at 590 MPa and the bending elastic modulus was 20 GPa.

(Comparative Example 1)
The member B containing the discontinuous reinforcing fibers and the member A containing the continuous reinforcing fibers obtained in Example 1 were each cut into a size of 680 mm square, and the surface temperature was 260 ° C. with an infrared heater as in Example 1. After heating until the bottom is 4 mm, the height is 30 mm, and the width is 200 mm, the outer shape of the mold is 700 mm square mold, and the sheet member B containing discontinuous reinforcing fibers is charged on the rib side. After molding with a cooling press at 150 ° C., a fiber-reinforced thermoplastic resin molded body was obtained. The inflow depth of the rib part of the sheet member A containing continuous reinforcing fibers was 0.2 mm.
In addition, the flow amount of the rib part of the sheet member A containing the continuous reinforcing fiber was controlled by the flow characteristic difference by changing the sheet size.
After that, the specimen was cut out with a width of 35 mm so that the rib part was exactly at the center of the measurement of bending properties, and the bending strength was measured in the form of applying a load from the back side of the rib part. The bending strength was as low as 490 MPa and the bending elastic modulus was 19 GPa.

(Comparative Example 2)
The member B containing the discontinuous reinforcing fibers obtained in Example 1 was cut into a size of 240 mm square, and after heating until the surface temperature reached 260 ° C. with an infrared heater in the same manner as in Example 1, the thickness of the root was 4 mm, A metal mold having an outer shape with a rib having a height of 30 mm and a width of 80 mm was charged to a 250 mm square, and after molding with a cooling press at 150 ° C., a fiber-reinforced thermoplastic resin molded body without continuous reinforcing fibers was obtained.
After that, the specimen was cut out with a width of 35 mm so that the rib part was just at the center of the measurement of bending properties, and the bending strength was measured by applying a load from the back side of the rib part. The bending strength was 460 MPa and the bending elastic modulus. Was as low as 18 GPa.

  According to the present invention, a fiber reinforced thermoplastic resin molded article comprising a continuous fiber reinforced thermoplastic composite material and a discontinuous fiber reinforced thermoplastic composite material having excellent mechanical properties and molding fluidity to a complicated shape portion such as a protrusion. Can be provided. In addition, the fiber-reinforced thermoplastic resin molded article of the present invention also contributes to the industry because it has a feature that peeling failure at the interface between the continuous fiber-reinforced thermoplastic composite material and the discontinuous fiber-reinforced thermoplastic composite material hardly occurs. be able to.

DESCRIPTION OF SYMBOLS 1 Base material part 2 Protrusion part 3 Continuous reinforcement fiber 4 Non-continuous reinforcement fiber 5 Flowing depth 6 Thickness of the base of a projection part 7 Height of a projection part

Claims (3)

A molded body having a base part and a protrusion having a base thickness of 2 mm to 30 mm and a height of 5 mm to 150 mm, the molded body comprising a member A made of continuous reinforcing fibers and a thermoplastic resin, It is composed of a member B made of continuous reinforcing fiber and thermoplastic resin, the member B is filled in the tip of the protrusion, and the depth of flow of the member A into the protrusion is 0.5 mm or more. Fiber reinforced thermoplastic resin molding. The member B is composed of a tape-like material of a thin film piece having a length of 5 mm to 100 mm, a width of 4 mm to 60 mm, and a thickness of 0.05 mm to 0.4 mm, and the mass ratio of the reinforcing fiber contained and the thermoplastic resin is 85. It is / 15-30 / 70, The fiber reinforced thermoplastic resin molded object of Claim 1. The fiber reinforced thermoplastic resin molded article according to claim 1 or 2, wherein the continuous reinforcing fiber of the member A is a cloth material, and the member A is a laminate including 2 to 10 layers of the cloth material.