JP2892061B2 - Laminate - Google Patents

Description

The present invention relates to a material obtained by laminating and integrating a film layer having a high strength and a high open modulus and a thermoplastic resin layer or a fiber-reinforced thermoplastic resin layer. More specifically, the present invention relates to a novel composite material having excellent mechanical strength such as bending, tension and compression, and extremely excellent impact resistance, and which can be easily formed by a simple method such as hot pressing.

[Conventional technology]

Thermosetting resin such as epoxy resin and phenol resin,
So-called fiber-reinforced plastics reinforced with carbon fibers, glass fibers, aramid fibers and the like have been conventionally known. The reinforcing fibers are filament yarn, woven fabric,
It is used in the form of a short fiber mat or the like, but in order to fulfill its function sufficiently, physical properties such as high strength and high elastic modulus are required.

Although fiber-reinforced thermosetting resin is excellent in mechanical strength or elastic modulus, it generally has poor toughness and has a problem in impact resistance, and once broken, there is a drawback that the reinforcing fiber exposes the sharply broken fractured surface. . Aramid fiber, which has attracted attention as a reinforcing fiber with excellent impact resistance, has a major practical drawback in that when the composite is machined, the fiber sprinkles, fluff, and the finished surface does not finish cleanly. I have. In addition, long-fiber reinforced plastics commonly have the disadvantage of anisotropy in mechanical performance and dimensional stability.

[Problems to be solved by the invention]

In view of this point, the present inventors have used a recently developed high-strength high-modulus film that is not yet known,
We have proposed a thermosetting resin composite material with low anisotropy in physical properties and excellent impact resistance. The present inventors have further studied diligently and studied the formation of a composite with a thermoplastic resin.As a result, they found that not only the toughness and impact resistance were further improved, but also a material having excellent moldability was obtained. This has led to the present invention.

An object of the present invention is to achieve a mechanical strength comparable to that of a so-called fiber-reinforced plastic by a combination of a film and a resin. On the other hand, another object of the present invention is to provide a fiber reinforced resin and a film, by combining the film, without impairing the rigidity inherent in the fiber reinforced resin, but rather to impart more excellent mechanical properties and impact resistance. It is in.

[Means for solving the problem]

That is, the present invention comprises an aramid having no melting point and decomposition point below 400 ° C., and has a tensile strength of 35 kg / mm ² or more and
700 kg / mm ² is a laminate obtained by laminating a film layer having a modulus of elasticity of ² or more and a thermoplastic resin layer, another invention is from aramid having no melting point and decomposition point below 400 ° C ... now, 35kg / mm ² or more of tensile strength and 700k
This is a laminate obtained by laminating and integrating a film layer having a tensile modulus of at least g / mm ² and a thermoplastic resin layer reinforced with fibers.

The thermoplastic resin used in the present invention, for example,
Examples include polyolefin, polyester, polyamide, polyacrylate, and polycarbonate. Although not particularly limited, so-called super engineering plastics are preferably used from the viewpoint of the heat resistance or usable temperature range of the obtained molded article. Examples thereof include polysulfone, polyamideimide, polyetherimide, polyetherketone, polyetheretherketone, polyethersulfone, polyphenylenesulfide, and the like.

Therefore, in the present invention, it is essential that the film used as the reinforcing member does not deform, melt, or decompose even at the molding temperature of the high melting point thermoplastic resin. And an organic polymer having a decomposition point.

According to the purpose of the present invention, the film used in the present invention is:
It is necessary to have high strength and high elasticity in itself,
That is, a tensile strength of 35 kg / mm ² or more and 700 kg / mm ²
It must have the above tensile modulus.
Preferably, a strength of 45 kg / mm ² or more and a modulus of elasticity of 1000 kg / mm ² or more, more preferably a strength of 50 kg / mm ² or more and 1200 kg
/ mm ² or more.

Examples of such an organic polymer include, for example, aramid, polyimide, polybenzimidazole, polybenzbisthiazole, and the like, but in the present invention, satisfactory adhesiveness with a resin, high strength, and high elastic modulus are satisfied. Aramid is used to achieve this.

Aramids preferably used include those having structures represented by the following general formulas (I) and (II) and copolymers thereof.

And these hydrogen atoms may be substituted with a functional group such as halogen, methyl, ethyl, methoxy, nitro, and sulfone. m and n are average degrees of polymerization and are about 50-1000. The film used in the present invention may contain a small amount of the above-mentioned components other than aramid as long as the effects of the present invention are not impaired. For example, organic polymers other than the above, organic low-molecular compounds, A small amount of an inorganic compound or the like may be contained.

The film may be a so-called tensilized type in which the tensile strength and the tensile modulus are increased in the direction in which the tensile strength is required as a composite product, but of course, a film having isotropic performance was used. The better is that the obtained molded article has less directivity in mechanical strength and dimensional stability. In the present invention, the tensile strength and the tensile elastic modulus may be such that at least one direction satisfies the above-mentioned value, but preferably, the average value of the characteristics in two directions orthogonal to each other arbitrarily selected is as described above. Value.

In the present invention, it is preferable that the film and the thermoplastic resin have a sufficient adhesive force in order to sufficiently exhibit the reinforcing effect. High adhesion is achieved by the following method. The method includes, for example, devising the film formation, roughening the surface of the film or tape by physical or chemical etching after the film formation, corona discharge treatment, plasma treatment, chemical decomposition, etc. , An impregnation pretreatment for bonding with an epoxy compound, an isocyanate compound, a resorcinol-formalin-latex mixture, or the like, or a combination thereof is preferably used.

The thickness of the film used in the present invention is appropriately determined in consideration of the resin layer in the molded article or the lamination structure with the fiber-reinforced resin layer, and is usually 2 to 100 μm, preferably 5 to 100 μm.
5050 μm.

The fiber-reinforced thermoplastic resin layer referred to in the present invention is obtained by immersing a thermoplastic resin in a reinforcing fiber, and the ratio between the reinforcing fiber and the resin is preferably such that the volume fraction of the reinforcing fiber is 40 to 70%. .

As the reinforcing fiber used in the present invention, glass fiber, carbon fiber, aramid resin, polybenzimidazole fiber, polybenzothiazole fiber, or a metal-coated carbon fiber such as nickel-plated carbon fiber, or alumina fiber And inorganic fibers such as silicon carbide fibers, and two or more of these fibers can be used in combination.

In addition, the fibers are used in the form of a sheet aligned in one direction or in the form of a woven fabric, and particularly in applications where isotropic mechanical properties are required, fibers cut to an appropriate length are randomly selected. Also used on oriented mats.

In a laminate of a film and a thermoplastic resin, which is one object of the present invention, the film itself has almost no integration capability such as heat sealability, pressure bonding property, and the thermoplastic resin serves as a binder. Take a role. Therefore, they must always be stacked alternately. Further, the ratio of the film and the thermoplastic resin in the molded body, the ratio of the film is 40 to 95
It should just be taken between%. If it is less than 40%, satisfactory physical properties cannot be obtained, and if it exceeds 95%, integration becomes difficult. Preferably it is in the range of 60-90%, more preferably 70-85%.

There is no particular limitation on the lamination structure and the lamination ratio in the laminate of the film and the fiber-reinforced thermoplastic resin, which is another object of the present invention. For example, the impact resistance can be improved without impairing the rigidity of the fiber-reinforced resin. A preferred configuration that can be dramatically increased is one in which the fiber reinforced resin layer is interposed between the film layers, and is particularly effective when the shape of the molded body is a hollow pipe. This is considered to be due to the effect that the film layer suppresses the deformation of the fiber reinforced resin layer and makes it difficult for cracks to occur. The lamination ratio is such that the volume fraction of the film to the whole molded body is between 5 and 50%, preferably 5 to 50%.
~ 30%.

As another example of the configuration, there is a method of alternately laminating the film and the fiber-reinforced thermoplastic resin one by one as in the case of the above-described film and thermoplastic resin. Alternatively, a method of combining these may be used as appropriate. Further, the film layers do not necessarily have to be laminated one by one, and a plurality of film layers may be arranged. At that time, it is necessary to laminate a resin as a binder between the films.

The laminate of the present invention can be manufactured by various methods.

A laminate composed of a high-strength, high-elastic modulus film and a thermoplastic resin is formed, for example, by molding the thermoplastic resin into a film from a melt or solution state, and then forming an infusible high-strength, high-elastic modulus After laminating the above film to form a laminate film, a plurality of these films can be further laminated and integrated using a hot press or the like. In addition, the laminated film is closely adhered to a rod-shaped mold, wound up, a heat-shrinkable tape or the like is wound up from the outside, once heated to a melting point of the thermoplastic resin or more to be cooled and solidified, and then taken out from the mold. Pulp with a cross section can be obtained. Alternatively, a thermoplastic resin film and an infusible high-strength and high-modulus film may be laminated without using a laminate film, and hot-pressed using a mold. At that time, by giving a desired shape to the mold, laminated bodies having various shapes can be easily obtained.

A laminate of a high-strength, high-modulus, infusible film and a fiber-reinforced thermoplastic resin can be produced by the following method. First, the fiber-reinforced thermoplastic resin is impregnated into a reinforcing fiber sheet such as a unidirectionally aligned thermoplastic resin (hereinafter referred to as a UD sheet), a woven or knitted material, or a mat-like material in a molten or solution state. It is manufactured by performing heating, desolvation and the like as required. A woven or knitted reinforcing fiber and a thermoplastic resin fiber or a woven or knitted yarn obtained by entanglement of the entangled yarn and blended yarn can also be used. If the fiber-reinforced thermoplastic resin sheet thus obtained and the high-strength, high-elasticity, infusible film are alternately laminated or laminated one by one and hot-pressed, a molded article of alternate lamination is obtained. Further, if a laminate obtained by laminating each layer is wound and formed into a mold, a pipe-shaped alternate laminate is obtained. In addition, high strength, high elastic modulus,
If a laminate of an infusible film and a thermoplastic resin is used, it is possible to produce a laminate having various desired laminated configurations by appropriately laminating the laminate with a fiber-reinforced thermoplastic resin sheet.

〔Example〕

 Next, the present invention will be described in detail with reference to examples.

Table 1 shows the physical properties of the laminates obtained in Examples 1, 3, 5, 6 and Comparative Examples 1, 3, 6, and 7, and the laminates obtained in Examples 2, 4, and Comparative Examples 2, 4, and 5. The physical properties of the body are shown in Table 2.

In addition, the measuring method of the physical property of the laminated body in an Example is as follows.

Axial compressive strength: A test piece of 13 mm length was cut out from a tubular molded product, and was used as a universal tester manufactured by Shimadzu (trade name: Autograph AG-
10), and the tube was compressed in the longitudinal direction at a compression speed of 1 mm / min to determine the maximum breaking strength. The axial compression strength was calculated by the following equation.

Where σ ₁ : axial compressive strength (kg / mm ² ) d ₁ ; inner diameter of test piece (mm) d ₂ ; outer diameter of test piece (mm) p; maximum breaking strength (kg) surface compressive strength; A test piece having a length of 17 mm was cut out from the body and compressed in the radial direction of the tube at a compression speed of 1 mm / min to determine the maximum breaking strength. The surface compressive strength was calculated by the following equation.

However, σ ₂ : plane compressive strength (kg / mm ² ) L; length of test piece (mm) Other symbols are the same as those for measuring axial compressive strength.

Izod impact absorption energy; 64 longer than tubular molded body
A test piece of mm was cut out and used as it was. Izod impact tester manufactured by Toyo Seisakusho Co., Ltd., hammer weight 3.874k
g, tested at 135 ° lift angle. The impact absorption energy was determined by the following equation.

However, E; Izod impact absorption energy (kgcm / c
m ² ) W; hammer weight (3.874 kg) R; distance between the axis and the center of gravity of the hammer (22.41 cm) β: angle at which the hammer breaks the sample and rises to the opposite side (degrees) Flexural strength and flexural modulus ; 25mm wide and 50mm long from laminate
The test piece was cut out, and the fulcrum distance was 35 using a universal tester (trade name: Autograph AG-10, manufactured by Shimadzu Corporation).
mm and a bending speed of 2 mm / min. The tip of the pressure wedge is R
5. The fulcrum tip used was R2. From the obtained load-deflection curve, flexural strength (σf) and flexural modulus (Ef)
Was calculated by the following equation.

Where σf; bending strength (kg / mm ² ) W; width of test piece (mm) h; thickness of test piece (mm) L; distance between fulcrums (mm) P; maximum breaking load (kg) Where, Ef; flexural modulus (kg / mm ² ) F / Y; gradient of the linear part of load-deflection curve (kg / m
m) Drop weight impact test: A test piece of 100 mm x 100 mm was cut out from the laminated plate, and a drop weight impact tester manufactured by Rheometrics was used.
The test was performed under the conditions of a load of 30 kg, a height of 20 cm, and a test speed of 2 m / sec. From the obtained absorbed energy curve, the total absorbed energy was determined.

 The aramid film was manufactured by the following method.

First, dissolve in 98% concentrated sulfuric acid, C is 0.5g / 100ml,
Poly-p-phenylene terephthalamide (hereinafter abbreviated as PPTA) having a logarithmic viscosity of 5.5 measured at 30 ° C. was dissolved in 99.5% sulfuric acid at a polymer concentration of 12% to obtain a dope having optical anisotropy. The dope was degassed under vacuum, filtered, extruded through a slit die through a gear pump and cast on a tantalum belt polished to a mirror surface.
The casting dope was passed through a zone having an air atmosphere of 90 ° C., was optically isotropic, and was introduced together with a belt into a 30% aqueous sulfuric acid solution at 20 ° C. for coagulation.

Next, the coagulated film was peeled off from the belt, neutralized with an aqueous solution of sodium hydroxide, and washed with water. Without drying the washed film, stretch it in the length direction (MD direction) with a roller, then stretch it in the width direction (TD direction) with a tenter, and dry it at 200 ° C while maintaining it at a constant length. A constant-length heat treatment was performed at 300 ° C. to produce a 30 μm PPTA film.

The resulting film is pale yellow and transparent and has a thermal analysis of 40
No melting or decomposition at 0 ° C or less was observed. Tensile strength and elastic modulus were 45 kg each in the length direction from the obtained PPTA film produced by changing the stretching ratio.
/ mm ² , 1390kg / mm ² , 44kg / mm ² , 1350 in width direction
A kg / mm ² film (referred to as film A) was used in the examples described below.

First, alternate lamination of a high-strength, high-modulus film layer and a thermoplastic film layer, which is one aspect of the present invention, will be described in Examples 1 and 2.

Example 1 Polyphenylene sulfide (hereinafter abbreviated as PPS) manufactured by Toray Phillips Co., Ltd. was heated and melted at 340 ° C., extruded from a slit die, formed on a film A running on a roll immediately below the die, and a pair immediately afterwards. To obtain a laminated film having a total thickness of 40 μm.

Cut out the film into strips and place it in a rectangular flat mold,
25 sheets were stacked and set. This is done using a heat press
It was heated and pressed under the conditions of 0 ° C. and 20 kg / cm ² for 10 minutes and cooled to 50 ° C. to obtain a 1 mm-thick laminate.

Example 2 The laminated film obtained in Example 1 was slit into a tape having a width of 10 mm, and a tape having a diameter of 10 mm was formed using a taping machine.
It was wound around a 2.5 mm pitch stainless steel round bar mold. This operation was repeated six times to form a laminate in which the film A overlapped with 24 layers. The start and end of the winding were fixed with stainless steel collars, and then heated in a 350 ° C. oven for 5 minutes. After cooling to room temperature, the mold was extracted to obtain a laminated tube having an inner diameter of 10 mm and an outer diameter of 12 mm.

Next, the lamination of a high-strength, high-modulus film layer and the amount of a thermoplastic resin reinforced with fibers, which is another invention of the present invention, will be described in Examples 3 to 6 and Comparative Examples 1 to 7.

Example 3 The laminate film obtained in Example 1 was laminated with a carbon fiber UD sheet / PPS (trade name: Ryton ACM) manufactured by Philippe Sporomium as follows. First, three laminated films are laminated, and Ryton ACM is placed on top of it.
Nine (trade name) are stacked with the fiber axis aligned, and three more laminated films are laminated, and mounted on a rectangular flat mold,
Heating and pressurization were performed at a temperature of 350 ° C. and a pressure of 20 kg / cm ² for 20 minutes. After cooling to 50 ° C., it was taken out to obtain a laminate having a thickness of 2 mm.

Example 4 A 150 mm diameter stainless steel round bar
UD sheet / PPS (trade name Ryton
ACM) was wound using a sheet rolling device so that four layers of carbon fiber were aligned with the length direction of the mold.
From there, 10 of the laminated film obtained in Example 1
A tape having a width of 2 mm was wound at a pitch of 2 mm using a taping machine. After firmly fixing both ends of the laminate with a stainless steel collar, the laminate was heated in an oven at 350 ° C. for 10 minutes. After cooling to room temperature, the mold was pulled out to obtain a laminated tube having an inner diameter of 10 mm and an outer diameter of 12 mm.

Example 5 Aramid fiber manufactured by DuPont (Kevlar 49)
The yarn of 1420d was set in krill, and the fiber was introduced into a 25% dimethylacetamide (hereinafter abbreviated as DMAc) solution of polyethersulfone (hereinafter abbreviated as PES) manufactured by ICI, and the solution was impregnated with the solution. Then, it was carefully wound at a pitch of 1 mm on a stainless steel drum on which silicon release paper had been set in advance so that no gap was formed between the yarns. While rotating the drum at 100 ° C. for 3 hours, the heating was performed to remove the solvent.
2 mm aramid fiber reinforced PES was obtained.

On the other hand, a 25% PES DMAc solution was applied to the film A using a gravure coater, and the solvent was removed by heating to obtain a 40 μm-thick laminated film coated with PES on one side. Aramid fiber reinforced PES on three layers of this laminated film
Nine layers were aligned in the direction of the fiber axis, and three layers of the laminated film were further stacked in a rectangular flat mold.
Heating and pressurization were performed at 0 ° C. and 100 kg / mm ² for 20 minutes. After cooling to 60 ° C., the laminate was removed from the mold. 2m thick
m.

Example 6 The surface of the film A was subjected to plast processing using 180-mesh river sand particles. The film and a carbon fiber UD sheet (trade name: APC-2) manufactured by ICI and impregnated with polyetheretherketone (hereinafter abbreviated as PEEK) are alternately layered in ten layers each in the same fiber direction, and this is molded into a mold. And load it on
After heating and pressing at 360 ° C. and 450 kg / cm ² for 20 minutes and cooling to 60 ° C., a 2.2 mm-thick laminate was taken out.

Comparative Example 1 Ten layers of carbon fiber / epoxy UD prepreg (trade name: Fiber Dux) manufactured by Asahi Composite Co., Ltd. were laminated and heated at 150 ° C. for 2 hours by an airbag / autoclave method to obtain a carbon fiber / epoxy laminate ( 2 mm thick).

Comparative Example 2 The same prepreg as that used in Comparative Example 1 was wound around a stainless steel round bar having a diameter of 10 mm in five layers such that the angle between the fiber axis and the length direction of the die was 0 °, 25 °. After wrapping it on a PET tape subjected to a release treatment, it was cured by heating in an oven at 150 ° C. After cooling to room temperature, the mold was extracted to obtain two types of laminated pipes having an inner diameter of 10 mm and an outer diameter of 12 mm.

Comparative Example 3 10 carbon fiber UD sheets / PPS (trade name Ryton ACM)
A UD laminate having a thickness of 2 mm was obtained under the same molding conditions as in Example 3.

Comparative Example 4 A polyimide film (trade name: Corpirex-R) having a tensile strength of 23.5 kg / cm ² and a tensile modulus of elasticity of 360 kg / cm ² (trade name: 25 μm) was used instead of Film A. Is 10 mm in inner diameter and 12 mm in outer diameter in the same manner as in Example 4.
Was formed.

Comparative Example 5 In the same manner as in Example 4, a stainless steel round bar having a diameter of 10 mm was used as a mold, and five layers of carbon fiber UD sheet / PPS (trade name: Ryton ACM) were wound. After being integrated under the same conditions as described above, the outermost film A of the obtained laminated tube was peeled off to obtain a sample.

Comparative Example 6 A laminated board was obtained by molding under the same conditions as in Example 5 except that film A was not laminated and 10 layers of aramid fiber reinforced PES were laminated.

Comparative Example 7 A laminate was formed in the same manner as in Example 6, except that the blasted film A was not used.

(Effect of the Invention) The laminate of the present invention has excellent mechanical properties.
It has extremely high shock absorption, which cannot be obtained with conventional materials. In addition, it has excellent machinability such as cutting workability and drilling workability, and has the advantage that the process at the time of working is even more simplified than in the case of fiber reinforcement.

A laminate comprising a high-performance film and a thermoplastic resin, which is one of the present invention, makes use of its excellent mechanical strength and extremely high impact resistance, for example, members around an automobile body, parts of an industrial robot. , Casing, piping of various machines, etc., or a wiring board.

Further, another laminate of the present invention in combination with a reinforcing fiber is a structural material in the space and aviation field from sports and leisure such as golf clubs, fishing rods, racket frames, and ski poles by obtaining high rigidity. Can be widely used.

Claims (2)

(57) [Claims] 1. An aramid having no melting point or decomposition point below 400 ° C., having a tensile strength of 35 kg / mm ² or more and 700 kg / mm ²
A laminate formed by laminating and integrating a film layer having a tensile modulus of at least ² mm and a thermoplastic resin layer. 2. An aramid having no melting point and decomposition point below 400 ° C., having a tensile strength of 35 kg / mm ² or more and 700 kg / mm ² or more.
A laminate formed by laminating and integrating a film layer having a tensile modulus of not less than mm ² and a thermoplastic resin layer reinforced with fibers.