JPH01190414A - Preparation and laminated molding of fiber-reinforced resin tape - Google Patents

Abstract

PURPOSE:To improve the transparency and mechanical strength of a molding, by impregnating a roving fiber with an aqueous suspension comprising dispersed fine powder of vinyl chloride and orienting the continuous fiber, obtained by diverging, developing heating and drying it, in a fixed direction. CONSTITUTION:Roving fiber that is an inorganic or organic fiber converged by gray goods is impregnated with an aqueous suspension comprising dispersed fine powder of vinyl chloride. As aqueous suspension is used the product made by dispersing the powder, obtained by drying resin slurry in a suspension by means of suspension polymerization and further fine-milling, in an aqueous medium. Next, in the state that the impregnated aqueous suspension is not yet dried, it is diverged to extend flatly the roving fiber and orient the continuous fiber in the longitudinal direction. Then, dry fine resin powder is adhered thereon and the fine resin powder is softened by heating. A fiber-reinforced tape obtained by such manner is characterized by transparency and excellent strength.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a fiber-reinforced resin tape in which continuous fibers are aligned in a fixed direction as a reinforcing material, a method for manufacturing the same, and a lamination process using the tape as a molding material. This relates to molded products.

[Prior Art] Various molding materials made of fiber-reinforced resins are known. Typical examples of such molding materials include FRP pellets made of thermosetting resins containing glass fibers, prepregs such as BMC and SMC, and FRTP made of thermoplastic resins containing glass fibers.
Various forms such as pellets, sheets, and tables are in practical use.

The fibers contained in the above-mentioned molding materials made of fiber-reinforced resins may be woven fabrics, but in most cases chopped strands obtained by cutting continuous roping fibers are used. Therefore, there is a problem in that the fibers are not continuous and tend to be non-uniform, and therefore the molded product obtained by molding them as a molding material cannot be expected to have sufficient strength.

Furthermore, the impregnation of the synthetic resin into the fibers in the molded product is not always sufficient, especially when thermoplastic resin is used.
Even if the synthetic resin is transparent and the refractive index of the synthetic resin and the fibers are similar, the impregnation is insufficient, resulting in an opaque molded product.

On the other hand, as continuous fibers, the continuous roping fibers shown in the previous 2 are impregnated with a synthetic resin ([including coalescence) emulsion 1], dried, and then compressed while heating, so that the fibers are pulled in a certain direction. Aligned thickness 0.
Fiber-reinforced resin molding materials in the form of thin sheets or tapes of 3 to 1 mm are in practical use. As a method for producing such a material, for example, a method for producing a sheet by impregnating glass fiber roping with an emulsion containing a vinyl chloride resin polymer, drying it, heating it and compressing it into a thin plate is disclosed in Japanese Patent Publication No. 47-13218. It is publicly known by the publication No. Further, JP-A-61-40113 discloses a resin-containing ribbon-shaped body obtained by a melt extrusion method in which a thermoplastic resin is flowed in a molten state from an extrusion head into a continuous fiber bundle under tension, and a method for manufacturing the same. There is.

[Problems to be Solved by the Invention] The sheet-like or tape-like fiber-reinforced resin molding material in which fibers are aligned in a certain direction, disclosed in Japanese Patent Publication No. 1i1, No. 47-13218, simply uses vinyl chloride resin on the surface of a roping fiber bundle. However, the resin easily peels off and falls off, resulting in areas where no resin is attached, resulting in a molding material containing a large amount of bubbles.

Therefore, when obtaining a molded article using the above materials, for example, during the heat compression process, the resin is not sufficiently impregnated between the fibers, and the resin is attached unevenly, resulting in a homogeneous resin layer. It has been difficult to obtain transparent molded products with no remaining bubbles. In addition, as a means of obtaining a fiber-reinforced resin molding material in the form of a thin plate or tape, for example, a method of spreading resin-impregnated roping fibers under pressure between compression rolls is also adopted, but such means do not cut or fluff the fibers. This causes standing up, resulting in a decrease in the strength of the molded product. Therefore, as a fiber-reinforced resin molding material in which continuous fibers are aligned in a certain direction, its thickness is naturally limited, and there are currently no products as thin as 0.2 mm or less.

A particular problem with the fiber-reinforced resin molding materials mentioned above is that the vinyl chloride resin polymer is impregnated into the roping fibers as an emulsion, but the vinyl chloride molecules in the emulsion are thermally unstable. The drawback is that the laminated molded product used has poor weather resistance and is easily discolored.

In addition, the resin 3 right ribbon-shaped body obtained by the melt extrusion method of the above-mentioned Japanese Patent Publication No. 47-13218 also suffers from non-uniform flow resistance in the fiber bundle due to the high viscosity of the melted resin during production. Due to the polarity of the surface, the inflow and wetting of the resin between the fibers is not always sufficient, and there is a tendency for the resin to be unevenly distributed only around the fiber bundle of the ribbon-like body. Therefore, as a molding material, it is far from being thin and sufficiently impregnated with resin, and the molded product used as the molding material lacks transparency.

Physical properties such as mechanical strength were also poor.

[Means for Solving the Problems] The present invention provides a fiber-reinforced resin molding material as described above,
In particular, this invention was made to solve the problems with tape-shaped molding materials in which a roping fiber bundle is impregnated with vinyl chloride resin, and the problems with laminated molded products using the same as the molding material.

That is, in the present invention, roping fibers are impregnated with an aqueous suspension in which fine powder of vinyl chloride resin is dispersed, the roping fibers are spread out, and the continuous fibers obtained by drying and heating are oriented in a certain direction. The present invention provides a fiber-reinforced resin tape made of aligned fibers, a method for producing the same, and a laminate molded product using the tape as a molding material.

The roping fibers used in the present invention include glass fibers, quartz glass fibers, and carbon fibers.

Fibers (filaments) such as inorganic fibers such as ceramic fibers and metal fibers, or organic fibers such as polyamide fibers, polyimide fibers, and polyamide-imide fibers are bundled with a binding agent. The fiber-reinforced resin tape produced by the production method of the present invention also has the characteristic that a transparent molded product can be obtained when used as a molding material, so it is considered a glass fiber roping. is appropriate.

Roping fibers are usually bundles made up of multiple fibers (filaments) with extremely small diameters bundled together using a binding agent. For example, a glass fiber roping with a diameter of about 2 mm has 4,500 filaments with a diameter of about 12 μm. It is a product that is concentrated to a certain degree and can be easily obtained commercially. The surface of such roping fibers may be treated with a surface treatment agent such as a silane coupling agent, or may not be surface treated. This is preferable in that the adhesiveness of the vinyl chloride resin is improved.

In the present invention, roping fibers are impregnated with an aqueous suspension in which fine powder of vinyl chloride resin is dispersed. Vinyl chloride resin is obtained as an emulsion in which a resin having a fine particle size is dispersed according to a polymerization method employed, for example, an emulsion polymerization method, but a molding material obtained by impregnating a roping fiber with such an emulsion is As mentioned above,
This has an unfavorable effect on the molded product, resulting in poor durability. Therefore, in the present invention, a powder having a particle size of 50 to 200 μm obtained by drying a resin slurry in a suspension obtained by a suspension polymerization method, or a fine powder obtained by further pulverization, is dispersed in an aqueous medium. Use a suspension.

Therefore, the average particle diameter of the resin fine powder in the present invention is 0.1
~5 μm gives a preferable effect as described below, so it is preferable to directly use a suspension of resin slurry dispersed by suspension polymerization, since the resin particle size is large as described above. do not have. In the present invention, by setting the average particle size of the fine resin powder in the aqueous suspension as described above, the filaments uniformly aligned by the opening development of the roping fibers are subjected to the following drying and heating steps. During this period, the filament remains extremely stable and does not undergo the focusing phenomenon in which the aligned filaments return to their original form, which normally occurs after immersion in a liquid. The reason for this favorable phenomenon is not necessarily clear, but
The fine resin powder dispersed in the aqueous suspension by the opening development of the roping fibers sufficiently penetrates between the filaments, and the fine powder particles exhibit a wedge-like action between the filaments.
It is presumed that this suppresses the tendency of the filament to converge, such as the return of the filament as described above. Therefore, the average particle diameter is 0.1~
There are no particular limitations on the means for pulverizing the particles to 5 μm, but freezing and pulverization, for example, is a suitable method in terms of pulverization.

Next, a method for manufacturing the fiber-reinforced resin tape of the present invention will be explained. The means for preparing the aqueous suspension in which the fine powder of vinyl chloride resin is dispersed is not particularly limited. The amount of resin fine powder dispersed in the aqueous suspension is suitably 25 to 75 tonne percent. Even if the amount is too large, the roping fibers will not be impregnated in large quantities, and workability may be lowered due to the upper limit of the viscosity of the aqueous suspension. On the other hand, if the amount is too small, the desired effect as a fiber-reinforced resin tape cannot be obtained. Small amounts of emulsifiers and surfactants may be added during preparation.

Furthermore, if desired, plasticizers, stabilizers, colorants, other compounding agents, auxiliaries, etc. can be added. Since the aqueous suspension in which the fine powder of vinyl chloride resin thus prepared is dispersed, it is water-based, so it wets the surface of the roping fibers, especially the glass fiber roping, very well, and penetrates sufficiently between the filaments. .

Next, the roping fibers are impregnated with an aqueous suspension in which fine powder of vinyl chloride resin is dispersed.

During impregnation, the roping fibers are continuously passed through an aqueous suspension in an impregnating tank. What is important in the production method of the present invention is that by passing through an aqueous suspension,
The process involves unbundling and unfolding roping fibers impregnated with an aqueous suspension. The bundle development can be carried out either inside or outside the impregnation tank, but it is necessary to spread the bundle in a wet state before the impregnated aqueous turbidity dries. , the effect will be less if it is dried.

Unbundling, which is usually also referred to as "straining," involves spreading out roping fibers with a specific diameter, which are made up of bundled fibers, in a plane, and also stretching the continuous fibers in a certain direction, that is, in the length direction. It is about aligning them. Such unbundling is carried out by passing the roping fibers impregnated with the aqueous suspension over the suitably curved surface of a fixed "straining member" whose surface is slidable.

Although it is sufficient to spread the bundle by passing it over a "straining member" once, it is preferable to pass the bundle over a second and third "straining member" subsequently. Therefore, it is not necessary to pressurize the roping fibers when the roping fibers are unfolded, but the degree of unfolding is adjusted by applying an appropriate tensile stress that is not excessive in the length direction of the fibers. Adjustment of the tensile stress is appropriately determined depending on the desired thickness and width/thickness ratio of the fiber-reinforced resin tape to be obtained. In such unbundling development, the surface shape of the "straining member" has an appropriate tensile stress.

It is necessary to have a suitable shape, since this will affect the thickness and width/thickness ratio of the tape produced.

Following unbundling development, drying occurs. Drying is to evaporate the water in the aqueous suspension and attach fine resin powder.
This can be done by any suitable means, such as passing through a heated air oven or infrared irradiation.

Next, the fine resin powder attached to the filament is softened by heating. At this time, if the heating temperature is too high, the resin may soften too much or decompose and come off, while if it is too low, sufficient softening and fixation cannot be expected. It's not appropriate. -A temperature of about 150 to 200°C is sufficient for boat fishing. The heating means is not particularly limited, and for example, passing between metal plates such as aluminum plates heated by an appropriate means,
Alternatively, heating means such as infrared irradiation may be employed as appropriate, but a method of passing between heating rolls is preferred.

The tape is completely made into a fiber-reinforced resin tape by heating, and after cooling, it is wound up by an appropriate means.

[... According to the manufacturing method described in
The diameter of approximately 4500 filaments bundled is approximately 2.
From glass fiber roping of mmφ.

As a fiber-reinforced resin tape, the thickness is approximately 1 mm, and the width is approximately I.
It is possible to easily manufacture a material having a width/thickness ratio of 100 mm.

The resin impregnation amount of the fiber reinforced resin tape thus obtained is:
The so-called ignition loss (Igloss) is more than 35% (up to 35% with the conventional simple impregnation method).
), it gives transparency to the molded product used as the molding material.

In the manufacturing method of the fiber-reinforced resin tape of the present invention, any shape can be obtained by changing the diameter of the roping fibers or by appropriate treatment during unbundling, but it is widely applicable as a molding material, and has transparency. In terms of providing a molded product having the following properties, it is preferable that the fiber-reinforced resin tape has a thickness of 0.2 mm or less and a width/thickness ratio of 25 to 200. When the width/thickness ratio is less than 25, the amount of resin is small and tends to be non-uniform, and molded products using this as a molding material have poor transparency and especially low strength.

On the other hand, a range exceeding 200 is difficult to put into practical use. For example, in the case of the above-mentioned product according to the present invention, which has a thickness of about 0.1 mm and a width of 20 mm and a width/thickness ratio of 100, the cross-sectional examination shows that there are about 5 filaments in the thickness direction and about 60 filaments in the width direction.
The filaments are arranged almost uniformly, and the resin is densely filled between the filaments. Moreover, it has transparency, and the strength of molded products made using it is sufficiently increased.

On the other hand, for example, even if similar roping fibers are used, the width is 8 mm with a thickness of 0.4 nv and a width/thickness ratio of 20.
In this case, the filaments are extremely unevenly distributed in the thickness direction, the resin is not sufficiently distributed between the filaments, is extremely heterogeneous, and is also inferior in transparency. Furthermore, if the thickness is extremely thin (less than 0.1 mm), the molding conditions will be film-like, making it difficult to handle and even if it contains fibers, it will not function effectively as a reinforcing material and will be unsuitable as a molding material. . These are actually based on the experimental °1.

The fiber-reinforced resin tape of the present invention is used as a molding material to form a laminated molded product in the following manner. For example, a plurality of pieces are cut to a certain length and arranged in parallel, and a sheet or film made of the same or different type of resin, preferably vinyl chloride resin, is abutted or placed on at least one of the lower surfaces. A laminate molded product in which the fibers are aligned in a certain direction can be obtained by laminate molding in which the fibers are aligned in a certain direction.

As another example, a laminated molded product with increased mechanical strength can be obtained by arranging pieces cut to a certain length in a vertical and horizontal manner and laminating them in the same manner. In such laminate molding, a transparent laminate molded product can be obtained by using a transparent sheet or film made of vinyl chloride resin to be placed on the arranged tapes.

Of course, opaque, colored, patterned, etc. sheets or sheets or films of appropriate thickness may be used to create a laminate molded product with improved aesthetics, strength, etc. In particular, when applying a fiber-reinforced resin tape as a molding material, by freely selecting its arrangement or forming it into a woven fabric, a laminated molded product with increased strength and aesthetically superior properties can be obtained. Furthermore, it is possible to laminate the laminated molded product into multiple layers or to perform post-processing, and since it has excellent mechanical strength and weather resistance, it is expected to have a wide range of applications.

[Example] Example 1 Vinyl chloride resin powder with an average degree of polymerization of 1000 and an average particle size of 100 μm produced by suspension polymerization was frozen in liquid nitrogen and pulverized in a pulverizer (“Albine”: manufactured by West Germany). It was pulverized to obtain a fine powder with an average particle size of 4.5 μm. 50 parts of fine powder of this vinyl chloride resin (parts by weight, the same applies hereinafter), 50 parts of water, 1 part of nonionic surfactant, 6 parts of dioctyl phthalate
1 part and 10 parts of a tin-based stabilizer were mixed in a homomixer at room temperature to prepare an aqueous suspension in which fine powder of vinyl chloride resin was dispersed.

Next, a glass fiber roping consisting of about 4,500 bundles of long glass fibers with a diameter of about 13 μm was immersed in the above aqueous suspension, thoroughly impregnated with an impregnation rod, and pulled out of the aqueous suspension. Immediately made of synthetic resin with a diameter of 20 mmφ
A roping member with a diameter of about 2 mmφ is passed over a first "iron member" which is made of a round rod and is machined in a reverse contact type so that the upper surface has a curvature of 10 mmR, and a roping with a diameter of about 2 mmφ is passed through a roping member with a width of 10 mm. The bundle was spread out into a tape shape, and then guided to the second and third "stretching members" to complete the spreading. Subsequently, the dry combustion roll heated to about 120°C and the two heating rolls heated to about 180°C were immediately passed to zero.
．． It is passed continuously at a speed of 5 m/min, and the fibers are aligned in the length direction, with a thickness of about 0.15 mm and a width of about 10 mm.
A transparent fiber-reinforced resin tape with good adhesion between the fibers and the resin was obtained.

As for the physical properties of the obtained tape, a cross-sectional filament investigation using a magnifying microscope, a 1g1oss measurement, a transparency investigation, and a tensile strength measurement in the longitudinal direction were performed. The results are shown in Table 1.

Examples 2-8 In Example 1. After the glass fiber roping was impregnated with an aqueous suspension, the tensile stress upon unfolding was adjusted so that a fiber-reinforced resin tape having a shape having the thickness and width/thickness ratio shown in Table 1 was obtained. Otherwise, a fiber-reinforced resin tape was obtained in the same manner as in Example 1.

The physical properties of these tapes were measured in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Examples 1 to 2 The tensile stress of the roping during bundle development was adjusted in the same manner as in the Examples to obtain a molding material having the thickness and width shown in Table 1. A fiber-reinforced resin tape having the shape shown in was obtained.

The physical properties of these tapes were measured in the same manner as in Example 1, and the results are shown in Table 1.

Table 1 $I: ASTM D638 Example 9 The fiber-reinforced resin tape obtained in Example 1 was used as a molding material, and the tapes were arranged in parallel with the same direction and an interval of 1 On + m, and then vinyl chloride resin was placed on top of the tape. The film was placed and laminated using a heating compression molding machine at about 160°C and 15 kg/mm'' to a thickness of 0.3 mm and a size of 30 x 30 cm.
A transparent laminate molded product having a glass fiber content of about 25% by weight was obtained.

The mechanical strength and weather resistance of this laminated molded product are determined by measuring the yellowing degree (ΔYl) and color difference (ΔE) after being kept at a temperature of 60°C and humidity of 60% for 500 and 1000 hours using a weather-ometer using a color computer. (manufactured by Suga Test Instruments Co., Ltd.). The results are shown in Table 2.

Example 10 The fiber-reinforced resin tape obtained in Example 2 was used as a molding material, and the tapes were aligned in the same direction and arranged in parallel with an interval of I 0 mm, and 1 mm thick vinyl chloride resin sheets were abutted on top and bottom of the tapes. Approximately 160℃ and 15kg using a heating compression molding machine.
/mm", laminated and molded to a thickness of 2.2mm, 30X 3
A transparent laminate molded product having a diameter of 0 cm and a glass fiber content of approximately 7% by weight was obtained.

The physical properties of this laminate were measured in the same manner as in Example 9, and the results are shown in Table 2.

Comparative Example 3 A fiber-reinforced resin was produced in the same manner as in Example 1, except that a vinyl chloride resin emulsion after polymerization by emulsion polymerization was used instead of the aqueous suspension in which fine powder of vinyl chloride resin was dispersed in Example 1. Got the tape.

Using this tape, the thickness was 0.3 in the same manner as in Example 9.
mm, 30X 3Gcm, glass fiber content approximately 25
A transparent laminate molded product of % by weight was obtained.

The physical properties of the laminate molded product thus obtained were measured in the same manner as in Example 9, and the results are shown in Table 2.

Comparative Example 4 Same as Example 9 for a commercially available hard vinyl chloride resin plate (thickness: I mm) (however, mechanical strength is not related to directionality)
The physical properties were measured and the results are shown in Table 2.

Comparative Example 5 Commercially available chopped glass fiber strands (content rate approx. 2
The physical properties of a vinyl chloride resin plate (thickness: I mm) made of a reinforcing material (5% by weight) were measured in the same manner as in Comparative Example 4, and the results are shown in Table 2.

Table 2 *2: ASTM D638. $2: ASTM D7
90 [Effects of the Invention] The fiber-reinforced resin tape of the present invention has transparency itself, and since the fibers are aligned in a certain direction, it has an extremely high mechanical strength in that direction. . Therefore, when applied as a molding material, it is recognized that by selecting various arrangements, molded products with improved strength and transparency can be obtained.

In addition, the manufacturing method is a unique method in which the roping fibers are impregnated with an aqueous suspension and spread out using a "straining member." Therefore, the fibers (filaments) are extremely thin, aligned in a certain direction, and are made of resin. This makes it possible to produce a fiber-reinforced resin tape with a sufficient number of filaments and no filament fluff. especially,
The filament that has been thinned by the unbundling development is also characterized in that the filament does not return to its original state during the next process.

Furthermore, the laminate molded product using the fiber-reinforced resin tape as the molding material is also recognized to have excellent mechanical strength and weather resistance.

Claims (6)

[Claims] (1) Roping fibers are impregnated with an aqueous suspension in which fine powder of vinyl chloride resin is dispersed, the roping fibers are unbundled, and the continuous fibers obtained by drying and heating are pulled in a fixed direction. Fiber reinforced resin tape. (2) The fiber-reinforced resin tape according to claim 1, wherein the fine powder of vinyl chloride resin is obtained by finely pulverizing a resin obtained by a suspension polymerization method and has an average particle diameter of 0.1 to 5 μm. (3) The fiber-reinforced resin tape according to claim 1, wherein the roping fiber is a bundle of a plurality of glass fibers. (4) Fiber-reinforced resin tape with a thickness of 0.2 mm or less, width/
The fiber reinforced resin tape according to claim 1, having a thickness ratio of 25 to 200. (5) The fiber reinforced resin tape according to claim 1 is arranged,
A laminate molded product obtained by laminating and molding a vinyl chloride resin sheet or film on at least one side of the tape. (6) Continuous fibers are obtained by impregnating roping fibers in an aqueous suspension containing fine powder obtained by finely powdering vinyl chloride resin, unbundling the roping fibers, drying and heating the fibers. A method for manufacturing a fiber-reinforced resin tape that is aligned in a certain direction.