JPH04173311A - Manufacture of fiber-reinforced sheet material - Google Patents

Abstract

PURPOSE:To manufacture a colored sheet material of superior appearance and mechanical strength and good molding properties by mixing respectively specified quantities of thermoplastic synthetic resin powder, inorganic fiber bundles of specified length or longer, a pigment and viscous liquid of specified viscosity almost uniformly, heating a mixture thus prepared at the temperature of melting point or softening point of thermoplastic synthetic resin and pressurizing. CONSTITUTION:100 pts.wt. of thermoplastic synthetic resin material, 2-300 pts.wt. of inorganic fiber bundles of 2mm long or longer, 0.01-5 pts.wt. of a pigment and 0.5-20 pts.wt. of viscous liquid of 10-100000 centipoise are mixed and agitated almost uniformly, and a mixture thus prepared is heated at the temperature of the melting point or softening point or higher of thermoplastic synthetic resin and pressurized to manufacture a colored fiber reinforced material. Glass fiber and carbon fiber are typical inorganic fibers. As thermoplastic synthetic resin, polyolefin resin, polyamide resin or the like is used, and the average grain diameter is preferably 2mm or less. When the average grain diameter is beyond 2mm, powder is settled by its own weight and sometimes a uniform mixture cannot be prepared.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing a colored sheet material made of thermoplastic synthetic resin and inorganic fiber suitable for stamping molding, etc. 100 parts by weight of powder, 2 to 300 parts by weight of inorganic fiber bundles having a length of 2N11 or more, 0.01 to 5 parts by weight of pigment, and a viscosity of 10 to ioo,
It is characterized by substantially uniformly mixing and stirring 0.5 to 20 parts by weight of a viscous liquid of ooo centipoise, and heating and pressurizing the resulting mixture at a temperature equal to or higher than the melting point or softening point of the thermoplastic synthetic resin. The present invention relates to a method for producing a colored fiber-reinforced sheet material.

[Prior Art] Conventionally, there are the following methods for producing thermoplastic synthetic resin sheets reinforced with inorganic fibers such as glass fibers and carbon fibers.

(A) A method in which cut inorganic fiber bundles are kneaded with thermoplastic synthetic resin and formed into a sheet using an extruder or the like.

(B) A method of bonding two molten thermoplastic synthetic resin sheets to a woven fabric or the like of an inorganic fiber bundle through the openings thereof.

(C) A method of impregnating a nonwoven fabric of an inorganic fiber bundle (for example, a continuous strand mat, a swirl mat, etc.) with a molten thermoplastic synthetic resin.

However, each of the above conventional techniques has the following drawbacks. Method (A) causes crosstalk and destruction of inorganic fibers during the sheet forming process, making it difficult to obtain a high-strength sheet. For example, 6
A sheet made by kneading chopped glass strands with a length of #2 with a thermoplastic synthetic resin and molding them using an extruder is cut into pieces that are almost the same length as the glass fibers. For method (B), it is difficult to impregnate a thermoplastic synthetic resin with a normal inorganic fiber nonwoven fabric, so a cloth with a low weave density, such as an open plain weave cloth, is required. Such a loss is not only costly, but also makes it difficult to obtain a sheet with high strength because the amount of inorganic fiber used relative to the thermoplastic synthetic resin can be kept low. Method (C) has an easier impregnation step than method (B), but it is difficult to obtain a sheet with a smooth surface. In addition, when the obtained sheet is shaped into a final product by means such as stamping molding (the sheet used for this purpose is called a stan-pull sheet), since the inorganic fibers are difficult to move, ribs, bosses, etc. It is unsuitable for products with

The present inventors have already proposed a sheet manufacturing method that eliminates the above-mentioned drawbacks in the prior art (Japanese Patent Publication No. 1-1122
Publication No. 9). The invention described in the publication is based on particle size.
100 parts by weight of thermoplastic synthetic resin powder of III+ or less is mixed with 5 to 30 discontinuous glass fibers with a fiber length of 2 to 50 mm.
0 parts by weight and mixed and stirred without opening, or mixed and stirred with opened glass fibers and uniformly dispersed. The present invention relates to a method for producing a smooth glass fiber-reinforced thermoplastic synthetic resin sheet, which is characterized by applying pressure while heating to a certain temperature or after heating until the gas (air) in the mat disappears. Note that "spreading" as used here refers to fiber bundles in which tens or hundreds of inorganic single fibers are bundled together, that is, strands, or yarns, etc., which are twisted and twisted into a predetermined number. An operation in which an external force is applied to loosen the material.

The above method of the invention provides a sheet with a smooth surface and excellent mechanical strength at a low cost, and when the obtained sheet is stamped, the inorganic fibers are discontinuous, so there are no ribs or bosses. It has many advantages such as a sufficient amount of fiber flowing into the molded product and the ability to obtain strong molded products. However, a major problem with this method is the coloring of the material.

For example, when manufacturing a black sheet by the above method using chopped strands of glass fiber as the inorganic fiber bundle and polypropylene (hereinafter referred to as PP) powder as the thermoplastic synthetic resin, carbon as the black pigment is used. When attempting to obtain a mixture by adding black powder, PP and carbon black separate and settle at the bottom of the mixer, making it impossible to obtain a homogeneous mixture with glass fibers. This method is based on the method of the invention described above. First, a spread mixture of PP and glass fibers is made, and carbon black is added to this and mixed further.
-The PP and glass fibers, which were once uniformly mixed, separate, and the PP and carbon black also settle. Therefore, when producing a colored sheet using this method, you must first knead the pigment into a thermoplastic synthetic resin to make a colored pellet, and then use a powder that is pulverized to a predetermined particle size using a pulverizer. However, it was extremely disadvantageous in terms of manufacturing cost. In addition, since the inorganic fiber bundles are opened in this method, the mixture with the thermoplastic synthetic resin (cotton-like mat) is bulky (low apparent density), and both are adhered and mixed by electrostatic attraction. However, since the thermoplastic synthetic resin powder is easily separated and scattered, and the particle size of the powder is less than 1 m, it tends to settle due to its own weight, which poses problems in handling during production.

[Problems to be Solved by Kouko] The present invention is a method for producing a fiber-reinforced sheet material that comprehensively solves the above-mentioned drawbacks of the prior art. The object of the present invention is to provide a method for manufacturing a sheet material with good productivity and at low cost.

[Means for Solving the Problems] The present invention provides thermoplastic synthetic resin powder JO [1 part by weight, 2 to 300 parts by weight of inorganic fiber bundles having a length of 2111111 or more,
Pigment 001-5 parts by weight and viscosity 10-100,0
0.5 to 20 parts by weight of a viscous liquid of 0.00 centipoise are mixed and stirred almost uniformly, and the resulting mixture is heated and pressurized at a temperature higher than the melting point or softening point of the thermoplastic synthetic resin. This is a method for producing colored fiber-reinforced sheet materials.

Typical inorganic fibers used in the present invention are glass fibers and carbon fibers. These include strands made of dozens to hundreds of single fibers tied together with a sizing agent, and rovings made by winding several to dozens of strands together. Either cut these to the specified length before using them, or
Use commercially available chopped strands whose strands have been cut to a predetermined length.

In the present invention, in order to increase the degree of dispersion of the inorganic fibers and improve surface quality and mechanical properties, it is preferable to use a part or most of the inorganic fiber bundle in a spread state. For this purpose, it is preferable to use an inorganic fiber bundle in which the amount of sizing agent is controlled. In addition, surface treatment (
For example, in the case of glass fiber, it is preferable to use a material coated with a silane-based coupling agent, etc.

The inorganic fibers used in the present invention have a length of at least 2r.
Mn or more is required, preferably 3 m or more. length
If inorganic fibers with a length of less than 2 m are used, the strength of the sheet is comparable to that of a conventional sheet obtained by kneading it with a thermoplastic synthetic resin and molding it with an extruder. There is no clear limit on the upper limit of the length, but if it exceeds 50 shoes, the strength does not particularly increase, and if it exceeds 1oos+, it may cause poor dispersion.

The thermoplastic synthetic resin used in the present invention is not particularly limited, and includes polyolefin resins, polyamide resins, polyester resins, polystyrene resins, polyvinyl chloride resins, polyacrylic ester resins, polycarbonate resins, and polyethers. Polymer resins such as polyphenylene oxide resins, polyphenylene sulfide resins, polyketone resins, polyimide resins, and polymer blends and alloys that are combinations of these resins are used.

Note that polyolefin resins suitably used in the present invention include PP, polyethylene, polybutene-1, polymethylpentene-1, and the like. In addition, PP includes copolymers with ethylene and other Baier olefins,
Polyethylene also includes copolymers of propylene and other Baier olefins and polar monomers such as vinyl acetate and acrylic esters.

These thermoplastic synthetic resins can also be used after being chemically modified in order to increase their bonding strength with inorganic fibers. In addition, in order to further improve mechanical strength such as flexural modulus, inorganic powder such as talc or calcium carbonate is blended into thermoplastic synthetic resin powder in advance, or when mixed with inorganic fiber bundles. It is also possible to add. Naturally, various additives such as antioxidants, weathering agents, antistatic agents, lubricants, plasticizers, flame retardants, etc. are added to ensure the various performances required when the products obtained by this manufacturing method are used. It is also possible to mix the agent into the thermoplastic synthetic resin powder in advance or add it when mixing with the inorganic fiber bundle.

The average particle size of the thermoplastic synthetic resin powder used in the present invention is
Preferably 2IIIm or less, more preferably 1.5J1
It is 1111 or less. The particle size is 21111! If the temperature exceeds +, even if a viscous liquid is used, the powder may settle under its own weight and a homogeneous mixture may not be obtained. This synthetic resin powder has
Although pulverized products of general pellet-like, bead-like products or molded products may be used, it is most advantageous from an economic point of view to use powder obtained during the manufacturing process of thermoplastic synthetic resins. Note that the average particle size is expressed by measuring the particle size distribution using a JIS sieve and using the median diameter.

The viscous liquid used in the present invention has a viscosity of 10 to 10
0,000 centipoise, preferably 50-1,000
Centipoise is used. If the viscosity is less than 10 centipoise, the mixture will be bulky and the powder will easily scatter, causing problems in the sheet manufacturing process. 1,000
If it exceeds centipoise, fluidity deteriorates, so it may be necessary to dilute it with an organic solvent before use. Moreover, if it exceeds 100,000 centipoise, the inorganic fiber and thermoplastic synthetic resin powder become sticky and a uniform mixture cannot be obtained. Examples of such viscous liquids include liquid polybutene, liquid polybutadiene, polyethylene glycol,
Polypropylene glycol, liquid ethylene propylene rubber, other plasticizers such as phthalic acid derivatives, stabilizers such as phosphite and phenol compounds,
Examples include mineral oil-based, synthetic-based and vegetable-based oils, aqueous solutions of water-soluble resins such as sodium polyacrylate and polyacrylamide, and linicasol. As mentioned above, in order to adjust the viscosity of a viscous liquid, it is also possible to use it by diluting it with an organic solvent or water. In this case, it is necessary to evaporate the solvent and water before or during heating and pressurizing to form a sheet.

There are various pigments used in the present invention, including carbon black,
Titanium white, titanium yellow, Bengara, cobalt blue, cadmium red, Gunjokasa inorganic pigments, phthalocyanine,
Examples include organic pigments such as azo lake, henzimidazolone, sialite yellow, quinacridone, and dioxazine.

The amount of inorganic fiber used in the present invention is thermoplastic synthetic resin 1
00 parts by weight, 2 to 300 parts by weight, preferably 10 parts by weight
~200 parts by weight. If this amount is less than 2 parts by weight, the reinforcing effect of the inorganic fibers will hardly be recognized, and if it exceeds 300 parts by weight, it will not be possible to obtain a sheet with good strength and appearance in which the gaps between the inorganic fibers are completely filled with thermoplastic synthetic resin. .

The amount of pigment used in the present invention is 0.00 parts by weight per 100 parts by weight of the thermoplastic synthetic resin. O1 to 5 parts by weight. This amount is 0,
If the amount is less than 0.1 part by weight, no coloring effect will be observed, and if it exceeds 5 parts by weight, the inorganic fiber and thermoplastic synthetic resin will tend to separate when they are mixed.

The amount of viscous liquid used in the present invention is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the thermoplastic synthetic resin. If the amount is less than 0.5 part by weight, the mixture will have a high bulk and the powder will easily scatter, which will cause problems in the heating and pressurizing process. On the other hand, if it exceeds 20 parts by weight, the mechanical strength will decrease and the characteristics of the fiber-reinforced sheet will be impaired.

Next, the manufacturing method of the present invention will be described. As an inorganic fiber bundle, for example, chopped strands of glass fiber, thermoplastic synthetic resin, such as PP powder, pigments, such as carbon black, and viscous liquids such as polybutene are stirred and mixed in a mixer. do. At this time, it is preferable that part or most of the inorganic fiber bundle is opened by the stirring force. If opening is insufficient, the inorganic fibers and thermoplastic synthetic resin will not be uniformly dispersed, and the surface of the resulting sheet may become rough, reducing its commercial value.

In the present invention, a ribbon type blender, an oscillating type mixer, etc. may also be used, but the most preferred mixer is a mixer with rotary blades at the bottom of the container. This type of mixer is the Henschel mixer (trade name).

Known examples include Mitsui Miike Seisakusho Co., Ltd.) and Super Mixer (product name; Yoda Seisakusho Co., Ltd.). When this mixer is used, it is easy to open the inorganic fiber bundle, and a mixture can be obtained in several tens of seconds to several minutes.

In the present invention, the order in which the above-mentioned four types of materials are introduced into the mixer is that they may all be added at once and stirred, but first, the inorganic fiber bundle and the thermoplastic synthetic resin powder are added, Either gradually add the viscous liquid dropwise without stirring and add the pigment after obtaining a homogeneous mixture, or first mix the inorganic fiber bundle and thermoplastic synthetic resin, and then mix the viscous liquid and pigment separately. A more homogeneous mixture can be obtained by adding the solution dropwise.

Next, the obtained mixture is formed into a mat shape, and then heated and pressed to form a sheet. In the case of a batch method, it is sufficient to use a heated press machine, or in order to increase productivity in the continuous method, the mixture is first formed into a continuous mat using a fleece former such as a batting machine, and then a heated press machine such as a double-held press is used. Heat while pressurizing with a continuous pressure machine. The heating temperature must be higher than the melting point or softening point of the thermoplastic synthetic resin. When pressurizing, it is necessary to apply enough pressure and time to drive out the air in the mixture and form a strong sheet.

[Effects of the Invention] The sheet obtained by the present invention has high mechanical strength and rigidity because long inorganic fibers are uniformly dispersed in the thermoplastic synthetic resin, and the degree of opening can be controlled. This provides excellent surface quality, which has desirable properties as a fiber-reinforced sheet material, and the method of the present invention allows for free coloring, further improving commercial value. Therefore, it is possible to use this sheet as it is as a plate material, or because it has a structure in which discontinuous fibers of appropriate length are randomly dispersed, it can flow if heated and melted, and it can be pressed. 6 using a machine
It can be suitably used as a so-called stampable sheet that is shaped into a ridge shape.

In addition, according to the method of the present invention, since a viscous liquid is used to obtain the mixture, powder with a larger particle size is used as the thermoplastic synthetic resin powder than when a viscous liquid is not used. In addition to expanding the range of application of the resulting mixture, there is less scattering of powder during mixing, and the resulting mixture has a low bulk, making subsequent handling easier, and productivity can be greatly improved.

[Example] Hereinafter, the present invention will be specifically explained with reference to Examples. The materials used here are as follows.

Thermoplastic synthetic resin> PP-1...Polypropylene, manufactured by Nippon Petrochemical Co., Ltd., 8
Stone Polypro J 180P, powder directly obtained in the PP manufacturing process, average particle size 0.6# PP-2...Polypropylene, manufactured by Nippon Petrochemical Co., Ltd., 8
Stone Polypro J 180G (Bellet), powder obtained by mechanically crushing PP pellets, average particle size 1.2mm HDPE・
...High-density polyethylene, Nippon Petrochemical Co., Ltd., Nisseki Stafrene E792J, powder obtained in the high-density polyethylene manufacturing process, inorganic fiber bundle with a 1'-average particle size of 0.2ttyn> GF-1...Fuji Manufactured by Fiberglass Co., Ltd., FES-1
3-1250, glass fiber chopped strand GF-2 with length lamm...manufactured by Fuji Fiberglass Co., Ltd., FES-6
-1250, chopped glass fiber strand with length of 6Nn, viscous liquid> PB-1...Liquid polybutene, manufactured by Nippon Petrochemical Co., Ltd., 8
Stone polybutene LV-100, viscosity 170 centipoise PB-2...Liquid polybutene, manufactured by Nippon Petrochemical Co., Ltd., 8
Stone polybutene HV-300, viscosity 25,000 centipoise, solution LPB diluted with 100 parts by weight and 80 parts by weight n-hexane...Liquid polybutadiene, manufactured by Nippon Petrochemical Co., Ltd., Nisseki Polybutadiene B-700, viscosity 300 centipoise, pigment 〉 CB...Carbon black, Mitsubishi Chemical PCB...
Phthalocyanine blue, manufactured by Toyo Ink Co., Ltd., Example 1 100 parts by weight of pp-i and 100 parts by weight of GF-1 were charged into a mixer (super mixer with a capacity of 20 J, manufactured by Yoda Seisakusho), and each While stirring at 1,300 rpm for 1 minute, 3 parts by weight of PB-1 was gradually added dropwise. Next, 0.5 parts by weight of CB was added, and the mixture was further stirred for 1 minute. The resulting mixture is moderately opened into glass fibers,
It was a homogeneous mixture in which PP and pigment were entangled.

Next, long side 250mm, short side L50m, thickness 3.5m
135 g of the mixture was piled up in a mat shape in an RTR iron mold, and the top and bottom of the mixture was covered with two pressing iron plates. Insert it into a 100 ton hydraulic press and heat it to 220℃.
After preheating for 5 minutes at 220℃, +00/(g
/ctj, and then transferred to another hydraulic press and cooled at 35° C. and ]OOAg/cm for 5 minutes.

The obtained sheet was uniformly colored black, had good dispersion of glass fibers, and had an excellent appearance. The physical properties of this sheet are shown in Table 1.

Comparative Example 1 100 parts by weight of PP-1 and 100 parts by weight of GF-1 were charged into the mixer used in Example 1, and the mixture was heated at 1.300 parts per minute.
Stir by rotating for 1 minute. Next, 0.5 parts by weight of CB was added, and the mixture was further stirred for 1 minute. Although the glass fibers of the obtained mixture were moderately opened, almost all of the black colored PP powder settled at the bottom of the mixer, making it impossible to obtain a homogeneous mixture. Therefore, a sheet as shown in Example 1 could not be made from this mixture.

Example 2 100 parts by weight of PP-2, 67 parts by weight of GF-2, PB
Example 1 using 5 parts by weight of -2 and 1 part by weight of CB
A sheet was manufactured using the same method. The appearance of the obtained sheet was good. The physical properties of this sheet were also good as shown in Table 1.

Comparative Example 2 A sheet was attempted to be created in the same manner as in Example 2, except that PB-2 was not used, or a homogeneous mixture could not be obtained and the sheet could not be created as in Comparative Example 1. Ta.

Example 3 100 parts by weight of PP-1, 20 parts by weight of GF-1, LP
Using 4 parts by weight of B and 1 part by weight of PCB, Example 1
The sheet was manufactured using the same method. The obtained sheet was uniformly colored blue, had good dispersion of glass fibers, and had an excellent appearance. The physical properties of this sheet were also good as shown in Table 1.

Example 4 100 parts by weight of HDPE, 2 parts by weight of GF-1, PB
A sheet was produced in the same manner as in Example 1 using 3 parts by weight of -1 and 0.5 parts by weight of CB. The appearance of the obtained sheet was good. The physical properties of this sheet were also good as shown in Table 1.

The physical property values shown in Table 1 were evaluated based on tensile yield strength and Izot impact value. It was conducted in accordance with D-256.

Table 1 Patent applicant: Japan Petrochemical Co., Ltd.

Claims (1)

[Scope of Claims] 1. 100 parts by weight of thermoplastic synthetic resin powder, 2 to 300 parts by weight of inorganic fiber bundles having a length of 2 mm or more, 0.01 to 5 parts by weight of pigment, and a viscosity of 10 to 100,000 centipoise. Colored fiber reinforcement characterized by mixing 0.5 to 20 parts by weight of a viscous liquid almost uniformly, and heating and pressurizing the resulting mixture at a temperature equal to or higher than the melting point or softening point of the thermoplastic synthetic resin. Manufacturing method for sheet materials. 2. 100 parts by weight of thermoplastic synthetic resin powder, 2 to 300 parts by weight of inorganic fiber bundles having a length of 2 mm or more, 0.01 to 5 parts by weight of pigment, and 0.0 parts by weight of a viscous liquid with a viscosity of 10 to 100,000 centipoise. Colored fiber reinforcement characterized in that 5 to 20 parts by weight are stirred in a container having a rotary blade at the bottom, and the resulting mixture is heated and pressurized at a temperature equal to or higher than the melting point or softening point of the thermoplastic synthetic resin. Manufacturing method for sheet materials. 3. 100 parts by weight of thermoplastic synthetic resin powder, 2 to 300 parts by weight of inorganic fiber bundles having a length of 2 mm or more, 0.01 to 5 parts by weight of pigment, and 0.0 parts by weight of a viscous liquid with a viscosity of 10 to 100,000 centipoise. The method for producing a colored fiber-reinforced sheet material according to claim 1 or 2, characterized in that 5 to 20 parts by weight of the inorganic fiber bundle is stirred until a part or most of the inorganic fiber bundle is opened.