JPH0820649A - Production of glass fiber-reinforced polyolefinic resin composition and production of preliminary molded product using the composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in surface (smoothness), toughness, impact resistance, etc., and useful for automotive interiors and exteriors, etc., in good efficiency for opening and mixing the fibers, by mixing the bundles of reinforcing glass fibers with the powder of a polyolefinic resin in the presence of a specific surfactant in the flow of a gas. CONSTITUTION:This resin composition is obtained by mixing (A) the chopped strands of reinforcing glass fiber bundles with (B) the powder of a polyolefin resin such as PE or PP in the presence of (C) an anionic surfactant having a long chain alkyl and an anionic polar group in (D) the flow of a gas such as air or nitrogen gas to open the component A and homogeneously mix the component A with the component B. The component C is preferably used in an amount of 0.01-5wt.% on the basis of the component A.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a glass fiber reinforced polyolefin resin composition for obtaining a glass fiber reinforced polyolefin resin molded product having excellent mechanical properties, particularly tensile strength, toughness and impact properties. And a method for producing a preform using the composition, wherein the composition or preform obtained by this method is
It can be effectively used as a material for fiber-reinforced polyolefin resin moldings used in exterior parts, home appliances, and various other fields.

[0002]

2. Description of the Related Art A fiber-reinforced PO resin molded product in which a polyolefin resin such as polyethylene or polypropylene (hereinafter referred to as PO resin) is used as a matrix and glass fibers are used as a reinforcing fiber in the matrix is relatively lightweight. In addition, it has excellent mechanical properties, and because it has the characteristics that it can be easily processed into any shape by secondary molding, it is widely used in various fields including the above-mentioned applications. It is used.

On the other hand, this type of glass fiber reinforced PO-based resin has been popularized as a composite of continuous long fiber reinforcing glass fibers and a matrix resin. Recently, however, continuous fibers such as BMC are suitable. Reinforcing glass fiber made of chopped strands cut into various lengths
Fiber-reinforced PO-based resin compositions that are mixed with an O-based resin and can be molded into various shapes have been widely used. As a method for producing such a chopped strand composite type glass fiber reinforced resin composition, for example, JP-A-63-135550 and 63-199.
Techniques such as those disclosed in Japanese Patent No. 611 have been proposed.

According to this method, the chopped strands of the glass fiber bundle are opened by mixing in a turbulent air flow, and at the same time, a PO-based resin powder serving as a matrix is added to the mixed system to uniformly mix the glass fiber with the glass fiber. PO
It is intended to obtain a bulk molding resin composition in which a system resin powder is uniformly mixed, and this bulk composition can be molded into an arbitrary shape by heat and pressure molding. It is expected to increase.

Further, a preformed body prepared by appropriately compressing the bulk composition and heating the surface thereof to melt the PO-based resin in the surface layer to form an outer cover is a simple glass. Bulk density is significantly increased compared to a bulk composition composed of a mixture of fibers and resin powder,
Not only is it convenient to carry and handle, but it also has the advantage that standardization of the shape of the preform makes it easy to apply it to the subsequent heating and pressurizing equipment. It is expected that the commercialization of will be further advanced in the future.

[0006]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention The inventors of the present invention have put into practice a method of mixing a bundle of reinforcing glass fibers with an PO resin powder while opening the fibers by mixing them in an air stream as described above. We have been conducting research for some time for the purpose of improvement, but we have found that the following problems occur during the research process. That is, in the method of opening the glass fiber bundle and mixing the PO-based resin powder in the air stream, the glass fiber breakage (reinforcement of the reinforcing fiber) which is observed when a conventional mixing device using, for example, a screw kneader is used. It is known that if the breakage progresses, the mechanical properties of the fiber-reinforced resin molded body, especially toughness and impact resistance, cannot be satisfactorily enhanced by making the glass fiber single-sized. Although there is an advantage that breakage during mixing of glass fiber which is easy to break can be suppressed and its strengthening property can be effectively extracted, on the other hand, in order to uniformly mix the glass fiber and the thermoplastic resin powder by this method, It is an important requirement that the opening of the fiber bundle is sufficiently promoted during the mixing.

However, when the ordinary glass fiber bundle is applied to the above-mentioned air flow mixing method, the fibers are often insufficiently opened, and the mixing with the PO-based resin powder is also insufficient, resulting in uniform molding. The material composition cannot be obtained, and the fiber bundle that remains due to insufficient opening remains as a coarse product in the final product and reduces the appearance and surface smoothness of the final molded product, which has a considerable adverse effect on the quality. .

That is, the ordinary glass fiber bundle is treated with a sizing agent or a sizing agent for the purpose of improving the productivity or the quality of the product in the manufacturing process, and the fine fibers constituting the bundle are subjected to the fiber treatment. Since it is bonded by the agent, it is not easy to open the fiber bundle even if the glass fiber bundle is stirred by air flow, and various problems due to insufficient fiber opening as described above occur. Come on.

Here, if the conditions for mixing the glass fiber bundle and the resin powder are set to be strict (that is, the airflow stirring conditions are set to be strict and for a long time), the opening of the bundle and the mixing of the resin powder will be performed. It is possible to proceed sufficiently, but if such conditions are adopted, the breakage of the glass fibers during the opening and mixing will proceed, and the characteristics of airflow mixing as described above cannot be utilized. Particularly in recent years, there is a tendency to use very thin fibers as the glass fibers in order to improve the surface smoothness and accuracy of the molded body, and in combination with this, insufficient opening of the glass fiber bundle during air flow mixing and glass fiber It is considered that the deterioration of physical properties due to breakage cannot be neglected.

Further, as another problem pointed out in the conventional method, since the glass fiber and the PO-based resin do not necessarily have a good affinity, the opened glass fiber may be obtained depending on the conditions of air flow mixing. The PO resin powder and the PO resin powder are not always uniformly mixed, and they may be partially aggregated individually, which also causes deterioration of mechanical properties and homogeneity of the final molded product. It is considered to be a thing.

The present invention has been made by paying attention to such problems, and an object thereof is to obtain a glass fiber bundle having a high sizing property by a fiber treatment agent even in an air stream. By the mixing, it is possible to efficiently open the glass fiber bundle and mix it with the PO-based resin powder in a short time while preventing the glass fibers from breaking as much as possible, and thereby to obtain a uniform, toughness and resistance. It is an object of the present invention to establish a method for obtaining a glass fiber reinforced PO resin composition which gives a molded article having excellent impact properties and excellent appearance and surface smoothness, and a preformed article made of the composition.

[0012]

A method for producing a glass fiber-reinforced PO-based resin composition according to the present invention, which has been able to solve the above-mentioned problems, is a method of producing a PO-based resin powder and a concentrating body of reinforcing glass fiber in an air stream. In producing the glass fiber-reinforced PO-based resin composition by mixing, the chopped strands of the reinforcing glass fiber bundle and the PO-based resin powder are mixed with a long-chain alkyl and anionic polar group-containing anionic surfactant. Mixing in an air stream in the coexistence of an agent to carry out the opening of the glass fiber bundle and the uniform mixing of the PO resin powder, or the above glass fiber bundle for reinforcement or the chopped strand thereof having the above-mentioned surface activity. The agent is attached and mixed with the PO-based resin powder in an air stream,
The gist is that the opening of the glass fiber bundle and the mixing of the polyolefin resin powder are performed.

When this method is adopted, the opening of the glass fiber bundle is remarkably promoted by the coexistence of the surfactant, and the glass fiber and the PO-based glass are mixed by the action of the surfactant attached to the surface of the opened glass fiber. The affinity with the resin powder is also enhanced, and it is possible to obtain a molding resin composition in which the opened glass fibers and the PO-based resin powder are uniformly mixed by mixing for a short time in an air stream.

The amount of the surfactant used in carrying out the above method is 0.01 to 5 relative to the glass fiber bundle.
%, More preferably 0.05 to 0.5% by weight. Further, the bundle of reinforcing glass fibers is preliminarily degreased with a solvent or alkaline water to remove the sizing agent, sizing agent, etc. adhering to the fibers, and then mixed in an air stream to obtain a fiber bundle. It becomes possible to perform the opening and mixing in a shorter time.

The mixture of the open fiber glass and the PO-based resin powder thus obtained can be used as it is as a fiber-reinforced resin composition for heat and pressure molding, but this composition is very bulky. Since it is expensive, when it is commercialized as an intermediate raw material for molding, the resin composition is compressed, and the PO layer resin in the surface layer portion is melted by heating the surface layer portion in the compressed body to strengthen the glass fiber. By forming an outer skin integrated with and forming a preformed body in an arbitrary shape and size, it is convenient for storage, transportation, and subsequent application to a heating and pressurizing apparatus. ,
The manufacturing method of such a preform is also included in the scope of right.

[0016]

As described above, in the present invention, it is premised that the chopped strands made of a bundle of reinforcing glass fibers and the PO resin powder are mixed in an air stream. In order to carry out uniform mixing with the PO-based resin powder in a short time, a specific surfactant is allowed to coexist in the mixing system, and the surfactant penetrates inside the glass fiber bundle and The surfactant exerting the action of releasing the focusing force and remarkably accelerating the opening of the bundle in the air stream, and the surfactant attached to the surface of the opened glass fiber is a mixture of the glass fiber and the PO-based resin powder. It exerts the effect of increasing the affinity, and it becomes possible to mix them uniformly in a short time due to the two effects of facilitating the opening and promoting the mixing, thereby improving the productivity and quality uniformity of the resin composition. Get and mix Breakage of the glass fibers are also minimized in toughness and impact resistance further can be obtained a resin composition which gives excellent molded article surface characteristics.

As is apparent from the action and effect of the above-mentioned surfactant, the surfactant used in the present invention has an action of promptly penetrating into the fiber gap in the glass fiber bundle to release the bundling force. It is necessary to select a substance that exerts the effect of adhering to the surface of the glass fiber open body and enhances the affinity (wettability) with the PO-based resin powder. In the present invention, as a surfactant that can be effectively exhibited, as a surfactant, a long-chain alkyl represented by higher fatty acid salt, higher fatty acid ester salt, higher alcohol sulfate ester salt, and anion such as carboxyl group or alcoholic hydroxyl group An anionic surfactant having a polar group is selected. Since these anionic surfactants have a good affinity with the glass fibers, they rapidly penetrate into the fiber gaps of the glass fiber bundle to significantly promote the opening in the air flow, and at the same time, they are PO Since it also has an excellent affinity with the system resin, it adheres to the surface of the opened glass fiber to enhance the wettability with the PO system resin powder, and accelerates the uniform mixing with the PO system resin powder. It works, and by mixing for a relatively short time in the airflow,
It becomes possible to efficiently proceed with the opening of the glass fiber bundle and the mixing of the PO-based resin powder.

As a result, the breakage of the glass fibers during air flow mixing can be suppressed as much as possible, and not only the toughness and impact resistance expected of the glass fibers can be exhibited to the maximum extent, but also from the mixture. In the molded product obtained by heat-press molding the resin composition, the unevenness of the physical properties and the deterioration of the surface property due to the bundle with insufficient opening are not observed, and the toughness, impact resistance and homogeneity are confirmed. It is possible to obtain a resin composition that gives a molded product that satisfies all required properties such as surface properties and surface accuracy.

The effect of the above-mentioned surfactant is effectively exhibited by allowing the glass fiber bundle and the PO resin powder to coexist in a mixed system in an air stream. Therefore, in carrying out the present invention, a method of diluting a surfactant into a suitable solvent as necessary in the above mixed system in an air stream, or spraying it as an aqueous emulsion, or a glass fiber bundle or its chopped A method may be employed in which the surface-active agent is previously attached to the strand by an impregnation method, a spray method, or the like, and the strand is supplied to the air flow mixing system.

In the reinforcing glass fiber bundle used in the present invention, the more the fine filaments are converged, the more the homogeneity, the mechanical characteristics or the surface property of the final molded article is easily obtained. In consideration of the openability at the time of mixing and the mixing efficiency with the PO-based resin powder, the most preferable one is
200 to 40 filaments with a diameter of 8 to 20 μm
About 100 pieces, more preferably about 400 to 1200 pieces, are bundled. The length of chopped strands varies depending on the required characteristics of the final molded product, so it cannot be uniformly determined, but opening in an air stream 1 to 50 mm, more preferably 10
It is desirable to use one having a size of about 30 mm.

At this time, if necessary, for further strengthening
As the fiber, for example, carbon fiber, metal fiber, ceramics
Inorganic fiber such as fiber, aramid fiber, polyamide fiber
Fiber, polyester fiber, organic fiber such as acrylic fiber,
Are SiC whiskers and S₃ N _Four Suitable amount of whiskers
It is also possible to use. It is also collected as a recycled resource.
Add an appropriate amount of crushed fiber of used paper in the mixing process in the air flow
By doing so, it is possible to reduce weight and cost.
Wear.

Examples of PO-based resins include polyethylene, polypropylene, ethylene-propylene copolymers, and blends thereof. These may be modified with acid, for example. Absent. Among these, particularly preferred are highly crystalline polyethylene and polypropylene. These PO-based resins include general-purpose resins such as ABS, polyethylene terephthalate, polycarbonate, polystyrene, polyacetal and polyacrylate as other thermoplastic resins, and heat-resistant materials such as polysulfone, polyphenylene sulfide, polyether ether ketone, polyimide and polyamideimide. It is also possible to use a small amount of a thermoplastic resin having excellent properties in combination.

The particle shape and particle size of these PO-based resin powders are not particularly limited, but a diameter of 0.01 to 5 mm is used in order to efficiently promote uniform mixing with glass fibers in an air stream.
Spherical shape, or diameter 1-8mm, length 2-10m
m pellets, or cross-sectional area 5-40 mm ² ,
A rectangular parallelepiped having a length of about 1 to 10 mm is exemplified as a preferable one. These PO-based resin powders have a shape such as a spherical shape or an elliptical shape that does not have a sharp edge in order to minimize the impact force applied to the fibers in the mixing process with the reinforcing fibers in the air flow. Good to do.

As a concrete method of mixing in an air stream,
For example, the airflow mixing device 1 as shown in FIG. 1 may be used. That is, from a plurality of hoppers 4a, 4b attached to the upper part of the cylindrical container 10, chopped strands of glass fiber bundles to which a surfactant has been attached in advance and PO-based resin powder are separately supplied into the container 10 by a predetermined amount or At the same time, the compressed gas (air, nitrogen, inert gas, water vapor, etc.) is blown from the nozzle 3 provided on the wall surface of the container, and the raw materials are mixed by the stirring force mainly of the air flow while slowly stirring by the stirrer 6 if necessary. Method (at this time, it is also effective to provide two or more nozzles 3 to further enhance the airflow stirring effect), or to supply the chopped strands with the surfactant and the PO resin powder into the container 10. At the same time, use a method such as blowing a surfactant-containing solution or aqueous emulsion from another blowing port and mixing with air flow. . The compressed gas is discharged to the outside air side from the filter 8 provided at a proper position on the wall surface of the container 10 through the exhaust port 9.

In another embodiment, the glass fiber bundle is impregnated with a surfactant-containing solution, and then the fibers are preliminarily opened by passing through a roll and compression. To the inside of the mixing device by air-flow mixing with the PO-based resin powder, or after spraying the surfactant in the pre-opening step by roll compression, cut into an appropriate length and continuously in the mixing device. It is also possible to employ as a preferable method a method of supplying the same to the PO-based resin and mixing the same with air flow.

The preferable mixing conditions at this time are not particularly limited, but normally a pressure of 1 to 5 kg / cm ² and a flow rate of blown air of about 0.1 to 0.5 kg / min are adopted. In addition, stirring with a stirrer that may be used in combination is preferably about 30 to 100 rpm. The mixture may be taken out in batches from the outlet 5 provided in the lower part of the container 10. This mixture may be commercialized as it is as a glass fiber reinforced PO resin composition in which almost completely opened glass fibers and PO resin powder are uniformly mixed, or it is compressed and the surface thereof is heated. It is also effective to melt the PO-based resin on the surface and commercialize it as a bulk preform.

In the case of a bulk preform, the homogeneous mixture obtained as described above is charged into a compression molding apparatus having a heating mechanism (heat transfer heater, etc.) on the inner surface side, The mixture is compressed to consolidate and the surface is heated to melt the PO-based resin powder on the surface, and after being integrated with the glass fiber of the surface layer part, the surface is skinned only by cooling and the inside is for reinforcement. A bulk preform may be used in which the glass fiber and the PO resin powder are still mixed.

In this mixing step, if necessary, an inorganic or organic filler such as carbon black, calcium carbonate or titanium dioxide is added for the purpose of imparting functionality to the resin composition or reducing the weight and cost. , Calcium sulphate, barium sulphate, kaolin clay, inorganic powdery fillers such as clay minerals such as quartz powder, inorganic hollow fine particle fillers such as shirasu balloon, glass balloon and fly ash balloon, used paper, wood powder, It is also possible to mix one or more kinds of organic powdery fillers such as coconut shell powder and organic crosslinked beads such as polystyrene and polyester.

The above-mentioned resin composition or preform obtained by the method of the present invention is a mixture of the reinforcing glass fiber and the PO-based resin powder as described above, and, as mentioned above, the surfactant is used in combination. As a result, the fiber opening and mixing can be performed efficiently in a short time.As a result, breakage of glass fibers during mixing in an air stream can be minimized, and the fiber length can be maintained substantially in the state of the feed material. It will be a homogeneous mixture in the state.

Therefore, when these are heated and pressure-molded to produce a final molded product, it is not necessary to apply a high shearing force at the heating-melting or compression-molding stage, and a conventionally known injection compression molding machine or the like can be operated at a low torque. Or by using a screwless melt extruder or the like to perform molding in a manner that does not damage the reinforcing fibers as much as possible, thereby improving the opening efficiency and mixing efficiency when obtaining the resin composition. The effect of preventing breakage and scratches of the reinforcing glass fiber can be more effectively utilized.

[0031]

The present invention will be described in more detail with reference to the following examples, but the following examples are not intended to limit the present invention, and any changes or modifications may be made without departing from the spirit of the above and the following. It is included in the technical scope of the invention.

Example 1 Glass fiber bundle chopped strand (fiber diameter 10 μm
A bundle of 800 pieces of m, a length of 13 mm) and a polypropylene resin (isotactic polypropylene manufactured by Showa Denko KK, average particle diameter 5 mm, spherical) in a weight ratio of 3
Used at a ratio of 0/70 and 0.1% by weight of anionic surfactant (Wardick
Product name "Sulfanol-A" manufactured by Chemical
N ”), each of the above raw materials is charged into an airflow agitation device as shown in FIG. 1, and the agitator is slowly agitated at 50 rpm, while 1.5 kg / cm ² of compressed air is added to 0.2 kg / a. The mixture was stirred for 5 minutes while blowing at a flow rate of minutes. By this mixing, the opening of the glass fiber and the mixing of the resin proceeded efficiently, and a bulky uniform mixture in which the opened glass fiber and the resin were uniformly mixed was obtained.

This mixture was taken out of the container, and 200 k
It is compression-molded at g / cm ² into a rectangular shape with a thickness of 1 mm, a width of 200 mm and a width of 300 mm, and then heated at 220 ° C. for 4 minutes to melt the resin powder only in the surface layer and integrate it with the glass fiber, and the surface is peeled. Preform in tension (density:
0.45 g / cc) was obtained. Using this preform,
By compression molding at a pressure of 200 kg / cm ² and a temperature of 110 ° C. for 1 minute, all the resin powder was melted and integrated with the glass fiber to obtain a glass fiber reinforced molded body having a thickness of 3 mm. The molded product had a bending strength of 121 MPa and an impact strength of 36 kgf · cm / cm ² , and had excellent physical properties.

Example 2 In Example 1, the anionic surfactant added in the airflow stirring step was omitted, and the same anionic surfactant was impregnated and adhered to the glass fiber chopped strand in an amount of 0.1% by weight. Then, air flow stirring and mixing, preforming and heat and pressure molding were performed in exactly the same manner as in Example 1 above. Then, when the physical properties of the finally obtained glass fiber reinforced resin molded product were examined, the bending strength was 123 MPa and the impact strength was 38 kgf · cm / cm ^2, showing excellent physical properties.

Comparative Example 1 Glass fiber reinforced resin moldings were prepared in the same manner as in Examples 1 and 2 above, except that the anionic surfactant was not used at all, airflow mixing, pre-molding and heat compression molding were carried out. Was manufactured. The bending strength of the molded body is 100 MPa,
The impact strength was 27 kgf · cm / cm ² , which was clearly inferior to those of Examples 1 and 2 above.

[0036]

EFFECTS OF THE INVENTION The present invention is constituted as described above, and when a reinforcing glass fiber bundle and a PO resin powder are uniformly mixed in an air stream, a specific surfactant is allowed to coexist in the mixing system. By accelerating the opening of the bundle by keeping it,
Mixing with PO-based resin powder can be performed efficiently,
It is possible to obtain a resin composition and a pre-molded article which are homogeneous and give a molded article excellent in surface properties and surface smoothness. Moreover, as a result that the opening and mixing can be efficiently performed in a short time,
Breakage of the glass fibers during the air flow mixing can be suppressed to a minimum, the reinforcing effect of the glass fibers can be maximized, and a molded product having excellent toughness and impact resistance can be obtained.

[Brief description of drawings]

FIG. 1 is an example of an air flow mixing device used in the method of the present invention.

[Explanation of symbols]

 3 Compressed gas blowing nozzles 4a, 4b Raw material charging hopper 5 Mixture discharge port 6 Stirrer 8 Filter 9 Air discharge port 10 Stirring container

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Mika Nishida 1-5-5 Takatsukadai, Nishi-ku, Kobe-shi, Hyogo Prefecture Kobe Steel Co., Ltd. Kobe Research Institute (72) Inventor Takako Takeda Takatsuka, Nishi-ku, Kobe-shi, Hyogo Prefecture 1-5-5 stand, Kobe Steel, Ltd. Kobe Research Institute

Claims (6)

[Claims] 1. When producing a fiber-reinforced polyolefin resin composition by mixing a polyolefin resin powder and a reinforcing glass fiber bundle in an air stream, the chopped strand of the reinforcing glass fiber bundle and the reinforcing glass fiber bundle are produced. A polyolefin resin powder is mixed in a gas stream in the presence of an anionic surfactant having a long-chain alkyl and an anionic polar group, and the opening of the glass fiber bundle and the mixing of the polyolefin resin powder are carried out. A method for producing a glass fiber-reinforced polyolefin-based resin composition, which is characterized by carrying out. 2. When producing a fiber-reinforced polyolefin-based resin composition by mixing a polyolefin resin powder and a reinforcing glass fiber bundle in an air stream, the reinforcing glass fiber bundle or the chopped strand thereof is used. An anionic surfactant having a long-chain alkyl and an anionic polar group is attached, and the anionic surfactant is mixed with the polyolefin resin powder in an air stream to open the glass fiber bundle and the polyolefin resin. A method for producing a glass fiber-reinforced polyolefin-based resin composition, which comprises mixing with a powder. 3. The method according to claim 1, wherein the surfactant is used in an amount of 0.01 to 5% by weight based on the glass fiber bundle. 4. The reinforcing glass fiber bundle is subjected to a degreasing treatment in advance and then subjected to mixing in an air stream.
The manufacturing method described in. 5. The reinforcing glass fiber bundle or chopped strand thereof is pre-degreased, a surfactant is attached thereto, and then the mixture is mixed with a polyolefin resin powder in an air stream. Manufacturing method. 6. A resin composition obtained by compressing the resin composition according to any one of claims 1 to 5 and heating the surface layer portion of the compressed body to melt the polyolefin resin in the surface layer portion and integrate the glass fiber for reinforcement into an outer skin. A method for producing a glass fiber reinforced polyolefin resin preform, characterized by forming a.