JP2001310346A - Method for manufacturing molded article formed of amorphous resin composition containing inorganic filler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the moldability, flowability and dimensional stability of an amorphous resin composition containing an inorganic filler to suppress deformation like warpage and a sink and to suppress the exposure of the inorganic filler added to the amorphous resin composition to the surface of a molded article. SOLUTION: Carbon dioxide in an amount of 0.2 weight % or more is dissolved or absorbed in the amorphous resin composition containing the inorganic filler before the resin composition is injected in a mold cavity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a molded article of an amorphous resin composition to which an inorganic filler has been added, in which a mold cavity is easily filled and the surface property of the molded article is improved. The present invention relates to a manufacturing method for reducing deformation after injection molding such as warpage, sink, and sink.

[0002]

2. Description of the Related Art Amorphous resins such as modified PPE resins are often used by adding an inorganic filler such as glass fiber for the purpose of securing dimensional accuracy and rigidity.
In the case of an injection molded article of an amorphous resin to which an inorganic filler is added, the following points are likely to appear as inconveniences, which are factors that are restricted by product design, mold design, molding conditions, and resin composition.

Since the melt viscosity is high, it is difficult to fill the mold cavity. Since resin that is difficult to fill is molded under high pressure, deformation such as warpage is likely to occur. Since the pressure is not sufficiently transmitted to the flow end of the resin,
Sink easily occurs. The surface roughness is rough because the inorganic filler is easily exposed on the surface of the molded product.

In injection molding of a thermoplastic resin containing an amorphous resin, usually, the resin is heated to a temperature having sufficient fluidity to fill a mold cavity. The fluidity of the molten resin not only determines the ease of filling into the mold cavity, but also determines whether sufficient pressure is transmitted to the resin in the cavity after filling. It can be said that this is an important factor that affects the quality of mold transferability, warpage, and occurrence of sink marks.

As the molding conditions for filling the mold cavity with the resin so as not to leave unfilled portions, it is effective to increase the injection speed, increase the holding pressure, and the like. But,
When the injection speed is increased, burrs may be generated, which easily causes damage to the mold. If the holding pressure is increased more than necessary, deformation such as warpage is likely to occur after removal from the mold because molding distortion tends to remain in the molded product. In addition, when the holding pressure cannot be sufficiently transmitted at the flow end portion of the resin, volume contraction due to cooling of the resin is likely to occur, which tends to cause sink marks and the like.

[0006] Molding conditions for enhancing the fluidity include:
It is effective to increase the resin temperature and the mold temperature. However, since a high resin temperature causes thermal decomposition of the resin itself and additives, problems such as a decrease in strength of a molded product, generation of foreign matters due to degraded resin, contamination of a mold, and discoloration are likely to occur.

The setting range of the resin temperature when molding the crystalline resin is narrow, usually in the range of 5 to 30 ° C. higher than the melting point, and in most cases, in the range of 10 to 20 ° C. higher than the melting point. This is because filling is difficult in a temperature range lower than a temperature higher than the melting point by 5 ° C. and the resin is decomposed in a temperature range higher than the melting point by 30 ° C. or more, so that a molded product having the original characteristics of the resin is obtained. In addition to this, there is a possibility that problems such as deterioration of the working environment may occur.

Inevitably, the molding temperature range of a resin obtained by alloying an amorphous resin and a crystalline resin (for example, an alloy of a polyphenylene ether resin and a polyamide resin) is also narrowed, and the flowability of the resin is improved. It is practically impossible to easily raise the molding temperature. Therefore, the application to thin-walled molded products is often limited. In addition, when the mold temperature is increased, there is a problem that the cooling time of the resin filled in the mold becomes longer, and the molding cycle time becomes longer.

On the other hand, as a resin modifying means for increasing fluidity, techniques such as lowering the molecular weight of the resin, introducing a comonomer component into the molecule, and adding a plasticizer have been used. However, when the molecular weight is reduced, the impact strength and chemical resistance are reduced. When a comonomer is introduced into the molecule, the rigidity during heating is reduced. There is a concern that the particles adhere.

[0010] On the other hand, polyphenylene ether resin is an amorphous resin having excellent flame retardancy. However, since the viscosity at the time of melting is high, modified polyphenylene ether resin alloyed with polystyrene or the like is used as a usual molding material. It is common that Modified polyphenylene ether resin with a large percentage of polystyrene has reduced flame retardancy,
Further, it is necessary to add a flame retardant as needed in order to further improve the flame retardancy. However, the viscosity of the flame retardant itself is high, and the addition of a certain amount or more causes a decrease in the fluidity of the resin, so that there are many cases where it is difficult to secure the flame retardant level.

On the other hand, in J.I. Appl. Polym. Sc
i. , Vol. 30, 2633 (1985), it is known that when carbon dioxide is absorbed by a resin, it acts as a plasticizer for the resin and lowers the glass transition temperature. It has not been widely applied to processing. Japanese Unexamined Patent Publication No. Hei 5-318541 discloses a method in which a gas such as carbon dioxide or nitrogen is contained in a thermoplastic resin, and the resin is filled in the cavity while removing the gas in the cavity. To obtain a molded article having no deterioration in strength or appearance. However, in this method, when carbon dioxide is used as the gas, the amount of the gas contained in the resin is as small as about 0.18% by weight at the maximum, and it can be said that it is difficult to obtain a sufficient effect of improving the fluidity.

In the foam molding, after the cavity is substantially filled with the resin in a non-foamed state, the volume shrinkage when the molten resin inside the surface layer of the molded product solidified at the time of filling the resin is cooled is foamed. It is. Basically, the amount of gas contained in the resin for the purpose of imparting foaming property to the resin is set to a minimum value that can compensate for the volume shrinkage. Generally, the amount of gas in the resin is less than 0.1% by weight of nitrogen and less than 0.15% by weight of carbon dioxide. Tokiko Sho 62-16
In the example of Japanese Patent Publication No. 166, the amount of nitrogen gas in the resin is 0.0
It is estimated to be about 1 to 0.15% by weight, and cannot improve the fluidity of the resin.

[0013] WO 98/52734 discloses that
In injection molding of thermoplastic resin,
A method is disclosed in which a molten resin whose viscosity has been reduced by dissolving it by weight or more is pressurized in advance with a gas at a pressure higher than a pressure at which foaming does not occur at the flow front of the molten resin, and injected into the mold cavity. ing. However, in this method, the filling of the resin is hindered by the pressurized gas in the cavity, so that the filling pressure increases and the filling time becomes longer. Therefore, when an amorphous resin to which an inorganic filler is added is injection-molded, the surface properties and mold transferability of the molded product are almost the same as those of a normal molded product. Also, a seal structure for maintaining the pressure of the pressurized gas filled in the cavity is required, and it is necessary to have a complicated mold structure.

As the molding conditions under which the inorganic filler is not exposed on the surface of the molded product, techniques such as increasing the mold temperature and increasing the injection speed are often employed. The problems that occur when the mold temperature is increased and the injection speed is increased are as described above. JP-A-62-5828
No. 7, "Rubber reinforced polystyrene resin injection molding method" and Japanese Patent Application Laid-Open No. 62-58288, "ABS resin injection molding method" are both performed with the mold open. By inserting an inductor between the molds and heating the mold surface, an amorphous resin molded product having a smooth surface is obtained. Regarding the inductor inserted between the molds, the high-frequency induction coil for mold heating and the molding device,
It is disclosed in Japanese Patent Application Laid-Open No. Hei 8-90623.

However, during the molding cycle, an inductor or a high-frequency induction heating coil is inserted between the molds, and the surface of the mold is heated to a temperature equal to or higher than the glass transition point of the resin to be molded. A step of drawing out the induction heating coil is required, and there is a problem in productivity because the molding cycle is elongated. In addition, in the case of high-frequency induction heating, an excessive amount of electricity is consumed, which is not preferable from the viewpoint of energy saving. In addition, high-frequency induction heating is also not preferable because it is limited to a molded product having a relatively flat shape, because it limits the degree of freedom in product design of the molded product.

[0016]

SUMMARY OF THE INVENTION The present invention improves the moldability, flowability, and dimensional stability of an amorphous resin to which an inorganic filler has been added, and suppresses the occurrence of deformation such as warpage and sink.
An object of the present invention is to provide, by improving a molding method, suppression of exposure of an inorganic filler added to the amorphous resin to the surface of a molded article. Specifically, it is easy to fill the mold cavity without limiting the resin composition of the amorphous resin to which the inorganic filler has been added, and without impairing the degree of freedom in product design. Improves mold transferability, suppresses warpage and sink marks, suppresses the exposure of inorganic filler added to the amorphous resin to the molded product surface, and enables application to thinner molded products. It is to be.

[0017]

Means for Solving the Problems The present inventors dissolve or absorb 0.2% by weight or more of carbon dioxide in an amorphous resin composition to which an inorganic filler is added, and then inject it into a mold cavity. As a result, the present inventors have found that while improving the fluidity and moldability of an amorphous resin to which an inorganic filler has been added, the moldability, fluidity, and dimensional stability are improved, and deformation such as warpage and sink is suppressed.

That is, the present invention relates to a method for producing a molded article of an amorphous resin composition to which an inorganic filler is added, wherein 0.2% by weight or more of carbon dioxide is dissolved or absorbed in the amorphous resin composition. The present invention relates to a method for producing a molded article of an amorphous resin composition to which an inorganic filler is added, wherein the molded article is injected into a mold cavity after the molding.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below. In the molding method according to the present invention, by dissolving or absorbing 0.2% by weight or more of carbon dioxide in the amorphous resin composition to which the inorganic filler is added, the viscosity at the time of melting is reduced and the fluidity is improved. . It is supposed that carbon dioxide is efficiently dispersed as a plasticizer in the amorphous resin to which the inorganic filler in the molten state is added. As a result,
Since there is no need to raise the resin temperature, there is no need to worry about thermal decomposition and deterioration of the resin, and there is no need to raise the mold temperature more than necessary.

In the molding method according to the present invention, by dissolving 0.2% by weight or more of carbon dioxide in an amorphous resin composition to which an inorganic filler has been added, deformation after molding such as warpage or sink mark is reduced. Less than the molding method. This is presumably because the filling pressure at the time of filling into the mold cavity is lower than that of the conventional molding method, so that residual strain hardly remains in the molded product and warpage hardly occurs.
Also, when the resin is cooled in the mold cavity and causes volume shrinkage, carbon dioxide dissolved in the amorphous resin foams moderately to compensate for this volume shrinkage. It is.

In the molding method according to the present invention, by dissolving 0.2% by weight or more of carbon dioxide in the amorphous resin composition to which the inorganic filler has been added, the viscosity of the amorphous resin can be reduced when filling the cavity. It is considered that the pressure is likely to be transmitted to the resin flow end by the decrease. As a result, since the inorganic filler is hardly exposed on the surface of the molded article, it is considered that a molded article having a smooth surface can be obtained regardless of the amorphous resin to which the inorganic filler is added.

In the present invention, as a method of dissolving or absorbing 0.2% by weight or more of carbon dioxide in the amorphous resin composition to which the inorganic filler is added, the amorphous resin composition in a molten state in a heating cylinder of an injection molding machine is used. A method in which carbon dioxide is mixed with an amorphous resin, a method in which resin pellets are granulated in a state in which carbon dioxide is mixed with the amorphous resin in a molten state in advance, and injection molding is performed using the granules, There is a method for absorbing carbon dioxide.

Considering the stable supply of resin to the injection molding machine and the workability during injection molding, it is generally considered that carbon dioxide is mixed with the amorphous resin in a molten state in the heating cylinder of the injection molding machine. Seem. The amorphous resin used in the present invention includes polystyrene (hereinafter, referred to as “PS”) resin, ABS resin, polycarbonate (hereinafter, referred to as “PC”) resin,
Amorphous resin mainly composed of PC / ABS resin, polyphenylene ether (hereinafter referred to as “PPE”) resin, etc., and one kind of resin alone or one kind of amorphous resin It refers to a mixture obtained by mixing resins having different properties as described above. For example, a modified PPE (hereinafter, referred to as “mPPE”) resin alloyed with another thermoplastic resin and modified is considered as the PPE resin.

The amorphous resin used in the present invention has a high heat resistance temperature, a non-halogen flame retardant property, a small molding shrinkage, a high resistance to acids and alkalis, and is excellent in molding processability. It is preferable to use a PPE-based resin because it is excellent in reworkability. The PPE
MPPE containing 20 parts by weight or more of a PPE component with respect to 100 parts by weight of a resin component excluding an inorganic filler.
It is preferably a resin. This is because the PPE component is 2
If the mPPE resin is less than 0 parts by weight, P
It is not preferable because characteristics of the PE resin hardly occur.

The resin having different characteristics which can be used by mixing with the above-mentioned amorphous resin as the main component is a resin having the same molecular structure as the amorphous resin as the main component, Resins having different molecular weight distributions or other resins having different molecular structures may be used. Also, if necessary,
It is also possible to mix two or more resins having different properties.

The other resin that can be used by being mixed with the above-mentioned amorphous resin as the main component is not particularly limited as long as it is compatible with the amorphous resin as the main component. , Polyethylene, polyacetal, polypropylene, polystyrene, ABS resin, polyvinyl chloride, polyamide, polycarbonate, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyimide, polyamideimide, polyetherimide, polyarylate, polysulfone, polyether Examples thereof include sulfone, polyetheretherketone, liquid crystal polymer, polytetrafluoroethylene, thermoplastic elastomer, polytetrafluoroethylene, and polyvinyl alcohol.

The amorphous resin according to the present invention is characterized by adding an inorganic filler. Preferred fillers include glass fiber, carbon fiber, metal fiber, aramid fiber, and the like.
Potassium titanate, asbestos, silicon carbide, ceramic, silicon nitride, barium sulfate, calcium sulfate, kaolin, clay, pyrophyllite, bentonite, sericite, zeolite, mica, mica, nepheline cinite, talc, atalpargite, water Last night,
Slag fiber, ferrite, silicon, calcium, calcium carbonate, magnesium carbonate, dolomite, zinc oxide,
Filling enhancers such as gypsum, glass beads, glass powder, glass balloons, quartz, quartz glass, and alumina can be used, and these may be hollow. In addition, two or more of these inorganic fillers can be used in combination. Further, if necessary, it can be used after being pre-treated with a coupling agent such as a silane-based or titanium-based coupling agent.

The amorphous resin according to the present invention is characterized in that an inorganic filler is added. The amount of the inorganic filler is preferably more than 5% by weight. 5 added
When the amount is less than the weight%, the effect of improving the rigidity and the dimensional accuracy by the inorganic filler is weak, and resin is easily foamed at the flow front when the molten resin is filled into the mold cavity. Not preferred. In the present invention, the added amount of the inorganic filler refers to the amount added when one kind of inorganic filler is added, and refers to the total added amount when two or more kinds of inorganic filler are added. Further, the added amount of the inorganic filler indicates a ratio when the total amount of the resin, the inorganic filler, and other additives is 100% by weight.

The amorphous resin of the present invention may contain additives usually used, such as antioxidants, flame retardants, release agents,
One or more lubricants, heat stabilizers, weathering stabilizers, rust preventives, fillers, coloring agents, antibacterial agents, antifungal agents and the like can be added as required. Further, by selecting one or more of carbon fiber, metal fiber, and graphite as other additives, the electric resistance value of the crystalline resin can be reduced. This is preferable because it is possible to prevent small powder such as dust from adhering to the amorphous resin molded product due to static electricity.

In the present invention, the method for producing an amorphous resin refers to a method for molding and processing a thermoplastic resin. In addition to a commonly used injection molding method, a hollow injection molding method, a gas assist molding method, a blow molding method, and an injection molding method. -Includes compression molding. In the present invention, after dissolving or absorbing carbon dioxide in the amorphous resin, it is preferable that the carbon dioxide is injected into a mold cavity at substantially atmospheric pressure without pressurizing the inside of the mold cavity in advance. This is because it is not necessary to hermetically seal the mold, so that it is easy to cope with a molded article having a complicated shape, and to suppress the filling pressure from being hindered by the pressurized gas from increasing the filling pressure.

In the present invention, the amount of carbon dioxide absorbed or dissolved is measured by the following procedure. Carbon dioxide is absorbed or dissolved in a resin in a pellet state or a molten state. Immediately after the molding, the weight of the molded article is measured (M1). The molded product is left in a hot-air dryer kept at 100 ° C. for 48 hours or more to emit carbon dioxide. Measure the weight immediately after taking it out of the hot air dryer (M
2). CO2 absorption or dissolved amount (% by weight) = (M1-M
2) Calculate from ÷ M2 × 100.

The molded article satisfactorily molded by the present invention includes inorganic parts such as internal parts typified by housings of optical equipment parts, light electric equipment, electronic equipment, office equipment, etc., various parts of automobile interior and exterior, and various daily necessities. It is an amorphous resin molded product to which an agent is added. Particularly preferably, an electronic device that is injection-molded at a multipoint gate, resulting in a large number of weld lines,
Electrical equipment, housing for office equipment, automobile exterior parts, motorcycle exterior parts, etc., which are mostly composed of thin parts. In addition to facilitating molding, the quality of molded products is improved.
The realization of an injection-molded product made of a resin composition, which could not be realized until now due to an increased degree of freedom in product design and a high viscosity during melting, can be expected.

Hereinafter, the effects of the present invention will be further described with reference to Examples and Comparative Examples. The resin used for the injection molding was a glass fiber reinforced ABS resin (“Stylac-ABS R240A (added with 20% glass fiber)” manufactured by Asahi Kasei Corporation) and a non-reinforced mPPE resin (“Xylon” manufactured by Asahi Kasei Corporation) 600H "), glass fiber reinforced mPPE resin (" Xylon G701H (10% glass fiber added) ", G702H (20%), G7 manufactured by Asahi Kasei Corporation
03H (30%), non-reinforced PPE / PA resin ("Zylon A0501" manufactured by Asahi Kasei Corporation), glass fiber reinforced PPE / PA resin ("Zylon AG511 (glass fiber 10% additive))). In addition, a non-reinforced mPPE resin and a glass fiber reinforced mPPE resin were appropriately mixed to granulate a 3% glass fiber added product and a 5% glass equivalent product. Both are in the form of pellets before molding.

As the molding machine, "TUPARL TR50S2" manufactured by Sodick Plustech and "SG125-HP" manufactured by Sumitomo Heavy Industries, Ltd. were used. The mold used was an ISO dumbbell-shaped mold as shown in FIG. 1 and a mold having a square base as shown in FIGS. 2 and 3 and four bosses provided on the base. . When using an ISO dumbbell mold, TR50S2 was used as a molding machine. The ISO dumbbell mold has a structure conforming to the ISO standard.

The product part of the flat mold with boss is 100 pieces in length and width.
mm and a thickness of 2.5 mm. For molding using this mold, SG125-HP was used as a molding machine. In the flat plate mold with boss, a film gate having a thickness of 1 mm was provided on one side of the square, and the cavity surface was a mirror surface. Unless otherwise specified, the cylinder temperature during injection molding was 220 ° C. when molding ABS resin, and 280 ° C. when molding mPPE resin and PPE / PA resin. Unless otherwise specified, the mold temperature is 60 ° C. when molding ABS resin and mPPE resin.
The temperature was set to 80 ° C. when molding the PPE / PA resin. For the same resin, the setting of the cylinder temperature and the mold temperature was basically the same for the GF reinforced grade and the non-reinforced grade.

[0036]

Examples 1 to 5 After dissolving carbon dioxide gas in the molten resin in the plasticizing section from the gas injection section provided in the plasticizing section of the molded product at the center of the plasticizing section of the TR50S2 molding machine,
Injection molding was performed to obtain an ISO dumbbell-shaped molded product.
Using glass fiber reinforced mPPE resin (glass fiber 30% additive), the dissolved amount of carbon dioxide is 0.22% by weight,
0.35% by weight, 0.50% by weight, 0.75% by weight,
Carbon dioxide gas was supplied from the plasticizing section of the molding machine so as to be 1.2% by weight, and injection molding was performed.

The filling pressure at the time of injection molding was measured by reading a resin pressure measurement value of a molding machine. After the injection molding, the surface roughness was measured at three places (A, B, C) shown in FIG. The surface roughness was measured using a surface roughness measuring device “Surfcom 575A” manufactured by Tokyo Seimitsu Co., Ltd.
0601-1995, the arithmetic average roughness Ra (μ
m) and the maximum height Ry (μm) value were measured, and this value was used as the value of the surface roughness. Table 1 shows the results.

[0038]

Comparative Examples 1 to 3 An ISO dumbbell-shaped molded product having the same shape as that of Examples 1 to 3 was prepared by using a glass fiber reinforced mPPE resin (a product containing 30% of glass fiber) and using a plasticizer from a plasticizing section of a molding machine. No carbon gas was supplied, and the cylinder temperature was set at 280 ° C., 300 ° C., and 320 ° C., and a molded product was obtained in the same process as ordinary injection molding. As in Examples 1 to 5, the filling pressure during injection molding and the surface roughness of the molded product were measured.
Table 1 shows the results.

[0039]

Comparative Examples 4 and 5 As in Examples 1 to 5, TR50S2
After dissolving carbon dioxide gas in the molten resin in the plasticized part from the gas injection part provided in the plasticized part of the molded product at the center of the plasticized part of the molding machine, injection molding is performed to form an ISO dumbbell-shaped A molded product was obtained. Using a glass fiber reinforced mPPE resin (30% glass fiber added), carbon dioxide gas is supplied from the plasticizing section of the molding machine so that the dissolved amount of carbon dioxide becomes 0.06% by weight and 0.18% by weight. Then, injection molding was performed. As in Examples 1 to 5, the filling pressure during injection molding and the surface roughness of the molded product were measured. Table 1 shows the results.

[0040]

Examples 6-9 As in Examples 1-5, carbon dioxide was introduced into the molten resin in the plasticizing section from the gas injection section provided in the plasticizing section of the molded product at the center of the plasticizing section of the TR50S2 molding machine. After dissolving the gas, injection molding was performed to obtain a molded product having an ISO dumbbell shape as shown in FIG. Using glass fiber reinforced mPPE resin (glass fiber 5% added equivalent, 10% added, 20% added, 30% added) so that the dissolved amount of carbon dioxide becomes 0.35% by weight Then, carbon dioxide gas was supplied from the plasticizing section of the molding machine to perform injection molding. As in Examples 1 to 5, the filling pressure during injection molding and the surface roughness of the molded product were measured. Table 2 shows the results.

[0041]

Comparative Examples 6 and 7 As in Examples 6 to 9, carbon dioxide was introduced into the molten resin in the plasticizing section from the gas injection section provided in the plasticizing section of the molded product at the center of the plasticizing section of the TR50S2 molding machine. After dissolving the gas, injection molding was performed to obtain a molded product having an ISO dumbbell shape. Using a non-reinforced mPPE resin and a glass fiber reinforced mPPE resin (equivalent to adding 3% glass fiber), carbon dioxide gas was supplied from the plasticizing section of the molding machine so that the dissolved amount of carbon dioxide was 0.35% by weight. Supplied and injection molded. In the same manner as in Examples 6 to 9, the filling pressure during injection molding and the surface roughness of the molded product were measured. Table 2 shows the results.

[0042]

Examples 10 to 13 Glass fiber reinforced ABS resin (with 20% glass fiber added) and glass fiber reinforced mPPE resin (with 20% glass fiber added) were each dried at 80 ° C. for 4 hours in a hot air drier. Then, the mixture was transferred to a closed container at 23 ° C., and the pressure in the container was reduced to 1 hPa or less.
The reactor was filled with carbon dioxide at 0.08 MPa, and allowed to stand for 24 hours while keeping the pressure constant. The amount of carbon dioxide absorbed by the resin obtained from the difference in resin weight after drying and after being left in a carbon dioxide atmosphere was 1.3% by weight and 3.8% by weight in the case of glass fiber reinforced ABS resin. And 5.4 wt% and 7.2 wt% in the case of glass fiber reinforced mPPE resin.

The carbon fiber-absorbed glass fiber reinforced ABS resin and glass fiber reinforced mPPE resin are injection-molded using the TR50S2 molding machine in the same process as in the usual manner to obtain an ISO dumbbell-shaped resin as shown in FIG. A molded product was obtained. The filling pressure and the surface roughness of the molded product during injection molding were measured.
Table 3 shows the results.

[0044]

Comparative Examples 8 and 9 Glass fiber reinforced ABS resin (with 20% glass fiber added) and glass fiber reinforced mPPE resin (with 20% glass fiber added) were each dried in a hot air drier at 80 ° C. for 4 hours. Then, the mixture was transferred to a closed container at 23 ° C., and the inside of the container was reduced under a reduced pressure of 1 hPa or less, and then left for 24 hours while keeping the pressure constant. This glass fiber reinforced mP
The PE resin was subjected to injection molding using the TR50S2 molding machine in the same process as usual to obtain a molded product having an ISO dumbbell shape as shown in FIG. The filling pressure and the surface roughness of the molded product during injection molding were measured. Table 3 shows the results.

[0045]

Examples 14 to 16 Glass fiber reinforced P in molten state
0.25 wt%, 0.45 wt%, 0.60 wt% in PE / PA resin (glass fiber 10% additive)
After kneading carbon dioxide so as to obtain, using the granulated resin pellets, T
Injection molding was performed using an R50S2 molding machine to obtain an ISO dumbbell shape as shown in FIG. The filling pressure and the surface roughness of the molded product during injection molding were measured. Table 4 shows the results.

[0046]

Comparative Example 10 Injection molding of a glass fiber reinforced PPE / PA resin (glass fiber 10% added product) was carried out using the TR50S2 molding machine in the same process as ordinary injection molding.
An ISO dumbbell shape as shown in FIG. The filling pressure and the surface roughness of the molded product during injection molding were measured. Table 4 shows the results.

[0047]

Comparative Examples 11 and 12 Carbon dioxide was kneaded with non-reinforced PPE / PA resin and glass fiber reinforced PPE / PA resin (glass fiber 10% added product) so that the added amount was 0.15% by weight. Thereafter, using the granulated resin pellets, an ISO dumbbell shape as shown in FIG. 1 was obtained in the same process as in normal injection molding. The filling pressure and the surface roughness of the molded product during injection molding were measured. Table 4 shows the results.

[0048]

Embodiments 17 to 20 Using a glass fiber reinforced mPPE resin (30% glass fiber added), a SG125-HP molding machine was provided at the center of the plasticizing section of the plasticizer from the gas injection section provided in the plasticizing section of the molded article. The amount dissolved in the molten resin in the plasticizing section is
0.22% by weight, 0.50% by weight, 0.75% by weight,
After dissolving the carbon dioxide gas so as to have a concentration of 1.2% by weight, injection molding was performed to obtain a boss-shaped flat molded product as shown in FIG.

The filling pressure at the time of injection molding was measured by reading a resin pressure measurement value of a molding machine. After the injection molding, the surface roughness was measured at three points (A, B, C) shown in FIG. The surface roughness was measured using a surface roughness measuring device “Surfcom 575A” manufactured by Tokyo Seimitsu Co., Ltd.
0601-1995, the arithmetic average roughness Ra (μ
m) and the maximum height Ry (μm) value were measured, and this value was used as the value of the surface roughness. FIG. 3 shows a view of the flat product with bosses shown in FIG. 2 as viewed from the back. At point D shown in FIG. 3, the amount of sink marks generated on the back side of the boss was measured using the above-mentioned surface roughness measuring device. Table 5 shows the measurement results.

[0050]

Comparative Example 13 In the same manner as in Examples 17 to 20, a glass fiber reinforced mPPE resin (glass fiber 30% added product) was used.
From the gas injection part provided in the plasticizing part of the molded product at the center of the plasticizing part of the SG125-HP molding machine, the carbon dioxide is dissolved so that the amount dissolved in the molten resin in the plasticizing part becomes 0.15% by weight. After dissolving the carbon gas, injection molding was performed to obtain a boss-shaped flat molded product as shown in FIG. Example 1
As in the case of 7 to 20, the filling pressure, surface roughness, and sink mark during injection molding were measured. Table 5 shows the measurement results.

[0051]

Comparative Examples 14 to 16 In the same manner as in Examples 17 to 20, using a glass fiber reinforced mPPE resin (30% glass fiber added), using a SG125-HP molding machine, a flat plate with a boss as shown in FIG. A shaped article was obtained. The mold temperatures were 60, 80, and 100 ° C., respectively. Examples 17 to 20
In the same manner as in the above, the filling pressure, surface roughness, and sink mark during injection molding were measured. Table 5 shows the measurement results.

[0052]

[Table 1]

[0053]

[Table 2]

[0054]

[Table 3]

[0055]

[Table 4]

[0056]

[Table 5]

[0057]

The method of the present invention improves the moldability, flowability and dimensional stability of an amorphous resin composition to which an inorganic filler has been added, suppresses deformation such as warpage and sink mark, and improves the amorphous resin composition. The exposure of the inorganic filler added to the article to the surface of the molded article is suppressed.

[Brief description of the drawings]

FIG. 1 shows an ISO dumbbell shape of the present invention.

FIG. 2 shows the shape of a flat plate with a boss of the present invention.

FIG. 3 shows the back surface of the flat plate with a boss of the present invention.

[Description of Signs] 1 ISO dumbbell 2 Flat plate with boss 3 Boss

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[Procedure amendment]

[Submission date] May 9, 2000 (200.5.9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction contents]

[0010] On the other hand, polyphenylene ether resin is an amorphous resin having excellent flame retardancy. However, since the viscosity at the time of melting is high, modified polyphenylene ether resin alloyed with polystyrene or the like is used as a usual molding material. It is common that Modified polyphenylene ether resin with a large percentage of polystyrene has reduced flame retardancy,
Also, for further improvement in flame retardancy, Ru need to add a flame retardant as required.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

[0032] The present invention in good molded article is molded, the optical equipment parts, light electrical appliances, electronic equipment, office equipment housings Representative is Ru parts articles such as, the parts of the car interior and exterior, inorganic filler and various household goods It is an amorphous resin molded product to which an agent is added. Particularly preferably, in electronic equipment, electrical equipment, office equipment housing, which is injection-molded at a multipoint gate, resulting in a large number of weld lines, automobile exterior parts, motorcycle exterior parts, etc., which are mostly composed of thin parts. is there. In addition to ease of molding, the quality of molded products is improved, the degree of freedom in product design is increased, and the high viscosity at the time of melting cannot be realized until now. .

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Claims (6)

[Claims] 1. A method for producing a molded article of an amorphous resin composition to which an inorganic filler is added, wherein 0.2% by weight or more of carbon dioxide is dissolved or absorbed in the amorphous resin composition. A method for producing a molded article of an amorphous resin composition to which an inorganic filler is added, wherein the molded article is injected into a mold cavity. 2. The amorphous resin composition according to claim 1, wherein the amount of the inorganic filler added to the amorphous resin is 5% by weight or more. Manufacturing method of molded article. 3. The method according to claim 1, wherein 0.2% by weight or more of carbon dioxide is mixed with the amorphous resin in a molten state in a heating cylinder of an injection molding machine and then injected into a mold cavity. Or a method for producing a molded article of an amorphous resin composition to which the inorganic filler according to 2 is added. 4. An amorphous resin composition to which an inorganic filler has been added according to claim 1 or 2, which is injection-molded using a resin pellet that has absorbed 0.2% by weight or more of carbon dioxide. Method for manufacturing molded articles. 5. An injection molding method using resin pellets granulated in a state where 0.2% by weight or more of carbon dioxide is mixed with the amorphous resin in a molten state. A method for producing a molded article of an amorphous resin composition to which the inorganic filler described in 1 is added. 6. The amorphous resin composition according to claim 1, wherein the amorphous resin is a polyphenylene ether resin containing at least a polyphenylene ether component. Method for manufacturing molded articles.