JPH1170560A - Extrusion molding method for specifically orienting fibrous reinforcing material, and molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance strength or rigidity in both of an extrusion direction and an orthogonal direction by rapidly cooling and solidifying the molten resin extruded from a diffusion die having a shape expanded toward a die outlet opening part. SOLUTION: A compsn. of a thermoplastic resin and a fibrous reinforcing material is melted and kneaded in an extruder to be extruded from a diffusion die 2 and the molten extrudate is corrected in its shape by the sizing die arranged in a cooling water tank to be rapidly cooled and solidified by cooling water. A resin passage 6 is formed to the diffusion die 2 and a resin passage 8 expanded toward its opening part 7 is formed to the diffusion die 2 from the resin passage 6. The expanding angle of the diffusion die 2 is set to θ and the orthogonal orientation of the fibrous reinforcing material increases as the angle θ becomes large but the angle is set to about 90±10 deg.. After the short sizing die, the extrudate is cooled and solidified in a water tank renewing a contact surface frequently. The inlet inner diameter dimension of the sizing die is made same to or slightly larger than the outlet inner diameter dimension of the diffusion die 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a molding method for obtaining an extruded product used under a condition where a large load is applied also in a direction perpendicular to the extrusion direction (hereinafter sometimes referred to as a "width direction"). It relates to molded articles obtained therefrom. Specifically, it can be used for applications where both ends are fixed in the width direction of an extruded product, such as a heat insulating spacer for an aluminum sash. Further, by applying this method, the load bearing strength of a pipe or the like can be improved by orienting the fibrous reinforcing material in the circumferential direction.

[0002]

2. Description of the Related Art A heat insulating spacer, which is a shaped material for heat insulating windows made of a polyamide resin, and a method for producing the same are described in Kunststoffe 74-7, p.
Introduced as rprofile aus Polyamid. By the way, windows are parts that weaken the thermal insulation of buildings and houses. Therefore, from the 1970s, due to legal regulations such as the West German Insulation Standard and DIN, sashes consisting of aluminum with poor insulation properties were replaced by aluminum sash members and the above-mentioned heat-insulating spacers, especially in Europe, especially in regions with high latitudes. Insulating sashes that integrate the above have been used. In this heat insulating sash, since the heat insulating spacer is sandwiched between the aluminum sash members in the width direction, direct heat flow through the aluminum sash having a high thermal conductivity in the conventional sash is prevented. A window using this heat insulating sash can be made thinner than a double window and has a higher heat insulating effect than double glass.

[0003] In Japan, double glazing has been used for a long time, especially in regions with high latitudes. However, in recent years, as the number of houses with high airtightness that has improved sound insulation and heating efficiency has increased, the above-mentioned insulating sash has become increasingly popular. Became heavily used.

By the way, the conventional sash shape is mainly simple for general houses and buildings. However, sashes with complicated shapes, such as sashes for bay windows or sashes in which a shutter guide, multiple curtain rails and the like are integrally formed, have been used in recent years. As a result, the load applied to both ends in the width direction of the heat insulating spacer constituting the heat insulating sash has increased. In particular, while demand for buildings is also expected from the viewpoint of energy saving, a larger width of the heat insulating spacer of a large heat insulating sash for a building, which is heavily loaded on the outside, has been required.

However, since most of the current spacer parts are obtained by extrusion molding, the rigidity and strength in the width direction are small and cannot be used for large-sized sashes to which a large load is applied in the width direction. In the above-mentioned document, one condition that the window frame portion having a length of 6 m is not largely bent is described. However, this can be understood as describing the rigidity in the extrusion direction. In fact, in a large sash that requires high rigidity and strength in the extrusion direction, a reinforced thermoplastic resin composition containing glass fibers added in an amount of 25% by weight or more of the entire composition is used. By the way, when a reinforcing material such as glass fiber is used, the difference between the strength and rigidity in the extrusion direction and the orthogonal direction of the resin composition is generally large, and in extreme cases, the rigidity in the orthogonal direction is the same as in the case of a non-reinforced product of the same material. The rigidity in the orthogonal direction is almost the same, and there is no effect of the reinforcing material.

As a solution, attempts have been made to increase the strength and rigidity in the orthogonal direction by orienting a reinforcing material such as glass fiber in the direction orthogonal to the extrusion direction of the resin composition. For example, in molding a heat insulating spacer, a continuous injection molding method from the lateral direction has been studied, but it has not been used much because a knot is formed at a molding end and productivity is extremely poor. Recent technologies include British Patent 8
No. 9-00434, Plastic Age 199
There is the SCOREX system introduced in the March 2013 issue.
This is a method in which a resin containing glass fibers or the like is alternately extruded in a die in a direction perpendicular to the extrusion direction, and the glass fibers or the like in the resin can be strongly oriented in a direction perpendicular to the extrusion direction. However, because the resin is extruded using the piston mechanism, the inflow of the resin is intermittent, and in the case of a profile extruded product such as a heat insulating spacer, uniformity may be impaired, and the production speed is increased. There is a drawback that there is no such thing, production equipment may be expensive, and economic efficiency is impaired.

Further, when molding a glass fiber reinforced thermoplastic resin composition, if the composition is allowed to flow from a narrow location to a wide location, the flow of the resin composition becomes slower as the location becomes farther from the location where the resin flowed out. an internal glass fibers Tsuneo Hirai be oriented in the direction perpendicular to the extrusion direction, etc., "material", 34, 2
56 (1985), and confirmed inside the actual molded article. However, the orthogonal orientation obtained here returns to the extrusion direction again because the flow is restricted by the wall surface with the mold when determining the shape of the molded article thereafter. Also,
When the resin composition is flowed from a narrow place to a wide place, the flow speed becomes slow, so that the pressure near the wall surface cannot be sufficiently secured, and the shape and dimensions of the molded article tend to be impaired.

[0008]

SUMMARY OF THE INVENTION The present invention provides a method which overcomes the problems encountered in the prior art when extruding a composition of a thermoplastic resin and a fibrous reinforcement.

[0009]

That is, the present invention relates to a method for producing a molded article by extruding a composition comprising a thermoplastic resin and a fibrous reinforcing material through a molding die and then through a sizing die. Is a diffusion die having a shape spreading toward the die outlet opening, and a method for extrusion-molding a molded article characterized by rapidly cooling and fixing the molten resin extruded from the diffusion die, and molding obtained therefrom. It is about goods.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. Examples of the thermoplastic resin that can be used in the present invention, polystyrene resin, polyolefin resin, polyurethane resin, polyester resin, polyamide resin,
Examples thereof include 1,2-polybutadiene-based resin, vinyl chloride-based resin, fluorine-based resin, polyoxymethylene-based resin, and polyphenylene sulfide-based resin. Among these, polyolefin resins, polyester resins, polyamide resins, polyphenylene sulfide resins are preferably used, polyolefin resins, polyester resins, polyamide resins are more preferably used, and polyamide resins are particularly preferably used. You.

Examples of the polyolefin-based resin include polyethylene, polypropylene and copolymers thereof.

Examples of polyester resins include polyethylene terephthalate and polybutylene terephthalate.

Examples of the polyphenylene sulfide resin include polyphenylene sulfide.

Examples of polyamide resins include lactam polymers such as polycaprolactam and polylaurolactam; aminocarboxylic acid polycondensates such as 6-aminocaproic acid, 11-aminoundecanoic acid and 12-aminododecanoic acid; Polycondensates of alkylenediamines and dicarboxylic acids such as methylene adipamide, polyhexamethylene dodecamide, polyhexamethylene terephthalamide, copolymers of hexamethylene adipamide / hexamethylene terephthalamide, hexamethylene adipamide / Examples thereof include semi-aromatic polyamides such as a copolymer of hexamethylene isophthalamide, but are not particularly limited. However, if there is a heat treatment such as baking after the combination with the metal portion, a material having a melting point of 250 ° C. or more, such as polyhexamethylene adipamide, is preferable. In order to maintain sufficient moldability, an appropriately slow solidification behavior is preferable, and polycaprolactam is more preferable than polyhexamethylene adipamide. Furthermore, when imparting a function such as surface smoothness, it is desirable to use a copolymer of a plurality of polyamide components.

[0015] The fibrous reinforcing material used in the present invention includes glass fibers, boron fibers, metal fibers, wollastonite, carbon fibers, potassium titanate whiskers, fibrous basic magnesium sulfate, zonotrite, etc. The same effect can be expected as long as it has a ratio, but glass fiber is most preferable. The amount of the fibrous reinforcement added is preferably 15% by weight or more of the composition. The upper limit of the amount added is not particularly limited, but is preferably substantially 45% by weight or less of the composition. A more preferred addition amount is 15 to 40% by weight. When the amount is less than 15% by weight, satisfactory mechanical strength in the orthogonal direction tends to be hardly obtained.
If the amount is more than 5% by weight, sufficient strength in the orthogonal direction can be maintained, but the surface state tends to deteriorate, which is not preferable. The method of adding the reinforcing material is usually a sufficient method and is not particularly limited. However, it is preferable to mix the fibrous reinforcing material into the melted thermoplastic resin to minimize the cutting thereof in order to increase the strength of the molded product in the direction perpendicular to the extrusion direction.

The extrusion molding method of the present invention will be described based on one embodiment shown in FIG. A composition of a thermoplastic resin and a fibrous reinforcing material is melt-kneaded in an extruder 1 and then extruded through a diffusion die 2. The shape of the molten extrudate is corrected by a sizing die 4 installed in the cooling water layer 3, and the molten extrudate is rapidly cooled by the cooling water and solidified. The solidified molded product is taken up by two pairs of take-up rolls 5 and is subjected to cutting and other post-processing steps (not shown).

An example of a diffusion die used in the present invention is shown in FIGS. FIG. 2 is a front view of the diffusion die, and FIG. 3 is a sectional view taken along line AA ′ of FIG. A resin passage 6 and a resin passage 8 extending from the resin passage 6 toward the opening 7 of the diffusion die 2 are formed in the diffusion die 2. The spread angle of the resin passage 8 with respect to the resin passage 6 as indicated by θ in FIG. 3 is defined as the angle of the diffusion die. The larger the angle θ of the diffusion die, the better the orthogonal orientation of the fibrous reinforcement. The angle θ of the diffusion die is generally from 60 degrees or more to 180 degrees.
Degrees, and for maintaining the shape of the molten composition, 90
± 10 degrees is most preferred. If the angle θ of the diffusion die is smaller than 60 degrees, it is difficult to obtain a sufficient orientation of the fibrous reinforcing material. Further, even if the angle θ of the diffusion die is set to 180 ° or more, it is practically meaningless considering the flow of the resin.

There is no particular limitation on the method of rapidly cooling and solidifying the molten extrudate whose shape has been modified by the sizing die 4. However, in order to keep the orientation of the fibrous reinforcing material in the resin coming out of the diffusion die 2, it is preferable to solidify the resin quickly, and it is desirable that the resin has excellent cooling efficiency. Although a metal die of a water cooling type can be used, a water tank cooling type in which the contact surface is frequently renewed, which is cooled in the water tank 3 after a short sizing die 4 as shown in FIG. 1, is preferable. . For this reason, it is effective to set the cooling water temperature as low as possible.
It is preferably at most 60 ° C, more preferably at most 25 ° C, particularly preferably at most 10 ° C.

The inner diameter of the inlet of the sizing die 4 is preferably equal to or slightly larger than the inner diameter of the outlet of the diffusion die 2. If the difference between the two dimensions is too large, pressure is not applied to the surface of the molded product in a molten state, and surface smoothness is impaired. Therefore, the difference between the two dimensions is generally within 1.0 mm, preferably within 0.5 mm, particularly preferably within 0.3 mm. If the entrance inner diameter of the sizing die 4 is smaller than the diffusion die 2, the sizing die 4
The flow of the resin composition used in the portion is reduced, so that the orthogonal orientation of the fibrous reinforcing material is returned to the extrusion direction, and the characteristics in the orthogonal direction are deteriorated. Further, if the sizing die 4 having the same shape of the entrance has a structure in which the dimensions are narrowed inside, the characteristics in the orthogonal direction are reduced due to the same influence.

The distance between the exit of the diffusion die 2 and the entrance of the sizing die 4 also depends on the extrusion speed and solidification characteristics of the resin composition. If this distance is excessively large, the fibrous reinforcing material oriented in the orthogonal direction will be used. Are reoriented in the extrusion direction, and the mechanical properties in the orthogonal direction of the molded article tend to decrease. Therefore, the above distance is generally 100 mm or less, preferably 30 mm or less, more preferably 20 mm or less, particularly preferably 8 mm or less.

The diffusion die 2 and the sizing die 4 may be directly connected. In this case, it is important to sufficiently cool the sizing die 4 in order to fix the orientation of the fibrous reinforcing material. For this purpose, it is necessary to ensure sufficient heat insulation of the directly connected portion to prevent heat from flowing from the diffusion die 2 to the sizing die 4, and to reduce the area of the contact portion and to make the joint portion used highly heat-insulating. It is necessary to use a material such as a hard low-foam resin molded product or glass.

The lower the extrusion speed at the time of molding, the higher the orthogonal orientation of the fibrous reinforcement and the easier it is to secure the shape and dimensions.
It is preferable to select an optimum speed in consideration of productivity. The value is usually at most 6 m / min, preferably at most 3 m / min, more preferably at most 2 m / min, particularly preferably at most 1.5 m / min. Want to be more productive?
By using a multi-cavity diffusion die having a plurality of diffusion dies and thereafter, a molded product with improved characteristics in the orthogonal direction can be obtained. In this case, it is desirable that the diffusion die portions be thermally independent of each other.

As the extruder 1 to be used, a single-screw, twin-screw or multi-screw screw type is sufficient, but a model capable of pressure-controlled extrusion or a model capable of constant-speed extrusion is desirable. Although a take-off machine (not shown) may be a usual one, it is desirable that the speed can be controlled in conjunction with the extruder so that the take-up can be performed while applying an appropriate pressure to the sizing die.

In the molded article obtained by the present invention, the fiber reinforcing material is oriented in a direction perpendicular to the extrusion direction. The degree of orientation of the fibrous reinforcing material (hereinafter, sometimes referred to as “orientation ratio”) can be specified by various methods. In this specification, a microscopic X-ray observation method of a cross section sliced in the orthogonal direction is used. That is, the orientation ratio of the fibrous reinforcing material is 70 to 70 per unit area of the sample taken by microscopic X-ray photography with respect to the extrusion direction.
It was determined as a ratio of the number of fibrous reinforcements oriented at 110 degrees to the total number of all fibrous reinforcements.

As the orientation ratio of the fibrous reinforcing material in the molded article increases, mechanical properties such as bending strength and flexural modulus of the molded article in a direction perpendicular to the extrusion direction, that is, in the width direction, are improved. You. Generally, it is preferable to adjust conditions such as the extrusion rate of the composition, the angle θ of the diffusion die, and the cooling rate so that the orientation rate of the fibrous reinforcing material is 10% or more. As an example, when using glass fiber,
By orienting the fibrous reinforcing material in the orthogonal direction by 10% or more, the bending strength and the elastic modulus in the orthogonal direction can be improved, and the characteristics required as a heat insulating spacer for a long time can be secured.

Other additives may be added to the composition used in the present invention as long as the effects of the present invention are not impaired. Examples of the additives include a plasticizer, an antioxidant, an ultraviolet absorber, an antistatic agent, a flame retardant, a colorant for plastics, a lubricant, and a fungicide for plastics. In particular, by adding a component having a lower melting point and / or a smaller molecular weight than the resin material used, the surface smoothness can be increased, the dimensional accuracy can be improved, and the extrusion pressure during molding can be reduced. In addition, by extruding oil such as turbine oil in advance, or by applying the oil at the exit of the diffusion die, extrudability can be improved, and these characteristics can be further improved.

[0027]

The present invention will be described more specifically with reference to the following examples and comparative examples. In the following Examples and Comparative Examples, all components used were prepared by premixing using a Henschel type mixer except for glass fibers,
The diameter is 13 μm and the length is 30 which is supplied from the beginning to a 44 mmφ co-rotating twin-screw kneader manufactured by Nippon Steel Works and is bundled in the middle.
A glass fiber having a diameter of 00 μm was charged and mixed by heating and melting. The mixed composition is pelletized and collected,
After drying, it was supplied to an extruder.

Example 1 A composition comprising 70% by weight of polyamide 6 (1022B manufactured by Ube Industries, Ltd.) and 30% by weight of glass fiber was prepared by the method shown in FIG.
A 50mmφ single screw extruder manufactured by Plastic Engineering Laboratory, which was set to a cylinder temperature of 240 ° C using an apparatus as shown in
Extruded at a speed of 1.5 m / min from a diffusion die at θ = 90 °. The extrudate was sized using a vacuum cooled sizing die 15 mm away from the extruder die lip,
The resulting mixture was cooled and solidified in a cooling water bath at a temperature of ° C to obtain a molded product having a cross section of 3 mm x 18 mm. At this time, a sizing die whose inner diameter at the entrance was 0.2 mm larger than the inner diameter at the outlet of the diffusion die was used.

Using a universal testing machine (ORIENTEC TENSILONUTM-2500), the obtained molded product is subjected to bending strength and bending elastic modulus in the extrusion direction and bending strength and bending elastic modulus in the orthogonal direction (width direction). Was measured. The molded product was extruded, adjusted for 48 hours at a temperature of 23 ° C. and a relative humidity of 65%, dried for 3 hours with a hot air drier at 120 ° C., returned to an absolutely dry state, and subjected to measurement. The measuring method of each bending elastic modulus is as follows. 1. Extrusion direction One-point support center at both ends Concentrated load 3-point bending method Specimen width 18 mm Thickness 3 mm Length 70 mm Bending fulcrum distance 50 mm Bending test speed 1.5 mm / min 2. Orthogonal direction Cantilever support free end 1 point concentrated load bending method Test piece Width 50mm Thickness 3mm Length 18mm Bending span (between support end and load application point) 11mm Bending test speed 1.0mm / min

After slicing a cross section of the molded product in the direction perpendicular to the extrusion direction with a microtome, the sliced pieces were taken with a microscopic X-ray photograph. In the obtained photograph, the number of glass fibers oriented in the direction perpendicular to the extrusion direction (width direction) per unit area is counted, and the ratio to the total number of glass fibers in the unit area is calculated. did. Table 1 shows the results.

Comparative Example 1 Example 1 was repeated except that a straight die (θ = 0 °) was used instead of the diffusion die. The results are also shown in Table 1.

[0032]

[Table 1]

Examples 2-5 Example 1 was repeated except that the distance between the diffusion die exit and the sizing die entrance (distance between dies) was changed as shown in Table 2. These results are also shown in Table 2.

[0034]

[Table 2]

Examples 6 to 8 Example 1 was repeated except that the temperature of the sizing tank was changed as shown in Table 3. The results are shown in Table 3.

[0036]

[Table 3]

Examples 9 to 12 Molding was performed under the same conditions as in Example 1 except that the extrusion speed was changed as shown in Table 4, and the obtained molded products were evaluated. The results at this time are also shown in Table 4.

[0038]

[Table 4]

Examples 13 to 15 Molding was performed under the same conditions as in Example 1 except that the angle of the diffusion die, the dimensional difference between the sizing die entrance and the dimensional difference between the diffusion die exit were changed as shown in Table 5, and the characteristics were compared. The results at this time are also shown in Table 5.

[0040]

[Table 5]

Examples 16 to 18 Example 1 was repeated except that the type of die, the type of polyamide, and the ratio of glass fiber added were changed as shown in Table 6. However, in Example 18, since the melting point of polyhexamethylene adipamide (polyamide 66) was higher than that of polycaprolactam (polyamide 6), the molding temperature was changed to 280 degrees. UBE nylon 2020B was used for polyamide 66. The results at this time are also shown in Table 6.

Comparative Examples 2 to 4 Examples 16, 17 and 18 were repeated except that a straight die (θ = 0 °) was used instead of the diffusion die. The results are also shown in Table 6.

[0043]

[Table 6]

[0044]

According to the present invention, it is possible to obtain a molded product having high rigidity and strength in a direction perpendicular to the extrusion direction.
It can be used as a profile extruded product for large insulated window frames.
In particular, since sufficient strength in the orthogonal direction can be obtained even at a low addition amount, a molded product having the required performance can be obtained using a composition having a low specific gravity and a low addition amount, which can also contribute to the weight reduction of the window frame. . In addition to the heat insulating window frame, an extruded product requiring high strength and rigidity in both the extrusion and orthogonal directions can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of the present invention.

FIG. 2 is a front view of an example of a diffusion die used in the present invention.

FIG. 3 is a top view of an A-A ′ cross section of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 2 Diffusion die 3 Cooling water layer 4 Sizing die 5 Take-up roll 6, 8 Resin passage 7 Diffusion die opening

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Kenichi Nakagawa 10 Ube Kosan Co., Ltd. Ube Chemical Plant at 1978 Kogushi, Ube City, Yamaguchi Prefecture

Claims (4)

[Claims] 1. A method for producing a molded product by extruding a composition comprising a thermoplastic resin and a fibrous reinforcing material through a molding die and then through a sizing die, wherein the molding die spreads toward a die outlet opening. What is claimed is: 1. A method for extruding a molded product, comprising: a diffusion die having a shape; and rapidly cooling and solidifying a molten resin extruded from the diffusion die. 2. The extrusion molding method according to claim 1, wherein the thermoplastic resin is a polyolefin resin, a polyester resin or a polyamide resin, and the fibrous reinforcing material is glass fiber. 3. A method for producing a molded product by extruding a composition comprising a polyamide resin and a glass fiber reinforcing material through a molding die and then through a sizing die, wherein the molding die is widened toward a die outlet opening. Wherein the molten resin extruded from the diffusion die is rapidly cooled and solidified to orient 10% or more of the glass fibers in a range of 70 to 110 degrees with respect to the extrusion direction. Extrusion molding method for molded products. 4. A molded product obtained by the extrusion molding method according to claim 1.