JP3241404B2 - Molding resin composition and method for producing the resin molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding resin composition comprising a composite material of a matrix resin composed of a thermoplastic resin and a reinforcing fiber composed of a liquid crystal resin, and a method for producing the molded product.

[0002]

2. Description of the Related Art Conventionally, molded articles made of synthetic resin having high strength and high rigidity include those obtained by mixing glass fibers with a thermosetting resin, or those made of long fiber glass in a thermoplastic resin called a stampable sheet. What is obtained by shaping the mixture etc. into a predetermined shape is known. A high-strength and high-rigidity synthetic resin using carbon fiber instead of the glass fiber is also known. Further, as a synthetic resin molded article having high strength and high rigidity in which glass fibers and carbon fibers are not mixed, as shown in JP-A-1-320128, a thermoplastic resin and a liquid crystal resin (liquid crystal polymer)
A strand obtained by extruding a composite material consisting of
There is also known one obtained by cutting into a length of ４０40 mm and extruding the obtained cut product at a temperature equal to or lower than the liquid crystal transition temperature of the liquid crystal resin. By the way, recently, it has been desired to recycle (re-mold) a synthetic resin body that has become a molded product from the viewpoint of resource protection and the like, but conventionally, when recycling a synthetic resin body having high strength and high rigidity, In particular, a fiber reinforced resin body obtained by mixing reinforcing fibers such as glass fibers and carbon fibers with a synthetic resin has been targeted.

[0003]

However, when the above-mentioned fiber reinforced resin body is re-formed, the crushed pieces obtained by crushing the fiber reinforced resin body have a reinforcing material mixed in the synthetic resin body. Since the fibers are cut short, the reinforcing fibers remain cut even in the molding material obtained by reshaping. For this reason, the remolded product obtained by recycling had to be reduced in strength and rigidity as compared with the original molded product. In view of the above, the present invention provides
An object of the present invention is to prevent the strength and rigidity of a re-formed product obtained by re-molding a high-strength, high-rigidity synthetic resin body from lowering than the original synthetic resin body.

[0004]

According to the present invention, when a thermoplastic resin is used as a matrix resin and a liquid crystal resin having a melting point higher than that of the thermoplastic resin is used as a reinforcing material, as shown in FIG. If both are heated above the melting point of the liquid crystal resin (region (c)), once melted and uniformly mixed, and molded at a moldable temperature below the melting point of the liquid crystal resin (region (b)), the room temperature region (( In a) region), it was completed by finding that the fibers of the liquid crystal resin were oriented in the molding direction in the matrix resin to obtain predetermined physical properties. That is, the molding resin composition of the present invention is a crushed piece of a composite molded article molded containing a matrix resin made of a thermoplastic resin and a reinforcing material made of a liquid crystal resin having a higher melting point than the thermoplastic resin. Containing, the crushed pieces are formed by crushing at least two types of the composite molded articles having different compounding ratios of the liquid crystal resin,
The compounding amount of the liquid crystal resin with respect to the thermoplastic resin is less than the phase inversion concentration at which the liquid crystal resin is on the matrix side,
In addition, the liquid crystal resin has a fibrillable region amount in the matrix resin in a fiber state having an aspect ratio of 3 or more.

As shown in FIG. 2, the mixing ratio between the thermoplastic resin as the matrix resin and the liquid crystal resin as the reinforcing material must be lower than the concentration at which phase inversion by the liquid crystal resin does not occur and higher than the fiberizable region. Yes, depending on the type of matrix resin and liquid crystal resin used. Here, the phase inversion means that the two components L (liquid crystal resin) and M (matrix resin), which are macroscopically phase separated, change from the Lin M type to the Min.
It means that the phase is reversed in the L-shape or the opposite direction, and the fibrillation region is a region where the liquid crystal resin has an aspect ratio of 3 or more after extrusion molding. As shown in FIG. 2, when the compounding amount of the liquid crystal resin enters the fibrillation region, the fluidity of the resin composition at the time of molding starts to decrease gradually, but the tensile strength starts to increase sharply and the phase inversion boundary starts to increase. The fluidity of the resin composition falls sharply between them. Therefore, it is understood that the compounding amount of the liquid crystal resin with respect to the matrix resin needs to be in a fibrous region below the phase inversion.

The composition of the present invention has renewable properties,
It is preferably prepared using a crushed piece of a composite molded article molded from a matrix resin composed of a thermoplastic resin and a reinforcing material composed of a liquid crystal resin having a melting point higher than that of the thermoplastic resin. It is also possible to add a thermoplastic resin material compatible with the resin or add a liquid crystal resin material to adjust the physical properties. That is, as shown in FIG. 3 (a), when molding is performed using only the pulverized powder of the composite, a molded body having substantially the original physical properties is obtained,
As shown in FIG. 3B, when a liquid crystal resin material L is added thereto,
The physical properties are improved, and when the matrix resin M is added thereto, the physical properties are reduced. Further, as shown in FIG. 3 (c), a molded product having intermediate properties can be obtained by mixing a pulverized powder of a molded product having a low content of liquid crystal resin and a pulverized powder of a molded product having a high content of liquid crystal resin. Further, as shown in FIG. 3 (d), it is also possible to add a thermoplastic resin material M which is compatible with the matrix resin or to add a liquid crystal resin material L so as to obtain a desired compounding ratio. it can. Thus, in the production method of the present invention, the compounding amount of the liquid crystal resin with respect to the thermoplastic resin includes the matrix resin composed of the thermoplastic resin and the liquid crystal resin having a melting point higher than that of the thermoplastic resin. A crushed piece from a molded product blended so as to have an area of less than a fiber can be used as a raw material, and heated to a temperature at which the liquid crystal resin has a melting point lower than the melting point and can be molded to be molded into a molded product having a desired shape. Thus, a resin molded product containing liquid crystal resin fibers is manufactured. As the matrix resin and the liquid crystal resin, two types of crushed pieces of a composite molded article formed by containing a matrix resin made of a thermoplastic resin and a reinforcing material made of a liquid crystal resin having a melting point higher than that of the thermoplastic resin are used. Using the above, a method of melt-blending this can be adopted. Two or more types of crushed pieces having different mixing ratios of the matrix resin and the liquid crystal resin can be used. Furthermore, in the process of melt-blending as a matrix resin and a liquid crystal resin, in addition to the above-mentioned crushed pieces, a thermoplastic resin material and / or a liquid crystal resin material that can be mixed with the matrix resin in the crushed pieces is replenished and melt-blended. Is preferred. It is preferable to provide a preforming step of preforming the melt-blended composition into a pellet or a plate to form a molding material, and heat-mold this into a molded product.

The first matrix resin used in the resin composition of the present invention is a mixture of a polycarbonate resin and an ABS (acrylonitrile-butadiene-styrene copolymer resin) (hereinafter simply referred to as “PC / ABS”). May be referred to). The physical properties of the polycarbonate and ABS are not particularly limited. The matrix resin is commercially available. Specific examples of commercially available products include, for example, Techniace T105 (manufactured by Sumitomo Nogatack Co., Ltd.), T-2600 (manufactured by Teijin Chemicals Limited), and Psychoroy 800 (manufactured by Ube Sycon Co., Ltd.). it can.

[0008] The second matrix resin used in the resin composition of the present invention is a mixture of a polycarbonate resin and polybutylene phthalate (PBT).
(Hereinafter sometimes simply referred to as “PC / PBT”). The physical properties of the polycarbonate and PBT are not particularly limited. The matrix resin is commercially available. Specifically, as commercially available products, for example, Zenoi 1101 (manufactured by Nippon GE Plastics Co., Ltd.) and AM
-9060 (manufactured by Teijin Chemicals Ltd.).

The third matrix resin used in the resin composition of the present invention is a mixture of polyphenylene oxide and nylon (particularly, nylon-6 (PA6) (hereinafter simply referred to as "PPO / PA"). The physical properties of the polyphenylene oxide and nylon are not particularly limited, and the matrix resin can be obtained as a commercial product, specifically, for example, Noryl GTX6006 (Nippon GE Plastics).
Co., Ltd.) and Iupiace NX-7000 (Mitsubishi Gas Chemical Co., Ltd.).

The modified polyphenylene oxide used as the fourth matrix resin used in the resin composition of the present invention is preferably a styrene-modified polyphenylene oxide (hereinafter abbreviated as M-PPO), and the above-mentioned M-PPO is used.
Is not particularly limited. The above matrix resin is
It is available as a commercial product. Specifically, as a commercial product,
For example, Noryl PX2623 (GE Plastics Japan)
Co., Ltd.), Iupiace AN-30 (Mitsubishi Gas Chemical Co., Ltd.)
And Xylon X5055 (manufactured by Asahi Kasei Corporation).

The physical properties of nylon as the fifth matrix resin used in the resin composition of the present invention are not particularly limited, but nylon-6 (PA6) is particularly preferred.
The matrix resin is commercially available. Specifically, as a commercially available product, for example, 1013B (Ube Industries, Ltd.)
And CM1017 (manufactured by Toray Industries, Inc.) and Technil C216 (manufactured by Showa Denko KK).

The physical properties of ABS (acrylonitrile-butadiene-styrene copolymer resin) which is the sixth matrix resin used in the resin composition of the present invention are not particularly limited. The matrix resin is commercially available. Specifically, as commercial products, for example, plastic MH (manufactured by Sumitomo Nogatack Co., Ltd.), Psycholac T
(Manufactured by Ube Sycon) and GR-2000 (manufactured by Denki Kagaku Kogyo).

The physical properties of polybutylene terephthalate (PBT), which is the seventh matrix resin used in the resin composition of the present invention, are not particularly limited. The matrix resin is commercially available. Specifically, as commercial products, for example, 1401 × 07 (manufactured by Toray Industries, Inc.), C
7000 (manufactured by Teijin Limited) and Planac BT-100
(Manufactured by Dainippon Ink and Chemicals, Inc.).

The physical properties of polypropylene (PP), which is the eighth matrix resin used in the resin composition of the present invention, are not particularly limited. The matrix resin is commercially available. Specifically, as commercial products, for example, H501 (manufactured by Sumitomo Chemical Co., Ltd.), J440 (manufactured by Mitsui Petrochemical Industry Co., Ltd.) and J950H (Idemitsu Petrochemical Co., Ltd.)
Manufactured).

The ninth matrix resin used in the resin composition of the present invention, polycarbonate (PC)
Is not particularly limited. The above matrix resin is
It is available as a commercial product. Specifically, as a commercial product,
For example, 141 (manufactured by Nippon GE Plastics Co., Ltd.), Panlite L1250 (manufactured by Teijin Chemicals Limited) and Iupilon S-
1000 (manufactured by Mitsubishi Gas Chemical Co., Ltd.).

The resin composition for reproduction of the present invention contains a liquid crystal resin. The liquid crystal resin has a fiber shape having an aspect ratio described later in a molded product of the resin composition, and serves as a reinforcing material for the molded product. As such a liquid crystal resin, one having a higher melting point than the above matrix resin, preferably 20
It is higher than ℃. If the melting point is lower than that of the matrix resin, the liquid crystal resin does not become fibrous in the molded product, the orientation is not constant, and sufficient strength cannot be obtained. Various conventionally known liquid crystal resins can be applied, and there is no particular limitation. Various types of liquid crystal resins are known, but those particularly preferably used in the present invention are thermoplastic liquid crystal polyesters and liquid crystal polyesteramides. Particularly preferred examples of such a material include those described below. That is

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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Here, Δni = 100. It is particularly preferable that ni of each structural formula is 4 or more. In each formula, various substituents such as halogen may be added. These are particularly preferred because they are easily melt-molded with the modified polyester of the present invention. Moreover, it is easy to make a composite fiber having high strength and high elastic modulus.

Similarly, a conventionally known liquid crystal polyesteramide can be applied, and the liquid crystal polyesteramide is not limited at all. Particularly preferred are those represented by the following structural formulas. That is

[0024]

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[0025]

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[0026]

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Here, Δni = 100 in each structural formula. It is particularly preferable that ni of each structural formula is 15 or more. In addition, various substituents such as halogen may be added to each formula. These materials have melt moldability and high strength similarly to the liquid crystal resin composed of polyarylate.

The content of the liquid crystal resin is determined in relation to the matrix resin, and the following combinations are preferred. Matrix resin (parts by weight) Compounding amount of liquid crystal resin (parts by weight) PC / ABS 30 to 97 parts 3 to 70 parts PC / PBT 40 to 98 parts 2 to 60 parts PPO / PA6 35 to 80 parts 20 to 65 parts PA6 20 to 60 parts 40-80 parts ABS 25-70 parts 30-75 parts PBT 30-90 parts 10-70 parts PP 25-98 parts 2-75 parts PC 80-98 parts 2-20 parts M-PPO 40-97 parts 3 When the amount of the liquid crystal resin is less than the lower limit, sufficient strength cannot be imparted. When the amount exceeds the upper limit, moldability of the resin composition decreases. The regenerating resin composition of the present invention may further contain, as other additives, a light stabilizer, an antioxidant, a plasticizer, and the like.

As shown in FIG. 4, the resin composition for reproduction according to the present invention uses a liquid crystal resin as a reinforcing material and a thermoplastic resin as a matrix resin, and as shown in FIG. A necessary amount of the crushed pieces alone or a suitable thermoplastic resin serving as a matrix resin and / or a liquid crystal resin serving as a reinforcing material is added thereto, and the mixture is once heated to a molten state, that is, a temperature higher than the melting point of the liquid crystal resin. It is molded or formed into a molding material in a state where orientation is imparted. Usually after extrusion molding into a strand, it is made into a molding material in the form of pellets,
Alternatively, it is extruded into a sheet. Using this molding material, the sheet material is preheated to a temperature range below the melting point of the liquid crystal resin and is moldable, and molded into a structural member or the like by press molding.
On the other hand, the pellet material is again melted by an extruder, an injection molding machine or the like to form an outer panel or the like. It is preferable that the re-melting temperature is higher than the melting point of the matrix resin and lower than the melting point of the liquid crystal resin, since the liquid crystal resin maintains a fibrous state. When a sheet material is used as the molding material, the molding sheet materials may be stacked and molded in a mold. In particular, by making the orientation directions the same or different, the characteristics of the molded article can be changed. The fibrous liquid crystalline resin composited in the molded article has an aspect ratio (ie, length / thickness) of 3 or more, preferably 10 or more. If the aspect ratio is less than 3, there is no anisotropy with respect to the strength of the molded product, and a large strength cannot be obtained in the orientation direction.

[0030]

According to the present invention, a reshaped product is obtained by using the above-mentioned shaped material as a raw material, pulverizing the material as necessary, and re-melting and re-molding according to the above-mentioned production method. The fibrous liquid crystalline resin in the remolded product thus obtained is essentially the same as that in the raw material molded product, and has an aspect ratio of 3 or more. Substantially equivalent. Such reshaped articles can also be reshaped any number of times, giving reshaped articles with substantially no loss in strength.

[0031]

[Embodiment 1] Hereinafter, the present invention will be described in detail with reference to embodiments. First, as a liquid crystal resin L, Polyplastics Co., Ltd.
Vectra A950 (aromatic polyester, liquid crystal transition temperature: about 280 ° C.), and Techniace T105 manufactured by Sumitomo Nogatack Co., Ltd. as PC / ABS as the matrix resin M. The mixture was mixed to obtain a liquid crystal resin composite material. Next, the liquid crystal resin composite material was initially extruded. The extrusion molding conditions in this case were as follows: a twin screw extruder (screw diameter: 30 mm) manufactured by Plastic Engineering Laboratory Co., Ltd. was used as the extruder, the resin temperature was 290 ° C., the screw rotation speed was 100 rpm, and the die diameter was The shear rate was set to 1700 sec ^-1 and the stretching ratio was set to 2 times.
Then, the above liquid crystal resin composite material was extruded while being stretched to obtain a strand-shaped initial molding material having a diameter of 1.4 mm for a test, and a part of the initial molding material was length: 3 mm.
To obtain an initial pellet material. Next, the initial pellet material was injection molded to obtain a liquid crystal resin composite. The injection molding conditions in this case were as follows: a 220 Ton injection molding machine manufactured by Toshiba Machine Co., Ltd. and a test piece mold were used.
It was set to 0 ° C. In this case, using the above-described injection molding machine and a spiral flow mold (semicircle having a diameter of 6 mm), the resin temperature was set to 250 ° C., and the injection pressure was set to 1000 kg / cm.
^The liquidity evaluation test was performed by setting each to ² .

Next, the liquid crystal resin composite was pulverized with a pulverizer of V-360 manufactured by Horai Co., Ltd., and the length was 3 to 4 mm.
After obtaining the crushed pieces of the above, the crushed pieces are recycled and extruded to obtain a strand-shaped recycle molding material having a diameter of 1.4 mm for a test, and a part of the recycle molding material has a length of: It was cut into 3 mm to obtain a recycled pellet material. The extrusion molding conditions in this case were the same as in the case of the initial extrusion molding. Next, a tensile test was performed on the strand-shaped initial molding material and the recycled molding material. A universal testing machine (Autograph) manufactured by Shimadzu Corporation was used as a measuring machine, and the tensile speed was set to 20 mm / min. FIG. 5 shows the results of a tensile test performed on the initial molding material and the recycled molding material.
% Of the liquid crystal resin occurs in a region exceeding%, and the tensile strengths of the two are substantially the same over the entire region of the content of the liquid crystal resin. In other words, according to the above-mentioned remolding method, a high-strength synthetic resin is remolded. Nevertheless, it was confirmed that the strength did not decrease. FIG. 6 shows the relationship between the liquid crystal resin content and the flow length ratio. It has been clarified that when the liquid crystal resin content exceeds 70%, the fluidity is extremely reduced, and it is difficult to use as a molding material. . From the above considerations, PC as a thermoplastic resin
When using / ABS, the content of the liquid crystal resin is 3 to 7
Preferably, it is within the range of 0%.

The morphological observation of the material for initial molding and the material for recycling molding by an electron microscope (SEM) revealed that when the content of the liquid crystal resin was 3%, most of the liquid crystal resin was granular and some Was fibrous. When the content of the liquid crystal resin was 4%, 6% or 8%, the liquid crystal resin was fibrous. From this result, it can be understood that when the liquid crystal resin is contained in an amount of 2 to 4% or more, the liquid crystal resin is formed into fibers and the tensile strength is improved. 40% by weight of the liquid crystal resin L is blended with respect to the matrix resin M, and melt extrusion is performed in the same manner as in Example 1 (test sample 1). Using this, the liquid crystal resin alone is added to the injection-molded and pulverized resin composition for reproduction so as to adjust the compounding amount of the liquid crystal resin to 50% by weight, and melt extrusion is performed (test sample 2). Only the matrix resin is added to the above-mentioned resin composition for reproduction so as to adjust the compounding amount of the liquid crystal resin to 30%, and the melt extrusion is performed (test sample 3). A molded product obtained by injection molding using the test products 1 and 2 was pulverized in the same manner as in Example 1 and then mixed in the same amount to adjust the compounding amount of the liquid crystal resin to 40%. Perform (Test 4). The above test product (strand)
Was carried out in the same manner as in Example 1, and the result was compared with the case where no recycled product was used (initial value). Test product 1 2 3 4 205 MPa 150 MPa 170 MPa Initial value 175 MPa 201 151 175 As is clear from this result, it is understood that almost the original physical properties are maintained even when recycled.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in state between a matrix resin and a reinforcing material of a resin composition for regeneration according to the present invention.

FIG. 2 is a view showing a change in state of a composite material exerted by a mixing ratio of a liquid crystal resin as a reinforcing material to a matrix resin in a resin composition for reproduction according to the present invention.

FIG. 3 is a diagram showing a correspondence between a preparation example of a resin composition for regeneration according to the present invention and a change in physical properties.

FIG. 4 is a view showing a recycling process of the resin composition for regeneration according to the present invention.

FIG. 5 is a graph showing the results of a tensile test on a material for initial molding and a material for recycling molding obtained in Examples.

FIG. 6 is a graph showing a liquid crystal resin content and a flow length ratio in a molded product obtained in an example.

──────────────────────────────────────────────────続 き Continuation of front page (51) Int.Cl. ⁷ Identification symbol FI // C08L 67:00 C08L 67:00 (56) References JP-A-62-116666 (JP, A) JP-A-2-84466 (JP, A) JP-A-1-141025 (JP, A) JP-A-3-24911 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29B 9/12 B29B 11 / 16 B29B 15/08 B29C 47/00-47/96 C08J 3/20

Claims (8)

(57) [Claims] 1. A crushed piece of a composite molded article formed by containing a matrix resin made of a thermoplastic resin and a reinforcing material made of a liquid crystal resin having a melting point higher than that of the thermoplastic resin. A mixture of the liquid crystal resin with respect to the thermoplastic resin, the compounding amount of the liquid crystal resin is less than a phase inversion concentration at which the liquid crystal resin is on the matrix side,
A resin composition for molding, wherein the liquid crystal resin has a fibrillable region amount in which the matrix resin has a fiber state having an aspect ratio of 3 or more. 2. The molding resin composition according to claim 1, which comprises a thermoplastic resin and / or a liquid crystal resin that can be mixed with the matrix resin. 3. The molding resin composition according to claim 1, wherein the melting point of the liquid crystal resin is higher than the melting point of the thermoplastic resin by 20 ° C. or more. 4. A composite molded article molded containing a matrix resin composed of a thermoplastic resin and a reinforcing material composed of a liquid crystal resin having a melting point higher than that of the thermoplastic resin, wherein A composite molded article in which the compounding amount with respect to the plastic resin is less than the phase inversion concentration at which the liquid crystal resin is on the matrix side, and the amount of the fiberizable region in which the liquid crystal resin is in a fiber state having an aspect ratio of 3 or more in the matrix resin. After preparing a remolding material by heating and melting the molding material containing the crushed pieces to a temperature higher than the melting point of the liquid crystal resin, the remolding material is melted at a temperature equal to or higher than the melting point of the matrix resin. A method for producing a resin molded product which is heated at a moldable temperature lower than the melting point and molded into a desired shape including the reinforcing fibers of the liquid crystal resin. 5. The method according to claim 4, wherein the melting point of the liquid crystal resin is higher than the melting point of the thermoplastic resin by 20 ° C. or more. 6. The method for producing a resin molded product according to claim 4, wherein the reinforcing fibers of the liquid crystal resin in the molded product have an aspect ratio of 10 or more. 7. The method for producing a resin molded product according to claim 4, wherein at least two types of crushed pieces having different mixing ratios of a matrix resin and a liquid crystal resin are melt-blended as the crushed pieces. 8. The method according to claim 4, wherein the matrix resin and the liquid crystal resin are melt-blended together with the crushed pieces together with a thermoplastic resin material and / or a liquid crystal resin material that can be mixed with the matrix resin in the crushed pieces. The method for producing a resin molded product according to any one of the above.