JP2000344957A - Gradient material, molded article and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gradient material whose phase structure and physical properties are gradient changed with gradient in the direction of thickness and which is useful for tire sides, the housings of various electric products, automotive parts, and so on, by producing the blend of two or more materials selected from rubbers and/or resins by a specific method. SOLUTION: This gradient material is obtained by charging two or more kinds of materials selected from rubbers (for example, natural rubber) and/or resins (for example, polyethylene) preferably into a continuous kneader (for example, a biaxial kneader) by the use of two weight feeders (A, B), while changing the compounding ratio of a material A to a material B, for example, while the amount of the material A is larger than that of the material B in the initial feeding time and is then gradually reduced to increase the charging amount of the component B (in the Figure). A gradient material molded article can also be produced by attaching a mold to the end of the continuous kneader to mold the gradient material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a gradient material,
More specifically, the present invention relates to a gradient material comprising a blend of two or more types of rubbers and / or resins and having a phase structure and physical properties gradiently changed in a thickness direction, a molded product thereof, and a production method thereof.

[0002]

2. Description of the Related Art Conventionally, poly (2,6-dimethyl-1,4
-Phenylene) ether (PPE) and polyethylene (P
As a result of examining the rheological properties of each component and the morphological change in the thickness direction of the molded product depending on the composition ratio using the blend system with E), in a certain blend system, the phase inversion in the thickness direction of the injection molded product was 1, The observation of the formation of a special tilted structure that occurs twice was reported by Sano et al. (Polymer Transactions, Vol. 54, No. 4, pp. 244-254 (Apr. 199).
7)). However, in this document, there is no mention of a rubber / resin-based or rubber / rubber-based gradient material for resin / resin, and the above-mentioned report results also relate to a gradient material of the skin layer / core layer. Yes,
It does not provide a more practical sheet material with a gradient material from front to back.

[0003]

Accordingly, in the present invention, a gradient material comprising a blend of two or more rubbers and / or resins, the phase structure and the physical properties of which are inclined in the thickness direction, the molded product thereof, and the molded product thereof It is intended to provide a manufacturing method.

[0004]

According to the present invention, there is provided a gradient material produced by introducing two or more kinds of materials consisting of rubber and / or resin into a continuous kneader while changing the mixing ratio over time, and the like. A method is provided for producing a graded material by means. Further, there is provided a gradient material molded article obtained by shaping the thus obtained gradient material using a mold.

Further, according to the present invention, a gradient material produced by kneading two or more kinds of materials composed of rubber and / or resin in advance, and then passing through a die having a structure in which the shear rate in the die is inclined, and The following graded material obtained by using a die having a specific structure by such means and a method for manufacturing the same are provided.

According to one aspect of the present invention, a plurality of auxiliary flow paths having different shear rates are provided in the inclined direction of the forming die inlet, and the auxiliary flow paths are merged and integrated at the forming die exit. And a method for producing a gradient material obtained using the die, and a die having the above structure.

According to another aspect of the present invention, there is provided a tilted die manufactured by using a die having a structure in which the total cross-sectional area of each row is substantially equal and the flow path diameter of each row is increased or decreased. A material, a method for producing a gradient material obtained using the die, and a die having the above structure are provided.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a gradient material comprising a blend of two or more types of rubbers and / or resins and having continuously different phase structures and physical properties in the thickness direction, and a method for producing the same. . The inclining material obtained in the present invention is considered to be formed into a sheet or a plate and used for various uses. However, the sheet or the plate made of such an inclining material is continuous in its thickness direction. Since the phase structure is changed and a special inclined structure is generated due to phase inversion or the like, it is possible to obtain a material whose physical properties change obliquely in the thickness direction. Therefore, such a gradient material can be effectively used for a tire side, a housing of various electric appliances, an automobile part (a wiper blade, a packing, a bumper, etc.), various building materials, sporting goods, and the like, which can utilize its characteristics.

[0009] As a first embodiment, the gradient material of the present invention is a method in which each material in two or more kinds of rubber, two or more kinds of resin, or two or more kinds of compound of rubber and resin is temporally combined. Then, the mixture is charged into a continuous kneader while changing the mixing ratio, kneaded, and finally injected into a mold attached to the continuous kneader to produce a desired inclined material molded product. FIG. 1 shows an outline of a specific production method of the gradient material for an example in which two types of materials (rubber / rubber, resin / resin or rubber / resin) are used. The two types of materials A and B are supplied to the kneader using two weight feeders while changing the feed amount over time. That is, at the beginning of the feed, a large amount of the A component and a small amount of the B component are started to flow. At this time, a structure in which the component B is dispersed in the phase A is adopted. Next, when the A component is gradually reduced and the B component is increased, the A component and the B component take a continuous phase, and when the A component is further reduced and the B component is increased,
Eventually, the B component becomes a matrix phase and the A component is dispersed. In this way, a graded material can be obtained. The kneader to be used is preferably a kneader capable of continuously supplying, kneading and discharging two or more kinds of materials, for example, a biaxial kneader as shown in FIG. As the mold, a normal mold or a resin mold can be used.

In the production, two types of rubber (rubber /
In the case of producing a gradient material with rubber,
It is necessary to knead the various types of rubber compounds at a low temperature (80 ° C. to 120 ° C.) and heat and vulcanize them in a mold. Also,
In the case of producing a gradient material with two kinds of resins, a technique of kneading at a temperature equal to or higher than the melting points of the two kinds of resins and cooling and fixing in a mold is adopted. When a gradient material is made of rubber and resin, it is necessary to put the rubber vulcanization system at the end of kneading and vulcanize in a mold without vulcanizing in a kneading machine. In this case, vulcanization may be carried out by an electron beam, ultrasonic waves, or the like, and further, a vulcanizing agent having thermoreversibility may be used. In this case, the rubber component may be in a crosslinked state.

The two types of rubber in the above case and / or
Even in graded materials using resin, mixing in the above kneader
After a certain period of time during the kneading operation, the conditional expression α = η_A/ Η_B
× φ _B/ Φ_A= 1 (where η_AIs the melt viscosity of material A
Degree, η_BIs the melt viscosity of the B material, φ_AIs the volume integral of material A
Rate, φ_BIs the volume fraction of material B)
When the material A is in the matrix phase,
From continuous to dispersed state.
Good.

As a second embodiment of the gradient material of the present invention, two or more types of rubber, two or more types of resin, or a mixture of two or more types of rubber and resin are kneaded in advance, and thereafter, The graded material is made by passing through a die of a specific configuration that is configured to ramp the shear rate in the die.

[0013] The die used in the second embodiment of the present invention includes:
As long as a uniform kneaded mixture of two or more types of rubber and / or resin passes through this die, the die is formed into any shape and structure as long as the die is configured to have an inclined shear rate in the die. As one form thereof, auxiliary flow paths having different shear rates in a plurality of rows are installed in the inclined direction of the forming die entrance portion, and the auxiliary flow paths are set so that the flow resistance of the auxiliary flow paths in each row becomes substantially equal. The die is adjusted according to the cross-sectional shape of the road, the flow path length, the surface roughness, and the like, and a die configured such that the auxiliary flow paths are merged and integrated at the exit of the forming die is effectively used. As a specific example, for example, FIG.
Can be used.

Further, other forms of the die include:
The total cross-sectional area of each row is substantially equal, the flow path diameter of each row is configured to be increased or decreased, and the flow resistance of the auxiliary flow path of each row is adjusted to be substantially equal to the above, and the die exit Are configured to be merged and integrated. As a specific example, for example, a die having a structure as shown in FIG. 3 can be used.

The outline of a specific method for producing a gradient material according to the second embodiment of the present invention will be described using two types of materials A and B.
Further, an example in which a die having the structure of the first embodiment is used will be described with reference to FIG. As an apparatus for manufacturing a gradient material in such an embodiment, an extruder provided with a predetermined die at the tip thereof is used. The materials A and B or pellets of the materials A and B that have been mixed in advance are dry-blended and then put into an extruder, kneaded in the machine until they are sufficiently molten and uniform, and injected into a predetermined die. In this predetermined die, the inside of the die is divided into small slits sequentially from large slits, so that the shear rate of the partition wall surface changes. On the other hand, in order to keep the pressure passing through each flow path in the die constant, the fine slit side is configured as a short flow path, and the large slit side is configured as a long flow path. Generally, when mixing two types of materials, as shown in FIG.
A material having a low melt viscosity has a property of enclosing a material having a high melt viscosity. Therefore, when the shear rate is low, the material A having a low melt viscosity wraps around the material B to form a matrix phase, in which the material B exists as a dispersed phase. Conversely, when the shear rate is high, material B forms a matrix phase and material A becomes a dispersed phase. In the die of the present invention, it is possible to change the shear rate inside the die obliquely by changing from the fine slit to the large slit in order. Therefore, the mixture of the two types of materials A and B is reversed in the sea-island structure at a shear rate existing during the passage through the die, and therefore, after passing through the die, the phase of the mixture passed through the fine slit side and the large slit side. Is reversed, and as a result, a desired gradient material having a continuous gradient composition and structure can be obtained.

As the resin component used in the gradient material of the present invention, a general thermoplastic resin is used, such as a polyolefin resin such as polyethylene (PE) or polypropylene (PP); nylon 6, nylon 66. , Nylon 46, nylon 11 (N11), nylon 12 (N
12), nylon 610 (N610), nylon 612
(N612), nylon 6T, nylon 6 / 6T copolymer, polyamide resin such as MXD6 nylon; polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene terephthalate /
Polyester resins such as tetramethylene glycol copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal polyester, polyoxyalkylenediimidic acid / polybutylene terephthalate copolymer; polyacrylonitrile (PAN), poly Polynitrile resins such as methacrylonitrile (PMN), acrylonitrile / styrene copolymer (AS), methacrylonitrile / styrene copolymer, methacrylonitrile / styrene / butadiene copolymer; polymethyl methacrylate (PMMA) Poly (meth) acrylate resins such as poly (meth) acrylate, poly (ethyl methacrylate), ethylene ethyl acrylate copolymer (EEA), ethylene acrylic acid copolymer (EAA), ethylene methyl acrylate (EMA); vinyl acetate (E A), polyvinyl chloride (PVC)
Polyvinyl resin such as cellulose acetate; cellulose resin such as cellulose acetate butyrate; polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), tetrafluoroethylene / ethylene copolymer Examples thereof include a fluorine-based resin such as (ETFE) and an imide-based resin such as an aromatic imide.

The rubber component used in the gradient material of the present invention includes natural rubber and synthetic polyisoprene rubber (I).
R), epoxidized natural rubber, styrene-butadiene rubber (SBR), polybutadiene rubber (BR), nitrile-
Butadiene rubber (NBR), hydrogenated NBR, hydrogenated SB
Diene rubbers such as R and hydrogen compounds thereof; ethylene propylene rubber (EPDM, EPM), maleic acid-modified ethylene propylene rubber (M-EPM), butyl rubber (IIR), isobutylene and aromatic vinyl or diene monomer copolymer , Acrylic rubber (ACM), ionomer, halogen-containing rubber (Br-IIR, Cl-IIR,
Brominated isobutylene paramethylstyrene copolymer (Br-IPMS), chloroprene rubber (CR), hydrin rubber (CHC, CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid-modified chlorinated polyethylene (M-CM)); olefin rubbers such as (M-CM)); silicon rubbers such as methyl vinyl silicone rubber, dimethyl silicon rubber and methyl phenyl vinyl silicone rubber; sulfur-containing rubbers such as polysulfide rubber; vinylidene fluoride rubbers and fluorine-containing vinyl ethers Rubbers such as rubbers, tetrafluoroethylene-propylene rubbers, fluorine-containing silicon rubbers, and fluorine-containing phosphazene rubbers; styrene-based elastomers, olefin-based elastomers, polyester-based elastomers, and urethanes Elastomers, and thermoplastic elastomers such as polyamide elastomer can be exemplified.

Further, these rubber components include reinforcing agents, fillers, cross-linking agents, softening agents, antioxidants, processing aids and the like which are generally compounded for improving dispersibility, heat resistance and the like. Can be appropriately compounded as needed.

In particular, when the gradient material is composed of a resin component and a rubber component, and the compatibility between the thermoplastic resin component and the rubber component is different, by further adding a compatibilizing agent, Is preferably compatibilized. By blending the compatibilizer, the interfacial tension between the thermoplastic resin and the rubber decreases, and the particle diameter of the component forming the dispersed phase becomes fine, so that the properties of both components are more effectively expressed. Will be. As such a compatibilizing agent, generally, a copolymer having a structure of both or one of a thermoplastic resin and a rubber component, or an epoxy group, a carbonyl group, and a halogen group capable of reacting with the thermoplastic resin or the rubber component ,
The copolymer may have a structure having an amino group, an oxazoline group, a hydroxyl group, or the like. These may be selected according to the type of the thermoplastic resin and the rubber component to be mixed, and commonly used ones are maleic anhydride-modified polypropylene, maleic anhydride-modified ethylene-ethyl acrylate copolymer, epoxy-modified styrene. Butadiene / styrene copolymer, styrene / ethylene / butylene block copolymer (SEBS) and its maleic acid-modified product, EPDM, EPDM / styrene or EPDM /
An acrylonitrile graft copolymer and its maleic acid-modified product, a styrene / maleic acid copolymer, a reactive phenoxy resin, and the like can be given. The amount of the compatibilizer is not particularly limited, but is preferably 0.5 to 20 parts by weight based on 100 parts by weight of the polymer component (total of the thermoplastic resin and the rubber component). Further, the particle diameter of the dispersed phase is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 0.1 to 2 μm by this compatibilizer.

A vulcanizing agent for vulcanizing the rubber component,
The vulcanization aid, vulcanization conditions (temperature, time) and the like may be appropriately determined according to the composition of the rubber composition to be added, and are not particularly limited. For vulcanization of the rubber component, vulcanization using heat is also possible, but in consideration of phase stability, it is desirable to vulcanize with an electron beam, ultrasonic wave, or the like after discharging from a die. As the vulcanizing agent, a general rubber vulcanizing agent (crosslinking agent) can be used. Specifically, examples of the ionic vulcanizing agent include powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, insoluble sulfur, dimorpholine disulfide, and alkylphenol disulfide. 4phr [Rubber component (polymer) 1
Parts by weight per 100 parts by weight].
Further, as organic peroxide-based vulcanizing agents, benzoyl peroxide, t-butyl hydroperoxide, 2,2
4-bichlorobenzoyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane,
Examples thereof include 2,5-dimethylhexane-2,5-di (peroxyl benzoate), and for example, about 1 to 20 phr can be used. Further, examples of the phenolic resin-based vulcanizing agent include brominated alkylphenol resins and mixed cross-linking systems containing a halogen donor such as tin chloride or chloroprene and an alkylphenol resin. Can be. In addition, zinc white (about 5 phr), magnesium oxide (4 ph)
r), litharge (about 10 to 20 phr), p-quinone dioxime, p-dibenzoylquinone dioxime, tetrachloro-p-benzoquinone, poly-p-dinitrosobenzene (about 2 to 10 phr), methylene dianiline (About 0.2 to 10 phr).

[0021] If necessary, a vulcanization accelerator may be added. Examples of the vulcanization accelerator include aldehyde / ammonia-based, guanidine-based, thiazole-based, sulfenamide-based, thiuram-based, dithioate-based, and thiourea-based general vulcanization accelerators, for example, from 0.5 to About 2 phr can be used. Specifically, aldehyde / ammonia vulcanization accelerators include hexamethylenetetramine and the like, guanidine vulcanization accelerators include diphenylguanidine, and thiazole vulcanization accelerators include dibenzothiazyl disulfide ( DM), 2-mercaptobenzothiazole and its Zn salt, cyclohexylamine salt and the like, as sulfenamide-based vulcanization accelerators, cyclohexylbenzothiazylsulfenamide (CBS), N-oxydiethylenebenzothiazyl-2- Examples of thiuram-based vulcanization accelerators such as sulfenamide, Nt-butyl-2-benzothiazolesulfenamide, 2- (thymopolynyldithio) benzothiazole and the like include tetramethylthiuram disulfide (TMTD), tetraethyl Thiuram disulfide, tetrame Le monosulfide (TMTM), dipentamethylenethiuram tetrasulfide and the like, as the dithio acid salt-based vulcanization accelerator,
Zn-dimethyldithiocarbamate, Zn-diethyldithiocarbamate, Zn-di-n-butyldithiocarbamate, Zn-ethylphenyldithiocarbamate, T
e-diethyldithiocarbamate, Cu-dimethyldithiocarbamate, Fe-dimethyldithiocarbamate,
Examples of thiourea-based vulcanization accelerators such as pipecoline pipecolyl dithiocarbamate include ethylene thiourea and diethyl thiourea. As the vulcanization accelerating auxiliary, a general rubber auxiliary can be used in combination, for example, zinc white (about 5 phr), stearic acid, oleic acid and Zn salt thereof (about 2 to 4 phr). Etc. can be used.

[0022]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but it goes without saying that the present invention is not limited to the following Examples.

Example 1 Using the apparatus shown in FIG. 1, a rubber compound 1 shown in Table 1 below was prepared.
And two kinds of rubber compositions consisting of rubber compound 2 were fed from a feeder to a twin-screw kneader while changing the feed amount,
After kneading, the mixture was poured into a mold (mold shape: 50 mm x 50 mm x thickness 20 mm) attached to the tip of the kneader. Next, the mold was removed and vulcanization was performed at 180 ° C. for 10 minutes. Slice the 20mm thickness of the obtained specimen into 5mm increments,
The oil swelling degree (JIS # 1) of each layer was measured, and the results are shown in FIG. SBR has a much higher degree of swelling with respect to oil than NBR. According to the obtained results, it is recognized that the degree of oil swelling is gradually increased in the thickness direction of the test piece according to Example 1, and it is considered that the amount of SBR is sequentially increased. It is thus clear that a rubber / rubber gradient material according to the invention has been obtained.

[0024]

[Table 1]

Examples 2 and 3 Using the apparatus shown in FIG. 1, rubber compound 3 shown in Table 2 below was used.
And each rubber composition excluding the vulcanization component from each of the rubber compound 4 and the polypropylene (PP) resin, while mixing the rubber / resin combinations shown in Table 3 below while biaxially kneading while changing the feed amount from the inlet feeder. After putting into the machine and kneading,
Further, the vulcanizing component of the rubber compound was charged and kneaded from the final feeder of the kneading machine, and then injected into a mold (mold shape: 50 mm × 50 mm × thickness 20 mm) attached to the tip of the kneading machine. Next, the mold was removed and vulcanization was performed at 180 ° C. for 10 minutes. The obtained test pieces were sliced into 5 mm pieces at a thickness of 20 mm, and the resin content of each section was dissolved with hot xylene.
FIG. 6 shows the ratio (%) of the amount of rubber separated into P and vulcanized rubber. In hot xylene, only PP is dissolved, and the vulcanized rubber is not dissolved because it is crosslinked. According to the obtained results, it was recognized that the rubber amount ratio (%) was gradually decreased in the thickness direction of the test pieces according to Examples 2 and 3, and therefore, the rubber / resin gradient material according to the present invention was obtained. It is clear that

[0026]

[Table 2]

[Table 3]

Example 4 Using the apparatus shown in FIG. 4, a rubber compound 3 shown in Table 4 below was prepared.
After dry-blending the rubber component excluding the vulcanization-based component and the nylon 666 copolymer resin at the rubber / resin compounding ratio shown in Table 5 below, the mixture was charged into the twin-screw kneader from the inlet feeder (flow rate). 120 cc / min, temperature 220 ° C.), and then the vulcanizing system component is charged and kneaded from the final feeder of the kneader, and then the auxiliary flow constituted by the slit shown in Table 6 below attached to the tip of the kneader. It was injected into a die having a path (die shape: length 100 mm × width 50 mm × thickness 10 mm). In each auxiliary channel, measure the melt viscosity with respect to the shear rate that the resin and rubber receive, with a capillary rheometer,
The results are shown in Table 7. The specimen coming out of the die was vulcanized at 180 ° C. for 10 minutes. From the obtained test piece, a thin sample corresponding to each zone (auxiliary flow path) of the die was taken, and T
The morphology was observed by EM (transmission electron microscope). The results are shown in Table 8 below. According to the obtained results, it can be seen that Example 4 provides a gradient material in which phase inversion between the matrix and the domain occurs at a certain zone and the layer structure is inclined in the thickness direction as a whole.

[0028]

[Table 4]

[Table 5]

[0029]

[Table 6]

[0030]

[Table 7]

[0031]

[Table 8]

[0032]

As described above, according to the present invention, it is possible to easily obtain a graded material having two or more kinds of rubbers and / or resins whose phase structure and physical properties are inclined in the thickness direction. It is extremely useful because various applied products utilizing the fact that the properties of such a gradient material differ in the thickness direction can be produced from this gradient material.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of one method for producing a gradient material of the present invention.

FIG. 2 is a diagram showing one embodiment of a die used in another embodiment of the method for producing a gradient material of the present invention.

FIG. 3 is a diagram illustrating another embodiment of a die used in another embodiment of the method for producing a gradient material according to the present invention.

FIG. 4 is a diagram illustrating an embodiment of another method for producing a gradient material according to the present invention.

FIG. 5 is a graph showing the gradient of physical properties in the thickness direction of the rubber / rubber gradient material obtained in one embodiment of the gradient material of the present invention.

FIG. 6 is a graph showing the gradient of the phase structure in the thickness direction of the rubber / resin gradient material obtained in one embodiment of the gradient material of the present invention.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuji Kawamo 2-1 Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd. Inside the Hiratsuka Plant (72) Inventor Yoshihiro Soeda 2-1 Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd. Inside the Hiratsuka Factory (72) Inventor Daisuke Kanari 2-1 Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd. Inside the Hiratsuka Factory (72) Inventor Shigeru Yamauchi 2-1 Oiwake, Hiratsuka-shi, Kanagawa Yokohama Yokohama F-term in Hiratsuka Works (reference) 4F207 AA04 AA11 AA24 AA29 AA45 AB03 AG01 AH17 AH20 AH42 AH46 AH59 KA01 KA17 KL55 KL58 KL65 4J002 AA00W AA00X AA01W AA01X AC00W AC00X AC01W AC01X00 AC02

Claims (10)

[Claims] 1. A graded material produced by introducing two or more types of materials consisting of rubber and / or resin into a continuous kneader while changing the mixing ratio over time. 2. A graded material molded product in which the graded material is shaped according to claim 1, wherein a mold is attached to an end of the continuous kneader. 3. A method for producing a graded material in which two or more kinds of materials composed of rubber and / or resin are charged into a continuous kneader while changing the mixing ratio over time. 4. A graded material produced by kneading two or more kinds of materials composed of rubber and / or resin in advance, and then passing through a die having a structure in which the shear rate in the die is inclined. 5. A die having a structure in which a plurality of rows of auxiliary flow paths having different shear rates are provided in the inclined direction of the forming die inlet portion and the auxiliary flow paths are merged and integrated at the forming die outlet. The gradient material according to claim 4, which is produced. 6. The inclined material according to claim 4, wherein the die is manufactured using a die having a structure in which the total cross-sectional area of each row is substantially equal and the diameter of the flow path of each row is increased or decreased. . 7. An auxiliary flow path in which two or more kinds of materials made of rubber and / or resin are kneaded in advance, and thereafter, a plurality of rows of auxiliary flow paths having different shear rates in the inclined direction of the entrance of the forming die,
A method of manufacturing a gradient material obtained through a die having a structure in which respective auxiliary flow paths are merged and integrated at a forming die outlet. 8. A method for producing a graded material, in which two or more kinds of materials composed of rubber and / or resin are kneaded in advance, and thereafter, the material is passed through a die having a structure in which the total cross-sectional area of each row is substantially equal. 9. An inclined material molding die having a structure in which a plurality of rows of auxiliary flow paths having different shear rates are provided in the forming die inlet portion inclined direction and the auxiliary flow paths are merged and integrated at the forming die outlet. 10. The total cross-sectional area of each row is substantially equal, and
An inclined material molding die having a structure configured to increase or decrease the flow path diameter of each row.