JP5577631B2 - Thermoplastic resin composition and method for producing the same - Google Patents

Description

  The present invention relates to a thermoplastic resin composition having rheological properties advantageous for blow molding, foam molding, film molding, extrusion molding, and the like. Specifically, a thermoplastic resin (composition) modified to a specific crosslinked state is used in the same system. The present invention relates to a thermoplastic resin composition in which the rheological properties of a non-crosslinked thermoplastic resin are improved by dispersing in the non-crosslinked thermoplastic resin.

  In blow molding, foam molding, film molding, extrusion molding, etc., there are various methods for obtaining rheological properties of thermoplastic resins that are advantageous in shape retention, molding stability, etc., depending on the resin. Most of them aim to develop appropriate melt tension and strain hardening at the time of melt elongation. As a method for increasing the melt tension, in addition to increasing the molecular weight in the polymerization stage and introducing a branched structure, for example, in the case of polyester or polyamide, a polyfunctional reactive compound or reactive polymer is added to increase the melt viscosity. Things have been done.

In general, as a method of developing strain hardening at the time of melt elongation, in addition to a method of strengthening the molecular entanglement by introducing a branched structure, a high polymerization degree polymer is alloyed, and strain hardening is expressed by the relaxation action of dispersed phase particles. There is a way. However, these methods use unique and special methods depending on the resin, and cannot always be easily applied to the target resin. Also, melt tension control by alloy of high polymerization degree polymer needs to control compatibility and dispersed particle size, etc., and it is very difficult to obtain strain hardening at melt elongation viscosity, and the effect may not be sufficient. Many.

Moreover, as a method for expressing strain hardening at the time of melt elongation, there is a method of introducing a crosslinked structure into a molecular chain (Patent Documents 1 and 2).
In Patent Document 1, strain hardening is imparted to polyethylene by organic peroxide treatment or ionizing radiation treatment, but the purpose of imparting strain hardening is to stabilize the performance of the polyethylene microporous film after molding. It does not give strain hardening for stabilization of molding of engineering plastics.

  Patent Document 2 discloses that a polymethacrylate-containing methacrylic acid ester compound and a peroxide are melt-kneaded to introduce a cross-linked structure to impart strain hardening to the polylactic acid resin composition. Although the strain hardening coefficient which parameterized the strain hardening property in the time-elongation viscosity curve of this is shown, since the whole system is bridge | crosslinked, the original characteristic of resin may be impaired. There are drawbacks such as deterioration of fluidity of the resin composition, applicable resins are limited, and it is not effective as a technique for developing strain-hardening properties for a wide range of thermoplastic resin compositions.

  Patent Document 3 discloses that a film is formed using a resin composition obtained by melt-kneading radiation-crosslinked polycaprolactone and an aliphatic polyester. However, the specifically disclosed crosslinked polycaprolactone has a high radiation dose and molecular degradation and promotes biodegradability, and there is no description regarding the dispersibility and dispersion structure of the crosslinked polycaprolactone. There is no description about the improvement of the specific rheological properties of the resin composition by the dispersion of the crosslinked polycaprolactone.

Japanese Patent Laid-Open No. 10-17694 JP 2003-128901 A JP 2000-256471 A

  The present invention is intended to solve the above-mentioned problems, and in a wide range of non-crosslinked thermoplastic resins (hereinafter sometimes simply referred to as thermoplastic resins), the original characteristics of the non-crosslinked thermoplastic resins are impaired. The object is to provide a thermoplastic resin composition having rheological properties capable of stable molding in extrusion molding, blow molding, foam molding and the like.

As a result of intensive research in order to solve such problems, the present inventors have melted and kneaded a thermoplastic resin modified and adjusted to a degree of crosslinking satisfying a specific condition into a non-crosslinked thermoplastic resin. By dispersing and structuring, it was found that the strain-hardening property was expressed in the non-linear region with respect to the rheological properties of the non-crosslinked thermoplastic resin, and the present invention was achieved.

That is, the present invention
(1) A cross-linked thermoplastic resin composition (A ′) having the following characteristics (a) obtained by cross-linking the non-crosslinked thermoplastic resin (A) and a non-crosslinked thermoplastic resin (B) are melt-kneaded. The (A ′) is dispersed in the particle size of at most 20 μm in the (B) or the (A ′) and the (B) are intricately mixed with each other. A thermoplastic resin composition characterized by having a co-continuous structure and having a strain-hardening property of (b) below in a non-linear region in melt uniaxial elongational viscosity.
(A) A solvent gel is formed with the solvent without dissolving in the solvent of the non-crosslinked thermoplastic resin (A).
(B) The following strain hardening coefficient is 2 or more in the time-extension viscosity curve obtained by measurement of the melt uniaxial extensional viscosity of the thermoplastic resin composition at a temperature at least 10 ° C. higher than the melting point of the non-crosslinked thermoplastic resin (B). is there.
Strain hardening coefficient = a2 / a1
a1: Slope of linear region in log-plot curve of time-extension viscosity
a2: The slope of the nonlinear region in the logarithmic plot curve of time-extension viscosity

(2) The cross-linked thermoplastic resin composition (A ′) has a frequency in the frequency range of 0.1 to 10 rad / s in a logarithmic plot curve of frequency-storage elastic modulus obtained by melt viscoelasticity measurement in the linear region. The thermoplastic resin composition according to the above (1), which is in a crosslinked state in which the slope of the storage elastic modulus with respect to is 0.2 to 1.0.
(3) The storage elastic modulus in the logarithmic plot curve of the frequency-storage elastic modulus in the cross-linked thermoplastic resin composition (A ′) in the frequency range of 0.1 to 10 rad / s in the melt viscoelasticity measurement in the linear region. (1) or (2) where the absolute value of the difference between α and β is 0.15 or less, where α is the slope of α and β is the slope of the loss modulus in the logarithmic plot curve of the frequency-loss modulus. ) The thermoplastic resin composition described.
(4) The thermoplastic resin composition according to any one of (1) to (3), wherein the crosslinked thermoplastic resin composition (A ′) is irradiated with radiation.
(5) The (1) to (4), wherein the crosslinked thermoplastic resin composition (A ′) is formed by irradiating a pellet obtained by melt-kneading a non-crosslinked thermoplastic resin and a crosslinking aid. The thermoplastic resin composition according to any one of the above.
(6) The crosslinked thermoplastic resin composition (A ′) is obtained by blending a crosslinking aid and / or an organic peroxide with the non-crosslinked thermoplastic resin (A) and crosslinking by melt kneading. The thermoplastic resin composition according to any one of (1) to (5).
(7) The crosslinked thermoplastic resin composition (A ′) according to any one of (1) to (6), wherein at least 50% by weight is any one of a polyamide resin, a polyester resin, and a polyolefin resin. Thermoplastic resin composition.
(8) crosslinked thermoplastic resin composition (A ') is obtained by melt kneading a resin composition containing a port re-caprolactone 50 to 99.9 parts by weight and the crosslinking aid 0.1-3 parts by weight pellets The thermoplastic resin composition according to any one of the above (1) to (7), which is irradiated with an absorbed dose of 0.5 to 25 kGy.
(9) crosslinked thermoplastic resin composition (A ') is, pellets of the resin composition obtained by melt kneading including port re ester elastomer 50 to 99.9 parts by weight and the crosslinking aid 0.1-3 parts by weight The thermoplastic resin composition according to any one of (1) to ( 7 ), which is irradiated with an absorbed dose of 0.5 to 60 kGy.
(10) crosslinked thermoplastic resin composition (A ') is the absorption pellets of the resin composition obtained by melt kneading including polyamides 50 to 99.9 parts by weight and the crosslinking aid 0.1-3 parts by weight The thermoplastic resin composition according to any one of (1) to ( 7 ), wherein the thermoplastic resin composition is irradiated with a dose of 0.5 to 20 kGy.
(11) Crosslinked thermoplastic resin composition (A ′) pellets and a noncrosslinked thermoplastic resin (A ′) crosslinked so as to form a solvent gel with the solvent without dissolving in the solvent of the noncrosslinked thermoplastic resin (A) B) A method for producing a strain-curable thermoplastic resin composition, in which pellets are melt-kneaded at a temperature equal to or higher than the melting points of (A ′) and (B) pellets.

In the thermoplastic resin composition of the present invention, since the crosslinked thermoplastic resin and the non-crosslinked thermoplastic resin are uniformly finely structured, the functional characteristics of the crosslinked thermoplastic resin and the non-crosslinked thermoplastic resin are not reduced. The rheological properties can be improved, and the composition has strain-hardening properties in a non-linear region in the melt uniaxial elongational viscosity (hereinafter sometimes simply referred to as melt elongational viscosity). For this reason, a thermoplastic resin composition having high functionality and good moldability in blow molding, extrusion molding, and foam molding can be obtained.
Further, the production method can be applied to various functional thermoplastic resin compositions, and the fine dispersion structure of the crosslinked thermoplastic resin composition and the non-crosslinked thermoplastic resin composition formed in this production process is various. This structure is useful for functional design by alloying functional thermoplastic resin. That is, in a wide range of combinations of crosslinked thermoplastic resins and non-crosslinked thermoplastic resins, this is a useful technique not only for improving rheological properties but also for various functional designs.

FIG. 1 is a diagram showing a time growth curve of 180 ° C. melt uniaxial elongation viscosity for the thermoplastic resin compositions of Example 1-1 and Comparative Example 1-1, and is a diagram showing strain hardening in a non-linear region. FIG. 2 is a view showing a time growth curve of 220 ° C. melt uniaxial elongation viscosity for the thermoplastic resin compositions of Example 2-3 and Comparative Example 2-3, and showing strain hardening in a non-linear region. FIG. 3 is a diagram (photograph) showing TEM images of the thermoplastic resin compositions of Example 2-2 and Comparative Example 2-2 in which frozen sections obtained with a cryomicrotome were stained with RuO ₄ . FIG. 4 shows the frequency-storage elastic modulus, loss elastic modulus and reduction at 190 ° C. and 220 ° C. of the crosslinked thermoplastic resin compositions blended in Examples 1-1 to 1-3 and Examples 2-1 and 2-3. It is a figure which shows the logarithm plot about a viscosity. FIG. 5 is a diagram (photograph) showing a phase contrast microscopic image and an SPM image of a frozen section obtained by a cryomicrotome for the thermoplastic resin composition of Example 4. 6 is a diagram (photograph) showing a phase contrast microscopic image and an SPM image of a frozen section obtained by a cryomicrotome with respect to the thermoplastic resin composition of Comparative Example 4. FIG.

The present invention will be specifically described below. The thermoplastic resin composition of the present invention can be obtained by forming a finely dispersed structure of the crosslinked thermoplastic resin composition (A ′) and the non-crosslinked thermoplastic resin (B) by melt-kneading. The crosslinked thermoplastic resin composition (A ′) is a modified thermoplastic resin (composition) crosslinked by introducing a bridge structure into the molecular chain of the non-crosslinked thermoplastic resin (A). It has a specific degree of cross-linking that makes it insoluble in the solvent of (A).
Specific resins corresponding to the non-crosslinked thermoplastic resins (A) and (B) include polyethylene (PE), polypropylene (PP), polymethylpentene (TPX), ethylene-propylene copolymer (EPM), Ethylene-propylene-diene copolymer (EPDM), ethylene-methyl acrylate copolymer (EEA), ethylene-methacrylic acid copolymer (EMAA), ethylene-acrylic acid copolymer (EAA), ethylene-vinyl acetate Olefin resins such as copolymer (EVA). Biodegradable and cross-linked polyester resins such as polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene succinate / adipate (PBSA). Polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polycarbonate (PC), polyacrylate (PAR), polybutylene terephthalate / polytetramethylene glycol block copolymer And polyester resins such as polybutylene terephthalate / polylactone block copolymers, polybutylene naphthalate / polylactone block copolymers, and polybutylene terephthalate / polymer prolactone copolymers. Nylon 6 (NY6), nylon 66 (NY66), nylon 46 (NY46), nylon 11 (NY11), nylon 12 (NY12), nylon 610 (NY610), nylon 612 (NY612), metaxylylene adipamide (MXD6) ), Hexamethylenediamine-terephthalic acid polymer (6T), hexamethylenediamine-terephthalic acid and adipic acid polymer (66T), hexamethylenediamine-terephthalic acid and ε-caprolactam copolymer (6T / 6), trimethylhexa Methylenediamine-terephthalic acid (TMD-T), metaxylylenediamine and adipic acid and isophthalic acid polymer (MXD-6 / I), trihexamethylenediamine, terephthalic acid and ε-caprolactam copolymer (TMD-T / 6 ), Polyamide resins such as diaminodicyclohexylenemethane (CA) and isophthalic acid and lauryl lactam polymer, etc., but are not limited to these, and a plurality of thermoplastic resins other than those mentioned above This includes resin copolymers and polymer alloy compounds.

  In order to obtain the thermoplastic resin composition in the present invention, it is important to appropriately control the degree of cross-linking of the cross-linked thermoplastic resin composition (A ′), and this specific cross-linking degree can be adjusted. However, it enables the realization of the present invention and easy application to various resins. Hereinafter, preferred forms of the crosslinked thermoplastic resin composition (A ′) in the present invention will be described.

The crosslinked thermoplastic resin composition (A ′) in the present invention must be crosslinked at least until it is insolubilized in the solvent of the non-crosslinked thermoplastic resin (A). Although it is preferable to adjust beforehand by the bridge | crosslinking in the melt kneading of use, etc., it is not limited to these. Among cross-linking methods that introduce a cross-linked structure into the molecular chain, cross-linking by radiation irradiation in particular can control the cross-linking degree of the cross-linked thermoplastic resin composition (A ′) in a state where the cross-linking density is uniform and the cross-linking density is not excessively increased. This is particularly preferable because it can be easily performed.

The solvent for the non-crosslinked thermoplastic resin is a solvent capable of dissolving the thermoplastic resin before crosslinking, and a solvent suitable for each thermoplastic resin may be selected. For example, nylon includes formic acid, sulfuric acid, etc., but formic acid is preferred. For polyester, a mixed solvent of phenol and tetrachloroethane, dichlorobenzene and the like can be mentioned, and a mixed solvent of phenol and tetrachloroethane is preferable.

  Crosslinking by radiation irradiation can cause intermolecular crosslinking by irradiating with electron beam or gamma ray (γ ray). The wavelength differs depending on the type of radiation, and gamma rays having a wavelength shorter than that of the electron beam can be cross-linked to the inside of the thick thermoplastic resin. The total amount of absorbed energy (absorbed dose) is expressed in gray (Gy). Radiation irradiation is particularly preferable for crosslinking of the crosslinked thermoplastic resin composition (A ′) of the present invention because the absorbed dose can be freely controlled and the degree of crosslinking of the thermoplastic resin can be controlled. Since the cross-linking by radiation irradiation to pellets and the like may not provide a uniform degree of cross-linking unless the transmitted dose is made uniform between the upper and lower portions to be irradiated, especially when pellets are cross-linked with radiation, the wavelength is short. Since a uniform degree of crosslinking can be obtained by crosslinking with gamma rays, the present invention is the optimum crosslinking method. The absorbed dose of radiation irradiation in the present invention is preferably 0.5 to 50 kGy. If it is less than 0.5 kGy, it becomes difficult to control the absorbed dose, and if it exceeds 50 kGy, the crosslinking proceeds too much, and depending on the type of polymer, the progress of molecular cutting proceeds so much that the crosslinked part and the non-crosslinked part are extremely uneven. You can only get things.

In adjusting the degree of crosslinking of the crosslinked thermoplastic resin composition (A ′) by irradiation, the crosslinking treatment efficiency of the crosslinked thermoplastic resin composition (A ′) is obtained by kneading a crosslinking aid in advance into the thermoplastic resin to be crosslinked. Can be promoted. Specific crosslinking aids include triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), trimethylallyl isocyanurate (TMPTA), trimethylolpropane trimethacrylate (TMPTA), trishydroxyethyl isocyanuric acrylate. Polyfunctional compounds such as (THEICA) and N, N′-m-phenylenebismaleimide (MPBM) can be exemplified, but are not limited thereto. Triallyl cyanurate (TAC) and triallyl isocyanurate (TAIC) are preferable in terms of ease of handling. These crosslinking aids can be used alone or in combination of two or more. The amount of the crosslinking aid is 0.01 to 10 parts by weight, preferably 0.03 to 5 parts by weight, based on 100 parts by weight of the thermoplastic resin to be crosslinked. If it is 0.01 parts by weight or less, the effect of promoting the crosslinking efficiency is reduced. On the other hand, when the amount is 10 parts by weight or more, the dispersion of the crosslinking aid itself is not uniform, and a crosslinked thermoplastic resin having a uniform crosslinking density cannot be obtained. Furthermore, addition of a large amount of a crosslinking aid is not preferable because not only the efficiency as a crosslinking aid is deteriorated but also the physical properties of the crosslinked thermoplastic resin composition (A ') are lowered.

  A cross-linking thermoplastic resin composition (A ′) can be produced by blending a cross-linking aid into a thermoplastic resin to be cross-linked, mixing well, and then irradiating the pellets obtained by melt kneading with radiation. . The apparatus for melting and kneading the crosslinking aid is not particularly limited, but it is preferable to use a twin screw extruder. The cylinder temperature of the twin-screw extruder is 10 to 50 ° C. from the glass transition temperature when the crosslinked thermoplastic resin composition (A ′) is a crystalline resin, and when the crosslinked thermoplastic resin is an amorphous resin, Alternatively, it is preferable to set at a higher temperature. The residence time in the melt kneading process is generally about 30 seconds to 15 minutes. The degree of crosslinking of the crosslinked thermoplastic resin composition (A ′) can be controlled by the blending amount of the crosslinking aid used and the absorbed dose of the irradiated radiation.

  In the case of crosslinking the crosslinked thermoplastic resin composition (A ′) in the present invention with an organic peroxide, an organic peroxide and a crosslinking aid are blended into the thermoplastic resin to be crosslinked, and mixing and melt-kneading. Can be manufactured. The degree of cross-linking is determined by the type and amount of organic peroxide and cross-linking aid, the temperature of melt kneading and the residence time during melt kneading. As the crosslinking agent, an organic peroxide is generally used. Specific examples of the organic peroxide include benzoyl peroxide, 1,1-bis-t-butylperoxy-3,3,5-trimethylcyclohexane, dicumyl peroxide, di- (t-butylperoxy) m. -Diisopropylbenzene, 2,5-dimethyl-2-5-di-t-butylperoxyhexane, 2,5-dimethyl-2-5-t-butylperoxyhexane-3, etc. It is not limited to. The addition amount of the organic peroxide is 0.02 to 5 parts by weight with respect to 100 parts by weight of the thermoplastic resin to be crosslinked. Preferably it is 0.05-3 weight part. As the crosslinking aid, the same crosslinking aid used at the time of crosslinking by radiation irradiation can be used. The blending amount of the crosslinking aid is also the same.

  The degree of crosslinking of the crosslinked thermoplastic resin composition (A ′) in the present invention needs to be increased until any thermoplastic resin is crosslinked and insolubilized in a solvent, for example, by the method described above. In the case where it is dissolved in a solvent, even if a bridge structure is introduced, the degree of crosslinking is not sufficient so that the intended rheology modification effect cannot be obtained, and the crosslinked thermoplastic resin composition (A ′) and Depending on the combination with the non-crosslinked thermoplastic resin (B), (A) may not have a uniform and stable dispersion structure or co-continuous structure.

The crosslinked thermoplastic resin composition (A ′) in the present invention has a certain degree of crosslinking that is insoluble in a solvent and at the same time is compatible and is 300 sec ⁻¹ or more with an uncrosslinked non-crosslinked thermoplastic resin. It is preferable that the degree of cross-linking is suppressed to such a degree that the gel is uniformly melt-dispersed without forming a gel having a size of 100 μm or more by melt-kneading at the shear rate. More preferably, a film molded product of 200 μm or less is formed using pellets obtained by melt kneading with a compatible and non-crosslinked thermoplastic resin at a shear rate of 300 sec ⁻¹ or more using a twin-screw extruder. In the case of melt molding, the film has a good surface property and has no irregularities due to a gel of 100 μm or more. Here, when the surface is in a state where unevenness due to gel is formed, it means that the crosslinked thermoplastic resin to be dispersed has been excessively crosslinked, and in the present invention, the non-crosslinked thermoplastic resin (B) and It is not preferable because it is impossible to make a fine structure by melt kneading.

  Adjustment of the preferable crosslinking state of the crosslinked thermoplastic resin composition (A ′) in the present invention can be controlled by the blending amount of the crosslinking aid and the absorbed dose of the irradiated radiation when crosslinking is performed using radiation. The degree of crosslinking in the case of melt kneading of a crosslinking aid and an organic peroxide is determined by the type and amount of the organic peroxide and crosslinking aid, the temperature of the melt kneading, and the residence time during the melt kneading. Is done. For any thermoplastic resin and resin composition to be cross-linked, there is an optimum cross-linking state and cross-linking condition, and a soft material that disperses in a non-cross-linked thermoplastic resin with a constant shear even if the desired degree of cross-linking is above the melting point. Therefore, it cannot be clearly defined by the solvent swelling rate or gelation degree that is generally used as an index of the degree of cross-linking. Insolubilization in good solvents (formation of solvent gel) and dispersibility in compatible thermoplastic resins It is the most efficient and accurate to obtain the desired cross-linked state using as an index.

  In the cross-linking treatment of the non-crosslinked thermoplastic resin (A) in the present invention, as a melt-kneading apparatus in the case of adding a crosslinking aid or kneading with an organic peroxide, a single-screw extruder, a twin-screw extruder, There are a pressure kneader, a banbury and the like, and a twin screw extruder is particularly preferable.

  The cross-linked thermoplastic resin composition (A ′) in the present invention undergoes a cross-linking treatment when the degree of cross-linking is increased in the process of adjusting the cross-linking degree, and the storage elastic modulus at the time of melting is measured in the melt viscoelasticity measurement. Will increase more than before. This can be confirmed by the fact that the storage elastic modulus increases with respect to an arbitrary frequency after the crosslinking treatment in the relationship between the frequency and the storage elastic modulus at the time of melting. This increase in storage modulus can be seen in the decrease of the slope of storage modulus with respect to frequency in the frequency-storage modulus log-log plot curve when the system crosslinks uniformly.

  The crosslinked thermoplastic resin composition (A ′) preferably has a reduced slope due to the introduction of a crosslinked structure into the molecular chain. More preferably, a frequency-storage modulus log-log plot of a single non-crosslinked thermoplastic resin that is uniform and generally non-alloyed with a large slope in the range of at least 0.1 to 10 rad / s. While the slope of the storage elastic modulus with respect to the frequency is close to 2 in the curve, it is preferably increased to a range of 0.2 to 1.0, more preferably 0.2 to 0.6. is there. The optimum value of this slope differs depending on the thermoplastic resin to be crosslinked, but if this value is greater than 1.0, it indicates that crosslinking is insufficient, and it is melt-kneaded with the non-crosslinked thermoplastic resin (B). But there is no rheology improvement effect. Further, if the introduction of the bridge structure is not sufficient, the relaxation behavior in the melt-dispersed state is rapid and the dispersion structure is not stable, so that it is difficult to form a stable fine dispersion structure with the non-crosslinked thermoplastic resin (B). Conversely, when the storage modulus in the logarithmic plot curve of the frequency-storage modulus is cross-linked until the slope of the storage modulus becomes smaller than 0.2, it means that it is already a hard gel and viscoelastic properties close to a solid. However, unless the particles are adjusted to the dispersed particle scale in advance, it is difficult to form a finely dispersed structure to 20 μm or less by melt kneading with the non-crosslinked thermoplastic resin (B).

The cross-linked thermoplastic resin composition (A ′) in the present invention preferably has a storage elastic modulus of 1E + 5 Pa or less in the range of 0.1 to 10 rad / s in the viscoelasticity measurement above the melting point. When it is 1E + 5 Pa or higher, it is an area where the shape can be maintained as a solid even at a melting temperature or higher, and even in kneading with a twin-screw extruder, it becomes a gel lump with poor dispersion exceeding 20 μm in the thermoplastic resin composition. Therefore, 1E + 5 Pa or less is preferable.

The thermoplastic resin composition of the present invention that exhibits strain-hardening properties in the non-linear region when melted is structured with a dispersed phase having a moderately elastic behavior as the crosslinked thermoplastic resin composition (A ′). Is preferred. In general, in the thermoplastic resin at the time of melting, the shear rate dependence of the storage modulus is larger than the shear rate dependence of the loss modulus. Assuming that the slope of the storage elastic modulus in the logarithmic plot curve of frequency-storage elastic modulus at least in the frequency range of 0.1 to 10 rad / s obtained by melt viscoelasticity measurement is α, α is a frequency dependence parameter of the storage elastic modulus. Can be treated as If the slope of the loss modulus in the log-log plot curve of the frequency-storage modulus is β, β can be treated as a frequency dependence parameter of the loss modulus. Furthermore, α-β can be treated as a frequency-dependent parameter of tan δ. In the case of a general thermoplastic resin, α> β and the absolute value of α-β is close to 1.0. If this value is large, the storage elastic modulus tends to be small with respect to the loss elastic modulus at low shear, indicating that the dispersed phase has a more viscous behavior.

As the moderately elastic behavior of the crosslinked thermoplastic resin composition (A ′) in the present invention, α-β is preferably 0.15 or less regardless of the size of α and β. More preferably, the absolute value of α-β is 0.10 or less. When α and β of the cross-linked thermoplastic resin composition (A ′) serving as the dispersed phase are α> β and the absolute value of α-β exceeds 0.15, the loss elastic modulus in the low shear region is stored. The elastic modulus is too low and does not contribute to the development of strain hardening. When α and β of the cross-linked thermoplastic resin composition (A ′) serving as the dispersed phase are α <β and the absolute value of α-β is 0.15 or more, the viscoelastic property is no longer close to a solid. Does not contribute to the development of strain hardening.

  In the process of adjusting the degree of crosslinking of the crosslinked thermoplastic resin composition (A ′) in the present invention, the crosslinking may be inhibited depending on the function other than the strain hardening desired to be expressed in the thermoplastic resin composition of the present invention. Or other resin, a functional filler, an additive, etc. can be mix | blended in the range which adjustment of a crosslinking degree is easy, without promoting too much. As fillers and compounding agents, for example, reinforcing materials such as glass fibers, carbon fibers, various inorganic fillers, heat stabilizers, UV stabilizers, weather resistance improvers, antioxidants, flame retardants, conductive fillers, thermal conductivity The compounding agents and additives such as fillers, antistatic agents, pigments and dyes are not limited to these. If these functional compounding agents are blended before the crosslinking treatment to the non-crosslinked thermoplastic resin (A) and the crosslinking treatment is carried out, the compounding agent can be constrained only in the crosslinked thermoplastic resin, and the crosslinking thermoplasticity. It can be selectively contained in the dispersed phase of the resin component. This enables higher-order distributed structure control and functional design.

It is preferable that at least 50% by weight in the crosslinked thermoplastic resin composition (A ′) is any one of a polyamide resin, a polyester resin, and a polyolefin resin.
When at least 50% by weight of the crosslinked thermoplastic resin composition (A ′) is a polyester resin, 50 to 99.9 parts by weight of polycaprolactone is crosslinked with 100 parts by weight of the crosslinked thermoplastic resin composition (A ′). Pellets obtained by melt-kneading a resin composition containing 0.1 to 3 parts by weight of an auxiliary agent are preferably irradiated with an absorbed dose of 0.5 to 25 kGy.
Further, when at least 50% by weight in the crosslinked thermoplastic resin composition (A ′) is a polyester resin, 50 to 99.9 parts by weight of the polyester elastomer with respect to 100 parts by weight of the crosslinked thermoplastic resin composition (A ′). And pellets obtained by melt-kneading a resin composition containing 0.1 to 3 parts by weight of a crosslinking aid are preferably irradiated with an absorbed dose of 0.5 to 60 kGy.
When at least 50% by weight in the crosslinked thermoplastic resin composition (A ′) is a polyamide-based resin, 50 to 99.9 parts by weight of polyamide and crosslinking aid are added to 100 parts by weight of the crosslinked thermoplastic resin composition (A ′). The pellet obtained by melt-kneading the resin composition containing 0.1 to 3 parts by weight of the agent is preferably irradiated with an absorbed dose of 0.5 to 20 kGy.
When the above range is not satisfied, it may be difficult to obtain a crosslinked thermoplastic resin composition (A ′) having desired characteristics.

  The thermoplastic resin composition of the present invention can be obtained by melt-kneading the crosslinked thermoplastic resin composition (A ′) and the non-crosslinked thermoplastic resin (B). The blending ratio of the crosslinked thermoplastic resin composition (A ′) and the non-crosslinked thermoplastic resin (B) is preferably (A ′) :( B) = 1: 99 to 95: 5. When (A ′) is less than 1 and (B) exceeds 99, the rheology improving effect of the non-crosslinked thermoplastic resin (B) becomes poor, (A ′) exceeds 95 and (B) is less than 5. And the characteristic of (B) becomes difficult to express and it is disadvantageous also in cost.

The thermoplastic resin composition of the present invention obtained by melt-kneading the crosslinked thermoplastic resin composition (A ′) and the non-crosslinked thermoplastic resin (B) is at least from the melting point of the non-crosslinked thermoplastic resin (B). It is necessary that the following strain hardening coefficient is 2 or more in a log-log plot curve of time-uniaxial extension viscosity obtained by uniaxial extension viscosity measurement at a temperature higher by 10 ° C. or more.
Strain hardening coefficient = a2 / a1
a1: Slope of linear region in log-plot curve of time-extension viscosity
a2: The slope of the nonlinear region in the logarithmic plot curve of time-extension viscosity When the strain hardening coefficient is less than 2, the rheology improving effect of the non-crosslinked thermoplastic resin (B) is poor. The strain hardening coefficient is preferably about 4 to 50 in terms of ease of production of the composition and molding stability.

  The non-crosslinked thermoplastic resin (A) and the non-crosslinked thermoplastic resin (B), which are thermoplastic resins before being subjected to the crosslinking treatment, are preferably compatible and are preferably the same series of resins. For example, combinations of polyester resins, polyamide resins, polyolefin resins, and the like are preferable.

  Further, according to the present invention, a functional filler can be used depending on the function to be expressed other than the strain-hardening property even at the time of melt-kneading the crosslinked thermoplastic resin composition (A ′) and the non-crosslinked thermoplastic resin (B). And additives can be blended. For example, reinforcing materials such as glass fibers, carbon fibers, various inorganic fillers, heat stabilizers, UV stabilizers, weather resistance improvers, antioxidants, flame retardants, conductive fillers, heat conductive fillers, antistatic agents, These are compounding agents and additives such as pigments and dyes, but are not limited thereto. In the melt-kneading of the crosslinked thermoplastic resin composition (A ′) and the non-crosslinked thermoplastic resin (B) that have already undergone crosslinking treatment, the blended fillers and additives have a very high melt elastic modulus. Since it does not easily enter the crosslinked thermoplastic resin composition (A ′) even under melt shearing, it is selectively dispersed in the matrix phase of the non-crosslinked thermoplastic resin (B). This enables higher-order distributed structure control and functional design.

Furthermore, the thermoplastic resin composition in the present invention is a mixture obtained by mixing a cross-linked thermoplastic resin composition (A ′) and a non-cross-linked thermoplastic resin (B), and, if necessary, a compounding agent, an injection molding machine, an extrusion It is also possible to directly carry out melt-kneading and commercialization by directly feeding into an injection molding machine, an extruder or the like for shaping the product. Even in such a case, the shear rate during melt-kneading is important for structuring the crosslinked thermoplastic resin composition (A ′) with the non-crosslinked thermoplastic resin (B). The shear rate during melt kneading needs to be 300 sec ^-1 or more. The shear rate is preferably 500 sec ⁻¹ or more, more preferably 1000 sec ⁻¹ or more.
In these cases, in an injection molding machine or an extruder, melt kneading is possible even from a hopper into which the mixture is charged to a mold or a die, and a crosslinked thermoplastic resin composition (A ′) is obtained depending on the shear rate between them. And the non-crosslinked thermoplastic resin (B) and other compounding agents are microstructured and are commercialized with a mold or a die at the tip of the molding apparatus.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example, unless the summary is exceeded. The measurement methods, evaluation methods, and experimental methods employed in the examples and comparative examples are shown below.
(1) Method for measuring storage elastic modulus and loss elastic modulus of cross-linked thermoplastic resin using TA Instruments ARES and a 25 mm parallel plate as a measurement jig were measured for dynamic viscoelasticity under the following conditions. Both log plots of storage modulus, frequency-loss modulus and frequency-shear viscosity were obtained.
・ Strain = 10%
・ Temperature = at least 10 ° C. of the crystalline melting point of DSC ・ Initial Frequency = 100 rad / s
・ Final Frequency = 0.1 rad / s
・ Gap = 0.7-1.5mm
・ Geometry Type = Parallel Plate (Diameter = 25mm)
The crosslinked thermoplastic resin composition in which the crosslinking proceeded too much in the crosslinked thermoplastic resin preparation example was determined to be “impossible to measure” because the storage elastic modulus could not be measured with ARES manufactured by TA Instruments.
Further, the slope α of the storage elastic modulus in the frequency-storage elastic modulus logarithmic plot curve in the frequency range of 0.1 to 10 rad / s of the crosslinked thermoplastic resin composition and the loss elastic modulus in the frequency-loss elastic modulus logarithmic plot curve. The slope β was obtained, and α-β that was a frequency dependent parameter of tan δ was obtained.

(2) Solvent dissolution test method for crosslinked products:
Diameter Φ approx. 3mm x Length approx. 3mm Cut pellet shaped cross-linked product, polyester resin is immersed in a mixed solvent of phenol and tetrachloroethane for normal temperature x 40 hr or more, polyamide type is immersed in formic acid at normal temperature x 40 hr or more, solvent The presence or absence of the residue after removal was confirmed visually. A transparent solvent gel remained in the swollen shape of the pellet before immersion, and when the same number of solvent swollen gels as the number of immersed pellets could be confirmed, it was expressed as “insoluble”. It is dissolved in the solvent and removed together with the solvent when removing the solvent, or the shape of the solvent swollen gel is greatly collapsed from the soaked pellet shape, and it is expressed as “dissolved” when it is divided and does not retain the shape X.

(3) Dispersion test method for non-crosslinked thermoplastic resin of crosslinked product:
With respect to the crosslinked thermoplastic resin composition X (A ′) obtained by subjecting any thermoplastic resin X (A) to a crosslinking treatment, dispersibility in the non-crosslinked thermoplastic resin X (A) was evaluated as follows. .
Cross-linked thermoplastic resin X (A ′) and non-crosslinked thermoplastic resin X (A) subjected to cross-linking treatment are used for a twin screw extruder (Ikegai Iron Works Co., Ltd., PCM30) at least 10 ° C. or more than the melting point of both resins. At a high cylinder temperature setting and a screw rotation speed of 120 rpm, the sum of X (A ′) and X (A) is 100 parts by weight, and the ratio of X (A) / X (A ′) = 70 parts by weight / 30 parts by weight. The mixture was melted and kneaded, extruded into a strand form in a water bath, cooled, and then cut to obtain pellets of a resin composition. The obtained resin composition pellets were dried by vacuum drying until the moisture content was 0.05% by mass or less, and then a sheet-like molded product having a thickness of 200 μm was prepared by extrusion molding.

  The obtained sheet surface state was confirmed by visual observation for irregularities due to the gel product or for a gel product of 100 μm or more. In the case of a sheet having a thickness of 200 μm, it was confirmed that unevenness was always observed when a gel product having a thickness of 100 μm or more was present. Therefore, a sheet having a smooth sheet surface was determined to be “dispersed”. A 200 μm sheet with conspicuous irregularities, or a sheet with no smooth strands without forming a sheet, was designated as “dispersion failure”. When the relationship between visual observation and the gel product is difficult to understand, the cross-linked thermoplastic resin composition X (A ′) is converted into the non-cross-linked thermoplastic resin X (A) by a transmission electron microscope (TEM) or a scanning electron microscope (SEM). ) To confirm the structure dispersed inside. In addition, regarding a resin such as polylactic acid, which has a strong tendency to decompose by radiation, the structure was observed with a scanning probe microscope (SPM) in order to show a decomposition tendency during observation with an electron microscope.

(4) Method for measuring strain hardening coefficient in log-log plot curve of time-uniaxial extensional viscosity:
Using TA Instruments ARES, EVF (Extensional Visibility Fixture) manufactured by TA Instruments was used as a measurement jig. The measurement conditions were a temperature up to at least 10 to 50 ° C. higher than the DSC melting point of the measurement resin and a strain rate of at least 1.0 (s ⁻¹ ). The strain hardening coefficient represented by the formula was obtained.
Strain hardening coefficient = a2 / a1
a1: slope of linear region in log-log plot curve of time-uniaxial extensional viscosity
a2: The slope of the nonlinear region in the logarithmic plot curve of time-uniaxial extensional viscosity Here, a1 was determined as follows without using a simple method.
That is, using ARES manufactured by TA Instruments and a parallel plate of 25 mm as a measuring jig, strain = 10%, temperature = same temperature as uniaxial extensional viscosity measurement, GAP = 0.7 to 1.5 mm and frequency 0 The frequency dependence data of the shear viscosity in the range of 1 to 100 rad / s was obtained, and the triple value of the shear viscosity obtained from this: 3ηs was plotted on the log-log plot of time-shear viscosity, and the slope of the plot line Was the slope a1 of the linear region in the logarithmic plot curve of time-extension viscosity.

(5) Dispersion structure observation method:
Depending on the characteristics of the sample, (a) TEM (transmission electron microscope), (b) SEM (scanning electron microscope) can be used to observe the structure of the crosslinked thermoplastic resin composition (A ′) and non-crosslinked thermoplastic resin (B). ), (C) SPM (scanning probe microscope), (d) phase microscope, (e) differential interference microscope, and the like.
In the examples and comparative examples, specifically, observation with an electron microscope is performed by wrapping pellets obtained by melt-kneading a crosslinked thermoplastic resin composition (A ′) and a non-crosslinked thermoplastic resin (B) in a photocurable resin. Polishing after embedding and staining with 5-10% phosphotungstic acid aqueous solution was observed with SEM, or frozen sections obtained with cryomicrotome were stained with RuO ₄ with TEM. The method is not limited. The SPM, phase microscope, and differential interference microscope were also observed using frozen sections obtained with a cryotome.
The observed morphology of the sample was determined and described as follows.
A dispersion structure with a uniform dispersion order and a uniform dispersion shape is defined as “uniform” in the uniformity of the dispersion structure, and a dispersion structure with a dispersion order non-uniform and a dispersion shape is not uniform in the uniformity of the dispersion structure. Non-uniform ”.

Regarding the dispersion form, if at least one of a plurality of types of melt-kneaded resins is made into a matrix and other resins are dispersed in the form of particles in the matrix, it is referred to as “independent dispersion” and the plurality of types of resins that are melt-kneaded. In the case where the two have a co-continuous structure intermingled with each other, it is regarded as “co-continuous”. In the case of “independent dispersion”, the particle size of the observed dispersed particles is described as the dispersion order, and in the case of a co-continuous structure, the width of the phase in the continuous phase having an apparently small ratio in the observed image is represented by the dispersion order. It was. In addition, the case where no clear micron-order structure was observed was defined as “no structure”. The particle diameter of the dispersed particles was measured from the observation image using the maximum diameter of each particle in the observation image as the particle diameter. The dispersion order of the width of the phase and the dispersed particle size in the continuous phase were confirmed by 10 observation images.
Concerning the usefulness of the structure, the dispersion order is 10 μm or less and uniformly dispersed and “independent dispersion” or “co-continuous” is designated as ○ as a useful structure for functional design, and the dispersion order, structure uniformity, dispersion Those which do not satisfy these in the form were marked as “x” as a structure not sufficiently useful for functional design.

<Raw materials used in Examples and Comparative Examples>
PA6: “Toyobo Nylon T-800” manufactured by Toyobo Co., Ltd., which is 6 nylon with relative viscosity RV = 2.5
MXD6: MXD6 nylon with relative viscosity RV = 2.1, “Toyobo Nylon T-600”
PA66: 66 nylon with relative viscosity RV = 2.78, “Torea Milan CN3001N”
PCL: “PCL-H7” manufactured by Daicel Chemical Industries, which is a polycaprolactone having a molecular weight of 70000
PLA: “Lacia H100” manufactured by Mitsui Chemicals, which is polylactic acid having a melting point of 164 ° C.
Polyester elastomer (A): “GS430” manufactured by Toyobo Co., Ltd., which is a polybutylene terephthalate / polycaprolactone = 57/43 (% by weight) copolymer having a melting point of about 210 ° C. and a solution viscosity of 1.45 dl / g.
Polyester elastomer (b): “GP84D” manufactured by Toyobo Co., Ltd., which is a polybutylene terephthalate / PTMG = 53/47 (wt%) copolymer having a melting point of about 203 ° C. and a solution viscosity of 1.95 dl / g.
PBT: Polyethylene terephthalate having a relative viscosity of IV = 0.8 “1200S” manufactured by Toray Industries, Inc.
Crosslinking aid A: “TMAIC” which is trimethallyl isocyanurate manufactured by Nippon Kasei Co., Ltd.
Crosslinking aid B: “TAIC” which is triallyl isocyanurate manufactured by Nippon Kasei Co., Ltd.
Mold release agent: Montanate ester wax "WE40" manufactured by Clariant
Stabilizer: “Irganox B1171” manufactured by Ciba Specialty Chemicals

<Production and Evaluation of Crosslinked Thermoplastic Resin Composition>
The thermoplastic resin to be crosslinked and the crosslinking aid are mixed in the ratios described in Tables 1 and 2 and described in Tables 1 and 2 using a twin-screw extruder (Ikegai PCM30 die diameter 4 mm × 2 holes). A pellet-shaped thermoplastic resin composition was obtained by melting and kneading by temperature and screw rotation kneading, and cooling and cutting the strand. The obtained pellets are dried and placed in an aluminum moisture-proof bag, and irradiated with γ-rays until the dose shown in Tables 1 and 2 is reached with a γ-ray irradiation device (MDS Nordion, model JS10000HD) using Co-60 as a radiation source. Thus, a crosslinking treatment was performed to obtain a crosslinked thermoplastic resin composition in which the crosslinking state was specifically controlled. The obtained crosslinked thermoplastic resin composition was evaluated for solvent solubility and dispersibility in a non-crosslinked thermoplastic resin. Further, a logarithmic plot of frequency-storage elastic modulus, loss elastic modulus, and shear viscosity was obtained for the crosslinked thermoplastic resin composition, and the slope of the storage elastic modulus with respect to the frequency was obtained. The obtained evaluation results are shown in Tables 1 and 2.

It was also confirmed that the crosslinked thermoplastic resin compositions A-1 to A-4 in Table 1 had been crosslinked until they became insoluble in the respective good solvents, and the dispersibility with respect to the non-crosslinked thermoplastic resin was good. It was.
Further, the cross-linked thermoplastic resin compositions A-1 to A-4 have storage elastic moduli with respect to frequency when the viscoelastic properties at the time of melting are at least 0.1 to 10 rad / s in a log-log plot of frequency-storage elastic modulus. Since the absolute value of α-β, which is a frequency dependence parameter of tan δ, is 0.15 or less, the cross-linked resin composition in the present invention is adjusted to a constant cross-linked state with a slope of 0.2 to 1.0 It was confirmed that the product was suitable as the product (A ′), and further, it was confirmed that the storage elastic modulus in the viscoelasticity measurement above the melting point was 1E + 5 Pa or less in the range of 0.1 to 10 rad / s.
The cross-linked thermoplastic resin compositions A-5 to A-8 in Table 2 were adjusted at double gamma ray absorbed doses with respect to A-1 to A-4, respectively, and these were cross-linked until they became insoluble in a good solvent. It was confirmed that was progressing. In addition, in dispersibility evaluation for non-crosslinked thermoplastic resins, there is a gel-like dispersive body close to 1 mm ³ to the original pellet shape (diameter Φ about 3 mm × length about 3 mm cut pellet shape), extruded strand, cut Severe irregularities are seen in the pellets and the molded product, and the degree of crosslinking is high. In this way, if the crosslinking conditions are excessive and the crosslinking proceeds too much, the shape retention at the melting point or higher becomes high, and in the kneading with the non-crosslinked thermoplastic resin, it is difficult to disperse even when shearing at the melting temperature or higher. It was confirmed that the hard gel was more crosslinked. Since the crosslinked thermoplastic resins A-5 to A-8 are not deformed when melted, numerical data such as storage elastic modulus could not be measured by rheology measurement with a rheometer. In addition, with respect to the crosslinking conditions described in Table 1, all the radiation doses halved were dissolved in the solvent, and a sufficient crosslinked state could not be obtained.

Example 1 and Comparative Example 1
The combination and ratio of the crosslinked thermoplastic resin composition and the non-crosslinked thermoplastic resin in Table 3 were melt kneaded under the melt kneading conditions in Table 3 using a twin screw extruder (Ikegai PCM30 die diameter 4 mm × 2 holes). The strands were cooled and cut to obtain thermoplastic resin composition pellets of Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-4. The obtained composition was subjected to (1) a strain hardening coefficient in a time-extension viscosity curve, (2) a dispersion structure observation, and the results are shown in Table 3.
The structures of Examples 1-1 and 1-2 and Comparative Examples 1-1 and 1-2 were observed by a phase contrast microscope observation and an SPM observation of a frozen section obtained by a cryomicrotome. Regarding Example 1-3 and Comparative Example 1-3, the structure was observed by TEM observation of a frozen section obtained by a cryomicrotome and stained with RuO ₄ .

Examples 1-1 to 1-3 are thermoplastic resin compositions comprising the crosslinked thermoplastic resin of the present invention and a non-crosslinked thermoplastic resin, and the dispersion structure of the dispersion structure of Example 1-2 is shown in FIG. As shown, it is stabilized in a fine and uniform state on the order of microns. Furthermore, it is shown that it is a thermoplastic resin composition having strain hardening in a non-linear region in melt elongational viscosity. Furthermore, the strain hardening coefficient is extremely high, and it is shown that the rheology is sufficiently improved.
In Comparative Examples 1-1 to 1-3, the results of melt kneading of thermoplastic resins not subjected to crosslinking treatment are described. In Comparative Examples 1-1 to 1-3, two different resins are finely structured. However, in Comparative Example 1-2, as shown in FIG. It is hard to say that it is stable. In any of the comparative examples, including those in which the dispersed structure is apparently uniform, strain hardening does not appear in the non-linear region in the melt elongational viscosity, and the composition is not a rheologically useful composition.
In Comparative Example 1-4, but the PCL was subjected to undesirable excessive crosslinking treatment is melt-kneaded with PBT, 2-screw extruder in at all when no fine dispersion of the crosslinking PCL remains close to 1 mm ³ ~ pellet Come out of the machine (Ikegai PCM30 die diameter 4mm x 2 holes). This indicates that the hard gel formed by the excessive crosslinking treatment apparently comes out without being dispersed from the extruder in a normal state such as an unmelted product without needing detailed structural observation. As described above, the crosslinked thermoplastic resin composition in a crosslinked state higher than the crosslinking degree of the preferred crosslinked thermoplastic resin composition (A ′) in the present invention is melted with the non-crosslinked thermoplastic resin unless it is finely divided into fine particles in advance. It can be seen that fine kneading does not occur during kneading.

Example 2 and Comparative Example 2
Example 2-1 to Example 2-1 to Example 2 were carried out in the same manner as in Example 1 and Comparative Example 1, except that the combinations, ratios, and melt-kneading conditions of the crosslinked thermoplastic resin composition and the non-crosslinked thermoplastic resin were as shown in Table 4. The thermoplastic resin compositions of 2-3 and Comparative Examples 2-1 to 2-4 were obtained. Table 4 shows the results of evaluating the obtained thermoplastic resin composition in the same manner as in Example 1 and Comparative Example 1.

Examples 2-1 to 2-3 are thermoplastic resin compositions of the present invention, and the dispersion structure thereof is fine and uniform on the order of microns as shown in FIG. 3 in which the dispersion state of Example 2-2 is shown in FIG. It is shown that it is stabilized in a stable state. Furthermore, it is shown that it is a thermoplastic resin composition having strain hardening in a non-linear region in melt elongational viscosity. Furthermore, the strain hardening coefficient is extremely high, and it is shown that the rheology is sufficiently improved.
In Comparative Examples 2-1 to 2-3, the results of melt kneading of thermoplastic resins not subjected to crosslinking treatment are described. In Comparative Examples 2-1 to 2-3, two different resins are finely structured. However, in Comparative Example 2-2, as shown in FIG. Since the ratio of the melt-kneaded polyester elastomer (a) is high, a non-uniform sea-island structure in which PBT is dispersed in the matrix of the polyester elastomer (a) is obtained. It is considered that the phase separation process is faster than the non-uniformity of diameter observed by TEM, and it is difficult to say that the structure is stable. In Comparative Examples 2-1 to 2-3, including those that have an apparently uniform dispersion structure, none of the Comparative Examples exhibits strain hardening in the non-linear region in the melt elongational viscosity, and is a rheologically useful composition. is not.
In Comparative Example 2-4, an undesirably excessive polyester elastomer (I) was melt-kneaded with PBT, but this crosslinked polyester elastomer (I) was 1 mm ³ to a very fine shape that remained close to the pellet shape. It comes out of a twin screw extruder (Ikegai PCM30 die diameter 4 mm × 2 holes) without being dispersed. This indicates that the hard gel formed by the excessive crosslinking treatment apparently comes out without being dispersed from the extruder in a normal state such as an unmelted product without needing detailed structural observation. As described above, the crosslinked thermoplastic resin composition in a crosslinked state higher than the crosslinking degree of the preferred crosslinked thermoplastic resin composition (a) in the present invention is melt kneaded with the non-crosslinked thermoplastic resin unless it is finely divided into fine particles in advance. It can be seen that no fine dispersion is obtained.

Example 3 and Comparative Example 3
Examples 3-1 to 3-1 were carried out in the same manner as in Example 1 and Comparative Example 1, except that the combinations, ratios, and melt-kneading conditions of the crosslinked thermoplastic resin composition and the non-crosslinked thermoplastic resin were as shown in Table 5. The thermoplastic resin compositions of 3-3 and Comparative Examples 3-1 to 3-4 were obtained. Table 5 shows the results of evaluating the obtained thermoplastic resin composition in the same manner as in Example 1.

Examples 3-1 and 3-2 are thermoplastic resin compositions of the present invention, and the dispersion structure is shown to be stabilized in a fine and uniform state on the order of microns. In contrast, Comparative Examples 3-1 and 3-2 are resin compositions composed of two types of non-crosslinked polyamides corresponding to Examples 3-1 and 3-2. A clear structure could not be confirmed. The details of this cause need to be further verified, but polyamide 6, polyamide 66 and polyamide MXD6 are very compatible with each other, and MXD6 has a fast amide exchange reaction with polyamide 6, polyamide 66 in the molten state. In melt-kneading, the appearance in the micron order structure is quickly uniform. Thus, it is considered that highly compatible polyamide species are difficult to disperse independently on the micron order, and are difficult to structure independently of each other. However, in the embodiment of the present invention, since the polyamide 6 is appropriately cross-linked, it is dispersed in the polyamide 66 or the polyamide MXD6 independently without being extremely compatible and uniform, while having an interface affinity. It has been shown that the structure can be controlled even with soluble polyamide species. Further, in the examples, it is shown that the composition is a thermoplastic resin composition having strain hardening in a non-linear region in melt elongational viscosity. This strain hardening coefficient is an extremely high value, which indicates that the rheology is sufficiently improved.
In Comparative Example 3-2, PA6 that had been subjected to undesirable excessive crosslinking treatment was melt-kneaded with MXD6, but this crosslinked PA6 was biaxially extruded in a state of 1 mm ³ to a pellet shape without any fine dispersion. Come out of the machine (Ikegai PCM30 die diameter 4mm x 2 holes). This indicates that the hard gel formed by the excessive crosslinking treatment apparently comes out without being dispersed from the extruder in a normal state such as an unmelted product without needing detailed structural observation. As described above, the crosslinked thermoplastic resin composition in a crosslinked state higher than the crosslinking degree of the preferred crosslinked thermoplastic resin composition (A ′) in the present invention is melted with the non-crosslinked thermoplastic resin unless it is finely divided into fine particles in advance. It can be seen that fine kneading does not occur during kneading.

Next, supplementary explanation will be given with respect to the drawings.
FIG. 1 shows strain hardening data in a non-linear region at 180 ° C. melt elongational viscosity of Example 1-1 and Comparative Example 1-1. It has been shown that the strain hardening property of the thermoplastic resin composition of the present invention is manifested in a wide range of strain rates, and the rise of the melt elongational viscosity is very large. With respect to Comparative Example 1-1, it was shown that even at a relatively high strain rate (= 1 s ⁻¹ ) in which strain hardening is likely to occur, the melt elongation viscosity does not show a rising behavior and there is no strain hardening. Yes.
FIG. 2 shows strain hardening data in a non-linear region at 220 ° C. melt elongational viscosity of Example 2-3 and Comparative Example 2-3. Similar to FIG. 1, Example 2-3 exhibited strain hardening, whereas Comparative Example 2-3 had no strain hardening. In both FIG. 1 and FIG. 2, 3ηs, which is three times the shear viscosity, agrees well with the melt extensional viscosity in the linear region, and the slope is used as a parameter as the linear viscosity in the viscosity time-extension viscosity curve. Shows that this is reasonable.

FIG. 3 shows TEM observation photographs of Example 2-2 and Comparative Example 2-2. In Example 2-2, 60% by weight of the crosslinked polyester elastomer (i) (black contrast part) and 40% by weight of the non-crosslinked PBT (white contrast part) were finely interlaced with each other. It has a continuous structure and can be expected to have good heat resistance and mechanical properties. Comparative Example 2-2 is an example in which the polyester elastomer (A) is not subjected to crosslinking treatment as compared with Example 2-2. Since the polyester elastomer (A) is not crosslinked, the polyester elastomer (A) / PBT = 60/40 (weight% ratio) indicates that the polyester elastomer (A) becomes a matrix and the PBT is unevenly dispersed. It is heat resistant and cannot be expected to have mechanical properties or molding stability.
FIG. 4 shows 190 ° C. of the crosslinked thermoplastic resin compositions (A-1) and (A-2) as an example of the crosslinked thermoplastic resin composition (A) essential as a component of the thermoplastic resin composition of the present invention. It shows the frequency dependence of storage elastic modulus at 220 ° C., loss elastic modulus, and step viscosity.
The storage elastic modulus of these cross-linked thermoplastic resin compositions is adjusted to a certain preferable cross-linked state in which the gradient with respect to the frequency is uniform and is 0.2 to 1.0 in the range of at least 0.1 to 10 rad / s. The situation is shown. In particular, in the illustrated region, the storage elastic modulus of A-1 shows a value higher than the loss elastic modulus, and clearly shows the result of increase in the storage elastic modulus by the crosslinking treatment.

FIG. 5 shows the phase-contrast microscope image and SPM observation result of Example 1-2. It is shown that 60% by weight of crosslinked PCL and 40% by weight of non-crosslinked PLA have a co-continuous structure in which they are uniformly fine and interleaved.
FIG. 6 shows a phase contrast microscope image and SPM observation result of Comparative Example 1-2. Although the reason is not clarified, it is difficult to say that a non-uniform dispersion state is observed depending on the observation place and that the state is good. Presumably, the blended PCL is non-crosslinked and has a high PCL ratio, and is well affected by compatibility, transesterification, shearing and solidification cooling conditions, etc. It's hard to say.

The thermoplastic resin composition of the present invention exhibits good rheological properties without reducing the functional properties of the matrix and the dispersed thermoplastic resin, and has high strain-hardening properties in the nonlinear region in the melt elongational viscosity. A thermoplastic resin composition having high functionality and good moldability in blow molding, extrusion molding and foam molding can be obtained.
As a result, it is possible to achieve a wide range of design and functionality in a wide range of fields such as manufacturing of fibers, films, blow-molded products, and composite products thereof in home appliances and automobile parts. For this reason, the thermoplastic resin composition of the present invention can be usefully used in a wide range of fields and greatly contributes to the industry.

Claims (11)

Obtained by melt-kneading a crosslinked thermoplastic resin composition (A ′) having the following characteristics (a) obtained by crosslinking the non-crosslinked thermoplastic resin (A) and the non-crosslinked thermoplastic resin (B): A thermoplastic resin composition in which (A ′) is dispersed in a particle size of at most 20 μm in (B) or (A ′) and (B) are intertwined with each other. A thermoplastic resin composition characterized by being structured and having a strain-hardening property of (b) below in a non-linear region in melt uniaxial elongational viscosity.
(A) Form a solvent gel with the solvent without dissolving in the solvent of the thermoplastic resin (A) before crosslinking.
(B) The following strain hardening in a logarithmic plot curve of time-uniaxial extensional viscosity obtained by measuring melt uniaxial extensional viscosity at a temperature of at least 10 ° C. higher than the melting point of the non-crosslinked thermoplastic resin (B). The coefficient is 2 or more.
Strain hardening coefficient = a2 / a1
a1: slope of linear region in log-log plot curve of time-uniaxial extensional viscosity
a2: Slope of nonlinear region in log-log plot curve of time-uniaxial extensional viscosity The cross-linked thermoplastic resin composition (A ′) has a storage elasticity against frequency in the frequency range of 0.1 to 10 rad / s in a logarithmic plot curve of frequency-storage elastic modulus obtained by measuring its melt viscoelasticity in the linear region. The thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is in a crosslinked state in which the slope of the rate is 0.2 to 1.0. The cross-linked thermoplastic resin composition (A ′) exhibits a slope of the storage elastic modulus in a logarithmic plot curve of frequency-storage elastic modulus in a frequency range of 0.1 to 10 rad / s in melt viscoelasticity measurement in the linear region. The thermoplasticity according to claim 1 or 2, wherein the absolute value of the difference between α and β is 0.15 or less, where β is the slope of loss modulus in the logarithmic plot curve of α and frequency-loss modulus. Resin composition. The thermoplastic resin composition according to claim 1, wherein the crosslinked thermoplastic resin composition (A ′) is irradiated with radiation. The crosslinked thermoplastic resin composition (A ') is obtained by irradiating a pellet obtained by melt-kneading a non-crosslinked thermoplastic resin (A) and a crosslinking aid. The thermoplastic resin composition according to claim 1. The crosslinked thermoplastic resin composition (A ′) is obtained by blending a non-crosslinked thermoplastic resin (A) with a crosslinking aid and / or an organic peroxide and crosslinking by melt kneading. The thermoplastic resin composition in any one of -5. Crosslinked thermoplastic resin composition (A ') at least 50% by weight polyamide resin, thermoplastic resin composition according to claim 1 is any one of polyester resins and polyolefin resins in. Crosslinked thermoplastic resin composition (A ') is absorbed dose pellets of the resin composition obtained by melt kneading which includes a port re-caprolactone 50 to 99.9 parts by weight and the crosslinking aid 0.1-3 parts by weight the thermoplastic resin composition according to any one of claims 1 to 7 is made is irradiated to 0.5～25KGy. Crosslinked thermoplastic resin composition (A ') is Po Li ester elastomer 50 to 99.9 parts by weight and absorb the resin composition containing a crosslinking assistant 0.1-3 parts by weight obtained by melt-kneading pellets dose 0 the thermoplastic resin composition according to any one of claims 1 to 7 made of is irradiated on .5～60KGy. Crosslinked thermoplastic resin composition (A ') is, Polyamide 50 to 99.9 parts by weight and absorb the resin composition containing a crosslinking assistant 0.1-3 parts by weight obtained by melt-kneading pellets dose 0. The thermoplastic resin composition according to any one of claims 1 to 7 , which is irradiated with 5 to 20 kGy. Crosslinked thermoplastic resin composition (A ′) pellets and non-crosslinked thermoplastic resin (B) pellets that are crosslinked so as to form a solvent gel with the solvent without dissolving in the solvent of the noncrosslinked thermoplastic resin (A) And (A ′) and (B) a method for producing a strain-hardening thermoplastic resin composition, which is melt kneaded at a temperature equal to or higher than the melting point of the pellets.