THERMOPLASTIC RESIN COMPOSITION AND METHOD FOR PRODUCING

Abstract

A thermoplastic resin composition including a fluororesin (A) and a crosslinked fluoroelastomer (B), wherein the fluororesin (A) is a copolymer that contains a chlorotrifluoroethylene unit and a tetrafluoroethylene unit and that has at least one functional group selected from a carbonyl group, an olefinic group and an amino group at a main chain terminal or side chain terminal of the polymer. The crosslinked fluoroelastomer (B) is obtained by subjecting a fluoroelastomer (b) to a dynamic crosslinking treatment along with a polyamine compound (c) having a thermal decomposition temperature of 210 C. or higher and a crosslinking accelerator (d) in the presence of the fluororesin (A) under conditions for melting the fluororesin (A). Also disclosed is a method for producing the thermoplastic composition, a molded article formed from the thermoplastic composition, and a laminated product including a resin layer formed from the thermoplastic composition.

Claims

1. A thermoplastic resin composition comprising a fluororesin (A) and a crosslinked fluoroelastomer (B), wherein the fluororesin (A) is a copolymer that contains a chlorotrifluoroethylene unit and a tetrafluoroethylene unit and that has at least one functional group selected from the group consisting of a carbonyl group, an olefinic group and an amino group at a main chain terminal or side chain terminal of the polymer, and wherein the crosslinked fluoroelastomer (B) is obtained by subjecting a fluoroelastomer (b) to a dynamic crosslinking treatment along with a polyamine compound (c) having a thermal decomposition temperature of 210 C. or higher and a crosslinking accelerator (d) in the presence of the fluororesin (A) under conditions for melting the fluororesin (A), the amount of the polyamine compound (c) is 0.5 to 15 parts by mass based on 100 parts by mass of the fluoroelastomer (b), the amount of the crosslinking accelerator (d) to be compounded is preferably 0.01 to 10 parts by mass based on 100 parts by mass of the fluoroelastomer (b).

2. The thermoplastic resin composition according to claim 1, wherein the fluoroelastomer (b) is a vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene-based fluoroelastomer.

3. (canceled)

4. A method for producing the thermoplastic resin composition according to claim 1, comprising: subjecting the fluoroelastomer (b) to the dynamic crosslinking treatment along with the polyamine compound (c) having a thermal decomposition temperature of 210 C. or higher and the crosslinking accelerator (d) in the presence of the fluororesin (A) under conditions for melting the fluororesin (A).

5. A molded article formed from the thermoplastic resin composition according to claim 1.

6. A laminated product comprising a thermoplastic resin layer (W) formed from the thermoplastic resin composition according to claim 1 and an elastomer layer (X) formed from an elastomer composition.

7. The laminated product according to claim 6, wherein the elastomer composition contains at least one elastomer selected from the group consisting of an acrylonitrile-butadiene rubber, a hydrogenated acrylonitrile-butadiene rubber, a blend rubber between an acrylonitrile-butadiene rubber and a polyvinyl chloride, a blend rubber between an acrylonitrile-butadiene rubber and an acrylic rubber, a chlorinated polyethylene, a fluoroelastomer, an epichlorohydrin rubber, an ethylene-propylene rubber, a chlorosulfonated polyethylene rubber, a silicone rubber and an acrylic rubber.

8. The laminated product according to claim 6 or 7, wherein the elastomer composition contains at least one compound selected from the group consisting of an onium salt, an amine compound and an epoxy resin.

9. A hose or tube for fuel, comprising the molded article according to claim 5.

10. The thermoplastic resin composition according to claim 1, wherein the crosslinking accelerator (d) is a quaternary phosphonium salt.

11. The thermoplastic resin composition according to claim 1, wherein the polyamine compound (c) is 2,2-bis[4-(4-aminophenoxy)phenyl]propane.

12. A hose or tube for fuel, comprising the laminated product according to claim 6.

Description

EXAMPLES

[0185] Hereinafter, embodiments of the present disclosure will be described with reference to Examples, but the present disclosure is not limited solely to such Examples.

[0186] Each numerical value in Examples was measured according to the following method.

[0187] Monomeric Composition

[0188] The monomeric composition was measured by .sup.19F-NMR analysis.

[0189] Melting Point

[0190] The melting point was obtained by recording the melting peak upon increasing the temperature at a rate of 10 C./min using a differential scanning calorimeter [DSC] and determining a temperature corresponding to the maximum value.

[0191] Melt Flow Rate (MFR)

[0192] The MFR was obtained by measuring the mass (g) of a polymer flowing out from the nozzle with a diameter of 2 mm and a length of 8 mm per unit time (10 minutes) under a load of 5 kg at 297 C., using a melt indexer (manufactured by Toyo Seiki Seisaku-sho, Ltd.).

[0193] Number of Functional Groups of Fluororesin

[0194] For a fluororesin sheet, the infrared absorption spectrum was analyzed by using a Fourier transform infrared spectrophotometer [FT-IR]. The absorbance of a certain peak was measured by automatically determining the baseline of the obtained infrared absorption spectrum using Perkin-Elmer Spectrum for windows Ver. 1.4C. Note that the peak derived from the carbonyl group of a carbonate group [OC(O)O] is exhibited at an absorption band of 1,810 to 1,815 cm.sup.1.

[0195] Mooney Viscosity

[0196] The Mooney viscosity was measured in accordance with ASTM D-1646 at 121 C. using a Mooney viscometer, Model MV2000E manufactured by Alpha Technologies.

[0197] Infrared Absorption Spectrum Analysis

[0198] (Fabrication of Thermoplastic Resin Sheet)

[0199] The thermoplastic resin composition was placed in a metal mold with a diameter of 120 mm, set in a press machine that had been heated to 300 C., and subjected to melt pressing at a pressure of about 2.9 MPa, thereby obtaining a thermoplastic resin sheet with a thickness of 0.25 mm or a thickness of 0.5 mm.

[0200] (Calculation of Ratio between Heights of Absorption Peaks)

[0201] For the thermoplastic resin sheet with a thickness of 0.25 mm, the infrared absorption spectrum was measured by the transmission method using a Fourier transform infrared spectrophotometer [FT-IR], and the ratio [K1] and the ratio [K2] were calculated according to the following equations.

Ratio [K1]=H1a/H1b

Ratio [K2]=H2a/H2b

[0202] H1a: the absorbance height at 3,451 cm.sup.1 from a straight line obtained by connecting each absorbance at 3,475 cm.sup.1 and 3,415 cm.sup.1 as the baseline

[0203] H1b: the absorbance height at 2,360cm.sup.1 from a straight line obtained by connecting each absorbance at 2,680cm.sup.1 and 2,030cm.sup.1 as the baseline

[0204] H2a: the absorbance height at 1,722cm.sup.1 from a straight line obtained by connecting each absorbance at 1,760cm.sup.1 and 1,660cm.sup.1 as the baseline

[0205] H2b: the absorbance height at 3,035 cm.sup.1 from a straight line obtained by connecting each absorbance at 3,170 cm.sup.1 and 2,900 cm.sup.1 as the baseline

[0206] Evaluation of Barrier Properties against Fuel

[0207] (Fuel Permeability Coefficient)

[0208] In a container made of SUS having a volume of 20 mL (opening area: 1.2610.sup.3 m.sup.2), 18 mL of CE10 (toluene/isooctane/ethanol=45/45/10% by volume), which is a simulant fuel, was placed, and the thermoplastic resin sheet with a thickness of 0.25 mm fabricated according to the method described above was set at the opening of the container to seal it, thereby creating a test piece. The test piece was placed in a thermostat (60 C.), the weight of the test piece was measured, and when the weight reduction per unit time became constant, the fuel permeability coefficient was determined according to the following equation. The fuel permeability coefficient of a fluororesin was determined in the same manner.

[00002]$\mathrm{Fuel}.Math..Math.\mathrm{Permeability}.Math..Math.\mathrm{Coefficient}.Math..Math.\left(\left(g.Math.\mathrm{mm}\right)/\left(m^2.Math.\mathrm{day}\right)\right)=\frac{\left[\mathrm{Weight}.Math..Math.\mathrm{Reduction}.Math..Math.\left(g\right)\right]\left[\mathrm{Sheet}.Math..Math.\mathrm{Thickness}.Math..Math.\left(\mathrm{mm}\right)\right]}{\left[\mathrm{Opening}.Math..Math.\mathrm{Area}.Math..Math.1.26{10}^{-3}.Math.\left(m^2\right)\right]\left[\mathrm{Measurement}.Math..Math.\mathrm{Interval}.Math..Math.\left(\mathrm{day}\right)\right]}$

[0209] Tensile Elasticity

[0210] From the thermoplastic resin sheet with a thickness of 0.5 mm fabricated according to the method described above, a dumbbell-shaped specimen with a distance between marked lines of 3.18 mm was punched out using an ASTM D638 Type V dumbbell. For the obtained dumbbell-shaped specimen, a tensile test was carried out at a tensile speed of 50 mm/min at 25 C. in accordance with ASTM D638 with Autograph (AGS-J 5kN manufactured by Shimadzu Corporation), thereby measuring the tensile elasticity. The tensile elasticity of a fluororesin was measured in the same manner.

[0211] Evaluation of Adhesiveness

[0212] (Fabrication of Elastomer Composition)

[0213] To 100 parts by mass of a VdF/TFE/HFP copolymer with a monomeric composition of VdF/TFE/HFP=58/20/22 (molar ratio) and a Mooney viscosity ML (1+10) at 121 C. of 44, 2.2 parts by mass of bisphenol AF and 0.56 parts by mass of DBU-B were added and kneaded, thereby obtaining an elastomer composition intermediate. To 100 parts by mass of the elastomer composition intermediate, 3.0 parts by mass of magnesium oxide, 6 parts by mass of calcium hydroxide and 13 parts by mass of SRF carbon black were added and kneaded, thereby obtaining an elastomer composition.

[0214] (Fabrication of Laminated Product)

[0215] The thermoplastic resin sheet with a thickness of 0.5 mm fabricated according to the method described above and a sheet of the elastomer composition with a thickness of about 2 mm were superposed, and these sheets were introduced in a metal mold for forming a sheet with a thickness of 2 mm and pressed at 160 C. for 45 minutes, thereby obtaining a sheet-like laminated product.

[0216] (Method for Evaluating Adhesiveness)

[0217] Each of the obtained laminated products was cut into strips having a width of 1.0 cm by 10 cm to fabricate a test piece for the adhesion test, and for this test piece, the peeling test was carried out at a tensile speed of 50 mm/min at 25 C. in accordance with the method described in JIS-K-6256 (adhesion testing method for vulcanized rubber) with Autograph (AGS-J 5kN manufactured by Shimadzu Corporation). In addition, the peeling mode was observed and evaluated according to the following criteria.

[0218] Good: The elastomer layer was broken without peeling at the interface of thermoplastic resin layer/elastomer layer.

[0219] Poor: The layers were peeled at the interface of thermoplastic resin layer/elastomer layer.

[0220] The following materials were used in Examples and Comparative Examples.

[0221] Fluororesin:

[0222] CTFE/TFE copolymer having a OC(O)OCH.sub.2CH.sub.2CH.sub.3 group. The monomeric composition is CTFE/TFE/perfluoro(propyl vinyl ether)=21.0/76.2/2.8 (molar ratio). The melting point is 245 C. The MFR at 297 C. is 19 g/10 min. The number of OC(O)OCH.sub.2CH.sub.2CH.sub.3 groups is 80 (per 10.sup.6 carbon atoms). The tensile elasticity is 610 MPa. The fuel permeability coefficient is 0.4 (g.Math.mm)/(m.sup.2.Math.day).

[0223] Fluoroelastomer (b1):

[0224] VdF/TFE/HFP copolymer with a monomeric composition of VdF/TFE/HFP=50/20/30 (molar ratio). The Mooney viscosity ML (1+10) at 121 C. is 50.

[0225] Fluoroelastomer (b2):

[0226] VdF/TFE/HFP copolymer with a monomeric composition of VdF/TFE/HFP=58/20/22 (molar ratio). The Mooney viscosity ML (1+10) at 100 C. is 45.

[0227] Polyamine compound: BAPP (thermal decomposition temperature: 315 C.)

[0228] Crosslinking accelerator: DBU-B

[0229] Acid acceptor: magnesium oxide

Example 1

[0230] (Step 1) To the fluoroelastomer (b1) described above, DBU-B and magnesium oxide were added and kneaded, thereby obtaining a fluoroelastomer composition (b1-1).

[0231] (Step 2)

[0232] The fluororesin described above was placed in LABO PLASTOMILL (manufactured by Toyo Seiki Seisaku-sho, Ltd.), BAPP was added thereto, and the contents were stirred until the dispersion and reaction sufficiently proceeded to result in a stable torque. Furthermore, the fluoroelastomer composition (b1-1) was added, and stirring was stopped when the dispersion and reaction sufficiently proceeded to result in a stable torque, thereby obtaining a thermoplastic resin composition. At this time, the temperature of the thermoplastic resin composition was 280 C. The amount of each material to be compounded and the results of various measurements are shown in Table 1.

Example 2

[0233] A thermoplastic resin composition was obtained by carrying out kneading under the same conditions as in Example 1, except that in the step 2, BAPP and the fluoroelastomer composition (b1-1) were added in the reverse order. The amount of each material to be compounded and the results of various measurements are shown in Table 1.

Comparative Example 1

[0234] A thermoplastic resin composition was obtained by carrying out kneading under the same conditions as in Example 1, except that in the step 1, DBU-B was not added to the fluoroelastomer (b1). The amount of each material to be compounded and the results of various measurements are shown in Table 1.

Comparative Example 2

[0235] A thermoplastic resin composition was obtained by carrying out kneading under the same conditions as in Example 1, except that in the step 1, DBU-B was not added to the fluoroelastomer (b1), and furthermore, that BAPP was added in the step 1 instead of the step 2. The amount of each material to be compounded and the results of various measurements are shown in Table 1.

Example 3

[0236] A thermoplastic resin composition was obtained by carrying out kneading under the same conditions as in Example 1, except that the amounts of magnesium oxide and BAPP to be compounded were changed. The amount of each material to be compounded and the results of various measurements are shown in Table 1.

Example 4

[0237] A thermoplastic resin composition was obtained by carrying out kneading under the same conditions as in Example 3, except that the amount of BAPP to be compounded was changed. The amount of each material to be compounded and the results of various measurements are shown in Table 1.

Example 5

[0238] A thermoplastic resin composition was obtained by carrying out kneading under the same conditions as in

[0239] Example 3, except that in the step 1, the fluoroelastomer (b2) was used instead of the fluoroelastomer (b1), that the amount of DBU-B to be compounded was changed, and furthermore, that BAPP was added in the step 1 instead of the step 2. The amount of each material to be compounded and the results of various measurements are shown in Table 1.

Example 6

[0240] A thermoplastic resin composition was obtained by carrying out kneading under the same conditions as in Example 5, except that the amount of DBU-B to be compounded was changed. The amount of each material to be compounded and the results of various measurements are shown in Table 1.

TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Formulation (parts by mass) Fluororesin 80 80 80 80 80 80 80 80 Fluoroelastomer (b1) 18.8 18.8 18.8 18.8 18.8 18.8 Fluoroelastomer (b2) 18.8 18.8 BAPP 0.6 0.6 0.6 0.6 0.8 1.6 0.8 0.8 DBU-B 0.045 0.045 0 0 0.045 0.045 0.027 0.019 Magnesium oxide 0.6 0.6 0.6 0.6 0.8 0.8 0.8 0.8 Mass ratio between 81/19 81/19 81/19 81/19 81/19 81/19 81/19 81/19 fluororesin and fluoroelastomer Volume ratio between 79/21 79/21 79/21 79/21 79/21 79/21 79/21 79/21 fluororesin and fluoroelastomer Infrared absorption spectrum Ratio [K1] between heights 0.037 0.008 0.036 0.036 0.033 0.035 0.033 0.042 Ratio [K2] between heights 1.84 0.86 0.17 0.12 2.25 2.58 1.90 0.53 Physical properties Fuel Permeability Coefficient (g .Math. mm)/ 1.2 1.0 1.0 0.7 1.1 1.0 1.2 1.2 (m.sup.2 .Math. day) MFR g/(10 min) 4 8 8 8 4 4 5 5 Tensile elasticity MPa 370 360 387 352 361 367 365 365 Evaluation of adhesiveness good good poor poor good good good good