Laminated article

Abstract

A laminated article includes a thermoplastic resin expanded beads molded layer A having a volume Va and a tensile modulus TMa which is 2 to 100 MPa, and a thermoplastic elastomer expanded beads molded layer B having a volume Vb and a tensile modulus TMb which is 0.05 MPa or more and less than 2 MPa, the layers A and B being laminated and bonded to each other. Va:Vb is 90:10 to 50:50 and TMb/TMa is 0.025 or less.

Claims

1. A laminated article comprising a molded layer A comprised of a multiplicity of first expanded beads of a first base polymer including a thermoplastic resin, and a molded layer B laminated and bonded to said molded layer A and comprised of a multiplicity of second expanded beads of a second base polymer including a thermoplastic elastomer, said first expanded beads being fusion-bonded to each other and each having a multiplicity of cells formed by said first base polymer, said second expanded beads being fusion-bonded to each other and each having a multiplicity of cells formed by said second base polymer, said molded layer A having a volume Va and a tensile modulus TMa which is 2 to 100 MPa as measured according to JIS K6767(1999), said molded layer B having a volume Vb and a tensile modulus TMb which is 0.05 MPa or more and less than 2 MPa as measured according to JIS K6767(199), wherein Va:Vb is 90:10 to 50:50 and TMb/TMa is 0.025 or less.

2. The laminated article according to claim 1, wherein said thermoplastic resin has a first flexural modulus of 200 to 4,000 MPa as measured according to JIS K7171(2008), and said thermoplastic elastomer has a second flexural modulus of 50 MPa or less as measured according to JIS K7171(2008).

3. The laminated article according to claim 1, wherein said thermoplastic resin is a polypropylene-based resin and said molded layer A has a density Da of 15 to 200 kg/m.sup.3.

4. The laminated article according to claim 1, wherein said thermoplastic elastomer is an olefin-based elastomer and said molded layer B has a density Db of 20 to 200 kg/m.sup.3.

5. The laminated article according to claim 4, wherein said molded layer B has a hot xylene insolubles content of 30% by weight or more.

6. The laminated article according to claim 1, wherein said molded layer B has void spaces that are in communication with an outside of said molded layer B and has a voidage of 5 to 50%, wherein said void spaces include interstices formed between said second expanded beads.

7. The laminated article according to claim 6, wherein the second expanded beads have through holes that constitute a part of the void spaces of said molded layer B.

8. The laminated article according to claim 1, wherein said molded layer A and said molded layer B are fusion-bonded to each other.

9. The laminated article according to claim 2, wherein said thermoplastic resin is a polypropylene-based resin and said molded layer A has a density Da of 15 to 200 kg/m.sup.3.

10. The laminated article according to claim 2, wherein said thermoplastic elastomer is an olefin-based elastomer and said molded layer B has a density Db of 20 to 200 kg/m.sup.3.

11. The laminated article according to claim 3, wherein said thermoplastic elastomer is an olefin-based elastomer and said molded layer B has a density Db of 20 to 200 kg/m.sup.3.

12. The laminated article according to claim 9, wherein said molded layer B has a hot xylene insolubles content of 30% by weight or more.

13. The laminated article according to claim 10, wherein said molded layer B has a hot xylene insolubles content of 30% by weight or more.

14. The laminated article according to claim 11, wherein said molded layer B has a hot xylene insolubles content of 30% by weight or more.

15. The laminated article according to claim 2, wherein said molded layer B has void spaces that are in communication with an outside of said molded layer B and has a voidage of 5 to 50%, wherein said void spaces include interstices formed between said second expanded beads.

16. The laminated article according to claim 3, wherein said molded layer B has void spaces that are in communication with an outside of said molded layer B and has a voidage of 5 to 50%, wherein said void spaces include interstices formed between said second expanded beads.

17. The laminated article according to claim 4, wherein said molded layer B has void spaces that are in communication with an outside of said molded layer B and has a voidage of 5 to 50%, wherein said void spaces include interstices formed between said second expanded beads.

18. The laminated article according to claim 5, wherein said molded layer B has void spaces that are in communication with an outside of said molded layer B and has a voidage of 5 to 50%, wherein said void spaces include interstices formed between said second expanded beads.

19. The laminated article according to claim 16, wherein the second expanded beads have through holes that constitute a part of the void spaces of said molded layer B.

20. The laminated article according to claim 17, wherein the second expanded beads have through holes that constitute a part of the void spaces of said expanded beads molded layer B.

Description

EXAMPLES

(1) The present invention will be described in detail below by way of examples. The present invention is not restricted to the examples, however.

(2) Expanded Beads:

(3) The following expanded beads were used In Examples and Comparative Examples.

(4) (1) Expanded Beads A

(5) P-BLOCK 15P manufactured by JSP Corporation (abbreviation: EPP), (apparent density: 78 kg/m.sup.3, bulk density: 49 kg/m.sup.3, average particle diameter: 2.5 mm, high temperature peak calorific value: 16 J/g, through hole: none, base polymer: propylene-ethylene random copolymer (melting point 142° C., flexural modulus 1,050 MPa))
(2) Expanded Beads B
2-1) Olefin-based thermoplastic elastomer expanded beads 1 (abbreviation ETPO1), (apparent density: 74 kg/m.sup.3, bulk density: 35 kg/m.sup.3, average particle diameter: 4.1 mm, hot xylene insolubles content: 48% by weight, through hole: provided (cylindrical), inner diameter: 2.2 mm, base polymer: TPO (INFUSE®9530 (block copolymer having a polyethylene block and an ethylene-octene random copolymer block, melting point: 121° C., flexural modulus: 28 MPa, durometer hardness HDA: 86)))
(2-2) Olefin-based thermoplastic elastomer expanded beads 2 (abbreviation ETPO2), (apparent density: 136 kg/m.sup.3, bulk density: 73 kg/m.sup.3, average particle diameter 3.7 mm, hot xylene insolubles content: 50% by weight, through hole: provided (cylindrical), inner diameter: 2.1 mm, base polymer: TPO (INFUSE®9530 (block copolymer having a polyethylene block and an ethylene-octene random copolymer block, melting point: 121° C., flexural modulus: 28 MPa, durometer hardness HDA: 86)))
(2-3) Olefin-based thermoplastic elastomer expanded beads 3 (abbreviation ETPO3), (apparent density: 196 kg/m.sup.3, bulk density: 96 kg/m.sup.3, average particle diameter 3.4 mm, hot xylene insolubles content: 52% by weight, through hole: provided (cylindrical), inner diameter: 1.9 mm, base polymer: TPO (INFUSE®9530 (block copolymer having a polyethylene block and an ethylene-octene random copolymer block, melting point: 121° C., flexural modulus: 28 MPa, durometer hardness HDA: 86)))
(2-4) Olefin-based thermoplastic elastomer expanded beads 4 (abbreviation ETPO4), (apparent density: 176 kg/m.sup.3, bulk density: 110 kg/m.sup.3, average particle diameter: 3.6 mm, hot xylene insolubles content: 50% by weight, through-hole: none, base polymer: TPO (INFUSE®9530 (block copolymer having a polyethylene block and an ethylene-octene random copolymer block, melting point 121° C., flexural modulus 28 MPa, durometer hardness HDA: 86)))
(2-5) Olefin-based thermoplastic elastomer expanded beads 4 (abbreviation: ETPO5), (apparent density: 128 kg/m.sup.3, bulk density: 80 kg/m.sup.3, average particle diameter 4.0 mm, hot xylene insolubles content: 50% by weight, through-hole: none, base polymer: TPO (INFUSE®9530 (block copolymer having a polyethylene block and an ethylene-octene random copolymer block, melting point 121° C., flexural modulus 28 MPa, durometer hardness HDA: 86)))

(6) HDA is a value measured in an atmosphere of 23° C. and a relative humidity of 50%.

Molding of Laminated Article

Examples 1 to 3 and Comparative Examples 1 and 2

(7) The expanded beads A and the expanded beads B were subjected to integral molding using a mold having a mold cavity having a longitudinal length of 250 mm, a lateral length of 200 mm and a thickness of 50 mm. First, with the dimension of the mold cavity in the thickness direction being made 45 mm, the expanded beads A were filled thereinto. The mold was then closed such that the dimension in the thickness direction became 40 mm. Thereafter, the expanded beads A were heated with steam of 0.16 MPa(G) and fusion-bonded together, thereby to obtain an intermediate molded layer having a large amount of void spaces between the expanded beads.

(8) Subsequently, the mold was opened until the dimension in the thickness direction of the mold cavity became 65 mm, and the expanded beads B shown in Table 1 were filled in the cavity. Thereafter, the mold was closed such that the dimension in the thickness direction became 50 mm. The intermediate molded layer and the expanded beads B were then heated with steam of 0.20 MPa (G). As a result, the fusion bonding of the expanded beads A proceeded to form a molded layer A in which the void spaces disappeared and, at the same time, the expanded beads B were fusion bonded to form an expanded beads molded layer B, thereby obtaining a laminated article in which the molded layer A and the molded layer B were laminated and bonded together.

(9) Various physical properties of the obtained laminated article and the molded layers A and B are shown in Table 1.

(10) TABLE-US-00001 TABLE 1 Comparative Comparative Example 1 Example 2 Example 3 Example 1 Example 2 Production method integral molding integral molding integral molding integral molding integral molding Molded Expanded beads EPP EPP EPP EPP EPP Layer Density Da [kg/m.sup.3] 60 60 60 60 60 A Tensile modulus TMa [MPa] 26 26 26 26 26 Shrinkage [%] 2 2 2 2 2 Molded Expanded beads ETPO1 ETPO2 ETPO3 ETPO4 ETPO5 Layer Void spaces exist exist exist not exist not exist B Voidage [%] 20 20 20 — — Density Db [kg/m.sup.3] 54 80 120 130 100 Tensile modulus TMb [MPa] 0.15 0.3 0.55 1.1 8.2 Hot xylene insolubles content [wt %] 48 50 52 50 50 Shrinkage [%] 11 8 5 4 5 Laminated Volume ratio (VaNb) 80/20 80/20 80/20 80/20 80/20 Article Whole apparent density [kg/m.sup.3] 60 64 72 74 68 Ratio (TMb/TMa) 0.006 0.012 0.021 0.042 0.031 Ratio (Db/Da) 0.9 1.33 2 2.17 1.66 Warpage immediately after molding A A A C C Warpage at high temperature A A A not evaluated not evaluated

Example 4 and Comparative Examples 3 and 4

(11) The expanded beads A were subjected to in-mold molding using a mold having a mold cavity having a longitudinal length of 250 mm, a lateral length of 200 mm and a thickness of 50 mm. With the dimension of the mold cavity in the thickness direction being made 55 mm, the expanded beads A were filled thereinto. The mold was then closed such that the dimension in the thickness direction became 50 mm. The mold was then closed such that the dimension in the thickness direction became 50 mm. Thereafter, the expanded beads A were heated with steam of 0.24 MPa(G) and fusion-bonded together, thereby to obtain a molded layer A.

(12) The expanded beads B were subjected to in-mold molding using a mold having a mold cavity having a longitudinal length of 250 mm, a lateral length of 200 mm and a thickness of 20 mm. With the dimension of the mold cavity in the thickness direction being made 25 mm, the expanded beads B were filled thereinto. The mold was then closed such that the dimension in the thickness direction became 20 mm. The mold was then closed such that the dimension in the thickness direction became 20 mm. Thereafter, the expanded beads B were heated with steam of 0.20 MPa(G) and fusion-bonded together, thereby to obtain a molded layer B.

(13) After drying each of the molded layers in an atmosphere of 23° C. for 24 hours, the molded layers A and B were sliced such that the cut molded layer A had a thickness of 40 mm, the cut molded layer B had a thickness of 10 mm, and each layer had a cut surface on one side thereof. Thereafter, the cut molded layer A and the molded layer B were bonded and laminated using an adhesive agent (manufacturer name: Cemedine Co., Ltd., product name: SX-PPK1000) such that the cut surfaces were bonded to each other, thereby obtaining a laminated article.

(14) Various physical properties of the obtained laminated article and the molded layers A and B are shown in Table 2.

(15) TABLE-US-00002 TABLE 2 Com- Com- parative parative Example 4 Example 3 Example 4 Adhesive Adhesive Adhesive Production method agent agent agent Molded Expanded beads EPP EPP EPP Layer Density Da [kg/m.sup.3] 60 60 60 A Tensile modulus 26 26 26 TMa [MPa] Shrinkage [%] 2 2 2 Molded Expanded beads ETPO1 ETPO4 ETPO5 Layer Void spaces exist not exist not exist B Voidage [%] 20 — — Density Db [kg/m.sup.3] 120 130 100 Tensile modulus 0.55 1.1 0.82 TMb [MPa] Hot xylene insolubles 52 50 50 content [wt %] Shrinkage [%] 5 4 5 Laminated Volume ratio (Va/Vb) 80:20 80:20 80:20 Article Whole apparent 72 74 68 density [kg/m.sup.3] Ratio (TMb/TMa) 0.021 0.042 0.031 Ratio (Db/Da) 2.00 2.17 1.66 Warpage at high A C C temperature

(16) Various physical properties of the expanded beads used for producing the molded layers A and B were measured as follows.

(17) Apparent Density of the Expanded Beads:

(18) In a 100 mL measuring cylinder, ethanol at a temperature of 23° C. was placed in an amount of 50 mL. A group of the expanded beads having a bulk volume of about 30 mL were measured for their weight (W1) and immersed in the ethanol in the measuring cylinder using a wire net. The apparent volume V1 of the expanded beads group was then measured by reading the rise in the water level with the consideration of the volume of the wire net. The apparent density [kg/m.sup.3] of the expanded beads was determined by dividing the weight W1 [kg] of the expanded beads group by the apparent volume V1 [m.sup.3] thereof (W1/V1).

(19) Bulk Density of the Expanded Beads:

(20) First, a 100 mL measuring cylinder was provided. Expanded beads were then filled, by free-fall, in the measuring cylinder up to the vicinity of the graduation line of 100 mL. The measuring cylinder was vibrated until the volume reached a constant. The bulk volume V2 [m.sup.3] was determined by reading the graduation. The total weight W2 [kg] of the expanded beads filled in the measuring cylinder was then measured and divided by the bulk volume V2 [m.sup.3] to determine the bulk density [kg/m.sup.3] of the expanded beads.

(21) Hot Xylene Insolubles Content of the Expanded Beads:

(22) About 1 g of a sample of the expanded beads was weighed to obtain a sample weight W1b. The weighed expanded beads were placed in a 150 mL round bottom flask, to which 100 mL of xylene was further added. The content was heated with a mantle heater and refluxed for 6 hours. The remaining residues were separated by filtration through a 100-mesh wire mesh and dried for 8 hours or more in a vacuum dryer at 80° C. The weight W2b of the obtained dried residues was measured. The weight percentage [(W2b/W1b)×100] of the weight W2b relative to the sample weight W1b represents the hot xylene insolubles content [% by weight] of the expanded beads.

(23) Inner Diameter of Through Holes of the Expanded Beads:

(24) Ten expanded beads were selected at random. A cross-sectional photograph of a cross section perpendicular to the extending direction of the through hole of each of these expanded beads was taken. The inner diameter (diameter) of the through hole in the cross-sectional photograph was measured.

(25) An arithmetic mean of the measured values was calculated to give the inner diameter [mm] of the through holes of the expanded beads.

(26) Various physical properties of the molded layers A and B of the laminated article were measured as follows.

(27) Densities Da and Db of the Molded Layers A and B:

(28) The laminated article was cut into a molded layer A and a molded layer B. A skin (molding skin) formed during the molding was removed from each of the divided molded layers. A rectangular parallelepiped sample having dimensions of 170 mm×50 mm×38 mm in the case of the molded layer B and 170 mm×50 mm×8 mm in the case of the molded layer B was cut out. The apparent volume H of each sample was determined from the external dimensions thereof, and the weight W of each sample was measured. The density [kg/m.sup.3] of the molded layer is a value obtained by dividing the weight W by the apparent volume H.

(29) Voidage of the Molded Layer B:

(30) A sample cut out from the molded layer B was divided into eight equal pieces of a rectangular parallelepiped shape of 85 mm×25 mm×8 mm. Ethanol at 23° C. was placed in an amount of 120 mL in a 200-mL measuring cylinder that has been placed in an atmosphere of 23° C. The eight equally divided measuring pieces were individually immersed in the ethanol using a wire net, and a light vibration was applied thereto to remove air existing between the expanded beads. Then, with the consideration of the volume of the wire net, the true volume of each measuring piece was measured by reading the rise of the water level. These volumes of the eight measuring pieces were summed to obtain the true volume I of the sample. From the thus obtained apparent volume H and the true volume I of the sample, the voidage [% by volume] of the molded layer B was determined according to the following formula (2).
Voidage (% by volume)=[(H−I)÷H]×100  (2)
Degree of Shrinkage of Molded Layers A and B:

(31) Each of the expanded beads A and the expanded beads B used in the above Examples and Comparative Examples were subjected to in-mold molding using a mold having a mold cavity having a length of 250 mm, a width of 200 mm and a thickness of 20 mm. Namely, the expanded beads were filled in the mold cavity with the dimension of the molding cavity in the thickness direction being made 24 mm. The mold was then closed so that the dimension in the thickness direction became 20 mm. The expanded beads were then heated and fusion bonded with steam to obtain a molded layer. The steam pressure at the time of the molding was 0.24 MPa (G) for the expanded beads A and 0.20 MPa (G) for the expanded beads B.

(32) The obtained molded layer was measured for its length in the longitudinal direction, and the degree of shrinkage of the molded layer was determined according to the following formula (3).
Degree of Shrinkage (%)=[250 [mm]−(Longitudinal length of molded layer [mm])]/250 [mm]×100  (3)
Tensile Modulus TMa and TMb of the Molded Layer:

(33) The tensile modulus [kPa] of the molded layer was measured according to JIS K6767(1999). A test piece was prepared as follows. The laminated article was cut and divided into the molded layer A and molded layer B. Each of the molded layers was sliced to a thickness of 5 mm such that a molding skin was not included, and punched into a dumbbell-shaped No. 1, thereby obtaining the test piece.

(34) Hot Xylene Insolubles Content of the Molded Layer B:

(35) The hot xylene insolubles content of the molded layer was measured in the same manner as the measurement of the hot xylene insolubles content of the expanded beads except for using a test piece cut out from a portion near the center of the molded layer B.

(36) Volume Ratio of the Molded Layer a and Molded Layer B:

(37) The laminated article was cut into the molded layer A and molded layer B. The volume of each of the divided molded layers was measured from the outer dimensions thereof. The volume ratio of the molded layer A to the molded layer B was determined from the measured volumes.

(38) Whole Density of the Laminated Article:

(39) The density of the laminated article as a whole was determined by calculation from the density of the molded layer A, the density of the molded layer B, and the volume ratio of the molded layer A to the molded layer.

(40) The warpage of the laminated article (warpage immediately after molding and warpage at a high temperature) was evaluated as follows.

(41) Warpage Immediately after Molding of the Laminated Article:

(42) In Examples 1 to 3 and Comparative Examples 1 and 2, immediately after the production of the laminated article by integral molding, the laminated article was allowed to stand on a horizontal surface in the atmosphere at 23° C. for 30 minutes. Immediately thereafter, one longitudinal end of the laminated article was pressed against a horizontal surface so that the other end thereof was floated. The floating amount of lifting of the other end from the horizontal plane (the lifted height in the vertical direction) was measured, and the warpage immediately after the molding was evaluated based on the following criteria.

(43) Evaluation Criteria:

(44) A: Floating amount is 5 mm or less

(45) B: Floating amount is more than 5 mm and less than 10 mm

(46) C: Floating amount is 10 mm or more

(47) Warpage of the Laminated Article at High Temperature:

(48) The laminated article was allowed to quiescently stand in an oven at 80° C. for 22 hours. Immediately after having been taken out of the oven, the laminated article was allowed to stand on a horizontal surface in an atmosphere at 23° C. for 1 hour. Immediately thereafter, one longitudinal end of the laminated article was pressed against the horizontal surface so that the other end was floated. The floating amount of lifting of the other end from the horizontal plane (the lifted height in the vertical direction) was measured, and the warpage after being left standing at high temperature was evaluated based on the following criteria.

(49) Evaluation Criteria

(50) A: Floating amount is 5 mm or less

(51) B: Floating amount is more than 5 mm and less than 10 mm

(52) C: Floating amount is 10 mm or more