Laminate

Abstract

To provide a laminate using a resin foam layer having a biomass polyethylene resin blended and maintaining physical strengths.SOLUTION: A laminate includes a resin layer 2 containing a synthetic resin as its main component and a metal layer laminated at least on one side of the resin layer 2. The resin layer 2, if including a biomass polyethylene resin, shows desired physical property values even in a case of using a resin layer of polyethylene derived from a petroleum resin not using biomass polyethylene. A blending amount of biomass polyethylene is preferably 5-70 wt.%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a laminate formed by bonding a metal plate to at least one of resin layers whose main component is a synthetic resin. [Background technology]

[0002] In recent years, in order to reduce the burden on the environment, the replacement of petroleum-derived resins with biomass resins, which are primarily composed of plant-derived components, has been considered. Furthermore, biomass resins are expected to have the same chemical structure as conventional petroleum-derived resins and to have the same performance.

[0003] However, a laminate using a resin layer containing a biomass resin exhibits properties different from those of a laminate using only a petroleum-derived polyethylene resin. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7311672 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology disclosed in Patent Document 1 describes a method for producing expanded polyethylene resin beads that has excellent moldability in a mold and can produce expanded polyethylene resin beads with a high biomass content over a wide density range. However, the technology is limited to the specific field of use, i.e., foams. [Means for solving the problem]

[0006] The present inventors have solved this problem by discovering that a laminate of a resin plate and a metal plate using biomass polyethylene with a high biomass content exhibits predetermined physical properties compared to a laminate using a petroleum-derived resin that does not use biomass polyethylene, and have thus completed the present invention.

[0007] That is, the laminate of the present invention is a laminate comprising a resin layer whose main component is synthetic resin and a metal layer laminated on at least one of the resin layers, and is characterized in that the resin layer contains biomass polyethylene resin.

[0008] In the laminate according to the present invention, the biomass polyethylene preferably accounts for 5 to 70% by weight of the total amount of synthetic resin.

[0009] In the laminate according to the present invention, the biomass content of the synthetic resin is preferably 5 to 70%.

[0010] Furthermore, in the laminate according to the present invention, it is preferable that the resin layer is a foamed resin layer, and that the foamed resin layer has an expansion ratio of 1.75 or less. [Effects of the Invention]

[0011] According to the present invention, even when biomass polyethylene resin is blended, physical strength can be maintained compared to when only petroleum-derived resin is used, making it possible to provide a laminate with excellent environmental friendliness. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view showing an embodiment of a laminate according to the present invention. [Figure 2] FIG. 2 is an enlarged cross-sectional view taken along the line AA in FIG. [Figure 3] 1 is a table showing the formulation of a synthetic resin according to the present invention and measurement results. [Figure 4] 1 is a table showing the formulation of a synthetic resin containing an additive according to the present invention and the measurement results. DETAILED DESCRIPTION OF THE INVENTION

[0013] The following describes in detail the embodiments of the present invention with reference to the drawings. However, the present invention is not limited to these embodiments. Various modifications that can be conceived by a person skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

[0014] Fig. 1 is a cross-sectional view showing one embodiment of a laminate according to the present invention, and Fig. 2 is an enlarged detailed cross-sectional view taken along the line AA in Fig. 1. Laminate 1 has a structure in which metal layers 3 are laminated on the front and back of a layered resin layer 2, with the resin layer 2 disposed between the metal layers 3, 3, and an adhesive layer 4 is provided for bonding the resin layer 2 and the metal layer 3. The thickness of laminate 1 is preferably about 1 to 6 mm, the thickness of resin layer 2 is preferably 0.5 to 5.8 mm, and the thickness of metal layer 3 is preferably 0.1 to 1 mm.

[0015] The resin layer 2 is a resin layer made of a synthetic resin containing a biomass polyethylene resin and a petroleum-derived resin, and the biomass polyethylene resin is primarily composed of plant-derived raw materials. The resin layer may also be a foamed resin layer containing an internal cellular structure, obtained by adding a foaming agent to the synthetic resin and foaming it.

[0016] Examples of foaming agents used to foam the resin layer 2 include chemical foaming agents that release nitrogen gas, carbon dioxide gas, etc. through thermal decomposition or chemical reaction, and agents that expand in volume when heated. Examples of the former chemical foaming agents include chemical foaming agents that expand in volume when heated. Examples of the former chemical foaming agents include inorganic chemical foaming agents such as bicarbonates (e.g., sodium carbonate) and nitrites (e.g., sodium nitrite). Examples of organic chemical foaming agents include azo compounds and hydrazide compounds. Specific examples include azo compounds such as 2,2'-azobisisobutyronitrile, azodicarbonamide, and azohexahydrobenzonitrile, and hydrazide compounds such as benzenesulfonylhydrazide and diphenylsulfone-3,3'-disulfonylhydrazide. Examples of the latter include thermally expandable microcapsules.

[0017] Furthermore, the resin layer 2 may contain, as necessary, for example, a heat stabilizer, an acid neutralizer, an ultraviolet absorber, a light stabilizer, a colorant such as a pigment or a dye, a filler, an antistatic agent, an antibacterial agent, an antifungal agent, a lubricant, a nucleating agent, a flame retardant, an antiblocking agent, a dehydrating agent, a gloss adjuster, and the like.

[0018] The blending amount of biomass polyethylene resin is preferably 5 to 70% by weight of the total amount of the synthetic resin. Also, the strength ratio is at least a certain level compared to laminates using only petroleum-derived resins. The blending amount of biomass polyethylene resin is more preferably 5 to 35% by weight.

[0019] The biomass content of the synthetic resin is preferably 5 to 70%. The biomass degree is determined by radiocarbon 14 Measuring the carbon content indicates the proportion of biomass-derived components. Measurement can be performed using an accelerator mass spectrometer in accordance with ISO 16620-2. The biomass degree can also be calculated using the biomass degree and weight ratio of each polyethylene resin in the synthetic resin.

[0020] The resin layer 2 can maintain a certain bending strength even when the amount of biomass resin blended is increased compared to a synthetic resin layer made of petroleum-derived resin, and the specific gravity of the resin layer 2 is preferably 0.54 or more.

[0021] The laminate in which the metal layer 3 is laminated on at least one of the resin layers 2 can have predetermined performance in the physical property tests described below.

[0022] Generally, aluminum alloy, stainless steel, iron, titanium, etc. are used for the metal layer 3. The same metal layers 3 are usually used on the front and back of the resin layer 2, but different types of metal layers may be used on the front and back, taking into consideration the installation location, application, etc.

[0023] The adhesive layer 4 is used to bond the resin layer 2 and the metal layer 3, and may be formed by applying a urethane-based, epoxy-based, or other adhesive during or after molding of the resin layer 2. However, when polyethylene is used as the resin layer 2, the adhesive layer 4 may be formed by extrusion molding simultaneously with molding of the resin layer 2 using a modified resin that is based on a polyolefin-based resin or a resin that is highly compatible with polyolefin-based resin and has adhesive strength with the metal layer 3.

[0024] EXAMPLES The configuration and effects of the present invention will be further explained below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0025] Example 1 A mixture of 85.0% by weight of petroleum-derived resin and 15.0% by weight of biomass polyethylene resin was extruded into a sheet using a single-screw extruder at a cylinder temperature of 120°C to 200°C and a T-die temperature of 180°C to create resin layer 2. Using this resin layer 2, modified polyethylene resin sheets were then placed on both sides of the resin layer 2 as adhesive layers, and a 0.1 mm thick aluminum layer was then placed as a metal layer, followed by heat bonding to create a laminate with a total thickness of 4.0 mm.

[0026] (bending strength) A portion of the obtained laminate was cut out to obtain a test piece. The thickness of the test piece was 4.0 mm, which is the total thickness of the laminate, and the size of the test piece was 10 mm x 80 mm. The bending strength was measured based on "JIS K7171 Plastics - Determination of bending properties." The number of values ​​was set to 5, and the average value was used as the measured value. The composition of the resin layer 2 produced in Example 1 and the measurement results of the bending strength are shown in Figure 3.

[0027] Example 2 A laminate was obtained in the same manner as in Example 1, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 71.9% and 28.1% in Example 1. As in Example 1, the blending amount of the resin layer 2 and the measurement results of the bending strength are shown in FIG.

[0028] Example 3 A laminate was obtained in the same manner as in Example 1, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 69.0% and 31.0% in Example 1. As in Example 1, the blending amount of the resin layer 2 and the measurement results of the bending strength are shown in FIG.

[0029] Example 4 A laminate was obtained in the same manner as in Example 1, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 65.0% and 35.0% in Example 1. As in Example 1, the blending amount of the resin layer 2 and the measurement results of the bending strength are shown in FIG.

[0030] Example 5 A laminate was obtained in the same manner as in Example 1, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 62.0% and 38.0% in Example 1. As in Example 1, the blending amount of the resin layer 2 and the measurement results of the bending strength are shown in FIG.

[0031] Example 6 A laminate was obtained in the same manner as in Example 1, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 57.4% and 42.6% in Example 1. As in Example 1, the blending amount of the resin layer 2 and the measurement results of the bending strength are shown in FIG.

[0032] Example 7 A laminate was obtained in the same manner as in Example 1, except that in Example 1, a pigment, a metal hydroxide, and a foaming agent were mixed as additives, the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 70.8% and 28.0%, the total thickness of the laminate was changed to 3.0 mm, and the test piece size was changed to 25 mm × 60 mm. The blending of the resin layer 2 and the measurement results of the bending strength are shown in Figure 4.

[0033] (tensile strength) A portion of the obtained laminate was cut out and the tensile strength was measured based on "JIS K7162 Plastics - Determination of Tensile Properties." The number of measurements was 5, and the average value was taken as the measured value. The measurement results of the tensile strength are shown in Figure 4.

[0034] Example 8 A laminate was obtained in the same manner as in Example 7, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 56.2% and 42.6% in Example 7. As in Example 7, the blending amount of the resin layer 2, and the measurement results of the bending strength and tensile strength are shown in FIG.

[0035] Example 9 A laminate was obtained in the same manner as in Example 7, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 36.2% and 62.6% in Example 7. As in Example 7, the blending amount of the resin layer 2, and the measurement results of the bending strength and tensile strength are shown in FIG.

[0036] (Comparative Example 1) A laminate was obtained in the same manner as in Example 1, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 100.0% and 0.0% in Example 1. As in Example 1, the blending amount of the resin layer 2 and the measurement results of the bending strength are shown in FIG.

[0037] (Comparative Example 2) A laminate was obtained in the same manner as in Example 7, except that the blending amounts of the petroleum-derived resin and the biomass polyethylene resin were changed to 100.0% and 0.0% in Example 7. As in Example 7, the blending amount of the resin layer 2, and the measurement results of the bending strength and tensile strength are shown in FIG.

[0038] As shown in Figure 3, Examples 1 to 6, which contain petroleum-derived polyethylene and biomass polyethylene resin as the resin layer 2, retain 90% or more of the "bending strength" compared to Comparative Example 1, which uses only petroleum-derived polyethylene. This demonstrates that the laminate according to the present invention, which is made up of a metal plate, a resin layer, and a metal plate, exhibits high "bending strength" even when biomass polyethylene is used in part of the resin layer. Furthermore, when the blending ratio of biomass polyethylene resin is set to 5 to 35 wt%, the strength ratio exceeds 95% compared to Comparative Example 1, which is more preferable.

[0039] As shown in Figure 4, Examples 7 to 9, in which the resin layer 2 contains petroleum-derived polyethylene and biomass polyethylene resin and the resin layer 2 is foamed, were found to retain 90% or more of the "tensile strength" compared to Comparative Example 2, in which only petroleum-derived polyethylene was used. This demonstrates that the laminate according to the present invention, which is made up of a metal plate, a foamed resin layer, and a metal plate, exhibits high "tensile strength" even when biomass polyethylene is used in part of the resin layer 2. At least, if the blending ratio of biomass polyethylene resin is 5 to 70 by weight, the strength ratio compared to Comparative Example 2 exceeds 90%, which is preferable.

[0040] On the other hand, the strength ratio of "bending strength" exceeded 50% compared to Comparative Example 2, indicating that a certain level of strength was maintained. Since the strength ratio tends to decrease when the blending ratio of biomass polyethylene resin is increased or the expansion ratio of resin layer 2 exceeds a certain value, it is more preferable that the blending amount of biomass polyethylene resin in resin layer 2 is 5 to 35% or the expansion ratio is 1.75 times or less, since this results in the strength ratios of "bending strength" and "tensile strength" compared to Comparative Example 2 exceeding 90%.

[0041] In a laminate using a resin layer whose main component is synthetic resin, if the blending ratio of biomass resin is in the range of 5 to 35% by weight, it can be used for the same purposes as current resin layers that use only petroleum-derived polyethylene resin, regardless of whether it is foamed or not. On the other hand, if the resin layer is not foamed, the resin can be used in the same applications as petroleum-derived polyethylene resins even if the blending ratio is 5 to 70% by weight. [Explanation of symbols]

[0042] 1. Laminate 2 Resin layer 3 metal layer 4 Adhesive layer

Claims

1. A laminate comprising a resin layer containing a synthetic resin as a main component and a metal layer laminated on at least one of the resin layers, The resin layer is a laminate containing a biomass polyethylene resin.

2. 2. The laminate according to claim 1, wherein the biomass polyethylene is 5 to 70% by weight based on the total amount of the synthetic resin.

3. 2. The laminate according to claim 1, wherein the biomass content of the synthetic resin is 5 to 70%.

4. The laminate according to claim 1 , wherein the resin layer is a foamed resin layer, and the foamed resin layer has an expansion ratio of 1.75 or less.

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