Resin compositions, molded articles, electric wires, and cables

Abstract

The present invention provides a resin composition that can be used as a carbon dioxide adsorbent, a resin composition that allows for visual confirmation of carbon dioxide absorption, a molded article thereof, and electric wires and cables manufactured using the resin composition. [Solution] A resin composition α is provided, comprising a resin β as a base material, at least one of an alkaline earth metal hydroxide γ and an alkali metal hydroxide δ added to the resin β, and a moisture sensing material ε added to the resin β that changes color in response to moisture.

Description

Technical Field

[0001] The present invention relates to a resin composition, a molded body, an electric wire, and a cable.

Background Art

[0002] Conventionally, a resin composition in which zeolite and calcium carbonate are added to a vinyl chloride resin has been known (see Patent Document 1). According to Patent Document 1, by adding a predetermined amount of zeolite and calcium carbonate to the vinyl chloride resin, it is said that the generation of carbon dioxide and the generation of harmful carbon monoxide and hydrogen chloride gas during combustion such as during incineration of the resin composition can be suppressed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A resin composition containing a substance having a property of adsorbing carbon dioxide, such as the resin composition described in Patent Document 1, is also assumed to be used as an adsorbent for carbon dioxide. In that case, it is desirable that it can be visually confirmed that carbon dioxide is adsorbed.

[0005] An object of the present invention is to provide a resin composition that can be used as an adsorbent for carbon dioxide, a resin composition and a molded body thereof that can visually confirm that carbon dioxide has been absorbed, and an electric wire and a cable manufactured using the resin composition.

Means for Solving the Problems

[0006] The present invention aims to solve the above problems and provides a resin composition comprising a resin as a base material, at least one of an alkaline earth metal hydroxide and an alkali metal hydroxide added to the resin, and a moisture-sensing material added to the resin that changes color in response to moisture. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a resin composition that can be used as a carbon dioxide adsorbent, a resin composition that allows for visual confirmation of carbon dioxide absorption, a molded article thereof, and electric wires and cables manufactured using the resin composition. [Brief explanation of the drawing]

[0008] [Figure 1] Figures 1(a), (b), and (c) are graphs showing the CO2 adsorption performance of zeolite, magnesium hydroxide, and calcium hydroxide, respectively. [Figure 2] Figure 2 is a table showing the gas and water permeability of various plastics. [Figure 3] Figure 3 is a table showing the material proportions of two samples (samples A1 and A2) prepared to evaluate the effect of resin β on the CO2 adsorption performance of resin composition α. [Figure 4] Figure 4(a) is a graph showing the CO2 adsorption performance of a 200g press-molded sheet made from sample A1, and Figure 4(b) is a graph showing the CO2 adsorption performance of a 200g square pellet made from sample A1. [Figure 5] Figure 5(a) is a graph showing the CO2 adsorption performance of a 200g press-molded sheet made from sample A2, and Figure 5(b) is a graph showing the CO2 adsorption performance of a 200g square pellet made from sample A2. [Figure 6] Figure 6 is a table showing examples of mixing ratios and molding conditions for resin compositions in which calcium hydroxide is used as a CO2 adsorbent in a base material such as PVC or silicone. [Figure 7]Figure 7 is a table showing the mixing ratios of resin compositions (samples B1 to B3) in which zeolite as a CO2 adsorbent is blended with polyethylene as the base material, and the mechanical properties of sheet-like molded products of these resin compositions. [Figure 8] Figures 8(a) and (b) show optical microscope images of the surface of a sheet-like molded body of a resin composition in which zeolite as a CO2 adsorbent is blended with polyethylene as the base material at a concentration of 25% by mass, and examples of Raman spectra obtained by Raman scattering measurements on the surface of the sheet-like molded body. [Figure 9] Figure 9(a) is a mapping image formed on top of the optical microscope image in Figure 8(a). Figure 9(b) is a three-dimensional mapping image of the mapping image in Figure 9(a). [Modes for carrying out the invention]

[0009] A resin composition according to an embodiment of the present invention (hereinafter referred to as resin composition α) comprises a resin as a base material (hereinafter referred to as resin β), at least one of an alkaline earth metal hydroxide (hereinafter referred to as alkaline earth metal hydroxide γ) and an alkali metal hydroxide (hereinafter referred to as alkali metal hydroxide δ) added to resin β, and a moisture-detecting material (hereinafter referred to as moisture-detecting material ε) added to resin β that changes color in response to moisture.

[0010] In resin composition α, alkaline earth metal hydroxide γ and alkali metal hydroxide δ are used as carbon dioxide (CO2) adsorbents. Typically, alkaline earth metal hydroxide γ and alkali metal hydroxide δ are dispersed in powder form within the base resin β.

[0011] In resin composition α, alkaline earth metal hydroxide γ and alkali metal hydroxide δ are contained in resin β as CO2 adsorbents, so there is no risk of them scattering and polluting the air environment. Furthermore, because resin composition α is based on a resin that is easy to mold and can maintain a self-supporting shape, it can easily take on a form that matches the shape of the space in which it will be installed.

[0012] The resin composition α can be molded into various shapes, such as sheets, pellets, tubes, fibers, or braided sheets made of woven fibers. In particular, when molded into pellets, fibers, or braided sheets, the surface area of ​​the molded body increases, thereby improving the CO2 adsorption performance.

[0013] The molded article of resin composition α preferably has a relatively large surface roughness and surface area to enhance CO2 adsorption performance. The following shows preferred numerical ranges for parameters related to surface roughness and surface area of ​​a sheet-shaped resin composition α that can be measured using a laser microscope (VK-X3000, manufactured by Keyence Corporation). The arithmetic mean surface roughness Sa is preferably 0.01 μm or more and 1.6 μm or less. The maximum surface height difference Sz is preferably 0.8 μm or more and 92 μm or less. The surface property aspect ratio Str is preferably 0.3 or more and 0.9 or less. The arithmetic mean curvature Spc of the peak is 110 mm. -1 More than 1150mm -1 The following is preferable: The ratio of the developed area of ​​the interface (surface area ratio) is preferably 0.001 or more and 0.08 or less. By setting the magnitude of each parameter of the molded body of resin composition α to be above the lower limit of the above numerical range, powdery CO2 adsorbent with a particle size of several tens of nanometers to several micrometers can be arranged three-dimensionally on the outermost surface of the molded body of resin composition α, thereby increasing the CO2 adsorption (exposure) area and enabling efficient adsorption of large amounts of CO2 gas. Furthermore, by setting the magnitude of each parameter of the molded body of resin composition α to be below the upper limit of the above numerical range, it is possible to avoid problems such as the surface roughness of the molded body of resin composition α being too large for the particle size of the CO2 adsorbent, which is several tens of nanometers to several micrometers, resulting in less space for the CO2 adsorbent to be placed on the outermost surface of the molded body of resin composition α, and the problem that the CO2 adsorption capacity of the molded body of resin composition α as a whole decreases because the concave surfaces (valleys) on the surface of the molded body of resin composition α become deeper, causing the concentration (amount) of CO2 gas that enters the concave surfaces where the CO2 adsorbent is placed to be relatively less than that of the outermost surface (peak).

[0014] As the hydroxide γ of alkaline earth metals, for example, calcium hydroxide or magnesium hydroxide can be used. As the hydroxide δ of alkali metals, for example, sodium hydroxide can be used.

[0015] The hydroxide γ of alkaline earth metals and the hydroxide δ of alkali metals adsorb CO2 by chemical reactions, and moisture is generated by these chemical reactions. For example, when calcium hydroxide adsorbs CO2 and when magnesium hydroxide adsorbs CO2, the chemical reactions shown by the following formulas (1) and (2) occur respectively.

[0016]

Number

[0017]

Number

[0018] Also, when sodium hydroxide adsorbs CO2, the chemical reactions shown by the following formulas (3-1) and (3-2) occur.

[0019]

Number

[0020]

Number

[0021] Also, when a mixture of calcium hydroxide and sodium hydroxide adsorbs CO2, in addition to the chemical reactions shown by formulas (3-1) and (3-2), the chemical reaction shown by the following formula (3-3) occurs.

[0022]

Number

[0023] In this case, the chemical reaction shown in formula (3-3) regenerates the sodium hydroxide used in the chemical reaction shown in formula (3-2). The chemical reactions shown in formulas (3-1) to (3-3) above occur when the resin composition α contains calcium hydroxide as an alkaline earth metal hydroxide γ and sodium hydroxide as an alkali metal hydroxide δ.

[0024] The moisture-detecting material ε changes color when it absorbs moisture produced by the chemical reaction that occurs when alkali metal hydroxides γ or alkaline earth metal hydroxides δ adsorb CO2.

[0025] The moisture-sensing material ε is, for example, silica gel containing at least one of cobalt chloride and dichloroline tetraphenylporphyrin chloride as an indicator. Typically, the moisture-sensing material ε is in powder form and dispersed in the base resin β.

[0026] Furthermore, as the moisture-sensing material ε, for example, a composition in which iron(III) salts are supported on silica gel, a sugar gel containing an ionic dye, a geopolymer (synthetic aluminosilicate compound) impregnated with an acid-base indicator, hydroxymethylcellulose impregnated with methylene blue and urea, or a composite of sodium borate hydrate and polyvinyl alcohol may be used. These are advantageous in that they do not contain cobalt, which may adversely affect the atmospheric environment.

[0027] Furthermore, the resin composition α may also contain carbonate compounds such as calcium carbonate, in addition to alkaline earth metal hydroxide γ and alkali metal hydroxide δ, as CO2 adsorbents. For example, when calcium carbonate adsorbs CO2, the chemical reaction shown in the following formula (4) occurs.

[0028]

number

[0029] As illustrated in equation (4), when a carbonate compound adsorbs CO2, H2O is used in the reaction. Therefore, the carbonate compound is included in the resin composition α in an amount such that when the resin composition α adsorbs CO2, some moisture remains that can be detected by the moisture sensing material ε.

[0030] Furthermore, the resin composition α may also contain zeolite as a CO2 adsorbent. Zeolite is a porous material with a pore size of approximately 0.2 to 1.0 nm and can physically adsorb CO2 molecules with a molecular diameter of 0.330 nm.

[0031] Figures 1(a), (b), and (c) are graphs showing the CO2 adsorption performance of zeolite, magnesium hydroxide, and calcium hydroxide, respectively.

[0032] The data shown in Figures 1(a), (b), and (c) were obtained by placing a sample (100g of zeolite, magnesium hydroxide, or calcium hydroxide powder), dry ice (a source of CO2), and two CO2 meters in a desiccator and measuring the change in CO2 concentration in the desiccator over time using the two CO2 meters. The data plotted with black circles and white circles in Figures 1(a), (b), and (c) represent measurements taken by one and the other of the two CO2 meters, respectively.

[0033] Figures 1(a), (b), and (c) show that calcium hydroxide has the highest CO2 adsorption performance among the three samples, followed by zeolite. Calculations show that 100g of calcium hydroxide can adsorb 32.5L of CO2 through the chemical reaction shown in equation (1) under conditions of 20°C and 1 atm. The volume of air containing 32.5L of CO2 is 81.25m³ when the CO2 concentration is 400ppm. 3 (For a room of approximately 20 tatami mats), if the CO2 concentration is 800 ppm, the volume is 40.625 m³. 3 (This is roughly the volume of a 10-tatami mat room.)

[0034] Figure 2 is a table showing the gas and water permeability of various plastics. The CO2 adsorption performance of resin composition α is also affected by the gas permeability of the base resin β. For this reason, it is preferable to use silicone, which has high gas permeability, as resin β. It is also preferable to use polyvinyl chloride (PVC), which has a certain degree of gas permeability and is inexpensive, as resin β. Furthermore, since the CO2 adsorption effect of resin composition α is highly likely to be affected by the amount of H2O (water) inside, a water permeability of 2600 cc (STP) / cm² is preferable. 2 / mm / sec / cm·Hg×10 10 It is preferable to use the above resins as resin β. Note that silicone and PVC satisfy the water permeability requirements.

[0035] Figure 3 is a table showing the material proportions of two samples (samples A1 and A2) prepared to evaluate the effect of resin β on the CO2 adsorption performance of resin composition α. ​​In Figure 3, PVC and silicone rubber are the base resins, and calcium hydroxide is the CO2 adsorbent. The peroxide crosslinking agent is a crosslinking agent required for silicone rubber.

[0036] Figure 4(a) is a graph showing the CO2 adsorption performance of a 200g press-molded sheet made from sample A1, and Figure 4(b) is a graph showing the CO2 adsorption performance of a 200g square pellet made from sample A1. The square pellet in Figure 4(b) was made from the same press-molded sheet as the press-molded sheet in Figure 4(a).

[0037] Furthermore, Figure 5(a) is a graph showing the CO2 adsorption performance of a 200g press-molded sheet made from sample A2, and Figure 5(b) is a graph showing the CO2 adsorption performance of a 200g square pellet made from sample A2. The square pellets in Figure 5(b) were made from the same press-molded sheet as the press-molded sheet in Figure 5(a).

[0038] The data shown in Figures 4(a), (b) and 5(a), (b) were obtained by placing molded samples of the above resin composition (press-molded sheets made from sample A1, square pellets made from sample A1, press-molded sheets made from sample A2, or square pellets made from sample A2), dry ice as a source of CO2, and a CO2 meter in a desiccator, and measuring the change in CO2 concentration in the desiccator over time using the CO2 meter.

[0039] Figures 4(a) and 4(b), and 5(a) and 5(b) show that molded samples of the resin composition in the shape of square pellets have higher CO2 adsorption performance than molded samples of the resin composition in the shape of sheets. This is thought to be because the molded samples of the resin composition in the shape of square pellets have a larger specific surface area than the molded samples of the resin composition in the shape of sheets.

[0040] Furthermore, Figures 4(a) and 5(a) and 5(b) show that molded samples of resin compositions using silicone as the base resin have higher CO2 adsorption performance than molded samples of resin compositions using PVC as the base resin. This is thought to be because silicone has better gas permeability than PVC.

[0041] Figure 6 is a table showing examples of mixing ratios and molding conditions for resin compositions in which calcium hydroxide is used as a CO2 adsorbent in a base material of PVC or silicone. In Figure 6, the four resin composition samples using PVC as the base material are referred to as PVC1-4, and the four resin composition samples using silicone as the base material are referred to as Silicone1-4.

[0042] In Figure 6, "water cooling" means that water was circulated inside the rolls to cool them and prevent adhesion between the surface of the rolls of the mixing machine and the silicone rubber. "6-inch rolls" indicates the diameter of the rolls of the mixing machine. "Number of turns" indicates the number of turns the strip-shaped resin composition was moved back and forth on the rolls to change the direction of mixing for each resin composition and to distribute the compound evenly. "150°C, 1 hour cure" means that a secondary cure was performed at 150°C for 1 hour to remove any remaining low-molecular-weight components and to reinforce crosslinking. Pellet molding was performed by crushing a molded strip of resin composition, approximately 2-3 mm thick, at room temperature using a square pelletizer.

[0043] In both cases, whether PVC or silicone was used as the base material, the calcium hydroxide content was limited to 80 wt%, and if more was added, the resin composition could not be molded.

[0044] The amount of adsorbent material that adsorbs CO2 through a chemical reaction, such as calcium hydroxide, in the resin composition is preferably 33 to 100 parts by weight (phr). If the amount is too small, the CO2 adsorption effect will not be sufficiently achieved, and if it is too large, the resin will not be able to accept all of the calcium hydroxide filler, making molding difficult.

[0045] Figure 7 is a table showing the mixing ratios of resin compositions (samples B1-B3) in which zeolite as a CO2 adsorbent is blended with polyethylene as the base material, and the mechanical properties of sheet-like molded articles of these resin compositions. In Figure 7, "TS" represents the tensile stress at fracture, "TE" represents the elongation (strain) at fracture, and "100%M" represents the modulus of elasticity at 100% elongation. These mechanical properties were measured by tensile tests specified in JIS K6251 (1994).

[0046] The amount of zeolite in the resin composition is preferably 50 to 100 parts by weight (phr). If the amount is too low, the CO2 adsorption effect will not be sufficiently achieved, and if it is too high, the resin will not be able to accept all of the zeolite filler, making molding difficult.

[0047] Figures 8(a) and (b) show optical microscope images of the surface of a sheet-like molded body of a resin composition in which zeolite as a CO2 adsorbent is blended with polyethylene as the base material at a concentration of 25% by mass, and examples of Raman spectra obtained by Raman scattering measurements on the surface of the sheet-like molded body. The two Raman spectra shown in Figure 8(b) were measured at measurement positions M1, M2, and M3, indicated by cross marks in Figure 8(a).

[0048] Figure 8(b) shows the positions of peak P1, which is attributed to the four-membered ring skeletal vibration of the zeolite, and peak P2, which is attributed to the CH2 torsional vibration of polyethylene, as indicated by dashed lines. The greater the amount of zeolite at the measurement location, the greater the intensity of peak P1, and the greater the amount of polyethylene at the measurement location, the greater the intensity of peak P2.

[0049] Figure 9(a) is a mapping image formed on top of the optical microscope image in Figure 8(a). Each pixel in the mapping image in Figure 9(a) contains data including the intensities of peak P1 and peak P2 obtained from the Raman spectrum measured at that location, and each pixel has a color corresponding to the intensities of peak P1 and peak P2. Therefore, the distribution of zeolite in polyethylene can be observed from the color distribution.

[0050] Figure 9(b) is a three-dimensional mapping image of the mapping image in Figure 9(a). The three-dimensional mapping image contains height information at each measurement position on the sample surface, and the surface irregularities of the sample are visualized.

[0051] Figures 9(a) and (b) show that in a resin composition in which polyethylene is blended with zeolite at a concentration of 25% by mass, the zeolite is dispersed almost uniformly.

[0052] The resin composition α according to the embodiments of the present invention can take various forms. For example, the resin composition α can be deposited on the surface of metal fibers or metal sheets made of metals such as copper, aluminum, or stainless steel by thermal deposition, sputtering, or CVD to form a CO2 adsorbent with excellent ductility and malleability, or it can be deposited on the surface of woven metal fibers to form an air filter. Furthermore, the resin composition α can be used as an interior wall material for indoor spaces where many people gather, such as theaters, or as an agricultural film that combines weed control by utilizing the inactivation of photosynthesis through the reduction of CO2 concentration in the atmosphere with fertilizer supply from the generated CaCO3.

[0053] Furthermore, according to embodiments of the present invention, it is possible to provide electric wires and cables having a CO2 adsorption function, with a resin composition layer made of resin composition α as the outermost layer.

[0054] (Effects of the embodiment) According to the above-described embodiment of the present invention, it is possible to provide a resin composition α that can be used as a CO2 adsorbent, and in which the absorption of CO2 can be visually confirmed, as well as a molded article thereof. Furthermore, it is possible to provide electric wires and cables manufactured using the resin composition α.

[0055] (Summary of the embodiments) Next, the technical concept understood from the embodiments described above will be described using the reference numerals and other symbols from the embodiments.

[0056] [1] A resin composition (α) comprising a resin (β) as a base material, at least one of an alkaline earth metal hydroxide (γ) and an alkali metal hydroxide (δ) added to the resin (β), and a moisture-detecting material (ε) added to the resin (β) that changes color in response to moisture.

[0057] [2] The resin composition (α) described in [1] above, comprising a zeolite.

[0058] [3] The resin has a water permeability of 2600 cc (STP) / cm². 2 / mm / sec / cm·Hg×10 10 The above is the resin composition (α) described in [1].

[0059] [4] The resin composition (α) according to [1] above, wherein the resin (β) is silicone or polyvinyl chloride (PVC).

[0060] [5] The resin composition (α) according to [1] above, wherein the alkaline earth metal hydroxide (γ) is at least one of calcium hydroxide and magnesium hydroxide.

[0061] [6] The resin composition (α) according to [1] above, wherein the alkali metal hydroxide (δ) is sodium hydroxide.

[0062] [7] The resin composition (α) according to [1] above, wherein the moisture sensing material (ε) is silica gel containing at least one of cobalt chloride and dichloroline tetraphenylporphyrin chloride as an indicator.

[0063] [8] The resin composition (α) according to [1] above, comprising calcium hydroxide as the alkali earth metal hydroxide (γ) and sodium hydroxide as the alkali metal hydroxide (δ).

[0064] [9] A molded article made of the resin composition (α) described in any one of the above [1] to [8], which is formed into a sheet.

[0065]

[10] The molded article according to [9] above, wherein the arithmetic mean surface roughness Sa is 0.01 μm or more and 1.6 μm or less.

[0066]

[11] The molded article according to [9] above, wherein the ratio of the developed area of ​​the interface (surface area ratio) is 0.001 or more and 0.08 or less.

[0067]

[12] A molded article made of the resin composition (α) described in any one of the above [1] to [8], which has been processed into pellet form, fibrous form, tubular form, or braided sheet form.

[0068]

[13] An electric wire having a resin composition layer made of the resin composition (α) described in any one of the above items [1] to [8] as its outermost layer.

[0069]

[14] A cable having a resin composition layer made of the resin composition (α) described in any one of the above items [1] to [8] as its outermost layer.

[0070] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. Furthermore, the embodiments described above do not limit the invention as claimed. It should also be noted that not all combinations of features described in the embodiments are necessarily essential for solving the problem of the invention.

Claims

1. The resin as the base material, At least one of an alkaline earth metal hydroxide and an alkali metal hydroxide is added to the aforementioned resin, A moisture-detecting material that changes color in response to moisture is added to the aforementioned resin, including, Resin composition.

2. Contains zeolite, The resin composition according to claim 1.

3. The aforementioned resin has a water permeability of 2600 cc (STP) / cm². ２ / mm / sec / cm・Hg×10 １０ That's all. The resin composition according to claim 1.

4. The aforementioned resin is silicone or polyvinyl chloride (PVC). The resin composition according to claim 1.

5. The aforementioned alkaline earth metal hydroxide is at least one of calcium hydroxide and magnesium hydroxide. The resin composition according to claim 1.

6. The alkali metal hydroxide is sodium hydroxide. The resin composition according to claim 1.

7. The moisture-detecting material is silica gel containing at least one of cobalt chloride and dichloroline tetraphenylporphyrin chloride as an indicator. The resin composition according to claim 1.

8. The following comprises calcium hydroxide as the hydroxide of the alkaline earth metal and sodium hydroxide as the hydroxide of the alkali metal. The resin composition according to claim 1.

9. A sheet made from the resin composition according to any one of claims 1 to 8, Molded body.

10. The arithmetic mean surface roughness Sa is between 0.01 μm and 1.6 μm. The molded article according to claim 9.

11. The ratio of the developed area (surface area ratio) of the interface is 0.001 or more and 0.08 or less. The molded article according to claim 9.

12. A resin composition according to any one of claims 1 to 8, processed into pellet form, fibrous form, tubular form, or braided sheet form. Molded body.

13. The outermost layer comprises a resin composition layer made of the resin composition described in any one of claims 1 to 8. Electric wire.

14. The outermost layer comprises a resin composition layer made of the resin composition described in any one of claims 1 to 8. cable.

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