Chlorinated polyethylene derived from biomass

Abstract

To provide a chlorinated polyethylene capable of reducing an environmental load (generation of greenhouse gases) in a life cycle by using a plant-derived polyethylene as a raw material of the chlorinated polyethylene instead of a polyethylene obtained from conventional fossil fuels.SOLUTION: The chlorinated polyethylene has a biomass degree of 10-100% measured according to ASTM D 6866.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a biomass chlorinated polyethylene obtained from plant-derived raw materials. More specifically, the present invention relates to a chlorinated polyethylene characterized by comprising: [Background technology]

[0002] In recent years, with the growing demand for the creation of a recycling-oriented society, there has been a desire to move away from petroleum-based raw materials in the materials field, and the use of biomass has been attracting attention.Similarly, in the field of rubber materials, the production of rubber materials using raw materials derived from biomass has been attracting attention, and various studies are being conducted in this regard.

[0003] For example, Patent Document 1 describes the synthesis of polybutadiene rubber using raw materials derived from biomass.

[0004] Furthermore, Non-Patent Document 1 reports the development of ethylene propylene rubber (EPDM) using raw materials derived from biomass. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-024915 [Non-patent literature]

[0006] [Non-Patent Document 1] NOK Corporation Press Release March 25, 2022 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention focuses on polyethylene, which is a raw material for chlorinated polyethylene, and provides chlorinated polyethylene that can reduce the environmental load (emission of greenhouse gases) throughout its life cycle by using plant-derived polyethylene as the raw material instead of conventional polyethylene obtained from fossil fuels. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems and have completed the present invention, which relates to the following items [1] to [6]. [1] Chlorinated polyethylene with a biomass content of 10-100% as measured in accordance with ASTM D 6866. [2] The chlorinated polyethylene according to [1], wherein the amount of chlorine is 10 to 50% by weight. [3] The chlorinated polyethylene according to any one of [1] and [2], which has a glass transition temperature (Tg) of −40 to 30° C. as measured by a differential scanning calorimeter (DSC). [4] The chlorinated polyethylene according to any one of [1] to [3], which has a Mooney viscosity (ML(1+4)100°C) of 10 to 150. [5] The chlorinated polyethylene according to any one of [1] to [4], which has a viscosity of a 10 wt % toluene solution of 100 to 10,000 mPa·s. [6] The method for producing chlorinated polyethylene according to any one of [1] to [5], comprising chlorinating polyethylene having a biomass content of 10 to 100% as measured in accordance with ASTM D 6866. [Effects of the Invention]

[0009] The chlorinated polyethylene of the present invention has mechanical properties equivalent to those of conventional chlorinated polyethylene produced from raw materials obtained from fossil fuels, and can replace conventional chlorinated polyethylene. Furthermore, since the biomass content as measured by ASTM D 6866 is 10 to 100%, the environmental load (emission of greenhouse gases) over the life cycle can be reduced. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below.

[0011] The biomass-derived chlorinated polyethylene according to one embodiment of the present invention is a chlorinated polyethylene having a biomass content measured in accordance with ASTM D 6866 of 10 to 100%.

[0012] Biomass refers to any renewable natural raw material or residue, whether plant- or animal-derived, including fungi, yeast, algae, and bacteria. The carbon in olefins derived from biomass contains a certain amount of the C14 isotope derived from the biomass (10 ―12 (Proportion of the degree).

[0013] Fossil fuels are oil, coal, natural gas, shale gas, and other materials made from the remains of plants and animals that have been deposited and pressurized over hundreds of millions of years and turned into fossils. The carbon in olefins derived from fossil fuels is much older than the half-life of the C14 isotope, which is 5,730 years, so the C14 isotope derived from biomass is not detectable.

[0014] The biomass ratio refers to the proportion of naturally derived raw materials contained in a product, and can be measured by measuring the amount of radioactive carbon C14, which is only found in naturally derived substances, contained in the product. In the present invention, the biomass ratio is determined in accordance with ASTM D 6866 by measuring the concentration of radioactive carbon C14 in chlorinated polyethylene using accelerator mass spectrometry (AMS) and calculating the ratio to carbon derived from fossil fuels that does not contain radioactive carbon C14.

[0015] The chlorine content of the biomass-derived chlorinated polyethylene is preferably 10 to 50% by weight, more preferably 25 to 48% by weight, and even more preferably 35 to 45% by weight, since excellent flexibility and mechanical properties can be obtained.

[0016] The Mooney viscosity (ML(1+4)100°C) of the biomass-derived chlorinated polyethylene is preferably 10 to 150, more preferably 20 to 120, since this achieves both particularly excellent mechanical properties and processability.

[0017] The glass transition temperature (Tg) of the biomass-derived chlorinated polyethylene measured by a differential scanning calorimeter (DSC) is preferably −40 to 30°C, more preferably −35 to 25°C, and even more preferably −30 to 20°C, since excellent flexibility and mechanical properties can be obtained.

[0018] In order to obtain excellent mechanical properties and processability, the weight-average molecular weight of the biomass-derived chlorinated polyethylene is preferably 5,000 to 600,000, and more preferably 10,000 to 500,000. The weight-average molecular weight refers to a value (polystyrene equivalent) measured by gel permeation chromatography (hereinafter sometimes abbreviated as GPC).

[0019] The viscosity of a 10 wt % toluene solution of the biomass-derived chlorinated polyethylene is preferably 100 to 10,000 mPa·s, more preferably 200 to 3,000 mPa·s, and even more preferably 200 to 500 mPa·s, in order to achieve both excellent mechanical properties and handleability.

[0020] The polyethylene used as a raw material for biomass-derived chlorinated polyethylene is polyethylene with a biomass content of 10 to 100% as measured in accordance with ASTM D 6866, and may be a single polyethylene or a blend of two or more polyethylenes. Furthermore, petroleum-derived polyethylene may be used as the polyethylene to be blended, as long as the biomass content after blending is within the range of 10 to 100%.

[0021] The main chain structure of polyethylene used as a raw material for biomass-derived chlorinated polyethylene is not particularly limited, and examples include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene. A single polyethylene or a blend of two or more polyethylenes may be used as the raw material.

[0022] Biomass-derived chlorinated polyethylene can be synthesized by a conventional method. For example, it can be dissolved in a chlorine-based solvent such as carbon tetrachloride, chloroform, or 1,1,2-trichloroethane, and then blown with chlorine gas in the presence of a radical initiator. The reaction temperature is not particularly limited, but is usually 60 to 180°C. The reaction pressure is not particularly limited, but is preferably normal pressure to 1.0 MPa.

[0023] After the chlorination reaction is complete, the chlorine gas remaining in the solution and the by-product hydrogen chloride gas are removed from the reaction system by blowing in an inert gas such as nitrogen under reflux of the solvent. The polymer and the solvent of the obtained chlorinated polyethylene are separated, if necessary, by steam distillation, drum drying, extrusion drying, etc.

[0024] The method for obtaining biomass-derived chlorinated polyethylene is not particularly limited, and examples thereof include a solution method in which polyethylene having a biomass degree of 10 to 100% measured in accordance with ASTM D 6866 is uniformly dissolved in an inert solvent and reacted, a suspension method in which polyethylene is suspended in a solvent and reacted, and a dissolution method in which polyethylene is dissolved and reacted in the absence of a solvent. Among these, the solution method, which can uniformly chlorinate polyethylene, is preferred.

[0025] The solvent used for chlorination by the solution method is not particularly limited, and examples thereof include carbon tetrachloride, trichloroethane, tetrachloroethane, chloroform, chlorobenzene, etc. in terms of solubility and reactivity, and trichloroethane is particularly preferred because it has good reactivity.

[0026] In the case of biomass-derived chlorinated polyethylene, the chlorinating agent used to chlorinate polyethylene is not particularly limited, and chlorine gas, sulfuryl chloride, or the like may be used alone or in combination. Furthermore, a catalyst or the like that promotes the chlorination reaction may be used as needed. Examples of the catalyst include azo compounds and organic peroxides. Examples of azo compounds include α,α'-azobisisobutyronitrile, azobiscyclohexanecarbonitrile, and 2,2'-azobis(2,4-dimethylvaleronitrile). Examples of organic peroxides include benzoyl peroxide, acetyl peroxide, t-butyl peroxide, and t-butyl perbenzoate. Azo compounds are preferred because of their high stability in handling, and α,α'-azobisisobutyronitrile is particularly preferred because the chlorination reaction proceeds appropriately.

[0027] The reaction temperature during chlorination is not particularly limited and can be appropriately selected depending on the melting point of the raw polyethylene, and in consideration of reactivity and handleability, it is preferably 50 to 150° C., more preferably 60 to 130° C. Furthermore, the reaction pressure during chlorination is not particularly limited and is, for example, 0 to 1.0 MPa, and preferably 0 to 0.6 MPa to ensure that chlorination proceeds appropriately.

[0028] After the chlorination reaction is completed, hydrogen chloride and the like remaining in the reaction solution can be removed by introducing nitrogen. There is no problem in removing hydrogen chloride and the like under reduced pressure.

[0029] Furthermore, additives such as antioxidants and stabilizers may be added either before or after the chlorination reaction. The type of additive is not particularly limited, and examples include hindered phenol-based antioxidants such as 4-t-butylcatechol, 2,6-di-t-butyl-p-cresol, and triethylene glycol bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], and epoxy compounds such as epoxidized polybutadiene and bisphenol A resin. These may be used alone or in combination of two or more. The timing of adding the additive is not particularly limited, but considering the ease of operation and the efficiency of the additive, it is preferable to add the additive after the chlorination reaction and after removing the residual gas.

[0030] The method for separating the polymer and the solvent from the chlorinated product polymer solution is not particularly limited, but for example, steam distillation, a drum dryer, a vented extruder, etc. can be used.

[0031] Biomass-derived chlorinated polyethylene is mainly used as a vulcanizate. To obtain a biomass-derived chlorinated polyethylene vulcanizate, the biomass-derived chlorinated polyethylene and various compounding agents are blended or kneaded using a roll or Banbury mixer, followed by press vulcanization, steam vulcanization, high-frequency (UHF) vulcanization, or electron beam vulcanization. The vulcanization temperature is not particularly limited, but is 130 to 200°C, preferably 150 to 180°C. Secondary vulcanization can also be performed as needed. The secondary vulcanization is performed in a heating oven at a temperature of 140 to 180°C for 2 to 6 hours. Examples of various compounding agents include vulcanizing agents, vulcanization accelerators, acid acceptors, plasticizers, reinforcing agents, fillers, processing aids, and antioxidants, which are used as needed.

[0032] Examples of vulcanizing agents include organic vulcanizing agents such as organic peroxides, inorganic vulcanizing agents such as sulfur, and organic vulcanizing agents such as thiuram polysulfides, dithiocarbamates, oximes, nitroso compounds, and organic peroxides. Examples of vulcanization accelerators include thioureas, guanidines, thiazoles, sulfenamides, thiurams, dithiocarbamates, and xanthogenates. Examples of acid acceptors include magnesium oxide, zinc oxide, hydrotalcite, and litharge. Examples of plasticizers include mineral oil-based softeners, vegetable oil-based softeners, synthetic softeners, and synthetic plasticizers. Examples of reinforcing materials include carbon black and white carbon. Examples of fillers include calcium carbonates, basic magnesium carbonates, silicic acid and silicates. Examples of processing aids include fatty acids, fatty acid esters, fatty acid metal salts, and hydrocarbon waxes. Examples of the antioxidant include amine-based antioxidants, phenol-based antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and waxes.

[0033] The uses of biomass-derived chlorinated polyethylene are not particularly limited, and it can be used for various industrial parts such as automobile hoses, gas hoses, industrial hoses, electric wire coatings, coated fabrics, packings, gaskets, rolls and linings, adhesives, etc. [Example]

[0034] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0035] The values ​​used in these examples were obtained in accordance with the following measurement methods.

[0036] (1) Raw rubber characteristics <Biomass Degree Measurement> The radioactive carbon C14 concentration of chlorinated polyethylene was measured by accelerator mass spectrometry (AMS) in accordance with ASTM D6866, and the biomass content of the chlorinated polyethylene was calculated.

[0037] ASTMD6866 specifies that the radiocarbon concentration of a sample should be measured against a standard material for the 1950 atmospheric radiocarbon concentration, and that the ratio should be used to determine the biomass ratio. However, since the current atmospheric carbon concentration of radiocarbon C14 has been increasing year by year, it is specified that this value should be multiplied by a coefficient to correct for this. In accordance with ASTMD6866-22, the current atmospheric C14 concentration was calculated as 100.0 pMC.

[0038] <Measurement of chlorine content> The chlorine content of biomass-derived chlorinated polyethylene was measured using the combustion flask method. Approximately 20 mg of chlorinated polyethylene was burned using the oxygen flask combustion method, and 15 mL of a 1.7 wt.% hydrazinium sulfate aqueous solution was allowed to stand as an absorption solution. After 40 minutes, the absorption solution was washed out with approximately 100 mL of pure water, and then the chloride ions were quantified by potentiometric titration using an automatic titrator (Hiranuma Sangyo Co., Ltd., MC-3000, TS-3000) with a 0.5 N silver nitrate aqueous solution to measure the chlorine content.

[0039] <Molecular weight measurement> The molecular weight of the polymer solution obtained by dissolving 10 mg of biomass-derived chlorinated polyethylene in 10 mL of THF was measured by GPC. The weight-average molecular weight (Mw) was calculated in terms of polystyrene using standard polystyrene (manufactured by Tosoh Corporation). The measurement conditions are shown below.

[0040] Model: (Product name) HLC8420GPC Solvent: THF Column temperature: 40℃ ·Measurement concentration: 10mg / 10mL ·Injection volume: 200μL Column: TSKgel® G7000HXL (manufactured by Tosoh Corporation) → TSKgel® GMHXL (manufactured by Tosoh Corporation) x 2 <Measurement of glass transition temperature> The glass transition temperature (Tg) was determined by measuring the starting point of the transition region in the DSC curve measured using a differential scanning calorimeter (NETZSCH, DSC3500Sirius) under a nitrogen gas flow while raising the temperature from -100°C to 150°C at a rate of 10°C / min.

[0041] <Measurement of solution viscosity> Chlorinated polyethylene was dissolved in toluene to a concentration of 10% by weight, and the viscosity was measured using a Brookfield viscometer. The sample container was immersed in a thermostatic bath at 23°C for 1 hour, and then the viscosity was measured at 30 rpm using a No. 3 rotor. The value measured after 60 seconds was used.

[0042] <Measurement of Mooney viscosity> Measurement was carried out in accordance with JIS K 6300 using an L-type rotor, with preheating for 1 minute, rotor rotation time for 4 minutes, and at 100°C.

[0043] (2) Compound characteristics <Measurement of Mooney's Coach> Chlorinated polyethylene was kneaded in accordance with JIS-K 6299, and the Mooney scorch ML(1) 125°C of the resulting compound was measured in accordance with JIS-K 6300. Vm is the minimum Mooney viscosity after the rotor starts rotating, and scorch time t5 is an index of processing stability and is the time it takes for the Mooney viscosity to increase by 5 from Vm.

[0044] <Rheometer vulcanization test> Measurements were carried out at 160°C for 45 minutes using a Rubber Process Analyzer RPA 2000 manufactured by Alpha Technologies, and the minimum torque value (ML), maximum torque value (MH), and 90% vulcanization time (Tc90) were determined in accordance with JIS K 6300.

[0045] (3) Vulcanized rubber properties <Normal physical properties> Chlorinated polyethylene was mixed according to JIS-K 6299, and the resulting sample was vulcanized in a 2 mm thick mold. Hardness (HS) was then measured at 23°C using a durometer according to JIS-K 6253. Tensile strength (TB), elongation at break (EB), and 100% tensile stress (M100) were evaluated according to JIS-K 6251 at a tension speed of 500 mm / min and 23°C.

[0046] <Heat aging resistance> Chlorinated polyethylene vulcanized rubber was aged in a Geer oven at 120°C for 72 hours in accordance with JIS K6257, and then the changes in normal physical properties were evaluated.

[0047] The reagents used in the synthesis of chlorinated polyethylene in the examples are as follows:

[0048] Raw material bio-polyethylene 1: Grade SHC7260 manufactured by Braskem. Melt mass-flow rate (ASTM D 1238, temperature 190°C, load 2.16 kg) 7.2 g / 10 min. High-density polyethylene (density 0.959 g / cm3). 3 ) Raw material: Petroleum-derived polyethylene 1: Nipolon Hard (registered trademark) 4030 manufactured by Tosoh Corporation, melt mass-flow rate (JIS K6922-1, temperature 190°C, load 2.16 kg) 4.8 g / 10 min, high-density polyethylene (density 0.964 g / cm 3 ) 1,1,2-Trichloroethane: Tosoh Corporation α,α'-Azobisisobutyronitrile: Fujifilm Wako Pure Chemical Industries, Ltd. Sulfuryl chloride: Sumitomo Seika Chemicals Co., Ltd. Pyridine: Fujifilm Wako Pure Chemical Industries, Ltd. 2,2-bis(4-glycidyloxyphenyl)propane: manufactured by Tokyo Chemical Industry Co., Ltd. The ingredients used in the examples are as follows:

[0049] Magnesium oxide (acid acceptor): Kyowamag #150 (manufactured by Kyowa Chemical Industry Co., Ltd.) Vulcanizing agent: Peroximon F-40 (NOF Corporation) Crosslinking aid: Taik M-60 (Mitsubishi Chemical Corporation) Example 1 Under a nitrogen atmosphere, 1440 g of raw biopolyethylene 1 was dissolved in 10 L of 1,1,2-trichloroethane at 110 °C in a 40 L glass-lined autoclave. A solution of 0.4 g of α,α'-azobisisobutyronitrile dissolved in 1 kg of 1,1,2-trichloroethane was added dropwise to this polymer solution over 180 minutes at 110 °C, while chlorine gas was blown into the autoclave at 3.4 L / min from the bottom. The pressure inside the reactor was maintained at 0.1 MPa during the reaction. The pressure inside the reactor was maintained at 0.2 MPa during the reaction. After the addition was completed, the temperature of the reaction solution was lowered to 70 °C, and nitrogen was blown into the reaction solution for 2 hours at 70 °C. 33 g of 2,2-bis(4-glycidyloxyphenyl)propane was added to the reaction solution, and the solvent was removed using a drum dryer heated to 155 °C, yielding biomass-derived chlorinated polyethylene 1.

[0050] The composition of the obtained chlorinated polyethylene 1 and its raw rubber properties, such as Mooney viscosity and biomass content, were measured. The results are shown in Table 1. As shown in Table 1, the chlorine content was 40.4 wt%, the Mooney viscosity was 73, the biomass content was 98%, and the viscosity of a 10 wt% toluene solution was 280 mPa s.

[0051] [Table 1]

[0052] To 100 parts by weight of the obtained chlorosulfonated polyethylene 1, 10 parts by weight of magnesium oxide was added using an open roll mixer, and then 7.5 parts by weight of a vulcanizing agent and 6.7 parts by weight of a cross-linking coagent were added using an open roll mixer to obtain a chlorinated polyethylene composition. The obtained chlorinated polyethylene composition was subjected to a Mooney scorch test of unvulcanized rubber and a rheometer vulcanization test, and the results are shown in Table 2. The obtained chlorinated polyethylene composition was also press-vulcanized at 160°C for 20 minutes to obtain a vulcanizate. The obtained vulcanizate was subjected to normal physical properties and heat aging resistance tests. These results are shown in Table 2. Table 2 shows that the physical properties of the obtained vulcanizate were comparable to those of chlorinated polyethylene made from petroleum-derived polyethylene.

[0053] [Table 2]

[0054] Comparative Example 1 Petroleum-derived chlorinated polyethylene 2 was obtained in the same manner as in Example 1, except that raw petroleum-derived polyethylene 1 was used instead of raw biopolyethylene 1. The composition of the obtained chlorinated polyethylene 2 and the raw rubber properties such as Mooney viscosity and biomass content were measured. The results are shown in Table 1. As shown in Table 1, the chlorine content was 40.0 wt%, the Mooney viscosity was 65, the biomass content was 0%, and the viscosity of a 10 wt% toluene solution was 480 mPa s.

[0055] Chlorinated polyethylene composition 2 was obtained in the same manner as in Example 1, except that petroleum-derived chlorinated polyethylene 2 was used instead of biomass-derived chlorinated polyethylene 1.

[0056] The obtained chlorinated polyethylene composition 2 was subjected to a Mooney scorch test of unvulcanized rubber and a rheometer vulcanization test, and the results are shown in Table 2. The obtained chlorinated polyethylene composition 2 was also press-vulcanized at 160°C for 20 minutes to obtain a vulcanizate. The obtained vulcanizate was subjected to normal state physical properties and heat aging resistance tests. The results are shown in Table 2.

Claims

1. Chlorinated polyethylene having a biomass content of 10 to 100% as measured in accordance with ASTM D 6866.

2. 2. The chlorinated polyethylene of claim 1, having a chlorine content of 10 to 50%.

3. 2. The chlorinated polyethylene according to claim 1, which has a glass transition temperature (Tg) of −40 to 30° C. as measured by differential scanning calorimetry (DSC).

4. 2. The chlorinated polyethylene according to claim 1, which has a Mooney viscosity (ML(1+4)100°C) of 10 to 150.

5. 2. The chlorinated polyethylene according to claim 1, which has a viscosity of a 10% by weight toluene solution of 100 to 10,000 mPa·s.

6. The method for producing chlorinated polyethylene according to any one of claims 1 to 5, wherein polyethylene having a biomass content of 10 to 100% as measured in accordance with ASTM D 6866 is chlorinated.

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