JP2018203930A - Natural rubber composition, rubber composition, and tire - Google Patents
Natural rubber composition, rubber composition, and tire Download PDFInfo
- Publication number
- JP2018203930A JP2018203930A JP2017112784A JP2017112784A JP2018203930A JP 2018203930 A JP2018203930 A JP 2018203930A JP 2017112784 A JP2017112784 A JP 2017112784A JP 2017112784 A JP2017112784 A JP 2017112784A JP 2018203930 A JP2018203930 A JP 2018203930A
- Authority
- JP
- Japan
- Prior art keywords
- natural rubber
- rubber composition
- mass
- index
- component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 244000043261 Hevea brasiliensis Species 0.000 title claims abstract description 104
- 229920003052 natural elastomer Polymers 0.000 title claims abstract description 103
- 229920001194 natural rubber Polymers 0.000 title claims abstract description 103
- 239000000203 mixture Substances 0.000 title claims abstract description 73
- 229920001971 elastomer Polymers 0.000 title claims description 94
- 239000005060 rubber Substances 0.000 title claims description 94
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 20
- 229910052757 nitrogen Inorganic materials 0.000 claims description 12
- 239000010734 process oil Substances 0.000 claims description 12
- 239000000945 filler Substances 0.000 claims description 11
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 8
- 229910052698 phosphorus Inorganic materials 0.000 claims description 8
- 239000011574 phosphorus Substances 0.000 claims description 8
- 229920006173 natural rubber latex Polymers 0.000 description 28
- 102000035195 Peptidases Human genes 0.000 description 22
- 108091005804 Peptidases Proteins 0.000 description 22
- 238000000354 decomposition reaction Methods 0.000 description 21
- 239000004365 Protease Substances 0.000 description 19
- 238000005096 rolling process Methods 0.000 description 19
- 239000003795 chemical substances by application Substances 0.000 description 16
- 238000007127 saponification reaction Methods 0.000 description 16
- 150000001875 compounds Chemical class 0.000 description 15
- 238000005259 measurement Methods 0.000 description 14
- 230000032683 aging Effects 0.000 description 13
- 230000003712 anti-aging effect Effects 0.000 description 13
- 235000019419 proteases Nutrition 0.000 description 13
- 238000000034 method Methods 0.000 description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 11
- 235000018102 proteins Nutrition 0.000 description 11
- 102000004169 proteins and genes Human genes 0.000 description 11
- 108090000623 proteins and genes Proteins 0.000 description 11
- 230000035882 stress Effects 0.000 description 11
- 239000006229 carbon black Substances 0.000 description 10
- 230000015271 coagulation Effects 0.000 description 9
- 238000005345 coagulation Methods 0.000 description 9
- 238000011156 evaluation Methods 0.000 description 9
- 238000005406 washing Methods 0.000 description 9
- 238000001035 drying Methods 0.000 description 8
- 238000002156 mixing Methods 0.000 description 8
- 239000004094 surface-active agent Substances 0.000 description 8
- 239000003513 alkali Substances 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- ROFVGYAMRSGUSQ-UHFFFAOYSA-N 1-(2-bromoethyl)piperazine;hydrobromide Chemical compound Br.BrCCN1CCNCC1 ROFVGYAMRSGUSQ-UHFFFAOYSA-N 0.000 description 6
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- -1 amine compounds Chemical class 0.000 description 6
- 238000002144 chemical decomposition reaction Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 239000007787 solid Substances 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 241000894006 Bacteria Species 0.000 description 5
- 102000004190 Enzymes Human genes 0.000 description 5
- 108090000790 Enzymes Proteins 0.000 description 5
- 230000015556 catabolic process Effects 0.000 description 5
- 238000006731 degradation reaction Methods 0.000 description 5
- 229940088598 enzyme Drugs 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 4
- 239000003963 antioxidant agent Substances 0.000 description 4
- 235000006708 antioxidants Nutrition 0.000 description 4
- 235000010354 butylated hydroxytoluene Nutrition 0.000 description 4
- 150000001732 carboxylic acid derivatives Chemical class 0.000 description 4
- 229920000126 latex Polymers 0.000 description 4
- 239000004816 latex Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000000704 physical effect Effects 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 235000019833 protease Nutrition 0.000 description 4
- 102100031415 Hepatic triacylglycerol lipase Human genes 0.000 description 3
- 108020002496 Lysophospholipase Proteins 0.000 description 3
- 102100037883 Phospholipase B1, membrane-associated Human genes 0.000 description 3
- 102000015439 Phospholipases Human genes 0.000 description 3
- 108010064785 Phospholipases Proteins 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- 239000002280 amphoteric surfactant Substances 0.000 description 3
- 239000003945 anionic surfactant Substances 0.000 description 3
- 230000003078 antioxidant effect Effects 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 125000004432 carbon atom Chemical group C* 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000004140 cleaning Methods 0.000 description 3
- GVJHHUAWPYXKBD-UHFFFAOYSA-N d-alpha-tocopherol Natural products OC1=C(C)C(C)=C2OC(CCCC(C)CCCC(C)CCCC(C)C)(C)CCC2=C1C GVJHHUAWPYXKBD-UHFFFAOYSA-N 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 238000005227 gel permeation chromatography Methods 0.000 description 3
- 238000009616 inductively coupled plasma Methods 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 3
- 230000007246 mechanism Effects 0.000 description 3
- 230000000813 microbial effect Effects 0.000 description 3
- 239000002736 nonionic surfactant Substances 0.000 description 3
- 108090000765 processed proteins & peptides Proteins 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- SPSPIUSUWPLVKD-UHFFFAOYSA-N 2,3-dibutyl-6-methylphenol Chemical compound CCCCC1=CC=C(C)C(O)=C1CCCC SPSPIUSUWPLVKD-UHFFFAOYSA-N 0.000 description 2
- ZIIUUSVHCHPIQD-UHFFFAOYSA-N 2,4,6-trimethyl-N-[3-(trifluoromethyl)phenyl]benzenesulfonamide Chemical compound CC1=CC(C)=CC(C)=C1S(=O)(=O)NC1=CC=CC(C(F)(F)F)=C1 ZIIUUSVHCHPIQD-UHFFFAOYSA-N 0.000 description 2
- 108091005502 Aspartic proteases Proteins 0.000 description 2
- 102000035101 Aspartic proteases Human genes 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 108010059378 Endopeptidases Proteins 0.000 description 2
- 102000005593 Endopeptidases Human genes 0.000 description 2
- 108010013563 Lipoprotein Lipase Proteins 0.000 description 2
- 102000011420 Phospholipase D Human genes 0.000 description 2
- 108090000553 Phospholipase D Proteins 0.000 description 2
- 239000005062 Polybutadiene Substances 0.000 description 2
- ZTHYODDOHIVTJV-UHFFFAOYSA-N Propyl gallate Chemical compound CCCOC(=O)C1=CC(O)=C(O)C(O)=C1 ZTHYODDOHIVTJV-UHFFFAOYSA-N 0.000 description 2
- 239000002174 Styrene-butadiene Substances 0.000 description 2
- 108090001109 Thermolysin Proteins 0.000 description 2
- 125000002015 acyclic group Chemical group 0.000 description 2
- 125000001931 aliphatic group Chemical group 0.000 description 2
- 235000001014 amino acid Nutrition 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- CZBZUDVBLSSABA-UHFFFAOYSA-N butylated hydroxyanisole Chemical compound COC1=CC=C(O)C(C(C)(C)C)=C1.COC1=CC=C(O)C=C1C(C)(C)C CZBZUDVBLSSABA-UHFFFAOYSA-N 0.000 description 2
- ZWLIYXJBOIDXLL-UHFFFAOYSA-N decanedihydrazide Chemical compound NNC(=O)CCCCCCCCC(=O)NN ZWLIYXJBOIDXLL-UHFFFAOYSA-N 0.000 description 2
- 230000001687 destabilization Effects 0.000 description 2
- 229920003244 diene elastomer Polymers 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- POULHZVOKOAJMA-UHFFFAOYSA-N dodecanoic acid Chemical compound CCCCCCCCCCCC(O)=O POULHZVOKOAJMA-UHFFFAOYSA-N 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 239000000446 fuel Substances 0.000 description 2
- 230000003993 interaction Effects 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- BYTFESSQUGDMQQ-UHFFFAOYSA-N octadecanehydrazide Chemical compound CCCCCCCCCCCCCCCCCC(=O)NN BYTFESSQUGDMQQ-UHFFFAOYSA-N 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 235000000346 sugar Nutrition 0.000 description 2
- 238000004073 vulcanization Methods 0.000 description 2
- GOJUJUVQIVIZAV-UHFFFAOYSA-N 2-amino-4,6-dichloropyrimidine-5-carbaldehyde Chemical group NC1=NC(Cl)=C(C=O)C(Cl)=N1 GOJUJUVQIVIZAV-UHFFFAOYSA-N 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- ZZMVLMVFYMGSMY-UHFFFAOYSA-N 4-n-(4-methylpentan-2-yl)-1-n-phenylbenzene-1,4-diamine Chemical compound C1=CC(NC(C)CC(C)C)=CC=C1NC1=CC=CC=C1 ZZMVLMVFYMGSMY-UHFFFAOYSA-N 0.000 description 1
- 108091005508 Acid proteases Proteins 0.000 description 1
- 239000004382 Amylase Substances 0.000 description 1
- 102000013142 Amylases Human genes 0.000 description 1
- 108010065511 Amylases Proteins 0.000 description 1
- 108091005658 Basic proteases Proteins 0.000 description 1
- KWIUHFFTVRNATP-UHFFFAOYSA-N Betaine Natural products C[N+](C)(C)CC([O-])=O KWIUHFFTVRNATP-UHFFFAOYSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 108010076667 Caspases Proteins 0.000 description 1
- 102000011727 Caspases Human genes 0.000 description 1
- 102000003908 Cathepsin D Human genes 0.000 description 1
- 108090000258 Cathepsin D Proteins 0.000 description 1
- 108090000317 Chymotrypsin Proteins 0.000 description 1
- 108010005843 Cysteine Proteases Proteins 0.000 description 1
- 102000005927 Cysteine Proteases Human genes 0.000 description 1
- ZZZCUOFIHGPKAK-UHFFFAOYSA-N D-erythro-ascorbic acid Natural products OCC1OC(=O)C(O)=C1O ZZZCUOFIHGPKAK-UHFFFAOYSA-N 0.000 description 1
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 1
- 229920002943 EPDM rubber Polymers 0.000 description 1
- 102000018389 Exopeptidases Human genes 0.000 description 1
- 108010091443 Exopeptidases Proteins 0.000 description 1
- 241000233866 Fungi Species 0.000 description 1
- WHUUTDBJXJRKMK-UHFFFAOYSA-N Glutamic acid Natural products OC(=O)C(N)CCC(O)=O WHUUTDBJXJRKMK-UHFFFAOYSA-N 0.000 description 1
- 108091005503 Glutamic proteases Proteins 0.000 description 1
- 108010010369 HIV Protease Proteins 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 239000006237 Intermediate SAF Substances 0.000 description 1
- 239000005639 Lauric acid Substances 0.000 description 1
- KWIUHFFTVRNATP-UHFFFAOYSA-O N,N,N-trimethylglycinium Chemical compound C[N+](C)(C)CC(O)=O KWIUHFFTVRNATP-UHFFFAOYSA-O 0.000 description 1
- 229920000459 Nitrile rubber Polymers 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 108090000526 Papain Proteins 0.000 description 1
- 102000057297 Pepsin A Human genes 0.000 description 1
- 108090000284 Pepsin A Proteins 0.000 description 1
- 108010058864 Phospholipases A2 Proteins 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 230000002292 Radical scavenging effect Effects 0.000 description 1
- 240000004808 Saccharomyces cerevisiae Species 0.000 description 1
- 108010022999 Serine Proteases Proteins 0.000 description 1
- 102000012479 Serine Proteases Human genes 0.000 description 1
- 241000872198 Serjania polyphylla Species 0.000 description 1
- 241000519995 Stachys sylvatica Species 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 108090000787 Subtilisin Proteins 0.000 description 1
- 108091005501 Threonine proteases Proteins 0.000 description 1
- 102000035100 Threonine proteases Human genes 0.000 description 1
- 229930003268 Vitamin C Natural products 0.000 description 1
- 229930003427 Vitamin E Natural products 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- IBVAQQYNSHJXBV-UHFFFAOYSA-N adipic acid dihydrazide Chemical compound NNC(=O)CCCCC(=O)NN IBVAQQYNSHJXBV-UHFFFAOYSA-N 0.000 description 1
- 150000001299 aldehydes Chemical class 0.000 description 1
- 150000007933 aliphatic carboxylic acids Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 150000001413 amino acids Chemical class 0.000 description 1
- 235000019418 amylase Nutrition 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 235000010323 ascorbic acid Nutrition 0.000 description 1
- 239000011668 ascorbic acid Substances 0.000 description 1
- 229960005070 ascorbic acid Drugs 0.000 description 1
- 238000004380 ashing Methods 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 229960003237 betaine Drugs 0.000 description 1
- 238000006065 biodegradation reaction Methods 0.000 description 1
- FCCCRBDJBTVFSJ-UHFFFAOYSA-N butanehydrazide Chemical compound CCCC(=O)NN FCCCRBDJBTVFSJ-UHFFFAOYSA-N 0.000 description 1
- 229920005549 butyl rubber Polymers 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 238000011088 calibration curve Methods 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229960002376 chymotrypsin Drugs 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 230000001112 coagulating effect Effects 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- ROGBVBLYGMXQRO-UHFFFAOYSA-N decanehydrazide Chemical compound CCCCCCCCCC(=O)NN ROGBVBLYGMXQRO-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 230000003544 deproteinization Effects 0.000 description 1
- GRGBENNNGZARRZ-UHFFFAOYSA-N dodecanedihydrazide Chemical compound NNC(=O)CCCCCCCCCCC(=O)NN GRGBENNNGZARRZ-UHFFFAOYSA-N 0.000 description 1
- YTQHSQQSLTYMSL-UHFFFAOYSA-N dodecanohydrazide Chemical compound CCCCCCCCCCCC(=O)NN YTQHSQQSLTYMSL-UHFFFAOYSA-N 0.000 description 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 230000007515 enzymatic degradation Effects 0.000 description 1
- 230000002255 enzymatic effect Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- WIGCFUFOHFEKBI-UHFFFAOYSA-N gamma-tocopherol Natural products CC(C)CCCC(C)CCCC(C)CCCC1CCC2C(C)C(O)C(C)C(C)C2O1 WIGCFUFOHFEKBI-UHFFFAOYSA-N 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 235000013922 glutamic acid Nutrition 0.000 description 1
- 239000004220 glutamic acid Substances 0.000 description 1
- 229920005555 halobutyl Polymers 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- FAWGDZUNQZJISX-UHFFFAOYSA-N heptanehydrazide Chemical compound CCCCCCC(=O)NN FAWGDZUNQZJISX-UHFFFAOYSA-N 0.000 description 1
- SSVSELJXJJCANX-UHFFFAOYSA-N hexadecanehydrazide Chemical compound CCCCCCCCCCCCCCCC(=O)NN SSVSELJXJJCANX-UHFFFAOYSA-N 0.000 description 1
- QKWRNBNHSRYCOE-UHFFFAOYSA-N hexanehydrazide Chemical compound CCCCCC(=O)NN QKWRNBNHSRYCOE-UHFFFAOYSA-N 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 239000003262 industrial enzyme Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 150000002632 lipids Chemical class 0.000 description 1
- 238000010077 mastication Methods 0.000 description 1
- 230000018984 mastication Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000000693 micelle Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- CMAUJSNXENPPOF-UHFFFAOYSA-N n-(1,3-benzothiazol-2-ylsulfanyl)-n-cyclohexylcyclohexanamine Chemical compound C1CCCCC1N(C1CCCCC1)SC1=NC2=CC=CC=C2S1 CMAUJSNXENPPOF-UHFFFAOYSA-N 0.000 description 1
- HMYRUXBSDBAVNN-UHFFFAOYSA-N nonanehydrazide Chemical compound CCCCCCCCC(=O)NN HMYRUXBSDBAVNN-UHFFFAOYSA-N 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- VMUZVGRNTPFTKE-UHFFFAOYSA-N octanehydrazide Chemical compound CCCCCCCC(=O)NN VMUZVGRNTPFTKE-UHFFFAOYSA-N 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 235000019834 papain Nutrition 0.000 description 1
- 229940055729 papain Drugs 0.000 description 1
- PJBQYCIDGYKEMN-UHFFFAOYSA-N pentanehydrazide Chemical compound CCCCC(=O)NN PJBQYCIDGYKEMN-UHFFFAOYSA-N 0.000 description 1
- 229940111202 pepsin Drugs 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 150000003904 phospholipids Chemical class 0.000 description 1
- 229920001084 poly(chloroprene) Polymers 0.000 description 1
- 229920002857 polybutadiene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 102000004196 processed proteins & peptides Human genes 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 235000010388 propyl gallate Nutrition 0.000 description 1
- 239000000473 propyl gallate Substances 0.000 description 1
- 229940075579 propyl gallate Drugs 0.000 description 1
- 230000002797 proteolythic effect Effects 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 238000000518 rheometry Methods 0.000 description 1
- 230000005070 ripening Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 235000010352 sodium erythorbate Nutrition 0.000 description 1
- 239000004320 sodium erythorbate Substances 0.000 description 1
- RBWSWDPRDBEWCR-RKJRWTFHSA-N sodium;(2r)-2-[(2r)-3,4-dihydroxy-5-oxo-2h-furan-2-yl]-2-hydroxyethanolate Chemical compound [Na+].[O-]C[C@@H](O)[C@H]1OC(=O)C(O)=C1O RBWSWDPRDBEWCR-RKJRWTFHSA-N 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 150000008163 sugars Chemical class 0.000 description 1
- 229920003051 synthetic elastomer Polymers 0.000 description 1
- 239000005061 synthetic rubber Substances 0.000 description 1
- 235000010384 tocopherol Nutrition 0.000 description 1
- 229930003799 tocopherol Natural products 0.000 description 1
- 229960001295 tocopherol Drugs 0.000 description 1
- 239000011732 tocopherol Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 235000019154 vitamin C Nutrition 0.000 description 1
- 239000011718 vitamin C Substances 0.000 description 1
- 235000019165 vitamin E Nutrition 0.000 description 1
- 239000011709 vitamin E Substances 0.000 description 1
- 229940046009 vitamin E Drugs 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
- 235000014692 zinc oxide Nutrition 0.000 description 1
- GVJHHUAWPYXKBD-IEOSBIPESA-N α-tocopherol Chemical compound OC1=C(C)C(C)=C2O[C@@](CCC[C@H](C)CCC[C@H](C)CCCC(C)C)(C)CCC2=C1C GVJHHUAWPYXKBD-IEOSBIPESA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/80—Technologies aiming to reduce greenhouse gasses emissions common to all road transportation technologies
- Y02T10/86—Optimisation of rolling resistance, e.g. weight reduction
Landscapes
- Tires In General (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Description
本発明は、天然ゴム組成物、ゴム組成物、及びタイヤに関する。 The present invention relates to a natural rubber composition, a rubber composition, and a tire.
天然ゴムは、天然ゴムラテックスとして採取し、凝固、必要に応じて熟成、洗浄、脱水、乾燥、パッキングの順の工程を経て得られる。この天然ゴムを素練りし、配合剤を配合して成形し、加硫を行うことにより、目的のゴム製品が製造される。
天然ゴムの優れた物理的特性として、機械的特性、低発熱性、耐摩耗性等が挙げられるが、その加工性については、合成ゴムと比較すると劣る部分がある。
特許文献１には、加工性を改良した天然ゴムを提供することを目的として、アンモニアを添加して天然ゴムを処理する方法が記載されている。
Natural rubber is collected as a natural rubber latex and obtained through the steps of coagulation, aging as necessary, washing, dehydration, drying, and packing. This natural rubber is masticated, compounded with a compounding agent, molded, and vulcanized to produce the desired rubber product.
The excellent physical properties of natural rubber include mechanical properties, low heat build-up, wear resistance, etc., but the processability is inferior to that of synthetic rubber.
Patent Document 1 describes a method of treating natural rubber by adding ammonia for the purpose of providing a natural rubber with improved processability.
特許文献１に記載されている処理された天然ゴムを使用することにより、加工性は改良されるものの、天然ゴムが本来有する低転がり抵抗性等の物性は、処理により低下するという問題があった。
本発明の目的は、加工性及び低転がり抵抗性を両立しうる天然ゴム組成物を提供することである。更に、本発明は、前記天然ゴム組成物を含有するゴム組成物、及び該ゴム組成物を使用したタイヤを提供することである。
Although the processability is improved by using the treated natural rubber described in Patent Document 1, the physical properties such as the low rolling resistance inherent to the natural rubber have a problem of being lowered by the treatment. .
An object of the present invention is to provide a natural rubber composition capable of achieving both processability and low rolling resistance. Furthermore, this invention is providing the rubber composition containing the said natural rubber composition, and the tire which uses this rubber composition.
本発明者は鋭意検討した結果、未処理の天然ゴムと、特定の物性を有する処理された天然ゴムとを併用することにより、上記の課題を解決しうることを見出した。
すなわち、本発明は、以下の〔１〕〜〔６〕に関する。
〔１〕 （Ａ）天然ゴム、及び（Ｂ）下記式（Ｉ）に基づき、７０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が３．０以上５．５以下であり、かつ、１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が２．０以上４．０以下である天然ゴムを含有し、（Ａ）成分と（Ｂ）成分との合計に対する（Ｂ）成分の含有量が１０〜４０質量％であることを特徴とする天然ゴム組成物。
ＬＣＢ Ｉｎｄｅｘ＝Ｇ’１／Ｇ’５ ・・・（Ｉ）
〔２〕 前記（Ｂ）成分が、７０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が３．０以上５．１以下であり、かつ、１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が２．０以上３．０以下である、〔１〕に記載の天然ゴム組成物。
〔３〕 前記（Ｂ）成分が、リン含有量が２００ｐｐｍを超え、かつ、窒素含有量が０．１質量％以上０．３質量％以下である、〔１〕又は〔２〕に記載の天然ゴム組成物。
〔４〕 〔１〕〜〔３〕のいずれかに記載の天然ゴム組成物と、充填材とを含有することを特徴とするゴム組成物。
〔５〕 プロセスオイルの含有量が（Ａ）成分及び（Ｂ）成分の合計を１００質量部としたとき、５質量部以下である、〔４〕に記載のゴム組成物。
〔６〕 〔４〕又は〔５〕に記載のゴム組成物を用いたタイヤ。
As a result of intensive studies, the present inventor has found that the above-described problems can be solved by using untreated natural rubber in combination with a treated natural rubber having specific physical properties.
That is, the present invention relates to the following [1] to [6].
[1] (A) Natural rubber and (B) Based on the following formula (I), the long chain branching index (LCB Index) at 70 ° C. is 3.0 or more and 5.5 or less, and the length at 130 ° C. It contains natural rubber having a chain branching index (LCB Index) of 2.0 or more and 4.0 or less, and the content of the component (B) with respect to the sum of the components (A) and (B) is 10 to 40% by mass. A natural rubber composition characterized by the above.
LCB Index = G ′ 1 / G ′ 5 (I)
[2] The component (B) has a long chain branching index (LCB Index) at 70 ° C. of 3.0 or more and 5.1 or less and a long chain branching index (LCB Index) at 130 ° C. of 2.0. The natural rubber composition according to [1], which is at least 3.0.
[3] The natural component according to [1] or [2], wherein the component (B) has a phosphorus content exceeding 200 ppm and a nitrogen content of 0.1% by mass to 0.3% by mass. Rubber composition.
[4] A rubber composition comprising the natural rubber composition according to any one of [1] to [3] and a filler.
[5] The rubber composition according to [4], wherein the content of the process oil is 5 parts by mass or less when the total of the component (A) and the component (B) is 100 parts by mass.
[6] A tire using the rubber composition according to [4] or [5].
本発明によれば、加工性及び低転がり抵抗性を両立しうる天然ゴム組成物を提供することができる。更に、本発明によれば、前記天然ゴム組成物を含有するゴム組成物、及び該ゴム組成物を使用したタイヤを提供することができる。 According to the present invention, it is possible to provide a natural rubber composition capable of achieving both processability and low rolling resistance. Furthermore, according to this invention, the rubber composition containing the said natural rubber composition and the tire which uses this rubber composition can be provided.
以下に、本発明をその実施形態に基づき詳細に例示説明する。なお、以下の説明において、数値範囲を示す「Ａ〜Ｂ」の記載は、端点であるＡ及びＢを含む数値範囲を表し、「Ａ以上Ｂ以下」（Ａ＜Ｂの場合）、又は「Ａ以下Ｂ以上」（Ａ＞Ｂの場合）を表す。
また、質量部及び質量％は、それぞれ、重量部及び重量％と同義である。
Hereinafter, the present invention will be described in detail based on the embodiments. In the following description, the description of “A to B” indicating a numerical range represents a numerical range including A and B as end points, and “A or more and B or less” (when A <B), or “A "B or more" (when A> B).
Moreover, a mass part and mass% are synonymous with a weight part and weight%, respectively.
［天然ゴム組成物］
本発明の天然ゴム組成物は、（Ａ）天然ゴム、及び（Ｂ）下記式（Ｉ）に基づき、７０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が３．０以上５．５以下であり、かつ、１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が２．０以上４．０以下である天然ゴム（以下、「処理天然ゴム」ともいう。）を含有し、（Ａ）成分と（Ｂ）成分との合計に対する（Ｂ）成分の含有量が１０〜４０質量％であることを特徴とする。
本発明者は、特許文献１に記載の処理された天然ゴムを使用すると、加工性は向上するものの、特にタイヤ用途に重要な、低転がり抵抗性等の性能が低下する問題があることを見出した。
本発明者は鋭意検討することによって、（Ａ）天然ゴム及び（Ｂ）処理天然ゴムを特定の範囲で含有する天然ゴム組成物とすることにより、上記の問題が解決されることを見出し、本発明を完成するに至った。その詳細な機構は不明であるが、一部は以下のように考えられる。
従来、天然ゴムの加工性を向上させるために、ゴム組成物にプロセスオイルを添加して加工性を向上させることが行われてきたが、プロセスオイルを添加すると、耐摩耗性が低下するという問題があった。特許文献１では、天然ゴムとして、特定の処理を施され、特定のＬＣＢ Ｉｎｄｅｘを有する処理天然ゴムを使用することで、加工性が向上することが明らかとなった。
一方、上記（Ｂ）処理天然ゴムは、処理に伴う分子構造の変化により、低転がり抵抗性等の一部の性能に関しては、（Ａ）天然ゴムに比べて性能が劣ると推定される。そこで、処理により加工性が向上した（Ｂ）処理天然ゴムを、デメリットが顕在化しない範囲で（Ａ）天然ゴムと併用することで、加工性に優れ、また、得られるタイヤが低転がり抵抗性に優れた天然ゴム組成物が得られることを見出した。
[Natural rubber composition]
The natural rubber composition of the present invention has (A) natural rubber, and (B) a long chain branching index (LCB Index) at 70 ° C. of 3.0 or more and 5.5 or less based on the following formula (I): And a natural rubber having a long chain branching index (LCB Index) at 130 ° C. of 2.0 or more and 4.0 or less (hereinafter, also referred to as “treated natural rubber”), the component (A) and the component (B) Content of (B) component with respect to the sum total with a component is 10-40 mass%, It is characterized by the above-mentioned.
The present inventor has found that, when the treated natural rubber described in Patent Document 1 is used, the processability is improved, but there is a problem that the performance such as low rolling resistance, which is particularly important for tire use, is deteriorated. It was.
The present inventor has intensively studied to find that the above-mentioned problems can be solved by making a natural rubber composition containing (A) natural rubber and (B) treated natural rubber in a specific range. The invention has been completed. Although the detailed mechanism is unknown, a part is considered as follows.
Conventionally, in order to improve the processability of natural rubber, it has been performed to improve processability by adding process oil to the rubber composition. However, when process oil is added, there is a problem that wear resistance decreases. was there. In patent document 1, it became clear that processability improves by using the processing natural rubber which gave the specific process and has a specific LCB Index as a natural rubber.
On the other hand, the (B) treated natural rubber is presumed to be inferior to the (A) natural rubber in terms of some performance such as low rolling resistance due to a change in the molecular structure accompanying the treatment. Therefore, (B) treated natural rubber, whose processability has been improved by treatment, is used in combination with (A) natural rubber within the range where the disadvantages do not become apparent, so that the processability is excellent and the resulting tire has low rolling resistance. It was found that an excellent natural rubber composition can be obtained.
＜（Ａ）天然ゴム＞
本発明において、天然ゴム組成物は、（Ａ）天然ゴムを含有する。（Ａ）天然ゴムは、長鎖分岐点となる化合物を分解する工程を行っていない、未処理の天然ゴムを意味する。なお、長鎖分岐点となる化合物を分解する工程としては、酵素分解及び微生物分解から選ばれる少なくとも１種の生化学的分解、又はけん化処理からなる化学的分解が例示され、詳細は後述する。
<(A) Natural rubber>
In the present invention, the natural rubber composition contains (A) natural rubber. (A) Natural rubber means untreated natural rubber that has not undergone a step of decomposing a compound that becomes a long-chain branching point. In addition, as a process of decomposing | disassembling the compound used as a long-chain branch point, the chemical decomposition which consists of at least 1 sort (s) of biochemical decomposition | disassembly chosen from enzyme decomposition | disassembly and microbial decomposition, or a saponification process is illustrated later.
＜（Ｂ）処理天然ゴム＞
本発明において、（Ｂ）処理天然ゴムは、下記の式（Ｉ）に基づき、７０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が３．０以上５．５以下で、かつ、１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が２．０以上４．０以下である。
ＬＣＢ Ｉｎｄｅｘ＝Ｇ’１／Ｇ’５ ・・・（Ｉ）
<(B) treated natural rubber>
In the present invention, the treated natural rubber (B) has a long chain branching index (LCB Index) at 70 ° C. of 3.0 or more and 5.5 or less and a long chain at 130 ° C. based on the following formula (I): The branching index (LCB Index) is 2.0 or more and 4.0 or less.
LCB Index = G ′ 1 / G ′ 5 (I)
長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）は、ＲＰＡ２０００型試験機（アルファテクノロジーズ社製）を用いてＬＡＯＳ測定方法により測定することができる。ＲＰＡ２０００型試験機（アルファテクノロジーズ社製）を用いてＬＡＯＳ測定方法により測定した長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）とは、溶解ポリマーのダイナミック特性において、近似した特徴を持つ長鎖分岐（ＬＣＢ）と分子量分布の挙動から、分子量分布による影響を取り除いた、より正確な長鎖分岐の指数を示す。なお、ＬＣＢ Ｉｎｄｅｘを求めるためのＬＡＯＳの詳細については、“FT-Rheology, a Tool to Quantify Long Chain Branching (LCB) in Natural Rubber and its Effect on Mastication, Mixing Behaviour and Final Properties.”（Henri G. Burhin, Alpha Technologies, UK 15 Rue du Culot B-1435 Hevillers, Belgium）などを参照することができる。
ここで、ＬＡＯＳは、Ｌａｒｇｅ Ａｍｐｌｉｔｕｄｅ Ｏｓｃｉｌｌａｔｏｒｙ Ｓｈｅａｒの略である
本明細書では、ＲＰＡ２０００型試験機（アルファテクノロジーズ社製）を用いて、ＬＡＯＳモードでの測定によって得られたシェアストレス信号を離散フーリエ変換にて、ｎ＝１〜９（ｎは整数）まで算出し、
The long chain branching index (LCB Index) can be measured by an LAOS measurement method using an RPA2000 type tester (manufactured by Alpha Technologies). The long chain branching index (LCB Index) measured by the LAOS measurement method using an RPA2000 type tester (manufactured by Alpha Technologies) is the long chain branching (LCB) having an approximate characteristic in the dynamic characteristics of the dissolved polymer and the molecular weight. A more accurate index of long-chain branching is shown by removing the influence of molecular weight distribution from the distribution behavior. For details of LAOS for obtaining LCB Index, see “FT-Rheology, a Tool to Quantify Long Chain Branching (LCB) in Natural Rubber and its Effect on Mastication, Mixing Behavior and Final Properties.” (Henri G. Burhin , Alpha Technologies, UK 15 Rue du Culot B-1435 Hevillers, Belgium).
Here, LAOS is an abbreviation for Large Amplitude Oscillator Shear. In this specification, using a RPA2000 type tester (manufactured by Alpha Technologies), a shear stress signal obtained by measurement in LAOS mode is converted into a discrete Fourier transform. N = 1 to 9 (n is an integer)
（式中、γ０：振幅、ｔ：時間、ω：角速度（単位：ｒａｄ／ｓ））
で表すシェアストレスτの式にフィッティングする。
更に、
(Where, γ0: amplitude, t: time, ω: angular velocity (unit: rad / s))
Fitting to the equation of share stress τ expressed by
Furthermore,
上記式で求めたτを用いて、測定条件として、質量５ｇの試験片に対して、測定中の圧力１５．６ｋＮ、温度７０℃、周波数１．６７Ｈｚ、歪が０．５％で１分間置いた後、１０秒間かけて（すなわち、０．１Ｈｚ）、角速度ωを０．５０ｒａｄ／ｓとして、角度が７１．５度、歪が１０００％で、測定中の圧力を１５．６ｋＮの条件下で、７０℃、８０℃、９０℃、１００℃、１１０℃、１２０℃、１３０℃と順次温度を上げながら、各温度でＧ’ｎを求め、Ｇ’１／Ｇ’５から７０℃と１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）を求めている。
なお、実施例においても上記同様の方法にて測定を行った。
Using τ determined by the above equation, the measurement conditions are a pressure of 15.6 kN, a temperature of 70 ° C., a frequency of 1.67 Hz, and a strain of 0.5% for 1 minute with respect to a test piece having a mass of 5 g. After 10 seconds (that is, 0.1 Hz), the angular velocity ω is 0.50 rad / s, the angle is 71.5 degrees, the strain is 1000%, and the pressure under measurement is 15.6 kN. , 70 ° C., 80 ° C., 90 ° C., 100 ° C., 110 ° C., 120 ° C., 130 ° C. While increasing the temperature sequentially, G ′ n was obtained at each temperature, and G ′ 1 / G ′ 5 to 70 ° C. and 130 ° C. The long chain branching index (LCB Index) is obtained.
In the examples, the measurement was performed in the same manner as described above.
上述のＬＡＯＳ測定方法により測定された、７０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）は、天然ゴムの分岐構造における弱い結合（すなわち、水素結合等）を含む分岐量を示し、一方、１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）は、天然ゴムの分岐構造における強い結合（すなわち、共有結合）による分岐量を示す。
そして、本発明の処理天然ゴムは、７０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が３．０以上、好ましくは３．２以上、より好ましくは３．５以上、更に好ましくは４．０以上であり、そして、５．５以下、好ましくは５．２以下、より好ましくは５．１以下、更に好ましくは５．０以下であり、かつ、１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が２．０以上であり、そして、４．０以下、好ましくは３．５以下、より好ましくは３．０以下である。
処理天然ゴムが、７０℃及び１３０℃において、いずれも上記範囲内の長鎖分岐指数であることにより、両方の結合に起因する分岐量が低減されているため、処理天然ゴムの加工性が格段に向上し、また、本発明のように両方の結合の分岐量が低減した処理天然ゴムは、例えば空気入りタイヤを製造する際にカーボンブラック等の充填材の分散性が高いため、タイヤの耐摩耗性が向上する。
The long chain branching index (LCB Index) at 70 ° C. measured by the LAOS measurement method described above indicates the amount of branching including weak bonds (ie hydrogen bonds etc.) in the branched structure of natural rubber, while at 130 ° C. The long chain branching index (LCB Index) indicates the amount of branching due to strong bonds (ie, covalent bonds) in the branched structure of natural rubber.
The treated natural rubber of the present invention has a long chain branching index (LCB Index) at 70 ° C. of 3.0 or more, preferably 3.2 or more, more preferably 3.5 or more, still more preferably 4.0 or more. And 5.5 or less, preferably 5.2 or less, more preferably 5.1 or less, and further preferably 5.0 or less, and a long chain branching index (LCB Index) at 130 ° C. of 2. 0 or more, and 4.0 or less, preferably 3.5 or less, more preferably 3.0 or less.
Since the treated natural rubber has a long chain branching index within the above range at 70 ° C. and 130 ° C., the amount of branching due to both bonds is reduced. In addition, the treated natural rubber having a reduced branching amount of both bonds as in the present invention has high dispersibility of fillers such as carbon black when manufacturing a pneumatic tire, for example. Abrasion is improved.
本発明において、処理天然ゴムにおけるリン含有量は、２００ｐｐｍを超えることが好ましく、９００ｐｐｍ以下であることが好ましく、７００ｐｐｍ以下であることがより好ましい。
処理天然ゴムのリン含有量が上記含有量であることにより、処理天然ゴムにおけるポリマー間の相互作用を促進し、高分子量化することで耐摩耗性を向上させる。
In the present invention, the phosphorus content in the treated natural rubber is preferably more than 200 ppm, preferably 900 ppm or less, and more preferably 700 ppm or less.
When the phosphorus content of the treated natural rubber is the above content, the interaction between the polymers in the treated natural rubber is promoted and the wear resistance is improved by increasing the molecular weight.
また、処理天然ゴムにおける窒素含有量は、０．１質量％以上０．３質量％以下であることが好ましく、０．１５質量％以上０．２５質量％以下であることがより好ましい。
処理天然ゴムの窒素含有量が上記範囲内であることにより、処理天然ゴム中に過剰量のたんぱく質が含まれず、ゲル化が抑制されると共に、処理天然ゴムにおけるポリマー間の相互作用が促進されることにより、耐摩耗性、低発熱性が向上する。
Further, the nitrogen content in the treated natural rubber is preferably 0.1% by mass or more and 0.3% by mass or less, and more preferably 0.15% by mass or more and 0.25% by mass or less.
When the nitrogen content of the treated natural rubber is within the above range, the treated natural rubber does not contain an excessive amount of protein, gelation is suppressed, and interaction between polymers in the treated natural rubber is promoted. As a result, wear resistance and low heat generation are improved.
〔処理天然ゴムの製造方法〕
処理天然ゴムの製造方法は、天然ゴムラテックス中の長鎖分岐点となる化合物を分解する工程と、天然ゴムラテックスを凝固させた後、予め定められた条件下で熟成させる工程（熟成工程）と、熟成後の凝固ゴムを水洗する工程（水洗工程）と、水洗後の凝固ゴムに老化防止剤を添加する工程と、老化防止剤を添加した凝固ゴムを乾燥させる工程（乾燥工程）と、を有する。
[Method for producing treated natural rubber]
A method for producing a treated natural rubber includes a step of decomposing a compound that becomes a long chain branching point in natural rubber latex, a step of coagulating the natural rubber latex, and then aging under a predetermined condition (aging step). The step of washing the coagulated rubber after aging (water washing step), the step of adding an anti-aging agent to the coagulated rubber after water washing, and the step of drying the coagulated rubber added with the anti-aging agent (drying step) Have.
（天然ゴムラテックス中の長鎖分岐点となる化合物を分解する工程）
天然ゴムラテックスとしては、ゴムの木から採取したフィールドラテックス、及びこれを処理した濃縮天然ゴムラテックスの少なくとも１種を使用することができる。天然ゴムラテックス中の乾燥ゴム分（以下「ＤＲＣ」（Dry Rubber Content）ともいう）は、特に制限されないが、１０質量％以上４０質量％以下が好ましい。
ここで、天然ゴムラテックス中の固形分とは、水分（しょう液）及びこれに溶解した成分を除いたすべての固形成分とする。
(Process for decomposing compounds that become long-chain branching points in natural rubber latex)
As the natural rubber latex, it is possible to use at least one of a field latex collected from a rubber tree and a concentrated natural rubber latex obtained by treating the latex. The dry rubber content in natural rubber latex (hereinafter also referred to as “DRC” (Dry Rubber Content)) is not particularly limited, but is preferably 10% by mass or more and 40% by mass or less.
Here, the solid content in the natural rubber latex is defined as all solid components excluding moisture (sodium liquid) and components dissolved therein.
本発明における、長鎖分岐点となる化合物を分解する工程は、酵素分解及び微生物分解から選ばれる少なくとも１種の生化学的分解、又はけん化処理からなる化学的分解である。 In the present invention, the step of decomposing the compound that becomes the long-chain branching point is at least one biochemical decomposition selected from enzymatic decomposition and microbial decomposition, or chemical decomposition comprising saponification treatment.
−生化学的分解−
生化学的分解は、けん化処理などの化学的分解に比べ、マイルドな分解反応で、安全性に優れ、また廃液等の処理が簡便になるという利点を有する。中でも酵素は天然ゴムラテックスに含まれる基質を選択的に分解することができる。特に、後述するプロテアーゼは天然ゴムラテックス中のタンパク質を選択的に分解し、また、アミラーゼは天然ゴムラテックス中の糖を選択的に分解する。その選択性から、ゴム物性にとって不要な成分のみを特異的に除けることから、例えば、空気入りタイヤに生化学的分解を行った天然ゴムを用いた場合、カーボンの分散性が向上し、かつ、適正な分岐量を保持することで、空気入りタイヤの低燃費性能が向上し、耐久性及び耐摩耗性が向上する。
また、生化学的分解は、界面活性剤やアルカリを用いる化学的分解に比べ、洗浄時間を短縮化することができる。これにより、天然ゴムの製造時間の短縮化が図れる。
酵素分解としては、例えば、タンパク質を分解するプロテアーゼ、リン脂質を分解するホスホリパーゼ等が挙げられ、天然ゴムの加工性及び耐摩耗性の観点からプロテアーゼが好ましい。
-Biochemical degradation-
Biochemical decomposition has a mild decomposition reaction as compared with chemical decomposition such as saponification treatment, and has an advantage that it is excellent in safety and the treatment of waste liquid and the like becomes simple. Among them, the enzyme can selectively decompose the substrate contained in the natural rubber latex. In particular, the protease described later selectively degrades proteins in natural rubber latex, and amylase selectively degrades sugars in natural rubber latex. From the selectivity, it is possible to specifically remove only the components unnecessary for rubber physical properties.For example, when natural rubber subjected to biochemical decomposition is used for a pneumatic tire, the dispersibility of carbon is improved, and By maintaining an appropriate amount of branching, the fuel efficiency of the pneumatic tire is improved, and the durability and wear resistance are improved.
In addition, biochemical decomposition can shorten the cleaning time as compared with chemical decomposition using a surfactant or alkali. Thereby, the manufacturing time of natural rubber can be shortened.
Examples of enzymatic degradation include proteases that degrade proteins, phospholipases that degrade phospholipids, and the like, and proteases are preferred from the viewpoint of processability and wear resistance of natural rubber.
プロテアーゼとしては、例えば、下記のものが例示される。
分解の位置による分類の観点から、エキソペプチダーゼ（タンパク質・ペプチド鎖の配列末端から（およそ１〜２アミノ酸残基ずつ）切り取るタイプのもの）、エンドペプチダーゼ（タンパク質・ペプチド鎖の配列中央を切断するタイプのもの）が挙げられる。
基質による分類の観点から、プロテイナーゼ（Proteinase、タンパク質を分解するもの）、（狭義の）ペプチダーゼ（Peptidase、より分子量の小さな合成ペプチドなどを分解するもの）が挙げられる。
また、触媒機構による分類の観点から、キモトリプシン（chymotrypsin）、スブチリシン（subtilisin）などのセリンプロテアーゼ；ペプシン、カテプシンD（cathepsin D）、HIVプロテアーゼなどのアスパラギン酸プロテアーゼ（酸性プロテアーゼ）（aspartic protease）；サーモリシン（thermolysin）などの金属プロテアーゼ（metallo protease）；パパイン、カスパーゼなどのシステインプロテアーゼ（cysteine protease）；この他、プロテアソーム（proteasome）で知られるようになったN-末端スレオニンプロテアーゼ（N-terminal threonine protease）やグルタミン酸プロテアーゼ（glutamic protease）などが挙げられる。
本発明では、分解位置の観点から、エンドペプチダーゼが好ましい。
更に、アンモニアを添加して、ｐＨ１０．５程度で活性が高いプロテアーゼ、すなわち、アルカリプロテアーゼが好ましく、また、天然ゴムラテックスの凝固を抑制する観点から、至適温度が１０〜４０℃であり、室温（例えば、２０℃）前後で活性が高いプロテアーゼが好ましい。
プロテアーゼは、上述したものを１種類のみを用いてもよいし、また、上述したものを２種類以上含む組成にしてもよく、更に、プロテアーゼを主成分としてプロテアーゼ以外の酵素を含んでもよく、また、プロテアーゼ以外が主成分で副活性成分としてプロテアーゼを含んでもよい。
Examples of proteases include the following.
From the viewpoint of classification according to the position of degradation, exopeptidase (type that cuts from the sequence end of the protein / peptide chain (approximately 1 to 2 amino acid residues)), endopeptidase (type that cuts the center of the protein / peptide chain sequence) For example).
From the viewpoint of classification by substrate, proteinases (proteinases that degrade proteins) and (narrowly defined) peptidases (peptidases, those that degrade synthetic peptides with a lower molecular weight) can be mentioned.
From the viewpoint of classification by catalytic mechanism, serine proteases such as chymotrypsin and subtilisin; aspartic proteases such as pepsin, cathepsin D and HIV protease (aspartic protease); thermolysin Metallo proteases such as (thermolysin); cysteine proteases such as papain and caspases; and N-terminal threonine proteases that have become known for proteasomes And glutamic acid protease (glutamic protease).
In the present invention, endopeptidase is preferable from the viewpoint of the degradation position.
Furthermore, a protease having a high activity at a pH of about 10.5 by adding ammonia, that is, an alkaline protease is preferable, and from the viewpoint of suppressing the coagulation of natural rubber latex, the optimum temperature is 10 to 40 ° C. Proteases with high activity around (for example, 20 ° C.) are preferred.
Only one type of the above-described protease may be used, or a composition including two or more of the above-described proteases may be used, and an enzyme other than protease may be included as a main component. In addition, a component other than the protease may be a main component and a protease may be included as a side active component.
ホスホリパーゼとしては、例えば、ホスホリパーゼＡ１（Phospholipase A1）、ホスホリパーゼＡ２（Phospholipase A2）等のホスホリパーゼＡ（Phospholipase A）；ホスホリパーゼＢ（Phospholipase B）（リゾホスホリパーゼ（Lysophospholipase）ともいう）；ホスホリパーゼＣ（Phospholipase C）；ホスホリパーゼＤ（Phospholipase D）等が挙げられる。 Examples of the phospholipase include phospholipase A1 (Phospholipase A1), phospholipase A2 (Phospholipase A); phospholipase B (Phospholipase B) (also referred to as lysophospholipase) (P) Phospholipase D (Phospholipase D) etc. are mentioned.
微生物分解としては、例えば、細菌（バクテリア）、真菌、酵母等が挙げられる。
例えば、熟成中の生分解のメカニズムとしてラテックスに含まれていた微生物や凝固後に付着した微生物が挙げられる。
また、プロテアーゼを多く産出するバクテリアが好ましい。
Examples of microbial degradation include bacteria, fungi, yeasts and the like.
Examples of biodegradation mechanisms during ripening include microorganisms contained in latex and microorganisms attached after coagulation.
Bacteria that produce a large amount of protease are preferred.
生化学的分解において、プロテアーゼの添加量は、天然ゴムラテックスの固形分１００質量部に対して、０．０５質量部以上、１．０質量部以下が好ましく、０．１質量部以上、０．３質量部以下がより好ましい。
プロテアーゼの添加量を上記範囲内にすることにより、工業用酵素の副活性による分解等を抑え、タンパク質を選択的に適度に分解するため、天然ゴムの加工性が向上し、また、天然ゴムを用いた空気入りタイヤにおいては、天然ゴムに対するカーボンブラック等の充填材の分散性が向上し、その結果、空気入りタイヤの耐摩耗性が向上する。
プロテアーゼを用いた場合の生化学的分解のｐＨは、アルカリ性領域（例えば、ｐＨ１０．５付近）であることが好ましく、また、分解温度は、天然ゴムラテックスの凝固抑制の観点から、１０〜４０℃、好ましくは室温（例えば、２０℃）前後が好ましい。分解時のｐＨをアルカリ性領域にすることで、タンパク質が分解されたことによる、脂質膜の不安定化が抑制され、その結果、所望のたんぱく質分解が進行すると共に、天然ゴムラテックスの凝固が抑制される。
また、タンパク質分解処理時の、天然ゴムラテックス中のミセルの不安定化を抑制するために、適宜、界面活性剤を添加してもよい。
プロテアーゼによる分解処理時間は、プロテアーゼの添加量、分解時のｐＨや温度により異なるが、例えば、１時間以上、４８時間以下であることが好ましい。
生化学的分解後の天然ゴムラテックスを凝固させて、ゴム成分を得る。
In the biochemical decomposition, the amount of protease added is preferably 0.05 parts by mass or more and 1.0 part by mass or less, and 0.1 parts by mass or more and 0.1 parts by mass or less with respect to 100 parts by mass of the solid content of the natural rubber latex. 3 parts by mass or less is more preferable.
By making the amount of protease added within the above range, the degradation due to the side activity of industrial enzymes is suppressed and the protein is selectively and appropriately decomposed, so that the processability of natural rubber is improved and the natural rubber is In the used pneumatic tire, the dispersibility of the filler such as carbon black with respect to the natural rubber is improved, and as a result, the wear resistance of the pneumatic tire is improved.
The pH for biochemical degradation when protease is used is preferably in the alkaline region (for example, around pH 10.5), and the decomposition temperature is 10 to 40 ° C. from the viewpoint of inhibiting coagulation of natural rubber latex. The room temperature is preferably around room temperature (for example, 20 ° C.). By making the pH at the time of decomposition alkaline, the destabilization of the lipid membrane due to the decomposition of the protein is suppressed. As a result, the desired protein decomposition proceeds and the coagulation of the natural rubber latex is suppressed. The
Moreover, in order to suppress the destabilization of the micelle in the natural rubber latex during the proteolytic treatment, a surfactant may be appropriately added.
The decomposition treatment time with protease varies depending on the added amount of protease, pH and temperature at the time of decomposition, but is preferably, for example, 1 hour or more and 48 hours or less.
The natural rubber latex after biochemical decomposition is coagulated to obtain a rubber component.
−化学的分解−
化学的分解として、けん化処理が挙げられ、けん化処理は、天然ゴムラテックスに、アルカリと必要に応じて界面活性剤を添加して、所定の温度で一定時間、静置することにより行う。なお、必要に応じて撹拌を行ってもよい。
けん化処理に用いるアルカリとしては、水酸化ナトリウム、水酸化カリウム、水酸化カルシウム、アミン化合物等が挙げられ、けん化効果やラテックスの安定性への影響の観点から、特に水酸化ナトリウム又は水酸化カリウムを用いることが好ましい。
アルカリの添加量は特に限定されないが、天然ゴムラテックスの固形分１００質量部に対して、下限は好ましくは０．１質量部以上、より好ましくは０．３質量部以上、上限は好ましくは１０質量部以下、より好ましくは５質量部以下である。アルカリの添加量を上記範囲内にすることで、適度なけん化処理時間で、天然ゴムラテックス中の非ゴム成分を分解することができる。
-Chemical degradation-
Examples of the chemical decomposition include saponification treatment, and the saponification treatment is performed by adding an alkali and a surfactant as necessary to natural rubber latex and allowing to stand at a predetermined temperature for a predetermined time. In addition, you may stir as needed.
Examples of the alkali used for the saponification treatment include sodium hydroxide, potassium hydroxide, calcium hydroxide, and amine compounds. From the viewpoint of the saponification effect and the influence on the stability of the latex, sodium hydroxide or potassium hydroxide is particularly used. It is preferable to use it.
The amount of alkali added is not particularly limited, but the lower limit is preferably 0.1 parts by weight or more, more preferably 0.3 parts by weight or more, and the upper limit is preferably 10 parts by weight with respect to 100 parts by weight of the solid content of the natural rubber latex. Part or less, more preferably 5 parts by weight or less. By making the addition amount of the alkali within the above range, the non-rubber component in the natural rubber latex can be decomposed in an appropriate saponification treatment time.
界面活性剤としては、陰イオン性界面活性剤、非イオン性界面活性剤、及び両性界面活性剤のうちの少なくとも１種が使用可能である。このうち陰イオン性界面活性剤としては、例えばカルボン酸系、スルホン酸系、硫酸エステル系、リン酸エステル系等の陰イオン性界面活性剤が挙げられる。非イオン性界面活性剤としては、例えばポリオキシアルキレンエーテル系、ポリオキシアルキレンエステル系、多価アルコール脂肪酸エステル系、糖脂肪酸エステル系、アルキルポリグリコシド系等の非イオン性界面活性剤が挙げられる。両性界面活性剤としては、例えばアミノ酸型、ベタイン型、アミンオキサイド型等の両性界面活性剤が挙げられる。
界面活性剤の添加量は、天然ゴムラテックスの固形分１００質量部に対して０．０１質量部以上、５質量部以下であることが好ましく、また、０．１質量部以上、３質量部以下であることがより好ましい。界面活性剤の添加量が上記範囲内であることで、けん化処理時に天然ゴムラテックスが安定化し、後の凝固にも影響を与えない。
As the surfactant, at least one of an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant can be used. Among these, examples of the anionic surfactant include carboxylic acid-based, sulfonic acid-based, sulfate ester-based and phosphate ester-based anionic surfactants. Examples of nonionic surfactants include nonionic surfactants such as polyoxyalkylene ethers, polyoxyalkylene esters, polyhydric alcohol fatty acid esters, sugar fatty acid esters, and alkyl polyglycosides. Examples of amphoteric surfactants include amphoteric surfactants such as amino acid type, betaine type, and amine oxide type.
The addition amount of the surfactant is preferably 0.01 parts by mass or more and 5 parts by mass or less, and 0.1 parts by mass or more and 3 parts by mass or less with respect to 100 parts by mass of the solid content of the natural rubber latex. It is more preferable that When the addition amount of the surfactant is within the above range, the natural rubber latex is stabilized during the saponification treatment and does not affect the subsequent coagulation.
けん化処理の温度は、アルカリによるけん化反応が十分な反応速度で進行しうる範囲、及び天然ゴムラテックスが凝固等の変質を起こさない範囲で適宜、設定できるが、３０℃以上、７０℃以下であることが好ましい。また、処理の時間は、天然ゴムラテックスを静置して処理を行う場合、処理の温度にもよるが、十分な処理を行うことと、生産性を向上することとを併せ考慮すると、３時間以上２４時間以下であることが好ましい。
けん化反応終了後、ギ酸凝固させることが好ましい。
The temperature of the saponification treatment can be set as appropriate as long as the saponification reaction by alkali can proceed at a sufficient reaction rate and the natural rubber latex does not cause alteration such as coagulation, but is 30 ° C or higher and 70 ° C or lower. It is preferable. In addition, when the natural rubber latex is allowed to stand for treatment, the treatment time depends on the treatment temperature, but it takes 3 hours when considering sufficient treatment and improving productivity. It is preferably 24 hours or less.
After completion of the saponification reaction, formic acid is preferably coagulated.
（熟成工程）
凝固後に、最終生成物として得られる天然ゴムの特性に応じて予め定められた条件下で熟成させる。
例えば、相対湿度４０％以上９０％以下、温度１０℃以上７０℃以下の環境下で、１日以上熟成させることが好ましい。
凝固ゴムを、前記雰囲気下で１日以上熟成させることにより、凝固ゴムの内部、外部に存在するバクテリアによって、タンパク質等が適度に分解され、得られた処理天然ゴムの加工性がより向上し、適度にタンパク質等が分解されたことで処理天然ゴムにおけるカーボンブラック等の充填材の分散性が高くなることから、この処理天然ゴムを用いたタイヤの耐摩耗性が向上する。
なお、けん化反応を行った場合には、必要に応じて熟成工程を省略して、後述する洗浄工程に移行してもよい。
(Aging process)
After coagulation, it is aged under conditions that are predetermined according to the properties of the natural rubber obtained as the final product.
For example, it is preferable to ripen for 1 day or more in an environment where the relative humidity is 40% to 90% and the temperature is 10 ° C to 70 ° C.
By aging the coagulated rubber for 1 day or more in the above atmosphere, proteins etc. are appropriately decomposed by bacteria present inside and outside the coagulated rubber, and the processability of the obtained treated natural rubber is further improved. Since the dispersibility of the filler such as carbon black in the treated natural rubber is increased by appropriately degrading proteins and the like, the wear resistance of the tire using the treated natural rubber is improved.
In addition, when performing a saponification reaction, you may abbreviate | omit an aging process as needed and may transfer to the washing | cleaning process mentioned later.
（洗浄工程）
生化学的分解で用いた酵素やバクテリア、及び熟成工程において分解した成分などを凝固ゴムから除去して、ゴムの所望の分子構造を得る観点から、熟成後の凝固ゴムを洗浄することが好ましい。なお、化学分解により、けん化反応を行った場合には、この反応後に、入念に水洗することが好ましい。また、分解工程で用いた酵素やバクテリア及びけん化反応に用いたアルカリや界面活性剤の除去の観点から、シュレッダー等で細断した後に水洗することが好ましい。
(Washing process)
From the viewpoint of obtaining the desired molecular structure of the rubber by removing the enzymes and bacteria used in the biochemical decomposition and components decomposed in the aging process from the coagulated rubber, it is preferable to wash the coagulated rubber after aging. In addition, when a saponification reaction is performed by chemical decomposition, it is preferable to carefully wash with water after this reaction. Further, from the viewpoint of removing the enzymes and bacteria used in the decomposition step and the alkali and surfactant used in the saponification reaction, it is preferable to wash with water after shredding with a shredder or the like.
例えば、けん化反応後、ギ酸凝固されたゴムは、上記熟成工程を省いて、このギ酸凝固させたゴムを細断した後に、入念に洗浄を行うことが好ましい。より洗浄効果を高めるために、例えばゴム分を水で希釈して、遠心分離処理を行い、非ゴム分を除去してもよい。例えば、遠心分離処理を行う場合、まず天然ゴムラテックスのゴム分が好ましくは５質量％以上４０質量％以下、より好ましくは１０質量％以上３０質量％以下となるように水で希釈する。得られたゴム成分に対して、好ましくは５，０００ｒｐｍ以上１０，０００ｒｐｍ以下で、好ましくは１分間以上６０分間以下で遠心分離すればよい。
洗浄後に、凝固させ、ゴム成分を得る。
For example, after the saponification reaction, the formic acid-coagulated rubber is preferably washed carefully after omitting the aging step and chopping the formic acid-coagulated rubber. In order to further enhance the cleaning effect, for example, the rubber component may be diluted with water and centrifuged to remove the non-rubber component. For example, when performing the centrifugal separation treatment, first, the natural rubber latex is diluted with water so that the rubber content is preferably 5% by mass or more and 40% by mass or less, more preferably 10% by mass or more and 30% by mass or less. The obtained rubber component is preferably centrifuged at 5,000 rpm to 10,000 rpm, preferably 1 minute to 60 minutes.
After washing, it is solidified to obtain a rubber component.
（老化防止剤を添加する工程）
洗浄後の凝固ゴムに、老化防止剤を添加した後、乾燥させることが好ましい。
老化防止剤の添加方法としては、例えば、ゴム成分に対して噴霧してもよく、また、ゴム成分を老化防止剤に浸漬してもよく、また、ゴム成分に老化防止剤を練り込んでもよい。
(Process of adding anti-aging agent)
It is preferable to dry the coagulated rubber after washing with an anti-aging agent.
Examples of the method of adding the antiaging agent include spraying the rubber component, dipping the rubber component in the antiaging agent, and kneading the antiaging agent in the rubber component. .
本発明者は脱蛋白及び熟成工程を行った後、ゴム成分を乾燥させる際に、二重結合に隣接する炭素原子に結合している水素原子は比較的反応性が高いので空気中の酸素によって酸化されてラジカル（遊離基）が発生しやすく、発生するラジカルによって、ゴム成分の主鎖間での再結合反応により共有結合が再度形成され、これにより、ゴム成分の分岐が増加する傾向があることを見出した。
そこで、老化防止剤としては、ゴム成分を乾燥させる際に発生するラジカルを捕捉する観点から、酸化防止剤、ヒドラジド化合物が好ましく、ヒドラジド化合物がより好ましい。
ヒドラジド化合物は、ゴム成分を乾燥させる際に、ゴム成分の酸化によって主鎖に生じたアルデヒドをキャップすることで、アルデヒド−タンパク質の結合やアルデヒド−リン脂質の結合による分岐化を抑制することができるため、乾燥時における分岐の増加を抑制することができる。
ヒドラジド化合物は、カルボン酸ヒドラジドであり、カルボン酸ヒドラジドのカルボン酸の炭素数は１〜２０であり、脂肪族カルボン酸及び芳香族カルボン酸から選ばれる少なくとも１種であることが好ましい。
また、ヒドラジド化合物は、環式のヒドラジド化合物、非環式のヒドラジド化合物のいずれを用いてもよいが、立体障害による反応性の観点から、非環式のヒドラジド化合物が好ましい。
When the present inventor performs the deproteinization and aging process and then dries the rubber component, the hydrogen atom bonded to the carbon atom adjacent to the double bond is relatively highly reactive. Oxidized radicals (free radicals) are likely to be generated, and the generated radicals form a covalent bond again by the recombination reaction between the main chains of the rubber component, which tends to increase the branching of the rubber component. I found out.
Therefore, as the antioxidant, an antioxidant and a hydrazide compound are preferable, and a hydrazide compound is more preferable from the viewpoint of capturing radicals generated when the rubber component is dried.
When the rubber component is dried, the hydrazide compound caps the aldehyde generated in the main chain due to oxidation of the rubber component, thereby suppressing branching due to the aldehyde-protein bond or aldehyde-phospholipid bond. Therefore, an increase in branching during drying can be suppressed.
The hydrazide compound is a carboxylic acid hydrazide, the carboxylic acid of the carboxylic acid hydrazide has 1 to 20 carbon atoms, and is preferably at least one selected from aliphatic carboxylic acids and aromatic carboxylic acids.
As the hydrazide compound, either a cyclic hydrazide compound or an acyclic hydrazide compound may be used, but an acyclic hydrazide compound is preferred from the viewpoint of reactivity due to steric hindrance.
酸化防止剤としては、例えば、アスコルビン酸（ビタミンＣ）、トコフェロール（ビタミンＥ）、ジブチルヒドロキシトルエン（ＢＨＴ）、ブチルヒドロキシアニソール（ＢＨＡ）、エリソルビン酸ナトリウム、没食子酸プロピル等が挙げられるが、ラジカル捕捉能の観点から、ジブチルヒドロキシトルエン（ＢＨＴ）が好ましい。
ヒドラジド化合物としては、炭素数２〜２０の脂肪族ヒドラジドが好ましく、炭素数２〜６の脂肪族ヒドラジドがより好ましい。これらのヒドラジド化合物として、具体的には、アジピン酸ジヒドラジド（ＡＤＨ）、セバシン酸ジヒドラジド（ＳＤＨ）、ドデカン二酸ジヒドラジド（ＤＤＨ）、プロピオン酸ヒドラジド（ＰＨＺ）、ステアリン酸ヒドラジド、パルミチン酸ヒドラジド、ラウリン酸ヒドラジド（ドデカン酸ヒドラジド）、酪酸ヒドラジド、ペンタン酸ヒドラジド、ヘキサン酸ヒドラジド、へプタン酸ヒドラジド、オクタン酸ヒドラジド、ノナン酸ヒドラジド、デカン酸ヒドラジド、ウンデカン酸ヒドラジド等が挙げられ、ラジカル捕捉能の観点から、プロピオン酸ヒドラジド（ＰＨＺ）、ステアリン酸ヒドラジドが好ましい。
Antioxidants include, for example, ascorbic acid (vitamin C), tocopherol (vitamin E), dibutylhydroxytoluene (BHT), butylhydroxyanisole (BHA), sodium erythorbate, propyl gallate and the like. From the viewpoint of performance, dibutylhydroxytoluene (BHT) is preferred.
As the hydrazide compound, an aliphatic hydrazide having 2 to 20 carbon atoms is preferable, and an aliphatic hydrazide having 2 to 6 carbon atoms is more preferable. Specific examples of these hydrazide compounds include adipic acid dihydrazide (ADH), sebacic acid dihydrazide (SDH), dodecanedioic acid dihydrazide (DDH), propionic acid hydrazide (PHZ), stearic acid hydrazide, palmitic acid hydrazide, and lauric acid. From the viewpoint of radical scavenging ability, hydrazide (dodecanoic acid hydrazide), butyric acid hydrazide, pentanoic acid hydrazide, hexanoic acid hydrazide, heptanoic acid hydrazide, octanoic acid hydrazide, nonanoic acid hydrazide, decanoic acid hydrazide, etc. Propionic acid hydrazide (PHZ) and stearic acid hydrazide are preferred.
老化防止剤の添加量は、天然ゴムラテックスの固形分１００質量部に対して、好ましくは０．０１質量部以上０．５質量部以下、より好ましくは０．０５質量部以上０．３質量部以下、更に好ましくは０．１質量部以上０．２質量部以下である。
噴霧、浸漬及び練り込みのいずれにより老化防止剤を添加するかにより、老化防止剤の添加量を適宜選択することが好ましいが、老化防止剤の添加量を上記範囲内にすることによって、乾燥時にゴム成分の分岐量が増加することが抑制され、処理天然ゴムとして優れた加工性を有する。
また、老化防止剤は、添加のばらつきを抑制する観点から、水溶液にして噴霧、浸漬することが好ましい。
The addition amount of the antioxidant is preferably 0.01 parts by mass or more and 0.5 parts by mass or less, more preferably 0.05 parts by mass or more and 0.3 parts by mass with respect to 100 parts by mass of the solid content of the natural rubber latex. Hereinafter, it is more preferably 0.1 parts by mass or more and 0.2 parts by mass or less.
Depending on whether the anti-aging agent is added by spraying, dipping or kneading, it is preferable to appropriately select the addition amount of the anti-aging agent, but by making the addition amount of the anti-aging agent within the above range, at the time of drying An increase in the branching amount of the rubber component is suppressed, and the process natural rubber has excellent processability.
The anti-aging agent is preferably sprayed and immersed in an aqueous solution from the viewpoint of suppressing variation in addition.
（乾燥工程）
前記処理天然ゴム前駆体を熟成させた後、真空乾燥機、エアドライヤー、ドラムドライヤー等の通常の乾燥機を用いて乾燥させる。
乾燥温度は、好ましくは７０℃以上１５０℃以下であり、ホワイトスポットの発生を抑制する観点から、乾燥時間は、例えば１５０℃であれば１時間、１００℃であれば１１時間、７０℃であれば１週間程度であることが好ましい。
(Drying process)
After aging the treated natural rubber precursor, it is dried using a normal dryer such as a vacuum dryer, air dryer, drum dryer or the like.
The drying temperature is preferably 70 ° C. or more and 150 ° C. or less, and from the viewpoint of suppressing the occurrence of white spots, the drying time may be 1 hour for 150 ° C., 11 hours for 100 ° C., 70 ° C., for example. If it is about 1 week, it is preferable.
＜天然ゴム組成物＞
本発明の天然ゴム組成物は、（Ａ）成分及び（Ｂ）成分を含有し、（Ａ）成分と（Ｂ）成分との合計に対する（Ｂ）成分の含有量が１０〜４０質量％である。（Ｂ）成分の含有量が１０質量％未満であると、加工性に優れた天然ゴム組成物を得ることが困難であり、４０質量％を超えると、転がり抵抗性が上昇し、該ゴム組成物を用いて得られるタイヤの燃費が悪化する。
（Ａ）成分と（Ｂ）成分との合計に対する（Ｂ）成分の含有量は、加工性の改良と、転がり性能の維持の観点、及び（Ｂ）成分の添加によるコストの上昇を抑える観点から、好ましくは１５質量％以上であり、そして、好ましくは３５質量％以下、より好ましくは３０質量％以下、更に好ましくは２５質量％以下である。
<Natural rubber composition>
The natural rubber composition of the present invention contains the component (A) and the component (B), and the content of the component (B) with respect to the sum of the components (A) and (B) is 10 to 40% by mass. . When the content of the component (B) is less than 10% by mass, it is difficult to obtain a natural rubber composition excellent in processability, and when it exceeds 40% by mass, rolling resistance increases, and the rubber composition The fuel consumption of the tire obtained using the object deteriorates.
The content of the component (B) relative to the sum of the components (A) and (B) is from the viewpoint of improving processability, maintaining rolling performance, and suppressing an increase in cost due to the addition of the component (B). , Preferably 15% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less, and still more preferably 25% by mass or less.
本発明の天然ゴム組成物は、ゴム成分のみからなる。該ゴム成分として、（Ａ）成分及び（Ｂ）成分に加え、他のゴム成分を含有していてもよい。
他のゴム成分としては、合成ジエン系ゴムが好ましく、合成ジエン系ゴムとしては、ポリブタジエンゴム（ＢＲ）、スチレン−ブタジエン共重合体ゴム（ＳＢＲ）、エチレン−プロピレン−ジエン三元共重合体ゴム、クロロプレンゴム、ブチルゴム、ハロゲン化ブチルゴム、アクリロニトリル−ブタジエンゴム等が例示される。これらの中でも、（Ａ）成分及び（Ｂ）成分と併用する観点から、ＳＢＲ、ＢＲが好ましく例示される。
The natural rubber composition of the present invention comprises only a rubber component. As the rubber component, in addition to the component (A) and the component (B), other rubber components may be contained.
As the other rubber component, a synthetic diene rubber is preferable, and as the synthetic diene rubber, polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), ethylene-propylene-diene terpolymer rubber, Examples include chloroprene rubber, butyl rubber, halogenated butyl rubber, and acrylonitrile-butadiene rubber. Among these, SBR and BR are preferably exemplified from the viewpoint of using together with the component (A) and the component (B).
本発明の天然ゴム組成物中の（Ａ）成分及び（Ｂ）成分の合計含有量は、５０質量％以上であり、好ましくは６０質量％以上、より好ましくは７０質量％以上、更に好ましくは８０質量％以上、より更に好ましくは９０質量％以上、特に好ましくは１００質量％である。すなわち、天然ゴム組成物が（Ａ）成分及び（Ｂ）成分のみからなることが特に好ましい。 The total content of the component (A) and the component (B) in the natural rubber composition of the present invention is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80%. More preferably, it is 90 mass% or more, Most preferably, it is 100 mass%. That is, it is particularly preferable that the natural rubber composition consists only of the component (A) and the component (B).
［ゴム組成物］
本発明のゴム組成物は、上記天然ゴム組成物に、ゴム成分を除く、各種添加剤を配合してなる。
本発明のゴム組成物は、添加剤として充填材を配合してなることが好ましい。
本発明のゴム組成物において配合される充填材は特に限定されるものではないが、カーボンブラック、シリカ、アルミナ、水酸化アルミニウム、クレー、炭酸カルシウムなど通常ゴム工業に用いられるものが使用できる。カーボンブラックとしては、例えば、ＳＡＦ、ＨＡＦ、ＩＳＡＦ、ＨＡＦ、ＦＥＦ、ＧＰＦなど種々のグレードのカーボンブラックを使用することができる。また、シリカとしては特に限定されないが、湿式シリカ、乾式シリカ、コロイダルシリカが好ましい。このような充填材は、単独で又は二つ以上のものを混合して用いることもできる。
これらの中でも、カーボンブラック及びシリカが好ましく、カーボンブラックがより好ましい。
この充填材の総配合量は、ゴム組成物中のゴム成分（天然ゴム組成物）１００質量部に対し、好ましくは３０質量部以上、より好ましくは４０質量部以上であり、そして、好ましくは１２０質量部以下、より好ましくは８０質量部以下である。
[Rubber composition]
The rubber composition of the present invention is obtained by blending the above natural rubber composition with various additives excluding the rubber component.
The rubber composition of the present invention is preferably formed by blending a filler as an additive.
The filler compounded in the rubber composition of the present invention is not particularly limited, but those usually used in the rubber industry such as carbon black, silica, alumina, aluminum hydroxide, clay, calcium carbonate, etc. can be used. As carbon black, carbon black of various grades, such as SAF, HAF, ISAF, HAF, FEF, GPF, can be used, for example. Silica is not particularly limited, but wet silica, dry silica, and colloidal silica are preferable. Such fillers can be used alone or in admixture of two or more.
Among these, carbon black and silica are preferable, and carbon black is more preferable.
The total blending amount of the filler is preferably 30 parts by mass or more, more preferably 40 parts by mass or more, and preferably 120 parts per 100 parts by mass of the rubber component (natural rubber composition) in the rubber composition. It is 80 parts by mass or less, more preferably 80 parts by mass or less.
本発明のゴム組成物には、本発明の目的が損なわれない範囲で、所望により、通常ゴム工業界で用いられる各種添加剤、例えば加硫剤、加硫促進剤、プロセスオイル、スコーチ防止剤、亜鉛華、ステアリン酸などを含有させることができる。
なお、本発明のゴム組成物は、プロセスオイルの含有量が少ないことが好ましい。上述したように、従来、ゴム組成物の加工性を向上させるために、プロセスオイルを配合していたが、プロセスオイルの配合により、得られた架橋ゴム組成物の耐摩耗性が低下するという問題があった。本発明では、（Ｂ）成分の配合により、加工性が向上し、プロセスオイルの配合なしに、又はプロセスオイルの配合量を少なくしても、良好なゴム組成物の加工性が得られる。従って、本発明のゴム組成物中のプロセスオイルの含有量は、（Ａ）成分及び（Ｂ）成分の合計を１００質量部としたとき、好ましくは５質量部以下、より好ましくは３質量部以下である。
In the rubber composition of the present invention, various additives usually used in the rubber industry, for example, a vulcanizing agent, a vulcanization accelerator, a process oil, and a scorch preventing agent are used as desired, as long as the object of the present invention is not impaired. , Zinc white, stearic acid and the like.
The rubber composition of the present invention preferably has a low process oil content. As described above, conventionally, process oil has been blended in order to improve the processability of the rubber composition, but the problem that the wear resistance of the resulting crosslinked rubber composition is reduced by blending the process oil. was there. In the present invention, processability is improved by blending the component (B), and good processability of the rubber composition can be obtained without blending process oil or reducing the blending amount of process oil. Therefore, the content of the process oil in the rubber composition of the present invention is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, when the total of the component (A) and the component (B) is 100 parts by mass. It is.
本発明の天然ゴム組成物及びゴム組成物は、タイヤ用途を始め、防振ゴム、ベルト、ホース、その他の工業品等の用途にも用いることができる。特にタイヤ用ゴムとして好適に使用され、例えばトレッドゴム（キャップゴム、ベースゴムを含む）、サイドゴム、プライゴム、ビードフィラーゴムなどあらゆるタイヤ部材に適用することができる。 The natural rubber composition and rubber composition of the present invention can be used not only for tire applications but also for applications such as anti-vibration rubber, belts, hoses and other industrial products. In particular, it is suitably used as tire rubber, and can be applied to all tire members such as tread rubber (including cap rubber and base rubber), side rubber, ply rubber, and bead filler rubber.
［空気入りタイヤ］
本発明の空気入りタイヤは、前記ゴム組成物を用いて作製したものであり、この空気入りタイヤは、本発明のゴム組成物を用いて通常の方法によって製造される。すなわち、必要に応じて前記各種薬品を配合した本発明のゴム組成物を未加硫の段階でタイヤの各部材の形状に合わせて押し出し加工し、タイヤ成型機上にて通常の方法にて成形し、未加硫タイヤを形成する。この未加硫タイヤを加硫機中で加熱加圧して空気入りタイヤを得る。
上述したように、本発明では、処理天然ゴムを含有することにより、加工性に優れると共に、カーボンブラック等の充填材の分散性に優れ、得られる空気入りタイヤは、耐摩耗性に優れる。
[Pneumatic tire]
The pneumatic tire of the present invention is produced using the rubber composition, and the pneumatic tire is manufactured by a normal method using the rubber composition of the present invention. That is, if necessary, the rubber composition of the present invention blended with the above various chemicals is extruded in accordance with the shape of each member of the tire at an unvulcanized stage, and molded by a normal method on a tire molding machine. And an unvulcanized tire is formed. This unvulcanized tire is heated and pressurized in a vulcanizer to obtain a pneumatic tire.
As described above, in the present invention, by containing the treated natural rubber, the processability is excellent, the dispersibility of the filler such as carbon black is excellent, and the resulting pneumatic tire is excellent in wear resistance.
以下に、実施例を挙げて本発明を更に詳しく説明するが、本発明は下記の実施例に何ら限定されるものではない。また、下記実施例中、「部」及び「％」は、特に断りのない限り質量基準である。 Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples. In the following examples, “part” and “%” are based on mass unless otherwise specified.
また、以下に示す測定方法により、測定を行った。
（１）長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）
試験装置として「ＲＰＡ２０００ Ａｕｔｏ１００」（アルファテクノロジーズ社製）を用い、更に前記装置におけるダイとして、「Ａｌｐｈａ Ｔｅｃｈｎｏｌｏｇｉｅｓ ＰＲＡ２０００Ａｕｔｏタイプダイ Ｄ５０５１」を用いて、サンプル５ｇを「ダイ Ｄ５０５１」に載置し、温度７０℃、周波数１．６７Ｈｚ、歪０．５％で１分間置いた後、ＬＡＯＳモードでの測定によって得られたシェアストレス信号を離散フーリエ変換にて、ｎ＝９まで算出し、上述した式を用い、測定条件として、質量５ｇの試験片に対して、測定中の圧力を１５．６ｋＮで、温度７０℃、周波数１．６７Ｈｚ、歪が０．５％で１分間置いた後、１０秒間かけて（すなわち、０．１Ｈｚ）、角速度ωを０．５０ｒａｄ／ｓとして、角度が７１．５度、歪が１０００％で、測定中の圧力を１５．６ｋＮの条件下で、７０℃、８０℃、９０℃、１００℃、１１０℃、１２０℃、１３０℃と順次温度を上げながら、各温度でＧ’ｎを求め、Ｇ’１／Ｇ’５から７０℃と１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）を求めている。
Moreover, it measured with the measuring method shown below.
(1) Long chain branching index (LCB Index)
“RPA2000 Auto100” (manufactured by Alpha Technologies) was used as a test apparatus, and “Alpha Technologies PRA2000Auto type die D5051” was used as a die in the apparatus, and a sample 5 g was placed on “die D5051” at a temperature of 70 ° C. Then, after placing for 1 minute at a frequency of 1.67 Hz and a distortion of 0.5%, the shear stress signal obtained by measurement in the LAOS mode is calculated up to n = 9 by discrete Fourier transform, and the above-described equation is used. As a measurement condition, a test piece having a mass of 5 g was placed at a pressure of 15.6 kN, a temperature of 70 ° C., a frequency of 1.67 Hz, and a strain of 0.5% for 1 minute, and then for 10 seconds ( That is, 0.1 Hz), the angular velocity ω is 0.50 rad / s, the angle is 71.5 degrees, and the strain is 1000. G ′ n at each temperature while increasing the temperature in the order of 70 ° C., 80 ° C., 90 ° C., 100 ° C., 110 ° C., 120 ° C., 130 ° C. under the conditions of 15.6 kN. The long chain branching index (LCB Index) at 70 ° C. and 130 ° C. is obtained from G ′ 1 / G ′ 5 .
（２）リン含有量の測定
処理天然ゴムを湿式灰化装置で分解した後、誘導結合プラズマ発光分光分析（ＩＣＰ分析）を行うため、ＩＣＰ発光分析装置（ＩＣＰＳ−８１００、（株）島津製作所製）を使用して、処理天然ゴムのリン含有量を求めた。
（３）窒素含有量の測定
処理天然ゴムの窒素含有量は、「ＴｒｕＳｐｅｃ ＣＨＮ」（ＬＥＣＯ社製）を用いて、測定した。測定には、まずＥＤＴＡを標準物質として、窒素含有量を求めるための検量線を作製した。次いで、各実施例及び比較例で得られた天然ゴム約１０ｍｇを秤量し、３回の測定結果から平均値を求めて、試料の窒素含有量とした。
(2) Measurement of phosphorus content ICP emission analyzer (ICPS-8100, manufactured by Shimadzu Corporation) is used to perform inductively coupled plasma emission spectrometry (ICP analysis) after decomposing treated natural rubber with a wet ashing device. ) Was used to determine the phosphorus content of the treated natural rubber.
(3) Measurement of nitrogen content The nitrogen content of the treated natural rubber was measured using "TruSpec CHN" (manufactured by LECO). For the measurement, first, a calibration curve for determining the nitrogen content was prepared using EDTA as a standard substance. Subsequently, about 10 mg of natural rubber obtained in each Example and Comparative Example was weighed, and the average value was obtained from the measurement results of three times to obtain the nitrogen content of the sample.
（４）重量平均分子量（Ｍｗ）の測定
ゲルパーミエーションクロマトグラフィー（ＧＰＣ：東ソー（株）製ＨＬＣ−８１２１ＧＰＣ／ＨＴ，カラム：東ソー（株）製ＧＭＨＨＲ−Ｈ（Ｓ）ＨＴ×２本、検出器：示差屈折率計（ＲＩ）、ＧＰＣ測定温度：１６０℃）により、単分散ポリスチレンを基準として、重合体のポリスチレン換算の重量平均分子量（Ｍｗ）及び分子量分布（Ｍｗ／Ｍｎ）を求めた。
(4) Measurement of weight average molecular weight (Mw) Gel permeation chromatography (GPC: HLC-8121GPC / HT manufactured by Tosoh Corp., column: GMHHR-H (S) HT x 2 manufactured by Tosoh Corp., detector : Differential refractive index meter (RI), GPC measurement temperature: 160 ° C.) Based on monodisperse polystyrene, the polystyrene-converted weight average molecular weight (Mw) and molecular weight distribution (Mw / Mn) of the polymer were determined.
（５）ゴム組成物の加工性（熱入れ作業性）
−ゴム組成物のムーニー粘度及び応力緩和時間−
後述するゴム組成物の加工性について評価した。
ＪＩＳ Ｋ６３００−１９９４に準じ、１００℃にてムーニー粘度［ＭＬ１＋４／１００℃］を測定した。また、応力緩和時間（Ｔ８０）は、上記ＭＬ１＋４測定直後にローター回転を停止し、ＭＬ１＋４の値が８０％低減するまでに必要な時間（秒）を測定した。
実施例１〜３、及び比較例１〜４では、比較例１の応力緩和時間（Ｔ８０）の値を１００とし、実施例４〜７、比較例５〜８では、比較例５の応力緩和時間（Ｔ８０）の値を１００とし、実施例及び比較例の指数を表すこととした。なお、指数が小さいほど、応力緩和時間が短く、加工性に優れることを示す。
熱入れ加工性の評価基準は、以下の通りである。
Ａ：応力緩和時間（Ｔ８０）の指数が９０未満
Ｂ：応力緩和時間（Ｔ８０）指数が９０以上１００未満
Ｃ：応力緩和時間（Ｔ８０）指数が１００以上
(5) Processability of rubber composition (heating workability)
-Mooney viscosity and stress relaxation time of rubber composition-
The processability of the rubber composition described later was evaluated.
The Mooney viscosity [ML 1 + 4/100 ° C.] was measured at 100 ° C. according to JIS K6300-1994. In addition, the stress relaxation time (T 80 ) was measured as the time (seconds) required to stop the rotor rotation immediately after the ML 1 + 4 measurement and reduce the ML 1 + 4 value by 80%.
In Examples 1 to 3 and Comparative Examples 1 to 4, the value of the stress relaxation time (T 80 ) of Comparative Example 1 is 100, and in Examples 4 to 7 and Comparative Examples 5 to 8, the stress relaxation of Comparative Example 5 is used. The value of time (T 80 ) was set to 100, and the index of Examples and Comparative Examples was expressed. The smaller the index, the shorter the stress relaxation time and the better the workability.
The evaluation criteria for hot-working workability are as follows.
A: Index of stress relaxation time (T 80 ) is less than 90 B: Stress relaxation time (T 80 ) index is 90 or more and less than 100 C: Stress relaxation time (T 80 ) index is 100 or more
（６）転がり抵抗ＩＮＤＥＸの測定
粘弾性測定装置［レオメトリックス社製］を用い、温度５０℃、歪み５％、周波数１５Ｈｚで損失正接（ｔａｎδ）を測定した。
なお、実施例１〜３、及び比較例１〜４の転がり抵抗ＩＮＤＥＸは、比較例１の評価結果を１００として相対評価した。また、実施例４〜７、及び比較例５〜８の転がり抵抗ＩＮＤＥＸは、比較例５の評価結果を１００として相対評価した。数値が大きいほど、転がり抵抗が低く、タイヤとして優れていることを示す。
(6) Measurement of rolling resistance INDEX A loss tangent (tan δ) was measured at a temperature of 50 ° C., a strain of 5%, and a frequency of 15 Hz using a viscoelasticity measuring apparatus (manufactured by Rheometrics).
In addition, the rolling resistance INDEX of Examples 1 to 3 and Comparative Examples 1 to 4 was relatively evaluated with the evaluation result of Comparative Example 1 being 100. Further, the rolling resistance INDEX of Examples 4 to 7 and Comparative Examples 5 to 8 was evaluated relative to the evaluation result of Comparative Example 5 as 100. The larger the value, the lower the rolling resistance and the better the tire.
（７）総合評価
総合評価は、以下の基準にて行った。
Ａ：熱入れ作業性の評価＝Ａ、かつ、転がり抵抗ＩＮＤＥＸ＝９５以上
Ｂ：熱入れ作業性の評価＝Ｂ、かつ、転がり抵抗ＩＮＤＥＸ＝９５以上
Ｃ：熱入れ作業性の評価＝Ａ又はＢ、かつ、転がり抵抗ＩＮＤＥＸ＝９５未満
Ｄ：熱入れ作業性の評価＝Ｃ
(7) Comprehensive evaluation Comprehensive evaluation was performed according to the following criteria.
A: Evaluation of hot workability = A and rolling resistance INDEX = 95 or higher B: Evaluation of hot workability = B and rolling resistance INDEX = 95 or higher C: Evaluation of hot workability = A or B , And rolling resistance INDEX = less than 95 D: Evaluation of hot workability = C
［処理天然ゴムの調製］
天然ゴムラテックスに対して、プロテアーゼ（Ｓａｒｉｎａｓｅ１６Ｌ、ノボザイムズ社製）を０．１ｐｈｒ、界面活性剤（ＦＲ−２５、花王（株）製）を１ｐｈｒ添加し、ｐＨ１０．５にて、１時間処理した。生化学的分解後の天然ゴムラテックスを凝固させて、ゴム成分を得た。
凝固後に、相対湿度５０％、温度５０℃にて１２日間熟成した。洗浄後に凝固させ、ゴム成分を得た。
得られた凝固ゴムに、老化防止剤としてＰＨＺ（プロピオン酸ヒドラジド）を０．２ｐｈｒで添加した後、乾燥した。
得られた処理天然ゴムの７０℃におけるＬＣＢ Ｉｎｄｅｘは４．８、１３０℃におけるＬＣＢ Ｉｎｄｅｘは２．９、リン含有量は５３０ｐｐｍ、窒素含有量は０．２４質量％、重量平均分子量は１４２×１０４であった。
[Preparation of treated natural rubber]
To natural rubber latex, 0.1 phr of protease (Sarinase 16L, manufactured by Novozymes) and 1 phr of surfactant (FR-25, manufactured by Kao Corporation) were added and treated at pH 10.5 for 1 hour. The natural rubber latex after biochemical decomposition was coagulated to obtain a rubber component.
After coagulation, aging was performed for 12 days at a relative humidity of 50% and a temperature of 50 ° C. After washing, it was solidified to obtain a rubber component.
To the obtained coagulated rubber, PHZ (propionic acid hydrazide) was added at 0.2 phr as an anti-aging agent and then dried.
The obtained treated natural rubber had an LCB Index of 4.8 at 70 ° C. of 4.8, an LCB Index of 2.9 at 130 ° C. of 2.9, a phosphorus content of 530 ppm, a nitrogen content of 0.24% by mass, and a weight average molecular weight of 142 × 10. 4 .
［ゴム組成物の調製］
以下の表１に示す配合にて、ゴム組成物を調製し、熱入れ作業性、転がり抵抗ＩＮＤＥＸを評価した。
[Preparation of rubber composition]
A rubber composition was prepared according to the formulation shown in Table 1 below, and hot-working workability and rolling resistance INDEX were evaluated.
［注］
＊１：表２に記載の量の天然ゴム及び処理天然ゴム
＊２：カーボンブラック：Ｎ３３９、東海カーボン（株）製、商品名「シースト７ＫＨ」
＊３：プロセスオイル：三共油化工業（株）製、商品名「Ａ／Ｏミックス」
＊４：老化防止剤６Ｃ：Ｎ−（１，３−ジメチルブチル）−Ｎ’−フェニル−ｐ−フェニレンジアミン：大内新興化学工業（株）製「ノクラック６Ｃ」
＊５：加硫促進剤ＤＺ：Ｎ，Ｎ’−ジシクロヘキシル−２−ベンゾチアジルスルフェンアミド、大内新興化学工業（株）製「ノクセラーＤＺ」
[note]
* 1: Natural rubber and treated natural rubber in the amounts shown in Table 2 * 2: Carbon black: N339, manufactured by Tokai Carbon Co., Ltd., trade name “SEAST 7KH”
* 3: Process oil: Product name “A / O mix” manufactured by Sankyo Oil Chemical Co., Ltd.
* 4: Anti-aging agent 6C: N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine: “NOCRACK 6C” manufactured by Ouchi Shinsei Chemical Co., Ltd.
* 5: Vulcanization accelerator DZ: N, N′-dicyclohexyl-2-benzothiazylsulfenamide, “Noxeller DZ” manufactured by Ouchi Shinsei Chemical Co., Ltd.
表１に記載のゴム組成物を１４５℃、３３分間の条件で加硫し、熱入れ作業性を評価し、また、得られた空気入りタイヤについて転がり抵抗ＩＮＤＥＸを評価した。結果を表２に示す。
なお、表２中の（Ａ）天然ゴムは、インドネシア産ＲＳＳ＃３グレードであり、７０℃におけるＬＣＢ Ｉｎｄｅｘは１４〜１６、１３０℃におけるＬＣＢ Ｉｎｄｅｘは３．０〜３．５、リン含有量は７５０ｐｐｍ、窒素含有量は０．６５質量％、重量平均分子量は１５７×１０４であった。
The rubber composition shown in Table 1 was vulcanized at 145 ° C. for 33 minutes to evaluate hot workability, and the resulting pneumatic tire was evaluated for rolling resistance INDEX. The results are shown in Table 2.
In addition, (A) natural rubber in Table 2 is RSS # 3 grade made in Indonesia, LCB Index at 70 ° C. is 14 to 16, LCB Index at 130 ° C. is 3.0 to 3.5, and phosphorus content is It was 750 ppm, the nitrogen content was 0.65 mass%, and the weight average molecular weight was 157 × 10 4 .
表２の実施例と比較例とを対比すると、天然ゴムと、処理天然ゴムとを特定の範囲で含むゴム組成物とすることにより、得られたゴム組成物の加工性が向上し、かつ、このゴム組成物を用いて製造されたタイヤの低転がり抵抗性も向上した。 Comparing the examples and comparative examples in Table 2, the rubber composition containing natural rubber and treated natural rubber in a specific range improves the processability of the rubber composition obtained, and The low rolling resistance of the tire produced using this rubber composition was also improved.
本発明によれば、加工性及び低転がり抵抗性を両立しうる天然ゴム組成物を提供することができる。更に、本発明によれば、前記天然ゴム組成物を含有するゴム組成物、及び該ゴム組成物を用いたタイヤを提供することができる。 According to the present invention, it is possible to provide a natural rubber composition capable of achieving both processability and low rolling resistance. Furthermore, according to the present invention, it is possible to provide a rubber composition containing the natural rubber composition, and a tire using the rubber composition.
Claims (6)
（Ｂ）下記式（Ｉ）に基づき、７０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が３．０以上５．５以下であり、かつ、１３０℃における長鎖分岐指数（ＬＣＢ Ｉｎｄｅｘ）が２．０以上４．０以下である天然ゴムを含有し、
（Ａ）成分と（Ｂ）成分との合計に対する（Ｂ）成分の含有量が１０〜４０質量％であることを特徴とする
天然ゴム組成物。
ＬＣＢ Ｉｎｄｅｘ＝Ｇ’１／Ｇ’５ ・・・（Ｉ） (A) natural rubber, and (B) a long chain branching index (LCB Index) at 70 ° C. of 3.0 to 5.5 based on the following formula (I), and a long chain branching index at 130 ° C. A natural rubber having an (LCB Index) of 2.0 or more and 4.0 or less,
Content of (B) component with respect to the sum total of (A) component and (B) component is 10-40 mass%, The natural rubber composition characterized by the above-mentioned.
LCB Index = G ′ 1 / G ′ 5 (I)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017112784A JP6835402B2 (en) | 2017-06-07 | 2017-06-07 | Natural rubber compositions, rubber compositions, and tires |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017112784A JP6835402B2 (en) | 2017-06-07 | 2017-06-07 | Natural rubber compositions, rubber compositions, and tires |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2018203930A true JP2018203930A (en) | 2018-12-27 |
| JP6835402B2 JP6835402B2 (en) | 2021-02-24 |
Family
ID=64956552
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2017112784A Active JP6835402B2 (en) | 2017-06-07 | 2017-06-07 | Natural rubber compositions, rubber compositions, and tires |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6835402B2 (en) |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008184506A (en) * | 2007-01-29 | 2008-08-14 | Bridgestone Corp | Powdery rubber-containing rubber composition |
| JP2012126792A (en) * | 2010-12-14 | 2012-07-05 | Sumitomo Rubber Ind Ltd | Rubber composition for bead filler, and pneumatic tire |
| JP2012126791A (en) * | 2010-12-14 | 2012-07-05 | Sumitomo Rubber Ind Ltd | Rubber composition for insulation or breaker cushion and pneumatic tire |
| JP2013159693A (en) * | 2012-02-03 | 2013-08-19 | Bridgestone Corp | Natural rubber, method for producing the same, rubber composition, and tire |
| JP2013203902A (en) * | 2012-03-28 | 2013-10-07 | Sumitomo Rubber Ind Ltd | Rubber composition for base tread and pneumatic tire |
| JP2014012750A (en) * | 2012-07-03 | 2014-01-23 | Sumitomo Rubber Ind Ltd | Rubber composition for tire, and pneumatic tire |
| WO2016043056A1 (en) * | 2014-09-18 | 2016-03-24 | 株式会社ブリヂストン | Natural rubber, process for producing same, and rubber composition and pneumatic tire obtained using same |
-
2017
- 2017-06-07 JP JP2017112784A patent/JP6835402B2/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008184506A (en) * | 2007-01-29 | 2008-08-14 | Bridgestone Corp | Powdery rubber-containing rubber composition |
| JP2012126792A (en) * | 2010-12-14 | 2012-07-05 | Sumitomo Rubber Ind Ltd | Rubber composition for bead filler, and pneumatic tire |
| JP2012126791A (en) * | 2010-12-14 | 2012-07-05 | Sumitomo Rubber Ind Ltd | Rubber composition for insulation or breaker cushion and pneumatic tire |
| JP2013159693A (en) * | 2012-02-03 | 2013-08-19 | Bridgestone Corp | Natural rubber, method for producing the same, rubber composition, and tire |
| JP2013203902A (en) * | 2012-03-28 | 2013-10-07 | Sumitomo Rubber Ind Ltd | Rubber composition for base tread and pneumatic tire |
| JP2014012750A (en) * | 2012-07-03 | 2014-01-23 | Sumitomo Rubber Ind Ltd | Rubber composition for tire, and pneumatic tire |
| WO2016043056A1 (en) * | 2014-09-18 | 2016-03-24 | 株式会社ブリヂストン | Natural rubber, process for producing same, and rubber composition and pneumatic tire obtained using same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP6835402B2 (en) | 2021-02-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4726490B2 (en) | Natural rubber latex, natural rubber, rubber composition and tire using the same | |
| US7045567B2 (en) | Rubber composition for tire tread and pneumatic tire using the rubber composition | |
| US7687602B2 (en) | Deproteinized natural rubber, its composition and use thereof | |
| RU2535681C2 (en) | Natural rubber and method of obtaining thereof, rubber mixture and pneumatic tyre, made with application of said mixture, modified and natural rubber and method of obtaining thereof and rubber mixture for protector or covering framework cord, and pneumatic tyre, made with application of said material | |
| JP5426605B2 (en) | Highly purified natural rubber and method for producing the same | |
| CN108976319B (en) | Rubber composition for tire and pneumatic tire | |
| JP2010138359A (en) | Natural rubber, method of producing the same, rubber composition, and pneumatic tire using the composition | |
| JPWO2003082925A1 (en) | Natural rubber, rubber composition and pneumatic tire | |
| JP2004182905A (en) | Rubber composition for tire tread and pneumatic tire produced by using the same | |
| JP2005041960A (en) | Rubber composition for tire tread and pneumatic tire using the same | |
| JP6798750B2 (en) | Natural rubber, its manufacturing method, rubber composition and pneumatic tires using it | |
| JP6835402B2 (en) | Natural rubber compositions, rubber compositions, and tires | |
| US7825185B2 (en) | Natural rubber latex, natural rubber, rubber composition, and tire using the same | |
| JP6594754B2 (en) | Natural rubber, method for producing natural rubber, rubber composition and tire | |
| JP2015151520A (en) | tire | |
| JP4076911B2 (en) | Rubber composition for tread and pneumatic tire using the same | |
| JP5236137B2 (en) | Natural rubber, process for producing the same and rubber composition | |
| JP4721614B2 (en) | Natural rubber, rubber composition and tire using the same | |
| JP5650794B2 (en) | Sidewall rubber composition and pneumatic tire | |
| JP4721613B2 (en) | Natural rubber, composition using the same, and tire | |
| JP2008263806A (en) | Enzyme-treated latex, enzyme-treated natural rubber, enzyme-treated natural rubber composition and method for producing enzyme-treated latex | |
| JP6006171B2 (en) | Cap tread rubber composition and heavy duty tire | |
| JP2014227482A (en) | Cap tread rubber composition and tire for heavy load | |
| JP6006168B2 (en) | Base tread rubber composition and heavy duty tire | |
| JP2014227481A (en) | Sidewall rubber composition and tire for heavy load |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20191219 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20200818 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20200825 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20201020 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20210105 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20210127 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 6835402 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |