Rubber composition and rubber product

Abstract

To provide an advanced rubber composition having improved reinforcement properties.SOLUTION: A rubber composition comprises: 100 phr of one or more diene-based elastomers; 30 phr to 200 phr of a filler; and a benzoxazine based on reaction of (i) a diphenol comprising two phenol groups and a bridge covalently connecting the two phenol groups, (ii) an aldehyde derivative, and (iii) an amine, where the bridge is connected to at least one of the phenol groups at a meta position of the at least one phenol group.SELECTED DRAWING: Figure 1

Description

[Technology Field]

[0001] The present invention relates to a rubber composition or a non-vulcanized rubber composition for rubber products such as tires or tire components. [Background technology]

[0002] The use of reinforcing resins has helped to further improve tire performance over the past several decades. In particular, reactive resin systems based on methylene donors and methylene acceptors, also known as novolac resins, are used to enhance the properties of different rubber compositions by reacting them in situ during the mixing of rubber compositions. However, the use of such resins requires the handling of methylene donors, also called formaldehyde donors, and resorcinol in the rubber mixing process, which can be undesirable from an environmental, health, and / or safety standpoint. Furthermore, there is a demand for further improvements in reinforcing properties, particularly with limited weight and hysteresis. Thus, there is considerable room for improvement in the field of rubber compositions, especially reinforcing resins used in tires. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] U.S. Patent No. 5,698,643 [Patent Document 2] U.S. Patent No. 5,451,646 [Patent Document 3] U.S. Patent No. 4,704,414 [Patent Document 4] U.S. Patent No. 6,123,762 [Patent Document 5] U.S. Patent No. 6,573,324 [Patent Document 6] U.S. Patent No. 6,242,534 [Patent Document 7] U.S. Patent No. 6,207,757 [Patent Document 8] U.S. Patent No. 6,133,364 [Patent Document 9] U.S. Patent No. 6,372,857 [Patent Document 10] U.S. Patent No. 5,395,891 [Patent Document 11] U.S. Patent No. 6,127,488 [Patent Document 12] U.S. Patent No. 5,672,639 [Patent Document 13] U.S. Patent No. 6,608,125 [Patent Document 14] U.S. Patent Application Publication No. 2003 / 0130535 [Non-patent literature]

[0004] [Non-Patent Document 1] Journal of the American Chemical Society, Vol. 60, p. 304 (1930) [Non-Patent Document 2] The Vanderbilt Rubber Handbook (1978), pp. 344-346 [Overview of the project] [Problems that the invention aims to solve]

[0005] One objective of the present invention may be to provide an advanced rubber composition with improved reinforcing properties. Another object of the present invention may be to provide a rubber composition having good rigidity, optionally with limited hysteresis.

[0006] Another object of the present invention may be to provide a rubber composition that enables a reduction in the amount of methylene donor handled during the manufacture of the rubber composition. Another object of the present invention may be to provide a cost-effective alternative to existing reactive resin systems.

[0007] The scope of protection of the present invention is defined by independent claim 1. Further preferred embodiments are described in the dependent claims, as well as in the aspects and embodiments provided herein in summary and description. [Means for solving the problem]

[0008] Accordingly, in a first aspect of the present invention, the present invention relates to a rubber composition comprising one or more preferably diene-based elastomers 100 phr, a filler 30 to 200 phr, and a benzoxazine based on (or a reaction product thereof) of a diphenol comprising i) two phenol groups and a crosslink covalently linking or interconnecting these two phenol groups, ii) an aldehyde derivative, and iii) an amine, wherein the crosslink is linked to at least one phenol group at the meta position of the at least one phenol group. The inventors have found that the use of such a benzoxazine provides excellent reinforcing properties. Furthermore, such a benzoxazine can be prepared in advance and then added to the rubber composition, thereby eliminating the need to handle reactive resin reactants during the production of the rubber composition. Furthermore, it was found that by providing a benzoxazine based on a diphenol crosslinked at at least one meta position of one of the phenol groups, the para and ortho positions are not blocked and are available for crosslinking in the rubber network structure, thus providing improved reinforcing properties compared to other configurations.

[0009] In another embodiment, the amine is a primary amine (i.e., a molecule having an amino group). In another embodiment, the aldehyde derivative is formaldehyde, paraformaldehyde, polyoxymethylene, and the formula RCHO[wherein R is a substituted or unsubstituted aliphatic C1-C having or not having a heteroatom]. 20 The reaction is selected from the group of aldehydes having an alkyl group. In particular, the reaction can occur in the presence of formaldehyde. Even if formaldehyde is involved in the reaction to form a benzoxazine, such a reaction does not occur during the production of the rubber composition, and a pre-prepared benzoxazine can be added to the rubber composition.

[0010] In another embodiment, the amine or primary amine is selected from the group consisting of aromatic amines, aliphatic amines, alicyclic amines, and heterocyclic amines. In yet another embodiment, the amine or primary amine is selected from the group consisting of ethanolamine, allylamine, methylamine, ethylamine, propylamine, butylamine, isopropylamine, hexylamine, cyclohexylamine, 2-aminofluorene, aminophenylacetylene, propargyl ether aniline, 4-aminobenzonitrile, furfurylamine, and aniline.

[0011] In yet another embodiment, and in the case of aliphatic amines, the aliphatic amine contains a carbon chain of less than 18 carbon atoms. In particular, longer chains have been found to impair crosslinking in the rubber network structure.

[0012] In yet another embodiment, the bridging includes one of an aromatic group, an aliphatic group, an alicyclic group, a heterocyclic group, a hexafluoropropane group, a monosulfide, an oxygen group, a sulfone group, and a disulfide. In particular, the disulfide group or bridging is very interesting because it adds another valuable aspect to crosslinking in sulfur-vulcanizable rubbers, or rather, in sulfur-crosslinkable rubbers.

[0013] In one embodiment, the diphenol is selected from 3,4'-dihydroxydiphenyldisulfide and 3,3'-dihydroxydiphenyldisulfide. These diphenols have been confirmed to provide good reinforcing properties at a limited cost.

[0014] In yet another embodiment, the benzoxazine has the following structure:

[0015]

Chemical Formula 1

[0016] [wherein, R1 and R2 are selected from an aromatic group, an aliphatic group, an alicyclic group, and a heterocyclic group, and R3 is an aromatic group, an aliphatic group, an alicyclic group, a heterocyclic group, hexafluoropropane, monosulfide (S), or disulfide (S-S)] It has at least one of the following. As is evident from the diagram of the structure above, when R3 is bonded at the meta position, the ortho and para positions are available. This further improves crosslinking in the rubber network structure.

[0017] In another embodiment, R1 and R2 are selected from ethanol, allyl, methyl, ethyl, propyl, isopropyl, hexyl, cyclohexyl, fluorene, phenylacetylene, propargyl ether benzyl, benzonitrile, furfuryl, and benzyl groups.

[0018] In another embodiment, R3 is a disulfide (SS). In another embodiment, the rubber composition is a sulfur-vulcanizable rubber composition containing a sulfur donor.

[0019] In another embodiment, the rubber composition is a (sulfur) vulcanized rubber composition. In another embodiment, the filler comprises one or more of silica, carbon black, aluminum hydroxide, ultra-high molecular weight polyethylene, and syndiotactic polybutadiene. Preferably, at least 50 phr of the filler comprises carbon black and / or silica.

[0020] In another embodiment, the rubber composition is a sulfur-vulcanizable (i.e., unvulcanized or uncured) rubber composition containing a methylene donor of less than 2 phr, preferably less than 1 phr, and more preferably less than 0.5 phr, and / or a methylene acceptor of less than 5 phr (such as those present in a reactive resin system).

[0021] In another embodiment, the rubber composition includes further benzoxazines based on the reaction of phenol with a primary amine. For example, the further or second benzoxazine may be one or more of monofunctional benzoxazines and main-chain benzoxazines. In particular, such second benzoxazines having at least one functional group (e.g., having silane, a long alkyl chain, or a carboxylic acid) can provide additional functionality and be incorporated into the benzoxazine network structure after the curing step. They may further help improve processability, reinforcement and / or hysteresis, and / or interaction with fillers, rubber, and / or cured packages.

[0022] In another embodiment, the rubber composition contains 5 phr to 40 phr, or 5 phr to 9 phr, or 10 phr to 20 phr, or 20 phr to 40 phr, or 10 phr to 40 phr.

[0023] In embodiments, the rubber composition may include at least one and / or an additional diene rubber. Typical synthetic polymers may be copolymers with other unsaturated monomers, such as butadiene and its congeners and derivatives, e.g., homopolymer products of methylbutadiene, dimethylbutadiene, and pentadiene, and those formed from butadiene or its congeners or derivatives. Among the latter may be acetylene, e.g., vinylacetylene; olefins, e.g., isoprene copolymerized with isoprene to form butyl rubber; vinyl compounds, e.g., acrylic acid, acrylonitrile (which polymerizes with butadiene to form NBR), methacrylic acid, and styrene (the latter compound polymerizes with butadiene to form SBR); and vinyl esters and various unsaturated aldehydes, ketones, and ethers, e.g., acrolein, methylisopropenyl ketone, and vinyl ethyl ether. Specific examples of synthetic rubbers include neoprene (polychloroprene), polybutadiene (including cis-1,4-polybutadiene), polyisoprene (including cis-1,4-polyisoprene), butyl rubber, halobutyl rubber such as chlorobutyl rubber or bromobutyl rubber, styrene / isoprene / butadiene rubber, copolymers of 1,3-butadiene or isoprene with monomers such as styrene, acrylonitrile and methyl methacrylate, and ethylene / propylene copolymers (also known as ethylene / propylene / diene monomer (EPDM)), particularly ethylene / propylene / dicyclopentadiene copolymers. Additional examples of rubbers that may be used include alkoxysilyl-terminated solution polymers (SBR, PBR, IBR and SIBR), and silicon-coupled / tin-coupled star-branched polymers. Preferred rubbers or elastomers may generally include natural rubber, synthetic polyisoprene, polybutadiene and SBR, including SSBR.

[0024] In another embodiment, the composition may contain at least two types of diene rubber. For example, preferred combinations of two or more rubbers include, for example, cis-1,4-isoprene rubber (which may be natural or synthetic, but natural is preferred), 3,4-isoprene rubber, styrene / isoprene / butadiene rubber, styrene / butadiene rubber derived from emulsions and solution polymerization, cis-1,4-polybutadiene rubber, and butadiene / acrylonitrile copolymers prepared by emulsion polymerization.

[0025] In another embodiment, emulsion polymerization-derived styrene / butadiene (ESBR) having a styrene content of 20–28 percent bound styrene, or for some applications, ESBR having a moderate to relatively high bound styrene content, i.e., 30–45 percent bound styrene, may be used. In many cases, ESBR has a bound styrene content in the range of 26–31 percent. Emulsion polymerization-prepared ESBR can mean that styrene and 1,3-butadiene are copolymerized as an aqueous emulsion. Such is well known to those skilled in the art. The bound styrene content can vary, for example, from 5 to 50 percent. In one embodiment, ESBR may also contain acrylonitrile to form a terpolymer rubber as ESBAR, for example, in an amount of 2–30 wt percent bound acrylonitrile in the terpolymer. Emulsion polymerization-prepared styrene / butadiene / acrylonitrile copolymer rubber containing 2–40 wt percent bound acrylonitrile in the copolymer may also be intended as a diene rubber.

[0026] In another embodiment, solution polymerization-prepared SBR (SSBR) may be used. Such SSBR has a bound styrene content of, for example, 5 to 50 percent, preferably 9 to 36 percent, and most preferably 26 to 31 percent. SSBR can conveniently be prepared, for example, by anionic polymerization in an inert organic solvent. In particular, SSBR can be synthesized by copolymerizing styrene and 1,3-butadiene monomer in a hydrocarbon solvent using an organolithium compound as an initiator. In another embodiment, the solution styrene-butadiene rubber is a tin coupling polymer. In yet another embodiment, the SSBR is functionalized to improve its compatibility with silica. Furthermore, or alternatively, the SSBR is thiofunctionalized. This helps to improve the stiffness of the compound and / or its hysteresis behavior. Thus, for example, the SSBR may be a thiofunctionalized tin coupling solution polymerization copolymer of butadiene and styrene.

[0027] In one embodiment, synthetic or natural polyisoprene rubber can be used. Synthetic cis-1,4-polyisoprene and natural rubber are well known as such to those skilled in rubber technology. In particular, the cis-1,4-microstructure content may be at least 90%, typically at least 95%, or much higher.

[0028] In one embodiment, cis-1,4-polybutadiene rubber (BR or PBD) is used. A suitable polybutadiene rubber can be prepared, for example, by organic solution polymerization of 1,3-butadiene. BR can conveniently be characterized by having, for example, at least 90 percent cis-1,4-microstructure content ("high-cis" content) and a glass transition temperature (Tg) in the range of -95 to -110°C. Suitable polybutadiene rubbers such as Budene® 1207, Budene® 1208, Budene® 1223, or Budene® 1280 are commercially available from The Goodyear Tire & Rubber Company. These high-cis-1,4-polybutadiene rubbers can be synthesized using a nickel catalyst system comprising (1) an organonicickel compound, (2) an organoaluminum compound, and (3) a mixture of fluorine-containing compounds, as described, for example, in U.S. Patents 5,698,643 and 5,451,646, which are incorporated herein by reference.

[0029] As used herein, the glass transition temperature (Tg) of an elastomer or elastomer composition represents the glass transition temperature of the respective elastomer or elastomer composition in its uncured state, or, in the case of an elastomer composition, in its cured state. Tg can be appropriately determined by differential scanning calorimeter (DSC) as the peak median with a temperature rise rate of 10°C per minute according to ASTM D3418.

[0030] Where used herein, the term "phr" refers, in accordance with customary practice, to "parts by weight of each material per 100 parts by weight of rubber or elastomer." Generally, using this convention, a rubber composition consists of 100 parts by weight of rubber / elastomer. A composition described in the claims may include rubber / elastomers other than those expressly listed in the claims, provided that the phr values ​​of the rubber / elastomers described in the claims match the phr range described in the claims and the total amount of rubber / elastomers in the composition amounts to 100 parts of rubber. For example, a composition may further include 1 phr to 10 phr, and optionally 1 to 5 phr, of one or more additional diene rubbers, such as SBR, SSBR, ESBR, PBD / BR, NR, and / or synthetic polyisoprene. In another example, a composition may include less than 5 phr, preferably less than 3 phr, of additional diene rubbers, or may not include any such additional diene rubbers at all. The terms “compound,” “composition,” and “formulation” may be used interchangeably in this specification unless otherwise indicated.

[0031] In embodiments, the rubber composition may also contain oil, particularly process oil. Typically, process oil may be included in the rubber composition as a filler oil used to increase the volume of the elastomer. Process oil may also be included in the rubber composition by direct addition of oil during rubber compounding. The process oil used may be present in the filler oil in the elastomer and may be added during compounding. Suitable process oils include a variety of oils known in the industry, including aromatic, paraffin, naphthenic, vegetable oils, MES, TDAE, SRAE, and low-PCA oils such as heavy naphthenic oils. Suitable low-PCA oils may include those having a polycyclic aromatic content of less than 3 weight percent as determined by the IP346 method. The IP346 procedure can be found in Standard Methods for Analysis & Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd edition, published by the Institute of Petroleum, United Kingdom. Some representative examples of vegetable oils that can be used include soybean oil, sunflower oil, canola (rapeseed) oil, corn oil, coconut oil, cottonseed oil, olive oil, palm oil, peanut oil, and safflower oil. Soybean oil and corn oil are typically preferred vegetable oils. When used, the rubber composition may also contain process oils up to 70 phr, preferably between 5 and 25 phr, or alternatively, oils with less than 10 phr, preferably less than 5 phr.

[0032] In embodiments, the rubber composition may contain silica. Commonly used siliceous pigments that may be used in the rubber compound include, for example, conventional calcined and precipitated siliceous pigments (silica). In one embodiment, precipitated silica is used. Conventional siliceous pigments may be precipitated silica, such as soluble silicates, or those obtained by acidification of sodium silicate, for example. Such conventional silica may be characterized by having a BET surface area, measured, for example, using nitrogen gas. In one embodiment, the BET surface area may be in the range of 40 to 600 square meters per gram. In another embodiment, the BET surface area may be in the range of 50 to 300 square meters per gram. The BET surface area can be appropriately determined by ASTM D6556 or its equivalent, as described in the Journal of the American Chemical Society, Vol. 60, p. 304 (1930). Conventional silica also has a BET surface area of ​​100 cm². 3 / 100g to 400cm 3 / 100g, alternative: 150cm 3 / 100g to 300cm 3 The silica may be characterized by having a dibutyl phthalate (DBP) absorption value in the range of / 100g, which can be appropriately determined according to ASTM D 2414 or an equivalent. Conventional silica can be expected to have an average ultimate particle size in the range of 0.01 to 0.05 microns, as determined, for example by electron microscopy, but silica particles may be even smaller in size, or possibly larger. The range of silica use may be, for example, between 5 and 120 phr, preferably between 20 and 70 phr or between 80 and 120 phr. Various commercially available silicas are used herein, but are not limited to these, but may include, for example, silica commercially available from PPG Industries under the Hi-Sil trademark with names such as 210, 315G, EZ160G, etc.; silica available from Solvay with names such as Z1165MP and Premium200MP, etc.; and silica available from Evonik AG with names such as VN2, Ultrasil 6000GR, 9100GR, etc.

[0033] In yet another embodiment, the rubber composition, for example, has a CTAB adsorption surface area between 130 m 2 / g and 210 m 2 / g, optionally between 130 m 2 / g and 150 m 2 / g, and / or between 190 m 2 / g and 210 m 2 / g, or further between 195 m 2 / g and 205 m 2 / g and may include presilanized and precipitated silica. The CTAB (cetyltrimethylammonium bromide) method (ASTM D6845) for measuring silica surface area is known to those skilled in the art.

[0034] In another embodiment, the presilanized (or alternatively pre-hydrophobized) precipitated silica used is hydrophobized by treatment with at least one silane prior to addition to the rubber composition. Suitable silanes include, but are not limited to, alkylsilanes, alkoxysilanes, organoalkoxysilyl polysulfides, and organomercaptoalkoxysilanes.

[0035] [[ID=2k]]Any silica dispersing aid, if used, may be present in an amount in the range of about 0.1% to about 25% by weight, based on the weight of the silica, with about 0.5% to about 20% being suitable, and about 1% to about 15% by weight, based on the weight of the silica, also being suitable. Various pretreated precipitated silicas are described in U.S. Patent No. 4,704,414, U.S. Patent No. 6,123,762, and U.S. Patent No. 6,573,324. The teachings of U.S. Patent No. 4,704,414, U.S. Patent No. 6,123,762, and U.S. Patent No. 6,573,324 are incorporated herein by reference.

[0036] Some non-limiting examples of pre-treated silica (i.e., silica pre-surface-treated with silane) suitable for the practical use of the present invention include, but are not limited to, Ciptane® 255 LD and Ciptane® LP (PPG Industries) silica pre-treated with mercaptosilane, and Coupsil® 8113 (Degussa) and Coupsil® 6508, which are products of the reaction between organosilane bis(triethoxysilylpropyl) polysulfide (Si69) and Ultrasil® VN3 silica, Agilon® 400 silica from PPG Industries, Agilon® 454 silica from PPG Industries, and Agilon® 458 silica from PPG Industries. Some representative examples of preferred pre-silanized precipitated silica include Agilon® 400, Agilon® 454, and Agilon® 458 from PPG Industries.

[0037] A typical silica coupler (silica coupling agent) having a portion of the presilanized precipitated silica and precipitated silica that is reactive with hydroxyl groups, as well as another portion that interacts with the elastomer, may consist, for example: (A) a bis(3-trialkoxysilylalkyl) polysulfide containing an average of about 2 to about 4 sulfur atoms in the bridging between which it couples, alternatively in the range of about 2 to about 2.6 or about 3.2 to about 3.8; (B) an alkoxyorganomercaptosilane; or (C) a combination thereof. A representative such bis(3-trialkoxysilylalkyl) polysulfide is bis(3-triethoxysilylpropyl) polysulfide. As shown, for presilanized precipitated silica, the silica coupler may preferably be an alkoxyorganomercaptosilane. For non-presilanized precipitated silica, the silica coupler may preferably consist of a bis(3-triethoxysilylpropyl) polysulfide.

[0038] In one embodiment, the rubber composition excludes the addition of silica couplers to the rubber composition (therefore, the silica couplers are excluded). As shown, in one embodiment, the rubber composition may contain, together with additional precipitated silica (non-presilanized precipitated silica) added to the rubber composition, additional silica couplers added to the rubber composition, particularly combinations of bis(3-triethoxysilylpropyl) polysulfides containing an average of about 2 to about 4 linked sulfur atoms in the polysulfide crosslinking, in which case the ratio of presilanized precipitated silica to the precipitated silica is preferably at least 8 / 1, or at least 10 / 1.

[0039] In embodiments, the rubber composition may contain carbon black. Typical examples of such carbon black include grades N110, N121, N134, N220, N231, N234, N242, N293, N299, N315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, N550, N582, N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990, and N991. These carbon blacks have iodine absorption in the range of 9 to 145 g / kg and DBP numbers in the range of 34 to 150 cm³ / 100 g. The iodine absorption value can be appropriately determined according to ASTM D1510 or its equivalent. Commonly used carbon black can be used as a conventional filler in amounts ranging from 10 to 150 phr. In another embodiment, carbon black in amounts of 20 to 80 phr may be used.

[0040] In another embodiment, other fillers that may be used in the rubber composition include, but are not limited to, granular fillers containing ultra-high molecular weight polyethylene (UHMWPE), crosslinked granular polymer gels including, but not limited to, those disclosed in U.S. Patents 6,242,534; 6,207,757; 6,133,364; 6,372,857; 5,395,891 and 6,127,488, and plasticized starch composite fillers including, but not limited to, those disclosed in U.S. Patent 5,672,639. Other such fillers may be used in amounts ranging from 1 to 30 phr.

[0041] In one embodiment, the rubber composition may contain a conventional sulfur-containing organosilicon compound or silane. An example of a suitable sulfur-containing organosilicon compound is given by formula: Z - Alk - S n - Alk - ZI [In the formula, Z is,

[0042] [Case 2]

[0043] (In the formula, R 1 R is an alkyl group, cyclohexyl, or phenyl group with 1 to 4 carbon atoms; 2 (These are alkoxys with 1 to 8 carbon atoms, or cycloalkoxys with 5 to 8 carbon atoms.) Selected from the group consisting of; Alk is a divalent hydrocarbon with 1 to 18 carbon atoms, and n is an integer from 2 to 8. In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(trimethoxy or triethoxysilylpropyl) polysulfide. In one embodiment, the sulfur-containing organosilicon compound is 3,3'-bis(triethoxysilylpropyl) disulfide and / or 3,3'-bis(triethoxysilylpropyl) tetrasulfide. Therefore, for formula I, Z is

[0044] [C3]

[0045] [In the formula, R 2 [n is an alkoxy with 2 to 4 carbon atoms, or alternatively, 2 carbon atoms; Alk is a divalent hydrocarbon with 2 to 4 carbon atoms, or alternatively, 3 carbon atoms; n is an integer 2 to 5, or alternatively, 2 or 4] It may also be the case that, in another embodiment, a suitable sulfur-containing organosilicon compound includes the compound disclosed in U.S. Patent No. 6,608,125. In one embodiment, the sulfur-containing organosilicon compound includes 3-(octanoylthio)-1-propyltriethoxysilane, CH3(CH2)6C(=O)-S-CH2CH2CH2Si(OCH2CH3)3, which is commercially available from Momentive Performance Materials as NXT®. In another embodiment, a suitable sulfur-containing organosilicon compound includes the one disclosed in U.S. Patent Application Publication No. 2003 / 0130535. In one embodiment, the sulfur-containing organosilicon compound is Si-363 from Degussa. The amount of sulfur-containing organosilicon compound in the rubber composition may vary depending on the levels of other additives used. Generally speaking, the amount of the compound is in the range of 0.5 to 20 phr. In one embodiment, the amount is in the range of 1 to 10 phr.

[0046] In another embodiment, the rubber composition contains a cobalt salt with less than 0.1 phr or 0 phr. It is readily apparent to those skilled in the art that rubber compositions can be formulated by methods generally known in rubber compounding technology, such as mixing sulfur vulcanizable rubbers of various constituent elements with various commonly used additive materials, including sulfur donors, curing aids (e.g., activators and retarders), processing additives such as oils, resins containing adhesive resins and plasticizers, fillers, pigments, fatty acids, zinc oxide, waxes, antioxidants, ozone degradation inhibitors and desorbents. As is known to those skilled in the art, the additives listed above are selected and generally used in conventional amounts depending on the intended use of the sulfur vulcanizable material and the sulfur vulcanized material (rubber). Some representative examples of sulfur donors include elemental sulfur (free sulfur), amine disulfides, polymeric polysulfides, and sulfur olefin adducts. In one embodiment, the sulfur vulcanizing agent is elemental sulfur. The sulfur vulcanizing agent may be used in amounts ranging from 0.5 phr to 8 phr, or alternatively, from 1.5 phr to 6 phr. A typical amount of tackifying resin, when used, constitutes, for example, 0.5 phr to 10 phr, usually 1 phr to 5 phr. A typical amount of processing aid, when used, constitutes, for example, 1 phr to 50 phr (this may include oil in particular). A typical amount of antioxidant, when used, constitutes, for example, 1 phr to 5 phr. Typical antioxidants may include, for example, diphenyl-p-phenylenediamine, or those disclosed, for example, in The Vanderbilt Rubber Handbook (1978), pages 344 to 346. A typical amount of ozone degradation inhibitor, when used, may constitute, for example, 1 phr to 5 phr. A typical amount of fatty acid, when used, may include stearic acid and may constitute, for example, 0.5 phr to 3 phr. A typical amount of wax, when used, may constitute, for example, 1 phr to 5 phr. Microcrystalline wax is often used. A typical amount of desorbent, when used, may constitute, for example, 0.1 phr to 1 phr. Typical interpreters may include, for example, pentachlorothiophenol and dibenzamide diphenyl disulfide.

[0047] Accelerators can be used, but are not necessarily required, to control the time and / or temperature required for vulcanization and to improve the properties of the vulcanized product. In one embodiment, a single accelerator system, i.e., a primary accelerator, may be used. Primary accelerators may be used in a total amount ranging from 0.5 phr to 4 phr, or alternatively, from 0.8 phr to 1.5 phr. In another embodiment, a combination of primary and secondary accelerators may be used, with the secondary accelerator being used in smaller amounts, such as about 0.05 to about 3 phr, to activate and improve the properties of the vulcanized product. These accelerator combinations can be expected to produce a synergistic effect on the final properties, which may be somewhat better than those produced by using either accelerator alone. Furthermore, slow-acting accelerators may be used that are not affected by normal processing temperatures but produce satisfactory curing at normal vulcanization temperatures. Vulcanization retarders may also be used. Suitable types of accelerators that may be used in the present invention include, for example, amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates, and xanthates. In one embodiment, the primary accelerator is a sulfenamide. When a second accelerator is used, the secondary accelerator may be, for example, a guanidine, a dithiocarbamate, or a thiuram compound. Suitable guanidines include diphenylguanidine, etc. Suitable thiurams include tetramethylthiuram disulfide, tetraethylthiuram disulfide, and tetrabenzylthiuram disulfide.

[0048] The mixing of rubber compositions can be carried out by methods known to those skilled in the art of rubber mixing technology. For example, the raw materials may typically be mixed in at least two stages, namely at least one non-productive stage followed by a productive mixing stage. The final curing agent, including a sulfur vulcanizing agent, may typically be mixed in a final stage conventionally called the “productive” mixing stage, where the mixing is typically carried out at a temperature or final temperature lower than the mixing temperature of the preceding non-productive mixing stage(s). The terms “non-productive” and “productive” mixing stages are well known to those skilled in the art of rubber mixing technology. In embodiments, the rubber composition may be subjected to a thermodynamic mixing step. The thermodynamic mixing step generally involves mechanical work in a mixer or extruder for a period of time suitable to produce a rubber temperature, for example, between 140°C and 190°C. The preferred duration of the thermodynamic work varies as a function of operating conditions and the amount and properties of the components. For example, the thermodynamic work may be 1 to 20 minutes.

[0049] The vulcanization of the pneumatic tire of the present invention can be carried out at conventional temperatures, for example, in the range of 100°C to 200°C. In one embodiment, vulcanization is carried out at temperatures in the range of 110°C to 180°C. Any conventional vulcanization method may be used, such as heating in a press or mold, or heating using superheated steam or hot air. Such tires can be assembled, shaped, molded and cured by a variety of methods known to those skilled in the art and readily apparent.

[0050] In a second embodiment, the present invention comprises one or more elastomers, preferably diene-based, 100 phr, a filler, 30 phr to 200 phr, and the following structure:

[0051] [C4]

[0052] [In the formula, R1 and R2 are selected from aromatic groups, aliphatic groups, alicyclic groups, and heterocyclic groups, and R3 is an aromatic group, aliphatic group, alicyclic group, heterocyclic group, hexafluoropropane, monosulfide, or disulfide.] The subject is a rubber composition comprising a benzoxazine having at least one of the following.

[0053] The second and other embodiments described herein can be combined with embodiments described in the context of other embodiments, in particular the first embodiment of the present invention. In a third embodiment of the present invention, a rubber product is provided which comprises a rubber composition according to the first embodiment or one or more embodiments thereof.

[0054] In one embodiment, the rubber product is selected from tires, power transmission belts, hoses, trucks, air sleeves, and conveyor belts. The tire may be, for example, a pneumatic tire or a non-pneumatic tire.

[0055] In a further embodiment, the rubber product is a tire comprising one or more rubber components selected from a tread, rubber shear bands, rubber spokes, undertread, sidewall, apex, flipper, chipper, chafer, carcass, belt, and overlay, and is one or more rubber components comprising a rubber composition.

[0056] In another embodiment, the rubber product is a tire comprising an apex or tread groove reinforcement comprising a rubber composition. In particular, the apex composition or tread groove reinforcement composition can benefit from the reinforcing properties of the rubber composition disclosed herein.

[0057] The tire according to the embodiment of the present invention may be, for example, a pneumatic or non-pneumatic tire, a racing tire, a passenger car tire, an aircraft tire, an agricultural tire, a leveling machine tire, an off-road (OTR) tire, a truck tire, or a motorcycle tire. The tire may also be radial or bias-ply.

[0058] In a fourth embodiment, the present invention relates to a method for producing a rubber composition, comprising the following steps: A. For example, in the first step, a diphenol (in other words, reacted in advance) is reacted with an amine, particularly a primary amine, in the presence of an aldehyde derivative (preferably formaldehyde) to obtain a benzoxazine, wherein the diphenol includes a crosslink that connects or links both phenol groups of the diphenol, and the crosslink is linked at the meta position of each phenol group to at least one of its terminals. B. A step of mixing benzoxazine with elastomer and filler, C. In the second step, a step of mixing the elastomer and filler, D. The third step involves adding benzoxazine (including the option of continuing the mixing in step B while adding benzoxazine in step C), E. Step of curing the rubber composition This applies to methods that include one or more of the following.

[0059] Further steps may be added between the steps listed above. The features and / or embodiments of the above-described aspects may be combined with each other. The structure, operation, and advantages of the present invention will become more apparent upon careful consideration of the following description in conjunction with the accompanying drawings. [Brief explanation of the drawing]

[0060] [Figure 1] This is a schematic cross-sectional view of a tire including a rubber component having a rubber composition according to an embodiment of the present invention. [Modes for carrying out the invention]

[0061] Figure 1 is a schematic cross-sectional view of a tire 1 according to an embodiment of the present invention. The tire 1 has multiple tire components, including a tread 10, an inner liner 13, a belt including four belt plies 11, a carcass ply 9, two sidewalls 2, and two bead regions 3, a bead filler apex 5, and a bead 4. The exemplary tire 1 is suitable for mounting on the rim of a vehicle, for example, a truck or a passenger car. As shown in Figure 1, the belt plies 11 may be covered by an overlay ply 12 and / or may include one or more breaker plies. The carcass ply 9 includes a pair of axially opposite ends 6, each connected to one of the beads 4. Each axial end 6 of the carcass ply 9 can be folded back around each bead 4 to a position that anchors each axial end 6. The folded portions 6 of the carcass ply 9 can engage with the axially outer surfaces of two flippers 8 and the axially inner surfaces of two chippers 7, which are also considered tire components. As shown in Figure 1, the exemplary tread 10 has circumferential grooves 20, each groove 20 being able to essentially define a U-shaped opening in the tread 10. The main portion of the tread 10 may be formed from one or more tread compounds. Furthermore, the grooves 20, in particular the bottom and / or sidewalls of the grooves 20, can be reinforced with a rubber compound having a higher hardness and / or rigidity than the rest of the tread compound. Such reinforcement may be referred to herein as groove reinforcement.

[0062] Although the embodiment in Figure 1 suggests multiple tire components, including, for example, an apex 5, a chipper 7, a flipper 8, and an overlay 12, such further components are not essential to the present invention. Also, the folded end of the carcass ply 9 is not required to the present invention, or it may pass through the opposing surface of the bead area 3 and terminate on the axially inward side of the bead 4 instead of the axially outward side of the bead 4. The tire may also have a different number of grooves than, for example, groove 20, for example, fewer than four grooves.

[0063] One or more of the above tire components are manufactured from a rubber composition according to an embodiment of the present invention, which comprises a diphenol comprising i) two phenol groups and a crosslink covalently linking the two phenol groups, ii) an aldehyde derivative, and iii) a benzoxazine based on the reaction of an amine, wherein the crosslink is linked to at least one phenol group at the meta position of the at least one phenol group.

[0064] In the first embodiment, such a rubber composition has the following structure

[0065] [C5]

[0066] It may contain 3,3'-dihydroxydiphenyldisulfide-furfurylamine. In this molecule, as shown in structure (I), the disulfide bridge connects both phenyl groups at the meta position, leaving the para positions vacant.

[0067] In another preferred embodiment, benzoxazine is structure II as follows:

[0068] [C6]

[0069] This is 3,3'-dihydroxydiphenyldisulfideethanolamine, as shown in [reference]. In structure II, the sulfur bridge similarly links to the phenyl group at the meta position. In another embodiment, the benzoxazine is 3,3'-dihydroxydiphenyldisulfideaniline, as shown in Structure III below.

[0070] [C7]

[0071] Numerous tests by the inventors have shown that the 4,4'-benzoxazine configuration provides weaker reinforcement by providing crosslinking at the para position of the phenyl group than by linking the crosslink to at least one of the phenyl groups at the meta position.

[0072] For example, the inventors also tested the following structures (IV) and (V), which are not according to the present invention.

[0073] [C8]

[0074] Structure IV, which is not part of the present invention, represents bis(4-hydroxyphenyldisulfidefurfurylamine), where the disulfide bridges both phenyl groups at the para position.

[0075] [C9]

[0076] Structure V is also bisphenol A furfurylamine, although this is not according to the present invention, and the crosslink (i.e., dimethylmethane) is also coupled at the para position of the phenyl group.

[0077] Table 1 below shows examples of diene rubber compositions with different reinforcing agents, particularly structures I, II, III, IV, and V. Control sample 1 is reinforced with carbon black alone. Control sample 2 is reinforced with carbon black, as well as a reactive resin system containing phenolic resin and hexamethylenetetramine. Examples 1 to 3 are reinforced with 3,3'-dihydroxydiphenyldisulfide-furfurylamine (also referred to herein as 3DPDS fa), which corresponds to structure I shown above. In particular, Example 1 contains 15 phr of 3DPDS fa (which corresponds to an equimolar amount with the resin content in control sample 2), Example 2 contains 10 phr of 3DPDS fa, and Example 3 contains 20 phr of 3DPDS fa.

[0078] [Table 1]

[0079] Table 2 further lists the control samples and the samples of the present invention. In particular, control sample 3 is reinforced with bis(4-hydroxyphenyldisulfidefurfurylamine), also referred to herein as 4DPDS fa. This benzoxazine corresponds to structure IV above and crosslinks both phenyl groups at the para position. Control sample 4 is reinforced with bisphenol A furfurylamine (also listed herein as BAfa) and also includes crosslinking at the para position of the phenyl groups (see also structure V). In contrast, Examples 4 and 5 also contain benzoxazines crosslinked at the meta position of each phenyl group, in which case Example 4 contains 3'-dihydroxydiphenyldisulfideethanolamine (3DPDS ea, also shown in structure II) and Example 5 contains 3,3'-dihydroxydiphenyldisulfideethanolaniline (3DPDS, shown in structure III).

[0080] [Table 2]

[0081] Table 3 shows the measured values ​​of Young's modulus E, an indicator of stiffness, for control samples 1-4 and Examples 1-5, corresponding to Tables 1 and 2 above. Control sample 1, which has only carbon black reinforcement, has the lowest stiffness. Control samples 3 and 4, reinforced with benzoxazine with phenyl groups coupled in the para position, show higher stiffness than control sample 1, but lower stiffness than control sample 2, which is reinforced with (equomolar) reactive resin. Furthermore, as shown in Table 3, each of Examples 1-5 has higher stiffness than any of the control samples and can be considered, for example, a valuable replacement for the reactive resin system of control sample 2. The Young's moduli shown in Table 3 were determined according to DIN 53504 using an INSTRON 5967 electromechanical testing machine with a 75 mm length Type S2 dumbbell-shaped test specimen. Young's modulus was determined to a strain of 1.5%.

[0082] [Table 3]

Claims

1. One or more diene elastomers at 100 phr, a filler at 30 phr to 200 phr, and 5 phr to 40 phr of a benzoxazine which is a reaction product of i) a diphenol containing two phenol groups and a bridge connecting the two phenol groups by a covalent bond, ii) an aldehyde derivative, and iii) an amine A rubber composition comprising the above, wherein the bridge is connected to the two phenol groups at the meta-position of each phenol group.

2. The rubber composition according to claim 1, wherein the amine is a primary amine.

3. The primary amine is selected from the group consisting of aromatic amines, aliphatic amines, alicyclic amines, and heterocyclic amines; and / or The primary amine is selected from the group consisting of ethanolamine, allylamine, methylamine, ethylamine, propylamine, butylamine, isopropylamine, hexylamine, cyclohexylamine, 2-aminofluorene, aminophenylacetylene, propargyl ether aniline, 4-aminobenzonitrile, furfurylamine, and aniline. The rubber composition according to claim 2.

4. The rubber composition according to claim 2, wherein the primary amine is selected from aliphatics, and the aliphatic amine contains a carbon chain with less than 18 carbon atoms.

5. The aldehyde derivative is selected from the group consisting of formaldehyde, paraformaldehyde, polyoxymethylene, and an aldehyde having the formula RCHO [wherein R is a substituted or unsubstituted aliphatic C having or not having a heteroatom] １ -C ２０ alkyl group], and the rubber composition according to any one of claims 1 to 4.

6. The rubber composition according to any one of claims 1 to 5, wherein the bridge contains one of an aromatic group, an aliphatic group, an alicyclic group, a heterocyclic group, a hexafluoropropane group, a monosulfide, an oxygen group, a sulfone group, and a disulfide.

7. The rubber composition according to any one of claims 1 to 6, wherein the diphenol is selected from 3,3'-dihydroxydiphenyldisulfide.

8. The benzoxazine has at least one of the following structures: 【Chemical 1】 [wherein, R １ and R ２ are selected from an aromatic group, an aliphatic group, an alicyclic group, and a heterocyclic group, and R ３ is an aromatic group, an aliphatic group, an alicyclic group, a heterocyclic group, hexafluoropropane, monosulfide, or disulfide] The rubber composition according to any one of claims 1 to 7.

9. R １ and R ２ are selected from ethanol, allyl, methyl, ethyl, propyl, isopropyl, hexyl, cyclohexyl, fluorene, phenylacetylene, propargyl ether benzyl, benzonitrile, furfuryl and benzyl groups; and / or R ３ characterized in that R is a disulfide The rubber composition according to claim 8.

10. The rubber composition according to any one of claims 1 to 9, which is a sulfur-vulcanizable rubber composition containing a sulfur donor.

11. The filler contains one or more of silica, carbon black, aluminum hydroxide, ultra-high molecular weight polyethylene, and syndiotactic polybutadiene, characterized in that The rubber composition according to any one of claims 1 to 10.

12. The rubber composition according to any one of claims 1 to 11, characterized in that it contains less than 2 phr of a methylene donor and less than 5 phr of a methylene acceptor and is a sulfur-vulcanizable rubber composition.

13. The rubber composition according to any one of claims 1 to 12, further comprising at least one second benzoxazine based on the reaction of a phenol and a primary amine, wherein the second benzoxazine may optionally be one or more of a monofunctional benzoxazine and a main-chain benzoxazine.

14. A rubber product, characterized in that it contains the rubber composition according to any one of claims 1 to 13.

15. The rubber product is selected from a tire (1), a power transmission belt, a hose, a track, an air sleeve, and a conveyor belt, or The rubber product is a tire (1) containing one or more rubber components selected from a tread (10), a shear band, a rubber spoke, an undertread, a sidewall (2), an apex (5), a flipper, a chipper, a chafer, a carcass, a belt, and an overlay, and one or more of the rubber components contain the rubber composition, characterized in that The rubber product according to claim 14.

16. A method for producing a rubber composition, comprising: Reacting a diphenol with an amine in the presence of an aldehyde derivative to obtain a benzoxazine, wherein the diphenol contains a bridging that connects both phenolic groups of the diphenol, and the bridging connects to the meta-position of each phenolic group at each of its ends, and Mixing the benzoxazine with an elastomer and a filler to obtain a rubber composition, wherein the rubber composition contains 100 phr of the elastomer, 30 phr to 200 phr of the filler, and 5 phr to 40 phr of the benzoxazine. A method comprising the above steps.

Images