Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L11/00—Compositions of homopolymers or copolymers of chloroprene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/10—Esters; Ether-esters
  • C08K5/11—Esters; Ether-esters of acyclic polycarboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L7/00—Compositions of natural rubber
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L9/00—Compositions of homopolymers or copolymers of conjugated diene hydrocarbons

Definitions

• the present invention relates to a rubber composition and a vulcanized molded body obtained by vulcanizing and molding the rubber composition. More specifically, the present invention relates to a blend rubber composition in which natural rubber or isoprene rubber is blended with chloroprene rubber and a vulcanized product thereof.
• Chloroprene rubber is excellent in heat resistance, weather resistance, ozone resistance and chemical resistance, and is used in a wide range of fields such as general industrial rubber products, automotive parts and adhesives.
• chloroprene rubber may lack rubber properties in a low-temperature environment depending on the application.
• studies have been made on the use of natural rubber, which is relatively excellent in low temperature characteristics, mixed with chloroprene rubber (see Patent Documents 1 to 3).
• Patent Document 1 by adding a sulfur-based vulcanizing agent and a thiuram-based compound to a blend rubber composed of chloroprene rubber and natural rubber, in addition to rubber properties at low temperature, storage stability and processing safety A rubber composition having improved properties has been proposed.
• Patent Document 2 discloses a rubber composition containing natural rubber, chloroprene rubber, sulfur and zinc white, and a vulcanization accelerator that vulcanizes natural rubber but does not vulcanize chloroprene rubber.
• damping properties are obtained by using a normal vulcanization accelerator and a vulcanization accelerator that is effective for natural rubber but less effective for chloroprene rubber. To improve the balance between low temperature and low temperature characteristics.
• Patent Document 3 discloses a chloroprene rubber composition in which a specific amount of a copolymer of styrene and butadiene is blended with a blend rubber of chloroprene rubber and natural rubber for the purpose of improving the mechanical strength of the vulcanized molded article. Proposed.
• a block copolymer of styrene and butadiene serves as a compatibilizer for chloroprene rubber and natural rubber, and these are co-vulcanized with natural rubber finely dispersed in chloroprene rubber. Therefore, a vulcanizate having good compression set and excellent mechanical strength over a wide temperature range can be obtained.
• the present invention provides a rubber that can provide a vulcanized product that retains the original mechanical strength of chloroprene rubber and is excellent in low-temperature characteristics without using a block copolymer of styrene and butadiene as a compatibilizer.
• the main object is to provide a composition and a vulcanized body.
• the rubber composition according to the present invention has a structure represented by the following chemical formula (I) with respect to 100 parts by mass of a rubber component consisting of 10 to 90% by mass of chloroprene rubber and 10 to 90% by mass of natural rubber or isoprene rubber. It contains 3 to 30 parts by mass of an adipic acid plasticizer.
• R 1 and R 2 are an alkyl group whose total number of carbon atoms is an integer of 1 to 20, or an alkyl group connected by one or more ether bonds and a total number of carbon numbers of 1 or more. Ether which is an integer of 20 or less is shown.
• chloroprene rubber for example, at least one chloroprene rubber selected from mercaptan-modified chloroprene rubber, xanthogen-modified chloroprene rubber and sulfur-modified chloroprene rubber can be used.
• adipic acid plasticizer examples include dimethyl adipate, diethyl adipate, dipropyl adipate, dibutyl adipate, diisopropyl adipate, diisobutyl adipate, diisononyl adipate, diisodecyl adipate, and bis (2 At least one compound selected from -ethylhexyl), bis (2-butoxyethyl) adipate and bis [2- (2-butoxyethoxy) ethyl adipate] can be used.
• the chloroprene rubber according to the present invention may further contain 0.1 to 10 parts by mass of a glycol ether plasticizer having a structure represented by the following chemical formula (II) per 100 parts by mass of the rubber component. .
• R 3 represents an alkyl group having a total number of carbon atoms of 1 to 20, or an integer in which the alkyl groups are connected by one or more ether bonds and the total number of carbon atoms is 1 to 20.
• An ether is shown.
• glycol ether plasticizer examples include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monophenyl ether, and diethylene glycol mono (2-ethylhexyl).
• ethers At least one compound selected from ethers can be used.
• the vulcanized molded body according to the present invention is obtained by vulcanizing and molding the rubber composition described above.
• a vulcanized molded article having excellent rubber properties at low temperatures and excellent mechanical strength can be realized without using a block copolymer of styrene and butadiene as a compatibilizer. .
• Chloroprene rubber is obtained by polymerizing raw material monomers containing 2-chloro-1,3-butadiene while adjusting the molecular weight.
• the chloroprene rubber used in the rubber composition of the present embodiment may be one obtained by polymerizing 2-chloro-1,3-butadiene alone, and may be one or more types copolymerizable with 2-chloro-1,3-butadiene. It may be copolymerized with other monomers.
• Monomers copolymerizable with chloroprene include esters of acrylic acid such as methyl acrylate, butyl acrylate and 2-ethylhexyl acrylate, and methacrylates such as methyl methacrylate, butyl methacrylate and 2-ethylhexyl methacrylate.
• Acid esters, hydroxy (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxymethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1-chloro-1,3- Examples include butadiene, butadiene, isoprene, ethylene, styrene, and acrylonitrile.
• the rubber composition of the present embodiment is particularly preferably a chloroprene rubber obtained by copolymerizing 2-chloro-1,3-butadiene and 2,3-dichloro-1,3-butadiene, and 2,3-dichlorobutadiene units. More preferred is a chloroprene rubber containing 5 to 20% by mass. When such a chloroprene rubber is used, a vulcanized molded product having not only heat resistance but also excellent rubber properties can be obtained in a wide temperature range from a low temperature range to a high temperature range.
• chloroprene rubber can be classified into a type having a low crystallization rate, a type having a moderate crystallization rate, a type having a high crystallization rate, and the like according to the crystallization rate. Any of the above-mentioned types of chloroprene rubber may be used for the rubber composition of the present embodiment, and the rubber composition can be appropriately selected and used according to the application.
• Chloroprene rubber can be classified into, for example, sulfur-modified chloroprene rubber and non-sulfur-modified chloroprene rubber.
• the sulfur-modified chloroprene rubber is obtained by copolymerizing a raw material monomer mainly composed of 2-chloro-1,3-butadiene and sulfur, and plasticizing the obtained copolymer with thiuram disulfide to obtain a predetermined Mooney viscosity. It has been adjusted to.
• non-sulfur-modified chloroprene rubber mercaptan-modified chloroprene rubber and xanthogen-modified chloroprene rubber are generally known.
• the mercaptan-modified chloroprene rubber is obtained by polymerization using an alkyl mercaptan such as n-dodecyl mercaptan, tert-dodecyl mercaptan and octyl mercaptan as a molecular weight modifier
• xanthogen-modified chloroprene rubber is used as a molecular weight modifier. Polymerized using an alkyl xanthogen compound.
• the rubber composition of the present embodiment is not subject to the above-described classification restrictions, and any type of chloroprene can be used. Moreover, although only one type of chloroprene rubber may be used, a plurality of different types of chloroprene rubber can also be used in combination, and the mixing ratio in that case is not particularly limited, and the purpose and application It can be set appropriately depending on the situation.
• Natural rubber or isoprene rubber A known natural rubber or isoprene rubber can be used for the rubber composition of the present embodiment, and the production area, type and structure thereof are not particularly limited. Further, only one kind of natural rubber and isoprene rubber may be used, but a plurality of natural rubbers or isoprene rubbers having different origins and structures are mixed and used in an arbitrary ratio according to the purpose and application. You can also.
• the rubber component of the rubber composition of this embodiment is chloroprene rubber and natural rubber or isoprene rubber.
• the chloroprene content of the rubber component is less than 10% by mass, that is, when the content of natural rubber or isoprene rubber is more than 90% by mass, the heat resistance and weather resistance of the vulcanized molded product are insufficient.
• natural rubber or isoprene rubber is mixed with chloroprene rubber, the low temperature characteristics of the vulcanized molded product can be improved.
• the chloroprene content of the rubber component exceeds 90% by mass, that is, natural rubber or isoprene rubber When the content is less than 10% by mass, the low temperature characteristics of the vulcanized molded product are insufficient.
• the chloroprene content of the rubber component is 10 to 90% by mass.
• the content of the natural rubber or isoprene rubber as the rubber component is 10 to 90% by mass
• the adipic acid plasticizer used in the rubber composition of the present embodiment has a chemical structure represented by the following chemical formula (I).
• R 1 and R 2 are an alkyl group whose total number of carbon atoms is an integer of 1 to 20, or an alkyl group connected by one or more ether bonds, and the total number of carbon atoms is The ether which is an integer of 1-20 is shown.
• the rubber composition of the present embodiment contains 3 to 30 parts by mass of the adipic acid plasticizer represented by the above chemical formula (I) with respect to 100 parts by mass of the rubber component. If the amount of adipic acid plasticizer is less than 3 parts by mass per 100 parts by mass of the rubber component, natural rubber or isoprene rubber is not stably dispersed in the chloroprene rubber, and the finely dispersed state of these rubbers becomes unstable. As a result, the mechanical strength of the vulcanized molded product decreases. Moreover, when the compounding quantity of an adipic acid type plasticizer exceeds 30 mass parts per 100 mass parts of rubber components, the amount of plasticizers will become excess and will cause the appearance defect by bleed-out.
• the adipic acid plasticizer represented by the above chemical formula (I) with respect to 100 parts by mass of the rubber component. If the amount of adipic acid plasticizer is less than 3 parts by mass per 100 parts by mass of the rubber component, natural rubber or isoprene rubber is
• the blending amount of the adipic acid plasticizer represented by the chemical formula (I) is preferably 5 parts by mass or more per 100 parts by mass of the rubber component from the viewpoint of improving the mechanical strength of the vulcanized molded product. From the viewpoint of suppressing the occurrence of bleeding out of the plasticizer, the amount is preferably 20 parts by mass or less per 100 parts by mass of the rubber component.
• the adipic acid plasticizer used in the rubber composition of the present embodiment is not particularly limited as long as it has a structure represented by the above chemical formula (I).
• adipic acid plasticizers dimethyl adipate, diethyl adipate, dipropyl adipate, dibutyl adipate, diisopropyl adipate, adipic acid from the viewpoint of the balance between tensile strength and elongation at break when vulcanized molded products
• Diisobutyl, diisononyl adipate, diisodecyl adipate, bis (2-ethylhexyl) adipate, bis (2-butoxyethyl) adipate, and bis [2- (2-butoxyethoxy) ethyl adipate] are preferred.
• These adipic acid plasticizers can be used alone or in combination.
• the rubber composition of the present embodiment may further contain a glycol ether plasticizer having a structure represented by the following chemical formula (II).
• R 3 is an alkyl group whose total number of carbon atoms is an integer of 1 to 20, or an alkyl group connected by an ether bond of one or more and a total number of carbon atoms of 1 to 20
• An ether which is an integer of
• the glycol ether plasticizer having the structure represented by the above chemical formula (II) is blended, it is preferably 0.1 to 10 parts by mass per 100 parts by mass of the rubber component. Thereby, the mechanical strength of the vulcanized molded body can be further improved. If the blending amount of the glycol ether plasticizer is less than 0.1 parts by mass or more than 10 parts by mass per 100 parts by mass of the rubber component, the effect of improving the mechanical strength of the vulcanized molded article becomes insufficient. .
• the glycol ether plasticizer blended in the rubber composition of the present embodiment is not particularly limited as long as it has a structure represented by the above chemical formula (II).
• various glycol ether plasticizers diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monopropyl ether from the viewpoint of improving mechanical strength when formed into a vulcanized molded product.
• Isobutyl ether, diethylene glycol monophenyl ether and diethylene glycol mono (2-ethylhexyl) ether are preferred.
• These glycol ether plasticizers can be used alone or in combination.
• a vulcanizing agent may be added to the rubber composition of the present embodiment.
• vulcanizing agents that can be added to the rubber composition of the present embodiment include sulfur, beryllium, magnesium, zinc, calcium, barium, germanium, titanium, tin, zirconium, antimony, vanadium, bismuth, molybdenum, tungsten, tellurium, and selenium. And simple metals such as iron, nickel, cobalt and osmium, or oxides or hydroxides of these metals.
• sulfur, calcium oxide, zinc oxide, antimony dioxide, antimony trioxide, and magnesium oxide are preferable because they have a particularly high vulcanizing effect.
• a vulcanizing agent may be used individually by 1 type, you may use 2 or more types together.
• the rubber composition of this embodiment includes rubber products such as vulcanization accelerators, fillers or reinforcing agents, plasticizers, processing aids and lubricants, anti-aging agents, and silane coupling agents in addition to the components described above.
• rubber products such as vulcanization accelerators, fillers or reinforcing agents, plasticizers, processing aids and lubricants, anti-aging agents, and silane coupling agents in addition to the components described above.
• Various auxiliary materials usually used in the production of the above may be added.
• the vulcanization accelerator blended in the rubber composition of the present embodiment is not particularly limited.
• a thiourea vulcanization accelerator, a thiazole vulcanization accelerator, a thiuram vulcanization accelerator, and a guanidine series are used. Examples thereof include vulcanization accelerators. These vulcanization accelerators may be used alone or in combination of two or more.
• Fillers and reinforcing agents are added to adjust the hardness of the rubber and improve the mechanical strength, and the type thereof is not particularly limited. For example, carbon black, silica, clay, talc And calcium carbonate. Further, the blending amounts of these fillers and reinforcing agents are not particularly limited, and can be appropriately set according to the physical properties required for the rubber composition and the vulcanized molded body thereof.
• the blending amount of the filler or reinforcing agent is usually 15 to 200 parts by mass per 100 parts by mass of the rubber component from the viewpoint of the balance between processability and mechanical strength of the vulcanized molded product.
• the blending amount of the filler or reinforcing agent is less than 15 parts by mass per 100 parts by mass of the rubber component, the strength of the vulcanized molded product may be insufficient.
• a filler or a reinforcing agent is blended in excess of 200 parts by mass per 100 parts by mass of the rubber component, the workability may be abruptly deteriorated.
• the rubber composition of the present embodiment may contain a plasticizer other than the adipic acid plasticizer and glycol ether plasticizer described above.
• Other plasticizers added to the rubber composition of the present embodiment are not particularly limited as long as they are compatible with chloroprene rubber.
• vegetable oils such as rapeseed oil, linseed oil, castor oil, coconut oil, etc.
• Phthalate plasticizer DUP (diundecyl phthalate), DOS (dioctyl sebacate), DOA (dioctyl adipate), ester plasticizer, ether ester plasticizer, thioether plasticizer, aroma oil, naphthenic oil And petroleum plasticizers such as lubricating oil, process oil, paraffin, liquid paraffin, petroleum jelly and petroleum asphalt.
• plasticizers may be used alone or in combination of two or more.
• the amount of other plasticizers can be appropriately set according to the physical properties required for the rubber composition and its vulcanized molded article. From the viewpoint of further improving the workability, 100 parts by mass of the rubber component It is preferably 5 to 50 parts by mass per unit.
• Processing aids and lubricants can be easily peeled off from rolls, molding dies, extruder screws, etc. when kneading or vulcanizing rubber compositions to improve processing characteristics and surface lubricity.
• processing aids and lubricants include fatty acid-based processing aids such as stearic acid, paraffin-based processing aids such as polyethylene, and fatty acid amides.
• An anti-aging agent can be blended with the rubber composition of the present embodiment for the purpose of improving heat resistance.
• Anti-aging agents used in ordinary rubber compositions include primary anti-aging agents that trap radicals to prevent auto-oxidation and secondary anti-aging agents that render hydroperoxides harmless. Any of these rubber compositions can be used.
• the primary anti-aging agent examples include phenol-based anti-aging agents, amine-based anti-aging agents, acrylate-based anti-aging agents, imidazole-based anti-aging agents, carbamic acid metal salts, waxes and the like.
• Specific examples of secondary anti-aging agents include phosphorus-based anti-aging agents, sulfur-based anti-aging agents, and imidazole-based anti-aging agents. These anti-aging agents may be used alone or in combination of two or more.
• ⁇ Silane coupling agent> In the rubber composition of the present embodiment, in order to increase the adhesion between chloroprene rubber or natural rubber and fillers or reinforcing agents, and to improve the mechanical strength of the vulcanized molded body, it is combined with fillers and reinforcing agents.
• a silane coupling agent may be added.
• the silane coupling agent may be added when the rubber composition is kneaded, but the filler or reinforcing agent is surface-treated with the silane coupling agent in advance, and the filler or reinforcing agent is used as an auxiliary material. When adding, the form added together can also be employ
• the normal manufacturing method of a rubber composition is applicable.
• the rubber composition of the present embodiment includes chloroprene rubber, natural rubber or isoprene rubber, an adipic acid plasticizer, and, if necessary, a glycol ether plasticizer, a vulcanizing agent, and other auxiliary agents.
• the raw material can be produced by weighing and mixing a predetermined amount.
• the mixing method in that case is not specifically limited, For example, what is necessary is just to knead
• the rubber composition of the present embodiment is excellent in rubber properties at low temperatures because a specific amount of adipic acid plasticizer having a specific structure is added to a blend rubber of chloroprene rubber and natural rubber or isoprene rubber.
• a specific amount of adipic acid plasticizer having a specific structure is added to a blend rubber of chloroprene rubber and natural rubber or isoprene rubber.
• Various vulcanized molded articles that are excellent in mechanical strength and industrially useful can be obtained.
• the vulcanized molded body of the present embodiment is obtained by vulcanizing and molding the rubber composition of the first embodiment described above into a shape according to the purpose.
• the vulcanization molding method in that case is not particularly limited. For example, press vulcanization, injection vulcanization, direct kettle vulcanization, indirect kettle vulcanization, direct steam continuous during or after molding the rubber composition.
• Vulcanization may be performed by a known method such as vulcanization, normal pressure continuous vulcanization, or continuous vulcanization press.
• the vulcanization temperature is not particularly limited, and can be appropriately set depending on the composition of the rubber composition and the type of the vulcanizing agent. Usually, from the viewpoint of productivity and processing safety, the vulcanization temperature is preferably 140 to 190 ° C, and more preferably 150 to 180 ° C.
• machining safety is a machining characteristic evaluated by the scorch time, and greatly affects the defect occurrence rate. Specifically, when the scorch time is short, the frequency of occurrence of defective molding is increased because the unvulcanized rubber component is vulcanized during molding at a high temperature.
• the effects of the present invention will be described in detail with reference to examples and comparative examples of the present invention.
• the rubber compositions of the examples and comparative examples were produced by changing the component composition, and the characteristics when the vulcanized molded body was obtained were evaluated.
• mercaptan-modified chloroprene rubber xanthogen-modified chloroprene rubber and sulfur-modified chloroprene rubber were used as the chloroprene rubber.
• standard Malaysian rubber was used as natural rubber, and a commercially available product was used as isoprene rubber.
• commercially available products were used as the adipic acid plasticizer and glycol ether plasticizer. Sulfur, zinc oxide and magnesium oxide were used as the vulcanizing agent, and ethylene thiourea was used as the vulcanization accelerator.
• N-762 was used as carbon black, and stearic acid was used as a processing aid.
• As the antioxidant N-phenyl-1-naphthylamine and 4,4'-bis ( ⁇ , ⁇ -dimethylbenzyl) diphenylamine were used.
• Tensile strength and elongation at break are values serving as indicators of mechanical strength, and were measured in accordance with JIS K6251. Specifically, a dumbbell-shaped No. 3 test piece was cut out from the vulcanized molded sheet, and the tensile speed was measured at a temperature of 23 ° C. using a fully automatic rubber tensile tester (AGS-H manufactured by Shimadzu Corporation). The measurement was performed under the condition of 500 mm / min. As a result, a sample having a tensile strength of 15 MPa or more and an elongation at break of 450% or more was regarded as acceptable.
• ⁇ Durometer hardness> The durometer hardness was measured in accordance with JIS K6253-3, under the temperature condition of 23 ° C., with three vulcanized molded sheets stacked. For the measurement, a hardness meter (Asker rubber hardness meter A type) was used. As a result, a durometer hardness of 40-70 points was accepted.
• the embrittlement temperature is a value that serves as an index of low temperature characteristics, and was measured in accordance with JIS K6261. Specifically, the embrittlement temperature is determined by giving a predetermined impact to a cantilever strip test piece placed in a constant temperature test tank, measuring the number of fractures at each temperature, and calculating the value in advance. Calculated by substituting into the formula. As a result, a sample having an embrittlement temperature of ⁇ 40 ° C. or lower was accepted.
• Tables 1 to 6 below collectively show the composition of rubber compositions of Examples and Comparative Examples and the evaluation results thereof.
• the rubber composition of Comparative Example 1 had a small amount of adipic acid plasticizer added, so that the mechanical strength of the vulcanized molded product was higher than that of the rubber compositions of Examples 1 to 4. Was inferior.
• Comparative Example 2 since the addition amount of the adipic acid plasticizer was large, an appearance defect due to bleeding out occurred.
• Tables 2 and 3 in the rubber compositions of Comparative Examples 3 to 6, since the plasticizer is not an adipic acid plasticizer having a structure represented by the above chemical formula (I), Compared with the rubber composition of No. 14, the mechanical strength of the vulcanized molded product was inferior.
• the rubber composition of Comparative Examples 8 to 10 in which the rubber component is only chloroprene rubber and no natural rubber or isoprene rubber is mixed the rubber component is a mixed rubber of chloroprene rubber and natural rubber.
• the low temperature characteristics were inferior.
• the rubber composition of Comparative Example 7 containing only natural rubber and no chloroprene rubber was inferior in mechanical strength (tensile strength) to the rubber compositions of Examples 2 and 15 to 19. It was.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Compositions Of Macromolecular Compounds (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=52008182

Family Applications (1)

Country Status (5)

Cited By (4)

Families Citing this family (1)

Citations (2)

Family Cites Families (12)

• 2014
  • 2014-06-03 WO PCT/JP2014/064777 patent/WO2014196544A1/ja active Application Filing
  • 2014-06-03 CN CN201480031828.1A patent/CN105377975B/zh active Active
  • 2014-06-03 KR KR1020157037062A patent/KR102187515B1/ko active IP Right Grant
  • 2014-06-03 JP JP2015521460A patent/JP6351586B2/ja active Active
  • 2014-06-03 TW TW103119328A patent/TWI625352B/zh active

Patent Citations (2)

Also Published As

Similar Documents

Legal Events