WO2002036671A1 - Vulcanization accelerator and fluororubber composition for vulcanization - Google Patents

Abstract

A vulcanization accelerator giving a vulcanizable fluororubber composition which can be effectively prevented from scorching during storage and in a pretreatment for vulcanization, has a high vulcanization rate in actual vulcanization to attain a reduction in vulcanization time, and has vulcanization characteristics optimal for injection molding. It comprises an onium salt in which the anion is a phenol compound, especially one represented by the formula (I) (I) (wherein A+ is the cation of the onium salt; X is a functional group which enables the substituted phenol constituting the anion of the onium salt to have a pK¿a? of 3.2 to 12.4; and n is an integer of 0 to 5). Also provided is a fluororubber composition for vulcanization which comprises the vulcanization accelerator, a fluororubber vulcanizable with a polyol, and a polyol vulcanizing agent.

Description

 Akira Itoda Vulcanization accelerator and fluororubber composition for vulcanization Technical field

 The present invention relates to a vulcanization accelerator which can prevent scorch at the time of vulcanization and storage and can complete vulcanization quickly after the start of vulcanization in a polyol vulcanization system, and vulcanization accelerator The present invention relates to a vulcanizing fluororubber composition containing an agent. Background art

 Fluoro rubbers, especially elastic copolymers of vinylidene fluoride and one or more fluorine-containing ethylenically unsaturated monomers, are used at high temperatures for products such as polyester rings, gaskets, packing, etc. In addition to the sealing material, it is used as a material for tubes, valves, bellows, and linings. In addition, due to its excellent oil and chemical resistance, the demand for sealing materials and hoses, which are important in the automotive and chemical industries, has been increasing in recent years. ing.

 Incidentally, a polyol vulcanization system is known as a vulcanization system which gives a vulcanized product having such properties, particularly a vulcanized product having excellent compression set. As the polyol-based vulcanizing agent, various polyols, for example, aromatic polyhydroxy compounds and aliphatic polyhydroxy compounds are used, and bisphenol AF is particularly preferably used. Polyol vulcanization systems further use vulcanization accelerators, metal oxides, metal hydroxides, and the like as auxiliary agents. Examples of vulcanization accelerators include onium salts, particularly phosphonium salts, ammonium salts, and sulfonium salts. Are known.

However, in order to form a large amount at low cost, Such problems are obstacles. That is, the vulcanizing composition to which the vulcanizing agent and the vulcanization accelerator are mixed significantly generates scorch during storage or before vulcanization, contaminates the mold, and releases the mold. The point is that the formality gets worse.

 Here, scorch refers to an inappropriate early vulcanization phenomenon in which a rubber composition mixed with a vulcanizing agent undergoes curing during its storage or before proper vulcanization conditions are reached.

 These problems are particularly important when performing injection molding suitable for labor saving and mass production. This is because in injection molding, it is necessary to preheat (80 to 140, usually 100 to 1200) before vulcanization, and thus scorch is generated in this preheating stage. Therefore, various proposals have been made with respect to scorch prevention in order to apply fluororubber to injection molding, as disclosed in Japanese Patent Application Laid-Open No. Sho 62-111555. Phosphonium salts having a phthalimide group have been proposed as inhibitors, and the vulcanization rate at low temperatures (about 150 ° C) has been slowed, but the scorch prevention properties are not satisfactory. Japanese Patent Application Laid-Open No. 11-1985-295 proposes to add a phenol compound having a functional group as a scorch inhibitor, and lists a large number of phenol compounds. The target squaw In order to obtain the effect, the amount of addition must be increased, resulting in an adverse effect such as an increase in compression set of the vulcanized molded product, and a slower vulcanization rate at high temperatures. Therefore, the balance between scorch prevention properties, vulcanization rate and physical properties of vulcanized molded products is not satisfactory, and Japanese Unexamined Patent Publication No. Hei 11-1985295 discloses alkoxide as anion of onium salt. And phenoxide, but do not teach any specific structure and effect.

U.S. Pat. No. 5,728,773 discloses a method of blocking the hydroxy end of bisphenol AF, a vulcanizing agent, by blocking it with a forceponate. There is a statement that anti-hinging properties can be obtained. Certainly, this method improves the prevention of scorch and maintains the vulcanization rate at high temperatures, but produces a compound in which the hydroxy terminal of the vulcanizing agent Pisphenol AF is blocked with a force-ponate. However, the vulcanization cost is high as a result.

 Thus, at present, the conventional proposals have not obtained a polyol vulcanization system that is inexpensive and suitable for mass production.

 The main object of the present invention is to provide a polyol vulcanization system which can be particularly suitably applied to injection molding which is inexpensive and suitable for mass production, and specifically, a novel vulcanization accelerator which can achieve the object, It is an object of the present invention to provide a vulcanizing fluororubber composition containing the vulcanization accelerator. Disclosure of the invention

 That is, the present invention relates to a vulcanization accelerator comprising an onium salt composed of a cation and an unsubstituted or substituted phenol compound anion.

 For example, this onium salt

Formula (I):

 (Wherein A + is a cation of the onium salt, X is a functional substituent that sets the pka of the unsubstituted or substituted phenol compound constituting the anion of the onium salt to 3.2 1 2. An integer). The present invention also relates to a vulcanizable fluororubber composition comprising a polyol vulcanizable fluororubber, a polyol vulcanizing agent and the vulcanization accelerator.

As the fluororubber, a fluororubber containing a methylene unit is preferable, and a fluororubber containing a vinylidene fluoride (VdF) unit is preferable. Binary copolymers of VdF with hexafluoropropylene (HFP), especially Preferred is a VdF-HFP copolymer having a molar ratio of 85Zl 5 to 50/50. Further, a ternary or more copolymer of VdF, HFP, and another copolymerizable monomer may be used. Other copolymerizable monomers include tetrafluoroethylene (TFE), perfluorovinylether, ethylene or propylene.

 Such a vulcanizing fluororubber composition is preferably prepared by previously mixing a polyol vulcanizing agent and a vulcanization accelerator.

 Further, among the onium salts of the formula (I), the formula (II):

Wherein X ¹ is a nitro group, a cyano group or a benzoyl group, and η is an integer of 0 to 5. The phosphonium salt represented by the formula is a novel compound. BEST MODE FOR CARRYING OUT THE INVENTION The vulcanization accelerator of the present invention is an ionic salt having an ion of a phenol compound as an anion, and is particularly preferably an ionic salt represented by the above formula (I). Formula (0) is preferably a cation of phosphonium, aminophosphonium, ammonium, 8-benzyl-1,8-diazabicyclo [5.4.0] indesium, sulfonium or imminium. The functional substituent X is preferably a nitro group, a cyano group, a benzoyl group or a halogen atom.

The number (η) of X is preferably one, but may be two to five. Also, 0 That is, it may be an unsubstituted phenol. In the case of a plurality, X may be the same or different. When X is one, the substitution position is preferably the 4-position of phenoxide (phenol). Hereinafter, the unsubstituted or substituted phenol is collectively referred to as “phenol compound”.

 Preferred specific examples of the honium salt include benzyltriphenylphosphonium 4-cyanophenoxide, benzyltriphenylphosphonium_4-1 nitrophenoxide, benzyltriphenylphosphonium-14-benzobenzoylphenoxide, benzyltrif Selected from the group consisting of enylphosphonium 2,4-dinitrophenoxide, benzyltriphenylphosphonium chlorophenoxide, benzyltriphenylphosphonium phenoxide and benzyltriphenylphosphonium 2,4, -dichlorophenoxide There is at least one species.

 The anionic salt constituting the vulcanization accelerator of the present invention preferably has an anion having a pka (measured in an aqueous medium) of 3.2 to 12.4. The lower limit of pka, 3.2, is the pka of hydrogen fluoride (HF). When the pka is within this range, stabilization of the hondium salt and an appropriate reaction rate of the dehydrofluorination reaction are ensured, so that scorch prevention, which is one of the objects of the present invention, can be achieved. Preferred pka's are 3.2-10, more preferably 4-12, especially 6-; L0.

 The phonium salt used in the present invention is prepared, for example, by dissolving a phenol compound (for example, a phenol in which 0 to 5 X is substituted) in a solvent, and then adding a metal alkoxide to cause a sufficient reaction. (Referred to as "starting onium salt"). Alternatively, when a metal salt of a phenol compound (metal pentoxide) is used, it may be immediately reacted with the starting hondium salt.

The phenol compound may be phenol, or may have 1 to 5 nitro, cyano, benzoyl or halogen atoms as functional substituents. May be a substituted phenol. Specific examples of the substituted phenol include monosubstituted phenols such as nitrophenol, cyanophenol, benzoxyphenol, and halogenated phenol; and disubstituted phenols such as 2,4-dinitrophenol and 2,4-dichlorophenol. Of these, phenol, 4-cyanophenol and 4-nitrophenol are preferred because of their excellent scorch prevention effect and inexpensiveness. Examples of these metal salts (metal phenoxides) include phenoxides such as sodium and potassium.

 The cation A + of the starting onium salt to be reacted is preferably phosphonium, aminophosphonium, ammonium, 8-benzyl_1,8-diazabi- sic mouth [5.4.0] undecenium (DBUB), sulfonium or iminium cation. Counter ions include halogens such as bromine and chlorine; and inorganic acids. Specific examples include benzyltriphenylphosphonium chloride, benzyldiphenyldiethylaminophosphonium chloride, tetrabutylammonium bromide and the like.

 Of these, phosphonium salts are preferred as the cation. In particular, benzyltriphenylphosphonium salt, specifically, benzyl 1, rifenylphosphonium chloride, and benzyltriphenylphosphonium bromide are preferred.

 The amount of the starting onium salt may be 0.5 to 2 moles, preferably 1 to 2 moles, of the phenol compound. If the starting sodium salt is large, even if unreacted starting sodium salt remains, it becomes a mixture with the product of the invention, which acts as a product to improve the anti-scorch property, and the vulcanization rate is reduced. Or contribute to adjustment.

Examples of the metal alkoxide to be reacted with the phenol compound include sodium methoxide, Is preferred. The amount of the metal alkoxide may be 0.1 to 2 equivalents, preferably 1 to 1.2 equivalents, of the hydroxy group of the phenol compound. The metal alkoxide may be added as a solid or a solution.

 In the reaction, if all of the reaction reagents are liquid, a solvent need not be particularly used, but generally, a solvent is preferably used. The amount of solvent used is sufficient to dissolve the reagent used. If the amount is too large, the halide as a by-product of the reaction may not precipitate, and isolation and purification may be difficult. As the solvent, for example, alcohols such as methanol and ethanol, and other polar solvents which do not dissolve the inorganic salt by-produced are preferable.

 The reaction temperature is not particularly limited, and varies depending on the type of the solvent, the reaction pressure and the like, but it is preferably within a range of 0 to 100 ° C, usually at normal temperature. The reaction pressure may be reduced or increased, but an appropriate pressure may be selected depending on the solvent used. The reaction atmosphere may be an air atmosphere or an inert gas atmosphere. The reaction product can be purified by filtering off the precipitate of the inorganic salt as a by-product, dissolving it in a solvent such as chloroform, filtering if necessary, washing with pure water, and drying.

 Thus, the onium salt of the present invention can be produced relatively easily and at low cost. The vulcanization accelerator of the present invention comprises the above-mentioned onium salt alone or in a mixture with other vulcanization accelerators, but a sufficient effect can be obtained when used alone.

 The compound represented by the formula (II) among the above-mentioned onium salts of the formula (I) is a new compound. The product can be identified by analytical methods such as NMR, IR and elemental analysis.

The present invention also relates to a fluororubber composition for vulcanization comprising the above vulcanization accelerator, a polyol vulcanizable fluororubber and a polyol vulcanizer. This composition can effectively prevent scoring during storage and vulcanization, and does not reduce the vulcanization rate at high temperatures. In addition, the mechanical properties and compression set of the resulting vulcanizate are The effect of not having a bad influence is also exerted.

 The fluororubber may be a polyol vulcanizable one, and preferably has a methylene unit. In particular, an elastomeric copolymer containing a vinylidene fluoride (VdF) unit as a main constituent unit and one or more monomer units copolymerizable with VdF is preferable. The content of VdF units is 30 to 96 mol%, preferably 50 to 85 mol%.

 The monomer copolymerizable with VdF may or may not contain fluorine, and specific examples thereof include hexafluoropropylene (HFP), tetrafluoroethylene (TFE), and perfluoro (alkyl vinyl ether) (for example, Fluoromonomers such as perfluoro (methyl vinyl ether) (PMVE)); trifluoroethylene (CTFE), dichlorodifluoroethylene, trifluoroethylene, propylene, 1-hydrofluorene, propylene, and fluoro Fluoromonomers such as polyaryl ethers and fluoroalkylvinyl ethers; and non-fluorinated monomers such as ethylene (Et) and propylene (Pr). Preferred among these are HFP, TFE, PMVE, Et, Pr and the like.

Specific examples include VdFZHFP, VdFZHFP / TFE, VdF / HF P / Et, VdF / TFE / Pr, VdF PMVE, VdF / PMVE / TFE, VdF / TFEZPMVEZEt, etc. VdF / HFP (30 to 95Z70 to 5 mol% ratio, especially 50 to 85/50 to 15 mol% ratio) or VdFZ HFP / TFE (30 to 95/5 to 30 / (5 to 40 mol% ratio). If necessary, a structural unit for forming a crosslinking point containing bromine or iodine may be introduced. Examples of the monomer that provides such a crosslinking unit include CF ₂ = CFR f Br, CF ₂ = CF—O—R f I (R f contains 0 to 3 ether bonds. A fluorinated alkylene group having 1 to 20 carbon atoms. Or a compound having two or more bromine or iodine atoms as a chain transfer agent.

 The polyol vulcanizing agent is not particularly limited, and conventionally known polyol vulcanizing agents can be used. Examples thereof include aromatic polyols, aliphatic polyols, and mixtures thereof, and may further have a functional group other than a hydroxy group, for example, an amino group, an epoxy group, or a cyano group. Specific examples include, for example, bisphenol AF, bisphenol A, bisphenol 3, hydroquinone, and the like.

 The fluororubber composition for vulcanization of the present invention is characterized in that the vulcanization accelerator of the present invention comprises the above-mentioned onium salt, preferably the onium salt of the formula (I), as a vulcanization accelerator. If necessary, other vulcanization accelerators may be added in addition to the vulcanization accelerator of the present invention comprising the onium salt. Examples of such other vulcanization accelerators include ionic salts other than those having the above-mentioned phenolic compound ion as anion, such as benzyltriphenylphosphonium chloride (BTPPC) and benzyldiphenyldiethylaminophosphonium chloride. And tetraptylammonium bromide.

 In addition, additives used for vulcanization of fluororubber, such as vulcanization aids, fillers, processing aids, and surfactants, may be added as necessary.

 Examples of the vulcanization aid include oxides or hydroxides of alkali metals or alkaline earth metals such as calcium hydroxide, magnesium oxide, and lead oxide. Examples of the filler include carbon black, silica, talc, octasite, molecular sieve, alumina, and bengalara. Processing aids are usually added for the purpose of improving extrudability during extrusion molding or improving mold releasability. For example, various esters, ethers, alcohols, fatty acids, fatty acid salts, and amines are known. I have.

The mixing ratio of each of the above components is 100 parts by weight of fluoro rubber (hereinafter, "parts" ), The vulcanizing agent is 0.05 to 10 parts, preferably 0.5 to 5 parts, and the vulcanization accelerator of the present invention is 0.01 to 10 parts, preferably 0.1 to 10 parts. 3 parts, other vulcanization accelerator is 0 to 10 parts, preferably 0.01 to 10 parts, vulcanization aid is 0 to 30 parts, preferably 1 to 30 parts, filler is 0 To 50 parts, preferably 1 to 50 parts, the processing aid is 0 to 10 parts, preferably 0 to 5 parts, and the surfactant is 0 to 10 parts, preferably 0 to 5 parts.

 The vulcanizing composition of the present invention is prepared by kneading each component with a two-roll rubber kneader, a kneader, a Banbury mixer and the like at a temperature between room temperature and 15 and cooling if necessary. it can. According to the vulcanizing composition of the present invention, the occurrence of scorch during such kneading and during subsequent storage can be effectively prevented.

 Compression molding, transfer molding, extrusion molding, injection molding, etc. can be used as the polyol vulcanization molding method, but it is particularly suitable for mass production, but the occurrence of scorch has been a problem. It can be suitably applied to the injection molding method. Usually, it is necessary to heat and re-knead the vulcanizing composition stored before vulcanization, or to preheat it in injection molding, but in the vulcanizing composition of the present invention, the scorch during this time is required. Can be effectively prevented.

 The vulcanization temperature depends on the molding method, but is usually from 100 to 23Ολ, preferably from 130 to 210. A vulcanization time of 1 to 100 minutes and even 3 to 60 minutes is sufficient, and the molding pressure is 0.3 to 3 MPa.

One of the features of the vulcanizing composition of the present invention is that the vulcanizing time can be reduced. Usually, the vulcanization time becomes longer at the expense of the vulcanization rate at high temperature to prevent scorch, but when using the vulcanization accelerator of the present invention, the vulcanization rate at high temperature is maintained. As a result, the vulcanization time can be shortened. Further, if necessary, after the above-mentioned primary vulcanization, open vulcanization (secondary vulcanization) may be performed. Oven vulcanization is carried out at 130 to 300 ° C., preferably 150 to 250 ° C., for 0.5 to 48 hours, preferably 1 to 24 hours. The vulcanizate obtained by vulcanizing the fluororubber composition for vulcanization of the present invention has excellent mechanical properties such as compression set, tensile strength and elongation, and is suitable for use in the following products. it can.

Chemical industry

 (Seal material, for example, rubber ring, gasket, packing, etc.) Sealing of chemical and solvent storage tanks, transport pumps, transport pipes

 Oxygen cylinder, piping system seal

 Heat exchanger seals

 Measuring instrument seal

 Chemical and solvent containers

 Vacuum or vacuum dryer seal

 (Tubes, valves, bellows, etc.)

 Transportation of chemicals and solvents, piping system parts

 Control valves, stop valves, diaphragm valves, bellows for transporting chemicals and solvents

 (Lining)

 Chemical and solvent storage tanks

 Corrosion prevention of reactor

 (Other)

 Protective equipment such as safety gloves and safety shoes

Electric industry

 Seals and insulating materials for motors, boilers, transformers, etc.

Machine industry (Seal materials such as O-rings, packing, oil seals, etc.) Seals for hydraulic and lubricating machines

 Bearing seal

 Washing machine seals

 Seals such as vacuum pumps and cyclotrons

 Oil seals and valve stem seals for automobiles, ships, aircraft, etc. Seals for agricultural chemical spraying machines

 Plastic molding machine seal

 (Belts, etc.)

 Transport belt for steel

 Belt for automatic packaging machine

 (Other)

 Anti-vibration rubber for industrial machinery

 Flexible hose for oil and steam

Other technical fields

 City gas piping, gas appliance seals, diaphragms, control valves

 Vending machine solenoid valve seal

 Feed belt for dry type copier, seal material

 Next, the present invention will be described specifically with reference to Examples, but the present invention is not limited to only such Examples.

Production Example 1

(4) 5.9 g (50 mmol) of monocyanophenol is dissolved in 15 g of methanol, and 2,70 g (50 mmol) of sodium methoxide is added thereto, and benzyltriphenylphosphonium chloride (BTPPC) is prepared in advance. A solution of 19.44 g (50 mmol) dissolved in 20 g of methanol was added, and the mixture was reacted at room temperature under atmospheric pressure for 60 minutes. The obtained reaction mixture was filtered, the filtrate was evaporated, and further dried under vacuum at 40 ° C. for 24 hours. The solid obtained was dissolved in 5 Oml of porcelain form, washed three times with 5 Oml of pure water, dried over sodium sulfate, filtered, the filtrate was evaporated, and then dried under vacuum at 40 ° C for 24 hours. As a result, 19.7 g of a light brown transparent semi-solid product was obtained (yield: 72%).

 The melting point or glass transition temperature (T g) of the obtained product was measured by DSC, and the characteristic absorption and peak were examined by IR and NMR. Benzyl triphenylphosphonidium 4-cyanophenoxide (hereinafter referred to as ΓΒΤΡ) P4CP ”).

Glass transition temperature: _21 ° C

 IR analysis (KB r): cm- ^ S 057.3 (C-H based on aromatic ring); 2211 (CN); 1437.1 (aromatic ring); 1603.8, 148.1, 1112.7 and 842.5 (p-substituted aromatic ring)

IH- NMR analysis (in _{CDC 1 3):.. 5} (p pm) = 4 93 and 4.1 98 (benzyl methylene); 6. 83~7 83 (m, aromatic)

Production Example 2

 The reaction was carried out in the same manner as in Production Example 1 except that 9.92 g of 4-hydroxybenzophenone was used instead of 4-cyanophenol, to give a light brown transparent semi-solid benzyltriphenylphosphonidine 4-hydroxybenzophenone. 27.9 g of ilfenoxide (hereinafter referred to as “BTPP4HBP”) was synthesized and identified in the same manner as in Production Example 1.

Glass transition temperature: 2 ° C

IR analysis (KB r): cm- ¹ = 3056.3 (C-H based on aromatic ring); 1635.2 (aromatic ketone); 1437.2 (aromatic ring); 1603.8, 1487.1, 1160 8, 1112.7 and 842.5 (p— - NMR analysis (in _{CDC 1 3):.. (} 5 (p pm) = 4 99 and 5.00 (benzyl methylene); 6. 82~7 76 (m, aromatic) Preparation 3

 The reaction was carried out in the same manner as in Production Example 1 except that 19.20 g (50 mmol) of benzyldiphenyldiethylaminophosphonidimide was used in place of BTPPC. 19.62 g of rucetylaminophosphonium-4-cyanophenoxide (hereinafter, referred to as “Onio 4CP”) was synthesized and identified in the same manner as in Production Example 1.

Glass transition temperature: — 16.5 ° C

1 Analysis (8 1 :): cm "^ 3059 (C one based on aromatic ring H); 2 978. 6 and _{2918. 7 (C 2 H 5)} ; 2209. 4 (CN); 1 438. 2 ( aromatic 1586.5, 145.1, 1157.8, 1112 and 843.8 (p-substituted aromatic ring)

- NMR analysis (in _{CDC 1 3): δ (ppm} ) = 1. 05, 1. 07 4, 1. 097 (t, CH 3); 3. 25 1 back and forth _{(m, CH 2); 4.} 5 9 And 6.64 (benzylmethylene); 6.629 to 7.604 (m, Production Example 4

 The reaction was carried out in the same manner as in Production Example 1 except that 6.96 g (50 mmol) of 4-nitrophenol was used in place of 4-cyanophenol, and the reaction was carried out in the same manner as in Preparation Example 1. 20.5 g of ditrophenoxide (hereinafter referred to as “BTPP4NP”) was synthesized and identified in the same manner as in Production Example 1.

Glass transition temperature: 15 ° C

 IR analysis (KB r): 3056.8 (C—H based on aromatic ring)

1515.1 and 1332.4 (NO ₂ ); 146.5 (aromatic ring) 158.7, 14483. 9, 1161.1, 1108 and 851.9 (p-substituted aromatic rings)

- NMR analysis (in _{CDC 1 3):. <5} (ppm) = 4 86 and 4.908 (benzyl methylene); 6. 695~ 7. 921 (m , aromatic) Preparation 5

 The reaction was carried out in the same manner as in Production Example 1 except that 9.21 g (50 mmol) of 2,4-dinitrophenol was used instead of 4-cyanophenol, and yellow transparent semi-solid benzyltriphenylphosphonium was obtained. 25.5 g of 2,4-dinitrophenoxide (hereinafter referred to as “BTPP 24DNP”) was synthesized and identified in the same manner as in Production Example 1.

1 shaku analysis (1 ^ 81 :): cm- ^ S 056 ( based on the aromatic ring C- H); 1 598. 9, 1553. 1, 1324. 3 and 1255.5 (N_〇 _2); 1435.3 (Aromatic ring); 919.1 and 831.4 (1, 2, 4-substituted benzene)

- NMR analysis (in _{CDC 1 3):. Δ (} ppm) = 4 82 and 4.868 (benzyl methylene); 6. 473~ 7. 819 (m , aromatic); 8. 442 8.729 and 8 . 739 (2,4-dinitro-substituted aromatic ring)

Production Example 6

 The procedure of Preparation Example 1 was repeated except that 28.37 g (50 mmol) of bis [benzyldiphenylphosphorane-diyl] ammonium chloride (hereinafter referred to as “BDP I CJ”) was used instead of BTPPC. The reaction was performed to synthesize 32.4 g of green-brown semi-solid bis [benzyldiphenylphosphoranediyl] ammonium-14-cyanophenoxide (hereinafter referred to as “BDP I 4CP”). It was identified in the same manner.

Glass transition temperature: 16.5 in 11 Analysis (1 ^: 81 "): cm- ^ S 054.6 (C—H based on aromatic ring); 2205 (CN); 143.8 (aromatic ring); 1603.7, 14493, 1158, 1112.1 and 843. 4 (p- substituted aromatic ring) IH- NMR analysis (in _{CDC 1 3):. <5} (ppm) = 3. 758 and 3 8 (benzyl methylene); 6.547 to 7.624 (m, aromatic ring) Production Example 7

 The reaction was carried out in the same manner as in Production Example 1 except that 4.71 g (50 mmol) of phenol was used in place of 4-cyanophenol, and a yellow transparent semisolid benzyltriphenylphosphonium phenoxide (hereinafter referred to as ΓΒΤΡΡΡ) ] Was synthesized and identified in the same manner as in Production Example 1.

Melting point: 77.9

 11 Analysis (81 :): 3056.9 (C—H based on aromatic ring); 1436.3 (aromatic ring); 1604.3, 1590.1, 1497.4 and 755.3 (mono-substituted benzene)

.丄H- NMR analysis (in _{CDC 1 3):. <5} (p pm) = 4 888 and 4 936 (benzyl methylene); 6. 677~ 7. 692 (m , aromatic) Example 1

 A fluororubber composition for vulcanization of a polyol having the following formulation (shown in parts by weight) was prepared by kneading the mixture in a two-necked flask under ice cooling.

 (Prescription)

 VdFZHFP copolymer 100 parts

 (Vd F / HFP = 78/22 mol%, ML (1 + 10) 100 ° C = 7

1)

Bisphenol A 1.989 parts

BTPP 4CP (Production Example 1) 0.797 parts Magnesium oxide 3 parts Ribon Bon Black (MT-C 30) 30 parts Calcium hydroxide 6 parts

 The vulcanization characteristics (T10 and T90) of the obtained fluororubber composition for vulcanization at 150 and 180 ° C, respectively, were measured with a Keilastometer II (manufactured by JSR Corporation) (frequency 6 cpm, amplitude angle ± 3 degrees). T10 is the time (minutes) required to increase to 10% of the maximum torque, and T90 is the time (minutes) required to increase to 90% of the maximum torque. In addition, according to JIS K6300, the Mooney coach (T5: Time (minute) until Mooney viscosity rises by 5 points) at 145, the Monsanto M21 viscometer (Rotor-1L) The measurement was performed using a mold and a rotation speed of 2 ± 0.02 rpm. Table 1 shows the results. The amounts of the vulcanization accelerators in Tables 1 to 3 are shown in parts by weight based on 100 parts by weight of the fluororubber. Except where otherwise specified, primary vulcanization was performed at 170 x 15 minutes, and secondary vulcanization was performed at 230 ° C for 24 hours to form a sheet having a thickness of 2 mm and a sealing (P24). The obtained sheet is checked for its normal physical properties in accordance with JIS K6251, and the hardness (Hs) is checked in accordance with JIS K6253. It was measured. Table 1 shows the results.

Comparative Example 1

 8? ? Four ? Instead of 8? ? The vulcanization properties, mu-111 scorch, physical properties in normal state, hardness and compression set were measured in the same manner as in Example 1 except that 0.564 parts (: were used. The results are shown in Table 1.

Comparative Example 2

8? ? Four. ? Eight instead of eight? ? (0.564 parts and 41-Cyanphenol (hereinafter referred to as “4CP”)) Vulcanization characteristics, muny nice coach, normal physical properties, hardness and compression set distorted Was measured. Table 1 shows the results.

As is clear from Table 1, in Example 1, the vulcanization (T10) at 150 ° C was slower than that in Comparative Example 1, and the length of the mu-221 scorch (Τ5) at 145 was longer. In addition, in comparison with Comparative Example 2, the vulcanization (T10) at 150 ° C is slow, the muniche coach (T5) at 145T: is long, and the vulcanization (180 ° C) T90) is closer to Comparative Example 1 than to Comparative Example 2. These results indicate that the vulcanizing composition of the present invention effectively prevents scorch at low temperatures (150 ° C) due to its low vulcanization rate, while vulcanizing at high temperatures (180 ° C). Speeds up, This shows that the vulcanization time can be shortened. These properties are suitable for injection molding.

Examples 2 to 4

 The vulcanization characteristics, Mooney scorch, physical properties, hardness, and compression set were measured in the same manner as in Example 1 except that the amount of BTPP4CP was changed as shown in Table 2. Table 2 shows the results.

 Comparative Examples 3 to 5

 The vulcanization properties, Mooney scorch, physical properties in normal state, hardness and compression set were measured in the same manner as in Example 1 except that BTPPC was used in the amount shown in Table 2 instead of BTPP4CP. Table 2 shows the results.

 Table 2

(注 1 ) ：プレス加硫 180 °C X 15分間 表 2に示す結果は、 本発明の加硫促進剤を添加した場合、 その添加量を 変化させても 15 O :での加硫 （T10) が遅く、 145 :でのム一ニース コーチ （T5) が長いという特性が奏されることを示している。 しかも加 硫物の物性は維持されている。 また、 実施例 2〜4における 150°Cでの T 90が添加量によって大きく変化しており、 このことは本発明の加硫促進 剤の添加量を変化させることによって、 加硫特性を調節できることを示し ている。

(Note 1): Press vulcanization 180 ° C for 15 minutes The results shown in Table 2 show that when the vulcanization accelerator of the present invention was added, vulcanization with 15 O: (T10) even when the amount of addition was changed Is slow, and the characteristic coach (T5) at 145: is long. Moreover, the physical properties of the vulcanizate are maintained. In addition, T90 at 150 ° C in Examples 2 to 4 greatly changed depending on the amount of addition, which indicates that the vulcanization characteristics can be adjusted by changing the amount of the vulcanization accelerator of the present invention. Is shown.

Example 5

 The vulcanization characteristics, Mooney scorch, physical properties in normal state, hardness and compression set were measured in the same manner as in Example 1 except that 0.798 parts of BTPP4HBP synthesized in Production Example 2 was used instead of BTPP4CP. Table 3 shows the results. Example 6

 The same vulcanization properties, mu-scientific properties, normal physical properties, hardness and compression set as in Example 1 except that 0.677 parts of Onion 4 CP synthesized in Production Example 3 were used instead of BTPP 4 CP The strain was measured. Table 3 shows the results.

Comparative example 6.

 Vulcanization properties, Mooney scorch, normal physical properties in the same manner as in Example 6 except that 0.557 parts of benzyldiphenyldiethylaminophosphonium chloride (hereinafter referred to as “onio compound”) was used instead of ONIO 4 CP. The hardness, compression set and compression set were measured. Table 3 shows the results.

Example 7

 The vulcanization characteristics, natural coach, normal physical properties, hardness and compression set were measured in the same manner as in Example 1 except that 0.73 parts of BTPP4NP synthesized in Production Example 4 was used instead of BTPP 4CP. did. Table 3 shows the results.

Example 8 Vulcanization characteristics, Mooney scorch, physical properties in normal state, hardness and compression set were measured in the same manner as in Example 1 except that 0.778 parts of BTPP 24DNP synthesized in Production Example 5 was used instead of BTPP 4 CP. Table 3 shows the results.

Comparative Example 7

 Example 1 was repeated except that 0.564 parts of BTPPC and 1.09 parts of 2,4-dinitrophenol (24DNP) (in equimolar amounts with bisphenol AF (vulcanizing agent)) were used in place of BTPP4C. The vulcanization characteristics, mu-scorch, physical properties under normal conditions, hardness and compression set were measured in the same manner as in. Table 3 shows the results.

Comparative Example 8

 Vulcanization characteristics were the same as in Example 1 except that 0.267 parts (equivalent to the vulcanization accelerator of the present invention) of 2,4-dinitrophenol (24DNP) was used instead of BTPP4C. , Much Nice Coach, physical properties in normal state, hardness and compression set were measured. Table 3 shows the results.

Example 9

 In the same manner as in Example 1 except that 0.99 3 parts of BDP14CP synthesized in Production Example 6 was used instead of BTPP4CP, vulcanization characteristics, The compression set was measured. Table 3 shows the results.

Example 10

 The vulcanization characteristics, Mooney scorch, physical properties in normal state, hardness and compression set were measured in the same manner as in Example 1 except that 0.647 parts of BT PPP synthesized in Production Example 7 was used instead of BTPP4CP. Table 3 shows the results.

Comparative Example 9

Vulcanization characteristics, green coach, normal physical properties, hardness and compression set were measured in the same manner as in Comparative Example 1 except that 0.873 parts of 80-10 was used instead of BTPP4C. Table 3 shows the results. Comparative Examples 10 to 11

Further, vulcanization characteristics, Mooney scorch, physical properties in normal state, hardness and compression set were obtained in the same manner as in Comparative Example 1 except that 0.136 parts (Comparative Example 10) and 0.557 parts (Comparative Example 11) of phenol were added. It was measured. Table 3 shows the results.

Table 3

The results of each example in Table 3 indicate that the vulcanization accelerator of the present invention can reduce the vulcanization rate (T10) at low temperatures and increase the vulcanization rate (T90) at high temperatures. Indicates that it can be done. Furthermore, in Comparative Example 7, in which 2,4-dinitrophenol (24DNP) was used in an equimolar amount with the vulcanizing agent, the vulcanization hardly proceeded at low temperatures and no scorch was generated, but the vulcanization took a long time even at high temperatures. Resulting in. In Comparative Example 8 in which 2,4-dinitrophenol (24DNP) was used in an equimolar amount instead of the vulcanization accelerator of the present invention, vulcanization (T10) occurred relatively quickly at low temperature (at 150). However, at a high temperature (180), the vulcanization rate was lower than that in Example 8.

 In addition, the effect of preventing scorch cannot be obtained by simply adding phenol (Comparative Examples 10 to L1), but by using a complex of BTPPC and phenol (BTPPP) (Example 9). ) It can be seen that excellent effects are created. Industrial applicability

 When the vulcanization accelerator of the present invention is used, preservation during vulcanization and vulcanization before the kneading of the fluororubber composition for vulcanization and pretreatment of vulcanization (pre-heat treatment in re-kneading and injection molding) Vulcanizing fluororubber with optimal vulcanization characteristics for injection molding, because it can effectively prevent the occurrence of scorch at times, and at the time of the original vulcanization it has a high vulcanization rate and can shorten the vulcanization time. A composition can be provided. The resulting vulcanizates have excellent mechanical properties, especially compression set.

Claims

Scope of word blue 1. A vulcanization accelerator consisting of an onium salt composed of a cation and an unsubstituted or substituted phenol compound anion.  2. The onium salt is of the formula (I):  X  A +

 (In the formula, A + is a cation of the onium salt, X is a functional substituent that makes the pka of the phenol compound composing the anion of the onium salt 3.2-12.4, and n is an integer of 0 to 5.) 2. The vulcanization accelerator according to claim 1, which is an onium salt shown.  3. The cation of claim 1, wherein the cation of the onium salt is a cation of phosphonium, aminophosphonium, ammonium, 8-benzyl-1,8-diazabicyclo [5.4.0] undesenium, sulfonium, or imminium. Or the vulcanization accelerator according to item 2.  4. The vulcanization accelerator according to claim 2, wherein X in the formula (I) is a nitro group, a cyano group, a benzoyl group, or a halogen atom.  5. The above-mentioned onium salt is benzyltriphenylphosphonium-41-cyanophenoxide, benzyltriphenylphosphonium 4-nitrophenoxide, benzyltriphenylphosphonium 4-benzoylphenoxide, benzyltriphenylphosphonium. 2,4-dinitrophenoxide, benzyltriphenylphosphoniumchlorophenoxide, benzyltriphenylphosphoniumphenoxide and benzyltriphenylphosphonium selected from the group consisting of 2,4-dichlorophenoxide The vulcanization accelerator according to any one of claims 1 to 4, which is at least one kind. 6. Polyol vulcanizable fluoro rubber, polyol vulcanizing agent and claims 6. A vulcanizing fluororubber composition comprising the vulcanization accelerator according to any one of items 1 to 5.  7. The composition according to claim 6, wherein the fluororubber contains a methylene unit. 8. The composition according to claim 7, wherein the fluororubber is a copolymer having a molar ratio of vinylidene fluoride to hexafluoropropylene of 85 Zl5 to 50/50.  9. The composition according to claim 7, wherein the fluororubber is a copolymer of vinylidene fluoride, hexafluoropropylpyrene, and another copolymerizable monomer.  10. The composition according to any one of claims 6 to 9, wherein the polyol vulcanizing agent and the vulcanization accelerator are mixed in advance.  11. Formula (II):

(Wherein X ¹ is a nitro group, a cyano group or a benzoyl group, and n is an integer of 0 to 5).