JP2000281856A - Crosslinkable elastic copolymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition capable of providing a vulcanized material having excellent polyol vulcanizing properties, heat resistance and oil resistance by making the composition include a specific elastic copolymer, a specified compound. an organic polyhydroxy compound, a metal oxide (hydroxide) and an amine compound. SOLUTION: This composition comprises (A) an elastomer copolymer containing 35-65 mol% of a polymerization unit based on tetrafluoroethylene, 20-50 mol% of a polymerization unit based on propylene and 0.5-15 mol% of a polymerization unit based on vinylidene fluoride, (B) one or more of an organic quaternary ammonium hydroxide of the formula R1R2R3R4NOH (R1 to R4 are each a 1-20C monofunctional hydrocarbon group) (e.g. tetrabutylammonium hydroxide, etc.) and a compound of the formula (R5 is a 1-20C monofunctional hydrocarbon group; n is 3-5), (C) one or more organic polyhydroxy compounds (e.g. biphenol A, etc.), (D) one or more selected from a metal oxide and a metal hydroxide and (E) an amine compound (e.g. 1,8- diazabicyclo[5.4.0]undeca-7-ene, etc.) except the compound of the formula.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinkable elastic copolymer composition having good vulcanizability of a polyol and obtaining a vulcanizate having good heat resistance and oil resistance.

[0002]

2. Description of the Related Art When an organic polyhydroxy compound is used as a vulcanizing agent, an elastic copolymer obtained by copolymerizing vinylidene fluoride (hereinafter referred to as "VdF") exhibits good mold releasability and excellent mold release properties. It is known to provide vulcanizates having heat resistance, oil resistance and compression set. The vulcanized product of this fluorinated elastic copolymer is suitably used for automobile parts such as oil seals, but with the improvement of the performance of engine oils, it has been found that the vulcanizates of engine oils containing a large amount of amine-based additives are Durability is an important issue.

[0003] In particular, a copolymer having a large number of polymerized units based on VdF, for example, hexafluoropropylene (hereinafter referred to as HF)
P) -VdF-based elastic copolymer, HFP-VdF-
The vulcanized product of the composition containing the tetrafluoroethylene (hereinafter, referred to as TFE) -based elastic copolymer has a problem that the degree of deterioration due to the reaction of the amine-based additive at the site of the polymerized unit based on VdF is large. .

On the other hand, copolymers having a low content of polymerized units based on VdF, for example, TFE-propylene-V
The vulcanized product of the composition containing the dF elastic copolymer has excellent engine oil resistance. JP-A-6-157858 states that
By using an organic quaternary ammonium hydrogen sulfate as a vulcanization accelerator, a favorable vulcanizate can be obtained even with a TFE-propylene-VdF elastic copolymer having a content of polymerized units based on VdF as small as 4 mol%. It is disclosed.

However, as seen in the embodiment, V
The vulcanization rate of the TFE-propylene-VdF elastic copolymer having a content of polymerized units based on dF of 4 mol% is lower than that of the TFE-propylene-VdF elastic copolymer as large as 10 mol% or more. ing. In fact, if a relatively large amount of organic quaternary ammonium hydrogen sulfate is added to increase the vulcanization rate, the heat resistance and oil resistance of the vulcanized product may be reduced.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to provide Vd
A crosslinkable elastic copolymer which contains a TFE-propylene-VdF-based elastic copolymer having a low content of polymerized units based on F, has good polyol vulcanizability, and gives a vulcanizate having excellent heat resistance and oil resistance. It is to provide a composition.

[0007]

Means for Solving the Problems The present invention is the following invention. (A) an elastic copolymer containing 35 to 65 mol% of polymerized units based on TFE, 20 to 50 mol% of polymerized units based on propylene, and 0.5 to 15 mol% of polymerized units based on VdF, (B) General formula R ¹ R ² R ³ R ⁴ NOH
(R ^{1 to} R ⁴ are the same or different monovalent hydrocarbon groups having 1 to 20 carbon atoms.) An organic quaternary ammonium hydroxide represented by the following formula 1 (where R ⁵ is 1 to 20 carbon atoms) Of 1
(C) organic polyhydroxy compound and one or more selected from organic polyhydroxy compounds and derivatives thereof, (D) metal oxide and One or more selected from metal hydroxides, and (E) an amine compound excluding the compound represented by Formula 1,
A crosslinkable elastic copolymer composition comprising:

[0008]

Embedded image

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The Mooney viscosity M, which is an index of the molecular weight of the elastic copolymer (A) in the composition of the present invention, is used.
L _{1 + 10} (121 ° C.) is not particularly limited, but is preferably in the range of 5 to 150, and particularly preferably in the range of 10 to 100, since a usual kneading operation is performed during the production of the composition.

When the ratio of polymerized units based on VdF is 0.5 to
15 mol%, preferably 0.5 to 10 mol% of the component (A) can give a vulcanizate having extremely good engine oil resistance. Component (A) having a proportion of polymerized units based on TFE of 35 to 65 mol%, preferably 45 to 65 mol%, can give a vulcanizate having good heat resistance and chemical resistance. Component (A) having a proportion of polymerized units based on propylene of 20 to 50 mol%, preferably 35 to 50 mol%, can give a vulcanizate having good oil resistance.

The component (A) may or may not contain an unsaturated bond as an easily vulcanizable site in the copolymer. By simply heat-treating the component (A) or heat-treating in the presence of a basic or acidic substance,
HF can be removed from polymerized units based on VdF to introduce carbon-carbon unsaturated bonds into the copolymer. An unsaturated bond can be similarly introduced by treating the aqueous dispersion of the component (A) obtained by polymerization with a basic substance such as potassium hydroxide.

The amount of unsaturated bonds to be introduced is preferably about 1 to 50 mol% of the polymerized units based on VdF. If it is less than this range, the effect of improving vulcanizability is small, and if it exceeds this range, the properties of the obtained vulcanizate may be reduced.

For the production of the component (A), various polymerization systems such as bulk polymerization, suspension polymerization, emulsion polymerization, and solution polymerization can be adopted.
A catalyst polymerization method using a radical initiator, an ionizing radiation polymerization method, a redox polymerization method, or the like can be appropriately employed.

The component (B) acting as a vulcanization accelerator includes:
Organic quaternary ammonium hydroxide represented by the general formula R ¹ R ² R ³ R ⁴ NOH (R ^{1 to} R ⁴ are the same or different monovalent hydrocarbon groups having 1 to 20 carbon atoms) or formula 1 ( Where R ⁵
Is a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms,
n is an integer of 3 to 5). The component (B) is much more active than the organic quaternary ammonium hydrogensulfate, and when the component (B) is used, the TFE-propylene-VdF-based fluorinated elastic copolymer having a small content of polymerized units based on VdF is also used. It can give good vulcanizates.

Examples of the component (B) include the following. Each of these compounds may be used alone,
Two or more kinds may be used in combination. Tetrabutylammonium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, trioctylmethylammonium hydroxide, tridodecylmethylammonium hydroxide, benzyltrimethylammonium hydroxide, 8-benzyl-1,8-diazabicyclo [5 .4.0] Undeca
7-enium, 5-benzyl-1,5-diazabicyclo [4.3.0] non-5-enium hydroxide, and the like.

The amount of component (B) used is 100 parts of component (A).
It is preferably 0.1 to 10 parts by weight per part by weight, particularly preferably 0.1 to 10 parts by weight.
1-3 parts by weight are preferred. If the amount is less than 0.1 part by weight, it is difficult to obtain sufficient vulcanization density and vulcanization physical properties. . Usually, the organic quaternary ammonium hydroxide is commercially available as an aqueous or alcoholic solution and is used in that form.

Preferred examples of the organic polyhydroxy compound of the component (C) acting as a vulcanizing agent include the following. 2,2-bis (4-hydroxyphenyl) propane [abbreviation: bisphenol A], 2,2-bis (4-
(Hydroxyphenyl) perfluoropropane [abbreviation: bisphenol AF], 1,3,5-trihydroxybenzene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 4,4′-dihydroxy Biphenyl, catechol,
p, p'-dihydroxystilbene, 2,6-dihydroxyanthracene, hydroquinone, 2,2-bis (4-
Hydroxyphenyl) butane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenylketone, tris (4-hydroxyphenyl) methane,
2,2,3,3,4,4-hexafluoropentane-
1,5-diol, polyethylene glycol, ethylene glycol and the like.

As the derivative of the organic polyhydroxy compound as the component (C) acting as a vulcanizing agent, a salt of an alkali metal or a salt of an alkaline earth metal of the organic polyhydroxy compound can be preferably exemplified.

As the component (C), an organic polyhydroxy compound and a derivative thereof may be used alone.
Two or more kinds may be used in combination. This amount is based on (A) component 10
0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 0 parts by weight. If the amount is too small, it is difficult to select a sufficient crosslinking density, and if the amount is too large, the effect does not change.

As the metal oxide or metal hydroxide of the component (D) acting as an acid acceptor, oxides of divalent metals such as magnesium, calcium, lead and zinc or water of these divalent metals can be used. Oxides and lithium hydroxide are exemplified. The amount used is 1 per 100 parts by weight of the component (A).
It is preferably from 50 to 50 parts by weight, particularly preferably from 2 to 30 parts by weight. These may be used in combination of two or more.

(E) used for improving the vulcanization rate
As the amine compound of the component, 1,8-diazabicyclo [5.4.0] undec-7-ene, 1,5-diazabicyclo [4.3.0] non-5-ene, 6-dibutylamino-1, 8-diazabicyclo [5.4.0] undec-7-ene, triethylamine, tributylamine and the like. This amount is preferably 0.01 to 3 parts by weight, particularly preferably 0.05 to 1 part by weight, per 100 parts by weight of the component (A). These may be used in combination of two or more.

In the composition of the present invention, reinforcing agents such as carbon black, fine silica, clay and talc, other fillers, pigments, antioxidants, stabilizers, processing aids and the like which are usually used in the production of rubber, An internal release agent or the like may be added and blended.

In producing the composition of the present invention, (A)
It is desirable that the components, (B) component, (C) component, (D) component, (E) component and other additives be mixed sufficiently uniformly as required. Further, the component (B) and the component (C) may be mixed in advance and used.

This mixing is carried out by a conventionally used kneading roll, kneader, Banbury mixer, extruder or the like. The working conditions at the time of mixing are not particularly limited, but the kneaded mixture is usually kneaded at a temperature of about 30 to 130 ° C. for about 1 to 60 minutes, so that the added compound can be dispersed in the elastic copolymer. Further, these additive compounds can be appropriately dissolved and dispersed in a solvent and mixed as a suspension solution.

Further, so-called wet mixing in which the mixing is performed in the medium from the beginning can also be performed. In this case, a solution-type composition can be obtained by using a mixer such as a roll, a ball mill, and a homogenizer. Further, by mixing the component (B) with the aqueous dispersion of the component (A) obtained by polymerization, the component (B) can be more effectively dispersed. In addition, it is desirable to select the optimal operating conditions for mixing according to the type and purpose of the raw materials and the compound used.

The composition of the present invention can be formed into a sheet, pipe, rod, tube, angle, or the like by a continuous molding method such as extrusion molding, transfer molding, roll coating, brushing, and impregnation in addition to mold molding and injection molding. , Channel, tabi,
It can be formed into a molded product such as a coated plate. In addition, it can be formed into a deformed product or a specially formed product such as a sponge-like rubber by any of various other forming methods. The composition of the present invention thus formed is vulcanized by a vulcanization operation as described below.

Thus, a rubber product as a vulcanized product is obtained from the composition of the present invention. The operation of vulcanizing the composition of the present invention may employ an operation conventionally used conventionally. The vulcanization conditions are desirably determined by selecting the optimum conditions according to the composition, molding conditions, and the like. The vulcanization temperature is usually 100 to 400
° C, preferably about 150 to 200 ° C, and the vulcanization time is about 30 seconds to several hours. The obtained vulcanized product may be subjected to secondary vulcanization. Physical properties may be improved by secondary vulcanization. The secondary vulcanization conditions are not particularly limited,
It is appropriately selected according to the shape and size of the molded product.
0-250 ° C, preferably 180-230 ° C, 2-2
It is about 5 hours.

[0028]

TFE with a low content of polymerized units based on VdF
In the propylene-VdF-based elastic copolymer, the polyol vulcanization proceeds at a favorable vulcanization rate by using a specific organic quaternary ammonium hydroxide and an amine compound.
Further, the obtained vulcanized product has excellent heat resistance and oil resistance due to a small content of polymerized units based on VdF.

[0029]

EXAMPLES Examples 1 to 7 show Examples and Examples 8 to 11 show Comparative Examples. Materials mixed with the compositions (parts by weight) shown in Tables 1 and 2 were uniformly mixed with two rolls to obtain a crosslinkable elastic copolymer composition. This composition, with oscillating disk rheometer (manufactured by Toyo Seiki), vulcanization characteristics, i.e., 170 ° C., at 24 minutes, the minimum torque (M _L), Maximum torque (M _H) and the maximum torque Value of 90
The time t _c (90) until reaching the% torque value was measured. The composition was press-vulcanized at 170 ° C. for 20 minutes, and then subjected to secondary vulcanization at 230 ° C. for 24 hours in an oven. In Example 10, a vulcanized sheet was not obtained even after press vulcanization at 170 ° C. for 20 minutes.

According to JIS-K6301, the obtained vulcanized product was subjected to normal physical properties, compression set (200 ° C., 70 hours), heat resistance (230 ° C., 70 hours), and oil resistance (sample was 175 ° C. in oil). , 70 hours immersion). For the measurement of oil resistance, an SH class engine oil (Castle Motor Oil Clean SH, manufactured by Toyota Motor Corporation) was used. The results are shown in Tables 1 and 2.

Table 3 shows the abbreviations of Tables 1 and 2. The elastic copolymers used were obtained by an emulsion polymerization method, and the content ratio (molar ratio) of polymerized units based on the respective monomers and Mooney viscosity ML _{1 + 10} (121 ° C.) are shown in Table 3.
Shown in The composition of the polymerized unit based on each monomer of the component (A) was determined by ¹⁹ F-NMR and ¹ H-NMR. The unsaturated bond in the elastic copolymer 5 obtained by heat-treating the elastic copolymer 4 at 290 ° C. for 1 hour has a wave number of 312 by infrared analysis.
0cm ^-1, presence than the absorption of 1722cm ^-1 was observed.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

EFFECT OF THE INVENTION T having a small content of polymerized units based on VdF
The composition containing the FE-propylene-VdF-based elastic copolymer exhibits good polyol vulcanizability, and gives a vulcanizate excellent in heat resistance and oil resistance. Furthermore, the vulcanized product has various excellent vulcanized properties, such as automotive radiators, O-rings around engines, gaskets, sealing materials, diaphragms, tubes, hoses, and similar parts in food plants and chemical plants. It is extremely useful for a wide range of applications such as

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08K 5/3462 C08K 5/3462 C08L 23/10 C08L 23/10 F-term (Reference) 4J002 BD151 CH022 DE078 DE088 DE108 DE158 EC047 EC077 EJ017 EJ037 EJ047 EJ057 EJ067 EJ077 EN029 EN136 EU136 EU139 EV227 FD010 FD142 FD147

Claims (3)

[Claims] (A) 35-65 mol% of a polymerization unit based on tetrafluoroethylene, 20-50 mol% of a polymerization unit based on propylene, and 0.5-15 mol% of a polymerization unit based on vinylidene fluoride. (B) represented by the general formula R ¹ R ² R ³ R ⁴ NOH (R ^{1 to} R ⁴ are the same or different monovalent hydrocarbon groups having 1 to 20 carbon atoms) Organic quaternary ammonium hydroxide and a compound represented by the following formula 1 (where R ⁵ is a monovalent hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 3 to 5). (C) one or more selected from organic polyhydroxy compounds and derivatives thereof, (D) one or more selected from metal oxides and metal hydroxides, and (E) a compound represented by Formula 1. Excluding amine compounds. The crosslinkable elastic copolymer composition. Embedded image 2. The crosslinkable elastic copolymer composition according to claim 1, wherein the component (E) is a tertiary amine excluding the compound represented by the formula 1. 3. The crosslinkable elastic copolymer composition according to claim 1, wherein the component (E) is 1,8-diazabicyclo [5.4.0] undec-7-ene.