JPH03220247A - Vulcanizing composition and packing material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a packing material having excellent properties and a vulcanizing composition providing the packing material.

2. Conventional technology 2. Conventionally, dichlorodifluoromethane (Freon-12) has been used as a refrigerant for car coolers, and the packing material used there needs to be heat resistant due to the operating environment of car coolers. Hexafluoropropylene/vinylidene fluoride (I(FP/VdF))-based fluororubber is used for this reason.However, as CFC-12 is becoming unusable due to problems with ozone layer depletion, CFC-12 is being used as an alternative refrigerant. .1. t,2-tetrafluoroethane (Freon-134a) is being considered.

However, when Freon-1, 34a is used as a refrigerant, the conventional packing material (FP/VdF-based fluororubber) has a large volume change (also causes cracks, blisters, etc.). It is desired to develop a new packing material that is resistant to a mixture of Freon-134a and glycol-based refrigeration oil.

[Problems to be Solved by the Invention] An object of the present invention is to exhibit resistance to a mixture of Freon-134a as a refrigerant and glycol-based refrigeration oil as a lubricating oil, The purpose of the present invention is to provide a relatively inexpensive packing material that exhibits long-term resistance to harsh operating environments with severe thermal changes.

“A means to solve problems.

The object of the present invention is to produce a hydrocarbon-based elastomer that has comb elasticity at a temperature in the range of -60 to 230°C and is capable of crosslinking.
20~so heavy If, vinylitine fluoride copolymer 80~
This is achieved by a vulcanizing composition consisting of 20 parts by weight and 1 part by 05 to 5 parts by weight of crosslinking agent.

The present invention provides a packing material obtained by vulcanizing the vulcanizing composition.

The hydrocarbon elastomer is a polymer having comb elasticity at a temperature in the range of -60 to 230°C. Examples of the hydrocarbon elastomer include ethylene/propylene copolymer, isobutylene/isoprene copolymer, acrylonitrile/butadiene copolymer, chloroprene polymer, and chlorosulfonated polyethylene. The hydrocarbon elastomer may be an elastomer that exhibits a weight change of 10% or less after being immersed in Freon 134a at 50'C for two weeks, and moreover, an elastomer that has a hardness/yaw value in the range of 40 to 95. is preferred.

In the ethylene/propylene copolymer, the molar ratio of ethylene and propylene is preferably from 50/50 to 70/30. Ethylene/propylene copolymers contain, in addition to ethylene and propylene, small amounts of monomers as a third component, such as cyclopentanene, methylenenorformane, ethylenenorformane, 1,4-hexadiene, It may contain a non-conjugated diene or triene such as a linear triene. Examples of the ethylene/propylene combination include commercially available EPM and EPTcomb containing EPDM.

In the isobutylene/isoprene copolymer, the isoprene content is 2 mol% or less and may be halogenated with chlorine, bromine, etc.

In the acrylonitrile/butanene copolymer, the total amount of acrylonitrile is preferably 30 mol% or more, and may be hydrogenated.

Examples of chlorosulfonated polyethylene include those having a chlorine content of 25 to 43% by weight and a sulfur content of 10 to 1.4% by weight.

Vinyritine heptafluoride (vaF)-based lia is a copolymer obtained by polymerizing vinylidene fluoride with a co'11 polymer, and is not particularly limited. Examples of VdF-based copolymers include tetrafluorox tile 7 (TFE).
/VdF copolymer, TFE/VdF/chlorotrifluoroethylene (CTFE) copolymer, trifluoroethylene (TrFE)/vdF copolymer, VdF/hexafluoropropylene (HFP) copolymer and VdF/TFE
/HFP copolymers, etc., and may also contain ethylene, propylene, self-fluorine/elementary olefins, etc.

In the TFE/VdF copolymer, the molar ratio of TFE and VdF is preferably 5/95 to 50/30. TFE/VdF copolymer has a melting point of 100 to 230
It is fine as long as it is at ℃. As an example of TFE/VdF copolymer, the molar ratio of TFE and VdF is 10/90 to 30/
Preferably, those having a melting point of 70° C. or less or a low melting point of about 150° C. or less are used.

~'dF/HFP copolymer and VdF/T F E/H
In the FP copolymer, those containing iodine or iodine in the molecule are preferable from the viewpoint of crosslinking properties.

Crosslinking agents are usually organic peroxides. Organic peroxides include commonly known ones, such as 1,1-bis(t-butylperoxy)-3,5,5-trimethylchlorohexane, 2,5-trimethylhexane 25-dihydroperoxide, and t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α, α°
-bis(1-butylperoxy)-p-diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2.5-7methyl-2,5-di(1-butyl) peroxy)-hequin-3, hexyl peroxide, t-butylperoxybenzene, 2.
5-dimethyl-2,5-cy(pensoylperoxy)hexane, t-butylperoxymaleic acid, t-butylbaroxyisobutylcarboxylate, etc., and the decomposition temperature is suitable for the crosslinking conditions. All you have to do is choose the one that has .

The amount of crosslinking agent is 0.5 to 5 parts by weight per 100 parts by weight of the polymer.
This is a heavy mold section.

The composition of the present invention may contain a crosslinking auxiliary reinforcing agent. As a crosslinking auxiliary agent, a triallyl compound (for example, triallyl isocyanate (TAIO), triallyl sheasate), Examples include diallyl compounds (eg, /allyl phthalate). Examples of reinforcing agents include carbon black and/or lime.

In the present invention, the blending ratio of the hydrocarbon elastomer and the VdF copolymer is 20 parts by weight/80 parts by weight to 80 parts by weight.
The weight part is 720 parts by weight. If the amount of the hydrocarbon elastomer is more than 80 parts by weight, the heat resistance will be poor. VdF
When the amount of the copolymer is more than 80 parts by weight, VdF
Since the copolymer is not a comb elastic material, the compressive strain characteristics required as a 7-ru material are large and the sealing performance is poor.

The composition of the present invention is produced by heating the VdF copolymer using a Pan Bali mixer knee gun or a hot roll until it reaches the melting point.
This can be done by making a blend of a hydrocarbon elastomer and a VdF copolymer, and adding and mixing a crosslinking agent, a crosslinking aid, and a skin reinforcing agent while cooling (to prevent scorch). A packing material can be obtained by vulcanizing a vulcanizing composition. Vulcanization can be carried out by press molding under appropriate conditions and, if necessary, further crosslinking in an oven. In vulcanization, the composition may be heated at 100 to 200°C, preferably 140 to 180°C, for 30 seconds to 2 hours, preferably 5 minutes to 30 minutes.

[Effects of the Invention] The vulcanizing composition of the present invention is a packing material that has good resistance to a mixture of Freon-134a and glycol-based refrigeration oil, has heat resistance, and is relatively low cost. give.

The vulcanizing composition of the present invention provides a packing material that can also be used as a sealing material for only Freon-134a.

[Preferred Embodiments of the Invention] The present invention will be specifically described below with reference to Examples and Comparative Examples.

Example i E I) M com (manufactured by Mitsui Ishiura Chemical Co., Ltd. No. 0O
45) and TFE/VdF (molar ratio 20:80
) The copolymers were mixed at a weight ratio of 11 without heating in a kneader. Next, to 1 part by weight of this blend, 1 part by weight of triallyl isocyanate (TAIC) and 0.0 parts of peroxide (Perphthyl Z manufactured by NOF Corporation) were added.
A composition for vulcanization was prepared by mixing 1 part of C.75 and 5 parts of Carphone (NUST 116 manufactured by Tokai Electrode Manufacturing Co., Ltd.) as a reinforcing agent while cooling.

This composition was dispensed with a roll, preformed, and press molded at 160°C for 10 minutes to form a sheet (dimensions).

50 x 125 x 2 mm) was created.

An immersion test in which the above sheet was immersed in a mixture of Freon 134a and refrigeration oil (glycol-based, 5RGTI manufactured by Kyodo Sekiyu Co., Ltd.) (Freon-134a: Refrigeration oil-3 = 2 (weight ratio)) at 75°C for 24 hours. I did this. The results of the immersion test are shown below.

Weight change (%) Volume change (%) Appearance 25.9
-” 5.7 No change Comparative Example 1 RFP/VdF copolymer (DAIEL G-801 manufactured by Taikin Industries, Ltd.) and TFE/VdF as a blend
(Molar ratio 20:80) The same procedure as in Example 1 was used for the pond using the copolymer at a weight ratio of 103. The results of the immersion test are shown below.

Weight change Volume change Appearance +17.1% Weight 43.2% Blister occurrence example 1
From the results of the immersion test in Comparative Example 1, it can be seen that the composition of the present invention provides a packing material with less change in weight, volume, and appearance at high temperatures.

Example 2 Hydrogenated acrylonitrile/butadiene copolymer (HNB
R) (Japan Zeo 7 and Zetpol 2010 manufactured by Sarasha)
and HFP/VdF copolymer (Daiel G-801, manufactured by Daikin Industries, Ltd.) at a volume ratio of 70:30, without heating in a kneader. Next, to 100 parts by weight of this blend, 40 parts by weight of Carphone (Nose l-116 manufactured by Tokai Electrode Manufacturing Co., Ltd.), 1 part by weight of ZnO, 1 part by weight of stearic acid, and triallylison aslate (T) were added as reinforcing agents.
A [C] 4 parts by weight, 3 parts by weight of peroxide (Percmill D, manufactured by NOF Corporation) and 0.5 parts by weight of anti-aging agent (Irganox 1010, manufactured by Chihakaiki Hinagami) were mixed while cooling, and for vulcanization. A composition was prepared.

The maximum viscosity (νma
x), minimum viscosity (vm1n), induction time (T, .), and appropriate vulcanization time (T, .) were measured to evaluate the crosslinking properties of the composition. 100% tensile stress (M,,,), tensile strength at break (T8), elongation at break (EB) and hardness (Hs) of the sample obtained by vulcanizing the composition at 160 ° C. for 20 minutes was measured. Mlo after heat aging this sample at 150°C for 72 hours or 170°C for 72 hours. , TB, EB and Hs were measured. The results are shown in Table 1.

Comparative Example 2) The same procedure as in Example 2 was repeated except that NBR was used alone in place of the blend of FP/VdF copolymer (with NBR). is 1
The test was carried out at 60°C for 40 minutes. The results are shown in Table 1.

The results of the heat aging tests of Example 2 and Comparative Example 2 show that the vulcanizate obtained from the composition of the present invention has excellent heat resistance.

Actual Example 3 Blend of ethylene/propylene copolymer (EPR) (EPT 0045 manufactured by Mitsui Petrochemicals Co., Ltd.) and HFP/VdF copolymer (G-801) (volume ratio 50.50)
) 100 parts by weight of the components shown in Table 2 were mixed to prepare a vulcanizing composition.

The physical properties of the sample obtained by vulcanizing the composition were measured. The results are shown in Table 2.

Example 4 A vulcanizing composition was prepared from the ingredients shown in Table 2.

EPR,! :G-801 volume ratio was 30 to 0. Table 2 shows the physical properties of the samples obtained by vulcanizing the compositions.

Comparative examples 3 and 4 A vulcanizing composition was prepared from the ingredients shown in Table 2.

Only EPR (Comparative Example 3) and G-80 as polymers
Table 2 shows the physical properties of samples obtained by oxidizing 7 compositions using only No. 1 (Comparative Example 4).

Test Examples The vulcanizates obtained in Examples 2 to 4 and Comparative Examples 2 to 4 were
A mixture of 1 part by weight of refrigeration oil (polyalkylene glycol) and 1.0 part by weight of Floneau 134a was heated to a pressure of 17 to 2 parts by weight.
0 kg/cm', and soaked for 24 hours at a temperature of 69-74°C. Weight changes and volume changes due to immersion were measured. Figure 1 shows the results of the weight change (△W), and the volume change (△V)
) The results are shown in Figure 2.

As can be seen from FIGS. 1 and 2, the vulcanizate of the present invention has expected values (dashed line) for both weight change and volume change.
has a value smaller than .

[Brief explanation of drawings]

Figure 1 is a graph showing the weight change that occurs when a vulcanizate is immersed in a refrigeration oil/Freon-134a mixture, and Figure 2 is a graph showing the weight change that occurs when a vulcanizate is immersed in a refrigeration oil/Freon-134a mixture. It is a graph showing the volume change that occurs.

Claims (1)

[Claims] 1. 20 to 80 parts by weight of a hydrocarbon elastomer that can be crosslinked and has rubber elasticity at a temperature in the -60 to +230°C range, 80 to 20 parts by weight of a vinylidene fluoride copolymer, and 0 parts by weight of a crosslinking agent. .5 to 5 parts by weight of a vulcanizing composition. 2. A packing material obtained by vulcanizing the vulcanizing composition according to claim 1.