JPH0730214B2 - Liquid composition for sealing - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid composition for sealing, which is applied to a seam of a can body of an aerosol product and dried to form a rubber-like solid sealing material, which is used for sealing the can body. It is about.

[0002]

2. Description of the Related Art Liquid compositions for sealing, which are applied to the seams of can bodies of aerosol products, are chloroprene elastomer (CR) vulcanizing agents, vulcanization accelerators, fillers, plasticizers and antioxidants. It is known that the above various additives are mixed and dissolved in a solvent. This liquid composition for sealing has a high physical strength because CR is crystalline, and it is relatively easy to adjust the viscosity of the composition by lowering the viscosity by shattering, so that it has been widely used until now. It had been.

However, in the above liquid composition, free chlorine of CR corrodes the constituent metal of the can body, especially aluminum,
In addition, if the use of CFCs, which had been used as a propellant for aerosol products, is restricted and LPG is used instead, the sealing material containing CR will shrink excessively when it touches LPG, making it unusable. There was a problem. Therefore, recently, as an elastomer, the above CR
Have replaced acrylonitrile butadiene elastomer (NBR).

[0004]

However, the NBR
When used, the viscosity cannot be lowered by shuffling, so the amount of the compound is reduced to lower the viscosity, which facilitates application, but in this case, the sealing material obtained by drying is used. There was a problem that the strength of the. When the liquid sealing composition is poured into the groove formed in the can and dried, when the volume after drying is 35 to 50% of the filling amount (volume) in the groove,
That is, when the solid content is 35 to 50% by volume, preferable sealing properties are obtained, whereas the composition containing NBR is
The volume decrease due to drying was large and the sealing property was poor. And, as described above, LPG instead of CFC gas
However, when the sealing material containing NBR comes into contact with the LPG, a part of the compounding components of the sealing material is extracted by the LPG to lose the thickness, and the sealing performance is further deteriorated.

The present invention does not corrode the metal forming the can body, is easy to apply, retains good sealability and excellent strength after drying, and uses LPG other than Freon gas as a propellant. The present invention provides a liquid composition for sealing which does not deteriorate in sealing property even when used.

[0006]

The liquid composition for sealing according to the present invention uses a low unsaturated acrylonitrile butadiene elastomer or a carboxylated acrylonitrile butadiene elastomer as an elastomer, and uses as an additive an amount of the volume reduction of the elastomer. A swelling regulator that gives swelling property is added. The blending amount of the elastomer is 10 to 30% with respect to the total weight of the elastomer and the additive, and the blending amount of the swelling regulator is set to 5 to 50% of the elastomer.
The acrylonitrile butadiene elastomer may be any one from low nitrile to extremely high nitrile as long as it is within the industrially produced range.

The swelling regulator is compatible with the elastomer, or does not cause phase separation even if it does not.
And is indicative of the non-solubility in LPG, polybutene, polyolefin elastomer, 1,2 polybut <br/> diene, et epoxidized natural elastomers, SBR and B
R and the like are exemplified. However, if the elastomer is a low unsaturated acrylonitrile-butadiene elastomer, polybutene, polyolefin-based elastomers or 1,2 polybutadiene down preferred. Further, when the elastomer is a carboxylated acrylonitrile butadiene elastomer, an epoxidized natural elastomer is preferable, and when this epoxidized natural elastomer is used, polybutene or 1,2 polybutadiene can be supplementarily added.

The solvent has an SP value of 8.0 to 13.0.
It is preferable to use those such as toluene, methyl alcohol, cyclohexane, and methyl isobutyl ketone, and these can be used alone or in combination of two or more. In addition, a non-solvent compatible with the above solvent can be used. The solid content of the above composition is preferably 35 to 50% by volume.

[0009]

A low-unsaturation type NBR having a higher strength than a normal NBR or a carbocyclized NBR is used as an elastomer, and a swelling regulator capable of compensating for the volume reduction when NBR is used is added. The viscosity becomes 3000 to 10000 CP at 30 ° C. to facilitate the application, and by applying and drying, a sealing material excellent in strength and sealing property is formed. In addition, the carbocyclized NBR and the low unsaturated NBR do not deteriorate in sealing performance even when LPG is used as the propellant.

However, if the amount of the above-mentioned elastomer compounded is less than 10% with respect to the total weight of the elastomer and the additive, the strength is insufficient, and if it exceeds 30%, the viscosity of the composition is too high and the composition is poured and poured into grooves. Becomes difficult.
Also, the amount of the swelling regulator added is 5% with respect to the elastomer.
If it is less than 50%, the adjustment is insufficient, and the thickness is reduced when the LPG is touched, and the sealing property is deteriorated. On the contrary, if it exceeds 50%, the strength of the sealing material is insufficient, and it cannot be used in any case. . Then, the amount of the solvent used is 50 to 65% by volume.
By setting the solid content ratio to 35 to 50% by volume, the sealing performance becomes particularly good, and if the solid content ratio is less than 35%, the sealing performance decreases and becomes insufficient, and if it exceeds 50%, the viscosity of the composition is high. It is too expensive and difficult to apply.

[0011]

【Example】

Example 1 As an elastomer, a low-unsaturation type NBR (manufactured by Nippon Zeon Co., Ltd., trade name “Z-Pole 1020”, nitrile amount 45)
Polybutene (manufactured by Nippon Soda Co., Ltd., trade name "H")
V-300 ") was used to produce a rubber composition having the following composition.

Low unsaturated NBR 100.0 parts by weight Zinc oxide 5.0 〃 Stearic acid 1.0 〃 2-Mercaptobenzimidazole zinc salt (MBZ) 2.5 〃 Substituted diphenylamine (445) 0.5 〃 MT Black 200.0 〃 FEF Black 60.0 〃 Tricresyl phosphate (TCP) 140.0 〃 Di- (butoxyethoxyethyl) adipate (Thiocol TP95) 10.0 〃 Polybutene 35.0 〃 Morpholine disulfide 2.0 〃 N- (cyclohexylthio) phthalimide 0.3 〃 Vulcanization accelerator TMTD 2.0 〃 Vulcanization accelerator MBTS 1.0 〃

Then, methyl isobutyl ketone was used as a solvent and the above rubber composition was dissolved to prepare a liquid composition for sealing of Example 1. However, the compounding ratio of the rubber composition and the solvent was set to 40/60 by volume. The resulting liquid composition for sealing had a solid content of 43.2% by volume, a viscosity of 4100 cp at 30 ° C., and a specific gravity of 1.028.

The liquid sealing composition of Example 1 was poured onto a glass plate, air-dried at 25 ° C. for 72 hours, and then placed in an oven at 70 ° C. for 30 minutes and 90 ° C. for 30 minutes.
Heating for 120 minutes, 120 ° C. for 20 minutes, 160 ° C. for 30 minutes, and 180 ° C. for 70 minutes. The obtained vulcanized sheet has a tensile strength of 65 kgf / cm ² , an elongation of 380%,
The rubber hardness (JIS-A) was 47 degrees, and it had a strength and thickness that could be used as a sealing material. When the above-mentioned vulcanized sheet was exposed to LPG at 40 ° C for 72 hours, the rate of change in thickness was + 2.6% and the rate of change in weight was -6.1%, indicating sufficient resistance to LPG. .

Comparative Example A commercially available CR composition was dissolved in toluene at the same compounding ratio as in Example 1. The resulting liquid sealing composition of Comparative Example had a solid content of 40.0% by volume and a viscosity at 30 ° C. of 660.
It was 0 cp. Also, after pouring the above composition onto a glass plate in the same manner as in Example 1 and naturally drying for 72 hours,
Put in oven, 60 ℃ for 50 minutes, 90 ℃ for 50 minutes, 1
50 minutes at 10 ° C, 50 minutes at 130 ° C and 5 at 160 ° C
0 minutes of heating was applied in sequence. The obtained vulcanized sheet had a tensile strength of 88 kgf / cm ² , an elongation of 810% and a rubber hardness (J
IS-A) was 43 degrees. Also, when the above vulcanized sheet was exposed to LPG in the same manner as in Example 1, the rate of change in thickness was -14%, and it shrank excessively.

Example 2 Carboxylated NBR as an elastomer (manufactured by Nippon Zeon Co., Ltd., trade name "Nipol 1072J", acrylonitrile amount 27% by weight, carboxylic acid amount 0.07% by weight)
Was used, and the epoxidized natural elastomer and the polybutene of Example 1 were mixed as a swelling modifier to produce a rubber composition having the following composition.

Carboxylated NBR 85.0 parts by weight Epoxidized natural elastomer 15.0 〃 Zinc oxide 5.0 〃 Stearic acid 1.0 〃 MT Black 175.0 〃 FEF Black 85.0 〃 Di- (butoxyethoxyethyl) Adipate 25.0 〃 Tricresyl phosphate (TCP) 130.0 〃 Polybutene HV-300 40.0 〃 Sulfur 0.5 〃 Vulcanization accelerator TMTD 1.5 〃 Vulcanization accelerator CBS 1.5 〃

Then, the above rubber composition was dissolved in methyl isobutyl ketone in the same manner as in Example 1 to prepare a liquid composition for sealing of Example 2. The resulting liquid composition for sealing has a solid content of 41% by volume and a viscosity of 5 at 30 ° C.
It was 100 cp. In addition, the above liquid composition for sealing is poured onto a glass plate, naturally dried at 25 ° C. for 48 hours, and then placed in an oven at 80 ° C. for 45 minutes and 180 ° C.
Then, heating was performed for 135 minutes in order. The obtained vulcanized sheet had a tensile strength of 63 kgf / cm ² , an elongation of 350% and a rubber hardness (JIS-A) of 45 degrees, and had a strength and a thickness usable as a sealing material. When the above-mentioned vulcanized sheet was exposed to LPG at 40 ° C for 72 hours, the rate of change in thickness was + 3.3%, indicating that it had sufficient resistance to LPG.

[0019]

As described above, the liquid composition for sealing of the present invention can be used as an elastomer in a conventional NBR.
A low-unsaturation NBR having a higher strength than that of NBR or a carbocyclized NBR is used, and a swelling regulator capable of compensating for volume reduction when NBR is used is added, and the NBR content is the total weight of the NBR and the additive. 10 to 30%, and the amount of the swelling regulator is set to 5 to 50% of the NBR, an appropriate viscosity can be obtained as a liquid sealing composition, which facilitates application. Moreover, by applying and drying, a solid sealing material having excellent strength and sealing properties is formed, and even when LPG is used as the propellant, the sealing property does not deteriorate and there is no free chlorine. Therefore, it does not corrode the can body.

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Claims (4)

[Claims] 1. A liquid composition for sealing, comprising a vulcanizing agent and other additives dispersed in an elastomer and dissolved in a solvent, wherein the elastomer is a low unsaturated acrylonitrile butadiene elastomer or a carboxylated acrylonitrile butadiene elastomer. As an additive, a swelling regulator to the extent of compensating the volume reduction of the elastomer is added, and the blending amount of the elastomer is 10 to 30% with respect to the total weight of the elastomer and the additive, and the blending amount of the swelling regulator. Is 5 to 50% by weight of the above elastomer
A liquid composition for sealing, characterized in that Wherein the elastomer is a low unsaturated acrylonitrile-butadiene elastomer, seal of claim 1 swelling modifier is either polybutene, polyolefin elastomers or 1,2 Po <br/> Ributajie down Liquid composition. 3. The liquid composition for sealing according to claim 1, wherein the elastomer is a carboxylated acrylonitrile butadiene elastomer and the swelling modifier is an epoxidized natural elastomer. 4. The liquid composition for sealing according to claim 1, which has a solid content of 35 to 50% by volume.