JP5499343B2 - Release agent composition and aerosol release agent - Google Patents

Description

  The present invention is a release agent composition that is high in safety because it does not contain chlorine and has excellent release performance, in particular, a release agent composition suitable for peeling gaskets, and an aerosol release agent containing the release agent composition About.

  Gaskets are sandwiched between piping joints, pressure vessel manholes or valve bonnets and compressed to prevent gaps and at the same time prevent leakage of fluid from the inside or entry of foreign objects from the outside. It is used in various fields such as construction machinery, agricultural machinery, and electrical equipment.

  Generally, gaskets are roughly classified into sheet gaskets and liquid gaskets. A sheet gasket generally refers to a joint sheet, in which rubber, polyamide fiber, glass fiber, expanded graphite, etc. are uniformly mixed and punched out from a 0.4 to 3.0 mm thick sheet that has been pressure-rolled. is there. The liquid gasket is a paste-like adhesive mainly composed of a synthetic resin (silicon-based, anaerobic acrylic-based) or the like, and is used for applications such as preventing leakage of low-pressure piping.

  The sheet gasket and the liquid gasket are used alone or in combination depending on conditions such as heat resistance, pressure resistance, chemical resistance, and workability. For example, in water and sewage piping, a liquid gasket is applied to the flange surface, a sheet gasket is applied thereon, and sealing is maintained by tightening with bolts.

  Gaskets constructed in this way need to be removed for repair or inspection after 6 months to 1 year. In that case, since the flange surface and the gasket material are usually firmly fixed, they cannot be easily peeled off in many cases. Further, in recent years, the adhesive performance of the liquid gasket has been improved, and it has become even more difficult to peel off.

  In order to remove the gasket that is difficult to peel off, for example, a method of scraping with a stainless scraper or a cutter knife, or mechanically separating from the interface with a sander or a brass shot is employed. However, these methods are liable to damage the flange surface and reduce the accuracy of the flange dimensions, which may adversely affect the subsequent sealing performance.

  For this reason, in industrial fields such as automobiles, construction machinery, agricultural machinery, and electrical equipment, a release agent mainly composed of organic solvents is applied to the applied gasket to swell, and when the gasket material becomes soft, a scraper is used. Then, a method of peeling is generally performed.

  The release agent that has been commercially available, for example, contains a chlorine-based solvent such as dichloromethane having a high dissolving power, as described in, for example, JP-A-11-080626 and JP-A-11-116862. Many are mixed with aromatic or alcohol co-solvents.

  However, in recent years, dichloromethane, which has an adverse effect on the human body and the like, has been avoided. Therefore, as described in, for example, JP-A Nos. 2001-123093 and 2001-131448, hydrocarbons and aromatics are used. Also, a chlorine-free release agent in which a plurality of organic solvents such as ketones are mixed is also known.

  In addition, as described in JP-A-2001-131448, a release agent containing a thickener is also proposed in order to keep the organic solvent component long on the painted surface to be peeled and promote penetration and swelling. Has been. As the thickener, waxes or cellulose-based materials are used, and these thickeners are said to have an action of preventing dripping on a vertical surface and scattering to the surroundings.

  However, the peeling performance of the chlorine-free release agent described above is currently lower than that of a chlorine-containing release agent mainly composed of dichloromethane. Therefore, for example, satisfactory peeling performance could not be exhibited with respect to peeling of a gasket such as a sheet gasket or a liquid gasket.

Japanese Patent Laid-Open No. 11-080626 JP-A-11-116862 JP 2001-123093 A JP 2001-131448 A

  The present invention is a chlorine-free release agent that is highly safe for the human body in view of the above-described problems of the prior art, and has a release performance equal to or higher than that of a chlorine-type release agent. It is an object of the present invention to provide a release agent composition capable of easily and reliably removing sheet gaskets and liquid gaskets of equipment and the like, and an aerosol release agent containing the release agent composition.

In order to achieve the above object, a release agent composition provided by the present invention is a release agent composition for peeling a gasket , comprising 30 to 89% by weight of an ether solvent and 1 to 60% based on the whole composition. In a mixed solvent consisting of four organic solvents , a ketone solvent of 1% by weight, an ester solvent of 1 to 60% by weight, and a sulfur-containing solvent of 1 to 10% by weight, 8% of the total composition. -20% by weight of an amide thixotropic agent is blended.

  The present invention also provides an aerosol release agent obtained by filling a spray container with the above-described release agent composition together with a propellant composed of a liquefied gas.

  ADVANTAGE OF THE INVENTION According to this invention, it is a chlorine-free type with high safety | security with respect to a human body, has the outstanding peeling performance, and provides the peeling agent composition which can peel the gasket which was conventionally difficult to peel easily and reliably. it can. Therefore, the release agent composition of the present invention is suitable for peeling sheet gaskets and liquid gaskets applied to piping flanges and equipment, and can exhibit excellent convenience by using an aerosol.

  The release agent composition of the present invention is composed of a mixed solvent composed of four organic solvents such as an ether solvent, a ketone solvent, an ester solvent and a sulfur-containing solvent, and an amide thixotropic agent. The four kinds of organic solvents are effective components for peeling off gaskets and the like. An amide thixotropic agent contains a polymer compound having an —NH—CO— bond in the molecule, and is added to and mixed with the mixed solvent composed of the above four organic solvents to develop thixotropic properties. Is.

  Therefore, the release agent composition of the present invention containing an amide thixotropic agent in a mixed solvent increases the viscosity and becomes thixotropic, and exhibits fluidity when an external force such as stirring is applied. When left standing, it loses fluidity and gels. Therefore, the release agent composition of the present invention has excellent anti-sagging performance when applied to an object to be peeled such as a gasket, and can retain the organic solvent component for a long time, and has the performance of preventing the organic solvent component from evaporating. Since it is provided, it is excellent in peeling performance of a gasket or the like and can maintain the performance.

  The compounding quantity of an amide type thixotropic agent shall be 8 to 20 weight% of the whole composition. When the blending amount is less than 8% by weight, the compatibility with the organic solvent component is deteriorated and the thixotropic property is not sufficiently exhibited. Therefore, when it is allowed to stand, separation occurs in the liquid phase and the dispersion stability is lowered. On the other hand, if it is added in excess of 20% by weight, the release agent composition becomes grease-like because the expression of thixotropic properties is too strong, and the permeability of the organic solvent component to the gasket is lowered, so that sufficient release performance is obtained. I can't get it.

  There is no restriction | limiting in particular regarding the said amide type thixotropic agent, A commercial item can be used. For example, Disparon 6900-20X, Disparon A670-20M, Disparon PFA220-20M, Disparon A671-EZ, Disparon F9050, Disparon PFA-231, Disparon PFA-220, Disparon PFA-131 (all manufactured by Enomoto Kasei) are suitable. Can be used.

  Of the above mixed solvents, ether solvents are effective for peeling gaskets and the like, and are particularly effective in swelling sheet gaskets and dissolving and swelling liquid gaskets. As the ether solvent, methyltetrahydrofuran, diethyl ether, 1,3-dioxolane, cyclopentylmethyl ether, dibenzyl ether and the like are preferable, and these can be used alone or in combination.

  Moreover, the compounding quantity of an ether solvent needs to be 30 to 89 weight% of the whole composition. When the blending amount of the ether solvent is less than 30% by weight of the whole composition, the swelling effect of the sheet gasket, the dissolution and swelling effect of the liquid gasket are insufficient. On the other hand, when the amount of the ether solvent exceeds 89% by weight, the amount of solvent components other than the ether solvent decreases, and the peeling performance of the gasket becomes insufficient.

  The ketone solvent is effective for peeling gaskets and the like, and is particularly effective in dissolving and swelling liquid gaskets. As the ketone solvent, for example, cyclohexanone, acetone, isophorone, methyl ethyl ketone, diacetone alcohol, dimethyl methyl cyclohexanone carbonate, methyl isobutyl ketone, 2-heptanone and the like are preferable, and these can be used alone or in combination.

  Moreover, the compounding quantity of a ketone solvent needs to be 1 to 60 weight% of the whole composition. When the blending amount of the ketone solvent is less than 1% by weight of the entire composition, the effect of dissolving and swelling the liquid gasket or the like becomes insufficient. Moreover, when the compounding quantity of a ketone solvent exceeds 60 weight%, since the addition amount of an above-described ether solvent decreases, peeling performance will become inadequate.

  The ester solvent is effective for peeling off gaskets and the like, and is particularly effective in dissolving and swelling liquid gaskets. As the ester solvent, ethyl acetate, amyl acetate, butyl acetate, isobutyl acetate, benzyl formate, phosphates and the like are preferable, and these can be used alone or in combination.

  Moreover, the compounding quantity of an ester solvent needs to be 1 to 60 weight% of the whole composition. When the blending amount of the ester solvent is less than 1% by weight of the entire composition, the effect of dissolving and swelling the liquid gasket or the like becomes insufficient. On the other hand, when the amount exceeds 60% by weight, the amount of the ether solvent or the like described above is reduced, resulting in insufficient peeling performance.

  The sulfur-containing solvent is effective for peeling off gaskets and the like, and is particularly effective in dissolving and swelling liquid gaskets. As the sulfur-containing solvent, diphenyl sulfone, dimethyl sulfoxide, sulfolane, thioanisole and the like are preferable, and these can be used alone or in combination.

  Moreover, the compounding quantity of a sulfur-containing solvent needs to be 1-10 weight% of the whole composition. If the amount of the sulfur-containing solvent is less than 1% by weight of the total composition, the effect becomes insufficient, and if it exceeds 10% by weight, the solubility with the amide thixotropic agent becomes poor and two-layer separation occurs. This is not preferable.

  In addition, the release agent composition of this invention can contain organic solvents other than the above-mentioned 4 types in the range which does not impair the characteristic similarly to the case of a general release agent. Examples of the organic solvent that can be added include hydrocarbon solvents, nitrogen-containing solvents, alcohol solvents, polyhydric alcohol solvents, and phenol solvents. Moreover, normal additives, such as a dispersing agent and a wetting agent, can also be contained.

  In order to obtain the release agent composition of the present invention, a strong shearing force is required in order to make the thixotropic agent compatible in the above mixed solvent. Therefore, for the dispersion treatment of the mixed solvent and the thixotropic agent, it is preferable to stir at high speed using a paint shaker, a ball mill, a dyno mill, a disper or the like.

  The release agent composition of the present invention can be made into an aerosol release agent by filling a spray container together with a propellant. As the propellant, liquefied petroleum gas (LPG) or dimethyl ether (DME) is preferable. Propellants such as chlorofluorocarbon gases and compressed gases (carbonic acid, nitrogen) are not compatible with the release agent composition of the present invention, and thus good spraying cannot be obtained.

  Moreover, about the compounding quantity of a propellant, it is preferable that the propellant component in aerosol product is the range of 40-70 volume%. If it is less than 40% by volume, dripping is likely to occur at the time of injection, and if it exceeds 70% by volume, the mist at the time of injection becomes fine and may spread to the periphery and adhere to parts other than the object to be removed or the human body. .

[Example 1]
Weighed four organic solvents, ether solvent, ketone solvent, ester solvent and sulfur-containing solvent, and an amide thixotropic agent so as to have a blending amount (% by weight) shown in Table 1 below. The mixture was stirred for 30 minutes using a PRIMIX homodisper to obtain stripping compositions of Samples 1-6. The amide thixotropic agent is Disparon PFA-230 (trade name; manufactured by Enomoto Kasei Co., Ltd.), the ether solvent is 1,3-dioxolane, the ketone solvent is dimethyl carbonate, the ester solvent is butyl acetate, and the sulfur content Dimethyl sulfoxide was used as the system solvent.

  For each of the obtained release agent compositions of Samples 1 to 6, the dispersion stability was observed when 10 minutes had elapsed after the completion of stirring and mixing. The results were evaluated as ◯ for uniformly mixed, △ for those with high viscosity and no fluidity, and × for two-layer separation, and are also shown in Table 1 below.

  As can be seen from the above results, all of the release agent compositions of Samples 1 to 3 of the present invention containing the amide thixotropic agent in the range of 8 to 20% by weight had good dispersion stability. However, the release agent compositions of Samples 4 and 5, which are comparative examples, were separated into two layers because the amount of the amide thixotropic agent was too small. Moreover, since the release agent composition of Sample 6 as a comparative example had too much amide thixotropic agent, the viscosity was high and fluidity was not obtained.

[Example 2]
The release agent composition of Sample 1 prepared in Example 1 was mixed with LPG (0.4 MPa) as a propellant to be aerosolized to obtain aerosol release agents of Samples A to E. At that time, in Samples A to E, the release agent composition and the propellant were mixed at the component ratio (volume ratio) shown in Table 2 below.

  For each of the obtained aerosol release agents, the solubility of the release agent composition and the propellant was confirmed. Moreover, it injected to the rolled steel plate (150 mm x 70 mmx thickness 0.8mm) stood upright at room temperature, and evaluated dripping prevention property. The results are shown in Table 2 below with ◯ indicating no sagging, Δ indicating slightly sagging, and x indicating sagging.

  As can be seen from the results, the solubility of the release agent composition and the propellant was good in all the aerosol release agents of Samples A to E. As for the sag prevention property when sprayed, the samples A to D having a propellant ratio of 40 to 70% by volume were substantially good, but the sample E having 20% by volume had a poor sag prevention property. .

[Example 3]
For the release performance of the aerosol release agent of Sample C according to the present invention prepared in Example 2 above, a comparative test with two commercially available representative aerosol release agents was performed. Of the commercially available aerosol strippers, Sample F is a chlorine type (trade name; α Packing Hagashi Spray, manufactured by Trusco Nakayama Co., Ltd.) containing methylene chloride, and Sample G is a chlorine-free type (trade name; Three Bond 3911D, Three Bond). Company-made).

  That is, after applying ThreeBond 1102 (trade name; manufactured by ThreeBond Co., Ltd.), a liquid gasket, to the surface of a rolled steel plate (150 mm × 70 mm × thickness 0.8 mm), non-asbestos of 30 mm × 30 mm × 0.8 mm thickness is formed thereon. A type sheet gasket (trade name; manufactured by Nippon Valqua) was placed, and a 2 kg weight was placed thereon and cured at room temperature for about 6 months.

  Each of the aerosol release agents was spray-applied to the cured gasket, and the gasket was scraped off using a stainless steel scraper at each of the elapsed time of 5 minutes, 10 minutes, 30 minutes, and 60 minutes. The result is ◎ that the majority of the surface of the rolled steel sheet is exposed, ◎ that the surface of the rolled steel sheet is exposed even a little, and that the surface of the rolled steel sheet is not exposed but the liquid gasket and sheet gasket are softened and can be scraped even a little. Δ and those that could not be removed at all were shown as x, and are also shown in Table 3 below.

  The commercially available aerosol release agent for chlorine type sample F and chlorine free type sample G is a gasket until the liquid gasket and sheet gasket are softened 10 minutes after application, and the surface of the rolled steel sheet is slightly exposed 30 minutes after application. Could be peeled off. However, the same state was observed after 60 minutes, and the gasket could not be peeled until most of the surface of the rolled steel sheet was exposed.

  In contrast, the aerosol release agent of Sample C of the present invention can peel the gasket until the surface of the rolled steel sheet is slightly exposed 10 minutes after application, and the gasket is exposed until most of the surface of the rolled steel sheet is exposed 60 minutes after application. Could be peeled off. From this, it was found that the aerosol stripper of the present invention has a stripping performance superior to conventional chlorine-type and chlorine-free type aerosol strippers.

Claims (6)

A release agent composition for peeling a gasket , comprising 30 to 89% by weight of an ether solvent, 1 to 60% by weight of a ketone solvent, and 1 to 60% by weight of an ester solvent with respect to the whole composition. 8 to 20% by weight of an amide thixotropic agent is blended with respect to the entire composition in a mixed solvent composed of four kinds of organic solvents with 1 to 10% by weight of a sulfur-containing solvent. A release agent composition.   The release agent composition according to claim 1, wherein the ether solvent is at least one selected from methyltetrahydrofuran, diethyl ether, 1,3-dioxolane, cyclopentylmethyl ether, and dibenzyl ether. .   The said ketone solvent is at least 1 sort (s) selected from cyclohexanone, acetone, isophorone, methyl ethyl ketone, diacetone alcohol, dimethyl methyl cyclohexanone carbonate, methyl isobutyl ketone, and 2-heptanone, The release agent composition described in 1.   The said ester solvent is at least 1 sort (s) selected from ethyl acetate, amyl acetate, butyl acetate, isobutyl acetate, benzyl formate, and phosphate ester, The any one of Claims 1-3 characterized by the above-mentioned. Release agent composition.   The release agent composition according to any one of claims 1 to 4, wherein the sulfur-containing solvent is at least one selected from diphenyl sulfone, dimethyl sulfoxide, sulfolane, and thioanisole.   An aerosol stripper obtained by filling a spray container with the stripper composition according to any one of claims 1 to 5 together with a propellant composed of a liquefied gas.