JP6867648B2 - Rust prevention composition - Google Patents

Description

The present invention relates to a rust preventive composition.

Metal products such as metal materials and metal parts are packaged in packaging materials containing rust preventives, desiccants, hygroscopic agents and the like, and stored in containers containing these additives before being stored or transported. The above-mentioned rust preventive agent prevents corrosion by the passivation action of the metal surface and the physical adsorption mechanism, and the above-mentioned desiccant and hygroscopic agent reduce the amount of water inside the package and prevent dew condensation. , The purpose is to protect the metal.

As a packaging material containing such a rust preventive, a hygroscopic agent, etc., for example, Patent Document 1 describes a first planar material having breathability and a second surface having a lower air permeability than the first planar material. A large number of cells are formed in at least one of the planar objects, and the inside of the cells is filled with a vaporizable rust preventive agent and a hygroscopic agent, and the other planar object is used. A rust-preventive packaging material configured to block the cell is disclosed.

Japanese Unexamined Patent Publication No. 2001-171723

However, the rust-preventive packaging material described in Patent Document 1 has a problem that the rust-preventive performance and the hygroscopic performance are inferior.

Therefore, an object of the present invention is to provide a rust preventive composition having excellent rust preventive performance and hygroscopic performance.

In order to solve the above problems, the present inventors have conducted diligent studies. As a result, for rust prevention, which contains a rust preventive material (A) containing a thermoplastic resin and a first rust preventive agent, and a hygroscopic agent (B) containing B-type silica gel and a second rust preventive agent. It has been found that the above-mentioned problems can be solved by the composition, and the present invention has been completed.

According to the present invention, a rust preventive composition having excellent rust preventive performance and hygroscopic performance is provided.

It is a schematic diagram which shows the function of the conventional rust preventive material. It is a schematic diagram which shows the mechanism of the effect expression of the rust preventive composition by one Embodiment of this invention.

The present invention contains a rust preventive material (A) containing a thermoplastic resin and a first rust preventive agent, and a rust preventive agent (B) containing B-type silica gel and a second rust preventive agent. Composition for use. The rust preventive composition of the present invention having such a structure is excellent in rust preventive performance and hygroscopic performance.

The detailed reason why the rust preventive composition of the present invention exerts the above effect is unknown, but it is presumed to be due to the following mechanism. The following mechanism is speculative, and its correctness does not affect the technical scope of the present invention.

FIG. 1 is a schematic view showing the function of a conventional rust preventive material. In the conventional rust preventive material as shown in Patent Document 1, silica gel 1 and rust preventive agent 2 are added separately (see FIG. 1 (A)), but a part of the rust preventive agent is added to silica gel 1 together with water vapor 3. There was a problem that the amount of the rust preventive agent present on the surface of the work (rust preventive object) was insufficient (see FIG. 1 (B)) and the rust preventive performance was inferior.

FIG. 2 is a schematic view showing the mechanism of effect manifestation of the rust preventive composition 10 according to the embodiment of the present invention. The rust preventive composition 10 according to one embodiment of the present invention includes the thermoplastic resin 5 and the second, together with the hygroscopic agent (B) 8 in which the second rust preventive agent 7 is previously added (adsorbed) to the B-type silica gel 1. The rust preventive material (A) 9 containing the rust preventive agent 6 of 1 is used (see FIG. 2 (A)). Since the hygroscopic agent (B) 8 has a configuration in which a second rust preventive agent 7 is previously added (adsorbed) to the B-type silica gel 1, the B-type silica gel 1 adsorbs the rust preventive agent more than necessary. The phenomenon can be suppressed, and the work (rust prevention) is released because the rust preventive material (A) 9 to the first rust preventive agent 6 and the hygroscopic agent (B) 8 to the second rust preventive agent 7 are released. It is considered that the amount of the rust preventive agent present on the surface of the object) 4 is sufficient and the rust preventive performance is excellent. Further, since the B-type silica gel 1, which is a component of the hygroscopic agent (B) 8, plays a role of removing water on the surface of the rust preventive material (A) 9, the first from the rust preventive material (A) 9. It is considered that the release of the rust preventive agent 6 is further promoted (see FIG. 2B), and the rust preventive performance is further improved.

Further, since the B-type silica gel 1 constituting the hygroscopic agent (B) 8 also has an effect of reducing the moisture in the atmosphere, the rust preventive composition 10 according to the embodiment of the present invention has a hygroscopic performance. Excellent.

In addition, the first rust preventive agent 6 is gradually released from the rust preventive material (A) 9, and the second rust preventive agent 7 is gradually released from the hygroscopic agent (B). It is considered that the rust preventive composition 10 according to the embodiment maintains the rust preventive performance for a long period of time.

Hereinafter, preferred embodiments will be described in more detail, but the invention is not limited to the following embodiments.

In the present specification, "X to Y" indicating a range means "X or more and Y or less". Unless otherwise specified, the operation and physical properties are measured under the conditions of room temperature (20 to 25 ° C.) / relative humidity of 40 to 60% RH.

In addition, the terms "first" and "second" used in the present specification are convenient for distinguishing the rust preventives used in the rust preventive material (A) and the adsorbent (B) from each other. The order itself, such as "first" and "second", has no special meaning.

[Rust preventive material (A)]
The rust preventive material (A) according to the present invention (hereinafter, also simply referred to as “component (A)”) contains a thermoplastic resin and a first rust preventive agent.

<Thermoplastic resin>
Specific examples of the thermoplastic resin used include polyvinyl acetate, polyvinyl butyrate, polyvinyl formal, polyvinyl carbazole, polyacrylic acid, polymethacrylic acid, polymethylacrylate, polymethylmethacrylate, polyethyl acrylate, and polybutyl acrylate. Polymethacrylonitrile, polyethylmethacrylate, polybutylmethacrylate, polyacrylonitrile, poly-1,2-dichloroethylene, ethylene-vinyl acetate copolymer, syndiotactic polymethylmethacrylate, poly-α-vinylnaphthalate, polycarbonate, Cellulose, cellulose acetate, cellulose triacetate, cellulose acetate butyrate, polystyrene, poly-α-methylstyrene, poly-o-methylstyrene, poly-p-methylstyrene, poly-p-phenylstyrene, poly-2,5-dichloro Styrene, poly-p-chlorostyrene, poly-2,5-dichlorostyrene, polyarylate, polysulfone, polyethersulfone, styrene-acrylonitrile copolymer, styrene-divinylbenzene copolymer, styrene-butadiene copolymer, styrene -Maleic anhydride copolymer, ABS resin, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polyvinyl chloride, polypropylene, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyvinylpyrrolidone, Polyvinylidene chloride, hydride-butadiene-styrene copolymer, polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene, hexafluoroethylene and vinyl alcohol, vinyl ester, vinyl ether, vinyl acetal, vinyl butyral, etc. Examples thereof include a coalescence, a copolymer of a (meth) acrylic acid cyclic aliphatic ester and a methyl (meth) acrylate, a polyvinyl acetate, polyvinyl alcohol, a methyl methacrylate-ethyl acrylate-acrylic acid copolymer and the like. The above-mentioned thermoplastic resin can be used alone or in combination of two or more. Further, as the thermoplastic resin, a commercially available product or a synthetic product may be used.

Among the above-mentioned thermoplastic resins, low-density polyethylene or linear low-density polyethylene is preferable from the viewpoint of the mixing property of the first rust preventive, the molding temperature, and the like.

The MFR (melt flow rate) of the thermoplastic resin is preferably 10 to 80 g / 10 min under the conditions of 190 ° C. and 10 kg from the viewpoint of molding processability and the like.

The content of the thermoplastic resin in the component (A) (the total amount in the case of two or more kinds) is preferably 50 to 95% by mass, more preferably 60 to 90% by mass, and 70 to 80%. It is more preferably mass%.

The shape of the thermoplastic resin is not particularly limited, and may have a shape such as a plate shape, a rod shape, a spherical shape, a sheet shape, a film shape, a hollow shape, a gas microdisperse shape, a foam, a fibrous shape, or a pellet shape.

<First rust preventive>
Specific examples of the first rust preventive agent contained in the component (A) include nitrite compounds such as dicyclohexylammonium nitrite, isopropylammonium nitrite, and nitronaphthalinammonium nitrite; cyclohexylammonium laurate and the like. Lauric acid derivatives; Acrylic acid derivatives such as dicyclohexylammonium acrylate and cyclohexylamine acrylate; Carbonated compounds such as cyclohexylamine carbonate); benzoic acid, sodium benzoate, monoethanolamine benzoate, cyclohexylamine benzoate, isopropyl benzoate, Aromatic carboxylic acids such as butyl benzoate, phthalic acid, sodium phthalate, salts thereof or derivatives thereof; cinnamon acid derivatives such as butyl silicate; capric acid; carbamic acid derivatives such as ammonium carbamate; salicylic acid such as dicyclohexylammonium salicylate Derivatives; monoethylamine, diethylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, N-methylmorpholine, dimethylaminoethanol, N-methylmorpholin stearate, N-methylmorpholin-laurate, N-ethylmorpholin , Ammonium compounds such as hexamethylenetetramine or salts thereof; heterocyclic compounds such as benzotriazole, tolyltriazole, methylhydroxypyrazole, mercaptobenzothiazole, dimercaptothiazyl, hydroxybenzotriazole, carboxybenzotriazole; urea, thiourea and the like. Compounds; alkali metal salts or ammonium salts of saturated or unsaturated fatty acids having 4 to 18 carbon atoms such as citric acid, succinic acid, tartaric acid, caproic acid, lauric acid, stearic acid, oleic acid, linoleic acid and linolenic acid; etc. Can be used.

Further, for example, a preservative such as L-ascorbic acid and a chelating agent such as sodium ethylenediaminetetraacetate can also be used as the first rust preventive according to the present invention.

The first rust preventive may be used alone or in combination of two or more. When two or more kinds are combined, for example, a reactive rust inhibitor obtained by using sodium nitrite and urea, sodium nitrite and hexamethylenetetramine-based compound, or sodium nitrite and ammonium benzoate in combination may be used.

Among these, N-methylmorpholine stearate, N-methylmorpholine laurate, and sodium benzoate are preferable from the viewpoint of the rust preventive effect on steel. Further, benzotriazole is preferable from the viewpoint of vaporizable rust preventive effect on non-ferrous metals. That is, the first rust preventive is preferably at least one selected from the group consisting of N-methylmorpholine stearate, N-methylmorpholine laurate, sodium benzoate, and benzotriazole.

The content of the first rust inhibitor in the component (A) (in the case of two or more types, the total amount) is preferably 5 to 50% by mass, more preferably 10 to 40% by mass. It is more preferably 20 to 30% by mass.

<Other additives contained in component (A)>
The component (A) is a filler, a plasticizer, an antioxidant, a heat stabilizer, a light stabilizer, a flame retardant, an antistatic agent, a neutralizing agent, a dispersant, and a lubricant as long as the above-mentioned effects of the present invention are not impaired. , UV absorbers, surfactants, colorants (pigments, dyes), defoamers, leveling agents, adhesion-imparting agents, polymerization inhibitors, surface modifiers, cross-linking agents, cross-linking aids, antibacterial agents, silane cups Other additives such as ringing agents, chelating agents, biodegradation additives and the like may be further included.

<Manufacturing method of component (A)>
The method for producing the component (A) is not particularly limited, and for example,
(A) A method of stirring and mixing a thermoplastic resin, a first rust preventive, and various additives added as needed:
(B) A method of impregnating a thermoplastic resin with a first rust preventive and various additives added as needed:
(C) Thermoplastic resin, first rust preventive, and various additives added as needed, such as single-screw extruder, twin-screw extruder, kneader, pressure kneader, Banbury mixer, super mixer, etc. A method of melt-kneading using the kneader of the above and cutting the obtained kneaded product into a desired size with a pelletizer to form a pellet shape.
And so on.

In the method (c) above, for example, when a twin-screw extruder is used, the L / D (barrel length / screw diameter) is not particularly limited, but is usually about 20 to 50, and the screw rotation speed is 150. ~ 600 rpm is preferable. The cylinder temperature cannot be unequivocally determined because it differs depending on the type of resin, but when low-density polyethylene is used, for example, it is preferably set to about 90 to 150 ° C.

[Adsorbent (B)]
The adsorbent (B) according to the present invention (hereinafter, also simply referred to as “component (B)”) contains B-type silica gel and a second rust preventive.

<B-type silica gel>
The component (B) according to the present invention contains B-type silica gel. In general, silica gel has a wide range of adsorption characteristics by chemical adsorption (silanol group: adsorption by Si-OH) and physical adsorption (adsorption by capillary condensation). A-type silica gel has a large surface area in which fine particles of silicon dioxide are densely aggregated. Since this surface has innumerable silanol groups (groups that easily bind to water molecules and the like), it selectively adsorbs (chemically adsorbs) substances having properties similar to those of water. On the other hand, the B-type silica gel has fine particles of silicon dioxide loosely aggregated and has a smaller surface area than the A-type silica gel. Therefore, physical adsorption by capillary condensation in the gaps between fine particles works preferentially over chemical adsorption by silanol groups. Since this physical adsorption force is gentle, the B-type silica gel has a property of gradually releasing the adsorbed water by placing it in a low relative humidity or heating its surroundings. Further, the B-type silica gel can increase the amount of water adsorbed when the relative humidity is high as compared with the A-type silica gel.

In addition, since A-type silica gel has stronger adsorption strength of rust preventives (particularly basic rust preventives) than B-type silica gel, once the rust preventive agent is adsorbed on A-type silica gel, the rust preventive agent is released. Since it becomes more difficult, the rust preventive performance is lowered, and the moisture absorption performance is also lowered due to the adsorption of the rust preventive agent.

Therefore, in the present invention, as the silica gel, B-type silica gel is more suitable than A-type silica gel. The A type and B type of silica gel are defined in JIS Z0701: 1977.

The content of B-type silica gel in the component (B) is preferably 90 to 99.5% by mass, more preferably 95 to 99% by mass, and further preferably 95 to 97% by mass. ..

<Second rust inhibitor>
A specific example of the second rust inhibitor contained in the component (B) is the same as that of the first rust inhibitor, and thus description thereof will be omitted here. The second rust preventive can be used alone or in combination of two or more.

Among these, N-methylmorpholine stearate and N-methylmorpholine laurate are preferable from the viewpoint of rust preventive effect on steel. Further, benzotriazole is preferable from the viewpoint of vaporizable rust preventive effect on non-ferrous metals. That is, the second rust preventive is preferably at least one selected from the group consisting of N-methylmorpholine stearate, N-methylmorpholine laurate, and benzotriazole.

The content of the second rust inhibitor in the component (B) is preferably 0.5 to 10% by mass, more preferably 1 to 5% by mass, and 3 to 5% by mass. Is even more preferable.

The first rust inhibitor contained in the component (A) and the second rust inhibitor contained in the component (B) may be of the same type or different types.

<Other additives contained in component (B)>
The component (B) may further contain other additives such as a binder, a pressure-sensitive adhesive, an antioxidant, and a pH indicator as long as the above-mentioned effects of the present invention are not impaired.

<Manufacturing method of component (B)>
The method for producing the component (B) is not particularly limited, and examples thereof include a method of stirring and mixing B-type silica gel and a second rust preventive agent. The conditions at the time of mixing can be appropriately set. For example, the mixing temperature is preferably 20 to 25 ° C., and the mixing time is preferably 1 to 5 minutes.

The rust preventive composition of the present invention may further contain one or more of the third rust preventive agents in addition to the above components (A) and (B). Examples of the third rust preventive agent include the same ones as those of the first rust preventive agent.

[Manufacturing method of rust preventive composition]
The method for producing the rust preventive composition is not particularly limited, and examples thereof include a method of producing the component (A) and the component (B) and then mixing them.

The method for producing the component (A) and the component (B) is as described above. The method of mixing the component (A) and the component (B) is not particularly limited, but dry blending (dry mixing) at a temperature of 15 to 45 ° C. using a device such as a Henschel mixer, a ribbon blender, a V blender, or a drum mixer. ) Can be mentioned.

Further, after the component (B) is produced by mixing the B-type silica gel and the second rust preventive agent using the above device, the component (B) is not isolated and is continued in the same device (A). ) The rust preventive composition of the present invention can also be produced by adding and mixing the components.

The mixed mass ratio of the component (A) and the component (B) is preferably (A) component / (B) component = 1/1 to 1/5, and preferably 1/4 to 1/5. More preferred.

The rust preventive composition of the present invention is suitably used as a rust preventive agent for copper, aluminum, magnesium, silver, iron, nickel, zinc, lead, tin, titanium, other metals or alloys thereof.

Hereinafter, specific examples and comparative examples will be described. However, the technical scope of the present invention is not limited to the following examples.

(Example 1)
≪Preparation of thermoplastic resin≫
Novatec® LJ-903 (pellet, manufactured by Japan Polyethylene Corporation, MFR (190 ° C., 10 kg): 50), which is a low-density polyethylene, was prepared.

≪Preparation of the first rust preventive (N-methylmorpholine stearate) ≫
N-methylmorpholine stearate was synthesized as the first component of the first rust preventive. Specifically, 36.89 g of stearic acid was placed in a glass beaker and placed in a hot stirrer set at 100 ° C. to liquefy the stearic acid. Then, 13.11 g of N-methylmorpholine was placed in a beaker and stirred at 100 ° C. for 10 minutes for reaction. After completion of the reaction, natural cooling and cooling with a water bath were carried out to solidify the reaction product to obtain N-methylmorpholine stearate.

≪Preparation of the first rust preventive (sodium benzoate)≫
Sodium benzoate was prepared as the second component of the first rust inhibitor.

≪Preparation of (A) component≫
Novatec® LJ-903 (registered trademark) LJ-903 (70.0 parts by mass), N-methylmorpholine stearate (10.0 parts by mass), and sodium benzoate (20.0 parts by mass) prepared above were mixed to obtain a premixture. .. The obtained premix was put into a main material / auxiliary material feeder (rotation speed 80 rpm) of a twin-screw extruder (manufactured by ZHANGJIAGAANG LIANGUAN, TE40, L / D = 40), and the temperature was set to 100 to 120 ° C. It was put into the cylinder.

The screw was melt-extruded at a screw rotation speed of 350 rpm, and the extruded strand was rapidly cooled in a water tank and pelletized using a pelletizer to obtain the component (A).

≪Preparation of B-type silica gel≫
Commercially available B-type silica gel (spherical) was prepared.

≪Preparation of second rust preventive (N-methylmorpholine stearate)≫
N-methylmorpholine stearate was prepared in the same manner as described in << Preparation of the first rust preventive agent (N-methylmorpholine stearate) >> in << Preparation of component (A) >> above. ..

≪Preparation of (B) component≫
5000 g of B-type silica gel prepared above and 263 g of a second rust preventive were placed in a drum mixer and stirred at 25 ° C. for 5 minutes to obtain component (B). The content of the second rust inhibitor in the component (B) is 5% by mass.

≪Preparation of rust preventive composition≫
After obtaining the above component (B), 1055 g of the above component (A) was added to the drum mixer as it was, and the mixture was stirred at 25 ° C. for 1 minute to obtain the desired rust preventive composition 1. ..

(Example 2)
A rust preventive composition 2 was obtained in the same manner as in Example 1 except that the amount of the second rust preventive used was changed to 155 g. The content of the second rust inhibitor in the component (B) is 3% by mass.

(Example 3)
A rust preventive composition 3 was obtained in the same manner as in Example 1 except that the amount of the second rust preventive used was changed to 50 g. The content of the second rust inhibitor in the component (B) is 1% by mass.

(Comparative Example 1)
A comparative rust preventive composition 1 was prepared in the same manner as in Example 1 except that A-type silica gel was used instead of the component (B).

(Comparative Example 2)
A comparative rust preventive composition 2 was prepared in the same manner as in Example 1 except that the second rust preventive agent was not used in the preparation of the component (B).

(Comparative Example 3)
Only the component (A) prepared above was used as the comparative rust preventive composition 3.

(Comparative Example 4)
Only the component (B) prepared above was used as the comparative rust preventive composition 4.

<Evaluation>
[Rust prevention performance evaluation]
The rust prevention performance of steel was tested according to the method described in JIS Z1519: 2013. However, the judgment was based on the following judgment criteria. AHAC-SDS A-CW manufactured by Nihon Kenshi Co., Ltd. was used for polishing the test steel material.

A test steel material (a steel material with a diameter of 16 mm and a length of 13 mm (general steel material for polished steel bars SGD3) with a hole of 9.5 mm in diameter and depth at one end) is attached to a test container to form a rust preventive composition. Was put into a test container, and then the first rust preventive agent and the second rust preventive agent contained in the rust preventive composition were left as they were for 20 hours in order to diffuse into the container. Then, cold water at 2 ° C. was poured to cause dew condensation on the surface of the test steel material. Three hours after the condensation was formed, the test steel material was taken out, and the appearance of rust was visually confirmed and checked with a 6-fold loupe. Evaluation was made with n = 3 according to the following criteria, and the average evaluation results are shown in Table 1 below:
◎: No rust is confirmed with the naked eye. When observing with a 6x loupe, minimal rust within a few pieces is confirmed. ○: Several rusts can be confirmed with the naked eye. When observed with a 6x loupe, minimal rusting of up to 10 pieces is confirmed. Δ: Rust or discoloration is confirmed in a circumferential shape with the naked eye. ×: Rust or discoloration on the entire peripheral surface ×× : Significant rust.

[Hygroscopic evaluation]
Moisture absorption of component (B) used in Examples 1 to 3 and Comparative Example 4, A-type silica gel used in Comparative Example 1, and B-type silica gel used in Comparative Example 2 according to the method described in JIS Z0701: 1977. The rate was evaluated. If it was equal to or higher than the moisture absorption rate described in JIS Z0701: 1977, it was accepted, and if it was less than the moisture absorption rate, it was rejected. Since the comparative rust preventive composition 3 of Comparative Example 3 did not contain silica gel, the hygroscopicity was not evaluated.

The configurations and evaluation results of the rust preventive compositions of Examples and Comparative Examples are shown in Table 1 below.

As is clear from Table 1 above, it was found that the rust preventive compositions of Examples 1 to 3 are superior in rust preventive performance and moisture absorption performance to the rust preventive compositions of Comparative Examples 1 to 4.

1 Silica gel (B-type silica gel),
2 Rust inhibitor,
3 steam,
4 Work (rust prevention object),
5 Thermoplastic resin,
6 First rust inhibitor,
7 Second rust inhibitor,
8 Moisturizer (B),
9 Rust preventive material (A),
10 Rust preventive composition.

Claims (6)

A rust preventive material (A) containing a thermoplastic resin and a first rust preventive agent,
A hygroscopic agent (B) containing B-type silica gel and a second rust preventive,
A rust preventive composition containing. The rust preventive composition according to claim 1, wherein the content of the first rust preventive agent in the rust preventive material (A) is 5 to 50% by mass. The rust preventive composition according to claim 1 or 2, wherein the content of the second rust preventive agent in the hygroscopic agent (B) is 0.5 to 10% by mass. The first rust preventive is at least one selected from the group consisting of N-methylmorpholine stearate, N-methylmorpholine laurate, sodium benzoate, and benzotriazole, claim 1. The rust preventive composition according to any one of 3 to 3. The second rust preventive agent is at least one selected from the group consisting of N-methylmorpholine stearate, N-methylmorpholine laurate, and benzotriazole, according to any one of claims 1 to 4. The rust preventive composition according to item 1. The rust preventive composition according to any one of claims 1 to 5, wherein the thermoplastic resin is low-density polyethylene or linear low-density polyethylene.

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