JPS58117881A - Wax emulsion type corrosion inhibitor for car body - Google Patents

Abstract

PURPOSE:To obtain a wax emulsion type corrosion inhibitor for a car body having improved corrosion inhibiting power, sag and penetrating properties, etc. by adding an org. amine, a water soluble high molecular compound and water to a wax mixture of the oxidation product of wax with natural wax. CONSTITUTION:The oxidation product of wax having 10-60mg.KOH/g acid value prepared by oxidizing petroleum wax with a gas contg. oxygen at 100- 200 deg.C is mixed with natural wax to adjust the acid value to 4-30mg.KOH/g. To 10-50wt% of the wax mixture are added <=4 equiv. org. amine basing on the acid value of the wax mixture, <=0.5% water soluble high molecular compound and the balance water, or 0-10% film modifying agent is further added to obtain a wax emulsion type corrosion inhibitor. By the composition the average particle size of the emulsion is adjusted to about 0.1-5.5mum, and the corrosion inhibitor for a car body has improved penetrating and primary sag properties, dryability, water resistance, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a car body rust preventive agent. More specifically, regarding wax emulsion type rust preventive agents used for bag parts (hereinafter referred to as closed cross section parts) of automobile doors, bonnets, etc., it has excellent rust prevention properties, water resistance, and dryness without using organic solvents such as mineral spirits. It is durable and stable, and can be applied to narrow areas such as closed cross-sections of automobile bodies. The rust preventive agent does not drip (hereinafter referred to as dripping resistance), and
It is an object of the present invention to provide an excellent rust preventive that does not melt and sag (hereinafter referred to as secondary sag) even when heated to about 89'C after drying.

In recent years, there has been a strong demand for improved quality of cars, and the conditions and environments in which cars are used have become very wide-ranging.In particular, cars exported to cold regions such as Canada and North America require rock salt to be sprayed to prevent roads from freezing in the winter. The environment for striped snow has become even more difficult due to the deterioration of the body parts of vehicles due to corrosion caused by snow melting agents such as It's getting tougher.

For the above reasons, conventionally, the closed cross section has been coated with a rust preventive agent prepared by dissolving wax, a metal salt of a wax oxide, etc. in an organic solvent such as mineral spirit.

However, since conventional rust preventives contain organic solvents, the effects of organic solvent fumes on the human body during the coating process.
It seriously harmed the working environment, such as the danger of fire. Therefore, if the wax is made into an emulsion, the working environment can be improved, but the desired rust prevention, water resistance, dripping properties, permeability, and drying properties cannot be satisfied, making it impossible to use.

Conventionally, wax emulsion type rust preventive agents exist as general rust preventive agents, but their composition is 8% wax and oil.
This is emulsified by adding rust preventives and emulsifiers,
Alternatively, there are wax [composed of 1,2-diethylaminoethanol, water, and a leveling agent, or compositions in which fatty acids are added to this, but these conventional wax emulsion type rust inhibitors have poor rust preventive power and water resistance. sex, imageability, penetrability,
The drying properties are not good enough for rust prevention on the closed eyelids.

In view of the above-mentioned current situation, the present inventors have conducted intensive studies to develop a wax emulsion-type rust preventive agent that has excellent rust prevention properties, water resistance, dripping properties, permeability, and drying properties even when wax is emulsified. As a result, polar waxes are easily emulsified as amine salts in the preparation of wax emulsions, but have poor rust prevention and water resistance. On the other hand, pyrophoric V-nox has excellent rust prevention and water resistance, but it cannot be emulsified. It was discovered that polar wax (
The composition of wax oxidation products) and non-polar wax (natural wax) is specific, and the emulsion particles are only 0.05 to 5.
．． Rust prevention, water resistance, dripping resistance,
The emulsion viscosity is 800-12 with excellent permeability and drying properties, and the addition of a water-soluble cylindrical molecular compound.
The present invention was developed based on the finding that the dripping properties and permeability are improved by setting the temperature to 00 cp.

Another feature of the present invention is the method for producing the emulsion.

That is, the present invention is a so-called direct method in which an emulsion is produced by gradually adding and stirring a wax mixture to an aqueous phase.
There is an inversion method in which a w10 type emulsion is first created, water is added to the colander, and then the emulsion is inverted to finally create a 0/w type emulsion.In this inversion method, the emulsion is The viscosity increases and uniform stirring becomes difficult.
Therefore, a cheap emulsion is not produced.

Figure 1 shows the frequency distribution of emulsion particle diameters prepared with the same composition by the direct method and the inversion method. Compared to the direct method, the inversion method has a wider distribution, or smaller distribution, and the emulsion properties are lower. Moreover, the oil phase and water phase tend to separate easily. Further, FIG. 2 shows the relationship between the average particle diameter of the emulsion and the rust prevention ability, permeability, blemish resistance, drying property, and water resistance.

According to this, the emulsion average particle size is 0.1 to 5.5μ
Rust prevention, permeability, sag resistance,
It can be seen that the drying properties and water resistance are good.

That is, the present invention uses petroleum wax at a temperature of io.

~200℃, wax oxidation product with an acid value of 10 to 60 T.KOH/g oxidized with oxygen-containing gas is mixed with natural wax and the acid value of the wax is II to 80 T.KOH/g (7
) 10 to 50 weight-1 based on the entire mixed wax rust preventive agent mixed so that the amount is within the range of 10 to 50% by weight, plus organic amines and water-bath polymer compound rust preventive agents having an amount of 4 equivalents or less based on the acid value of the mixed wax. A wax emulsion type rust preventive agent for car bodies that is characterized by comprising 0 to 10% by weight of the entire rust preventive agent, with the remainder being water.

The polar wax used in the present invention has an acid value l obtained by reacting one or more types of polyethylene wax, paraffin wax, microcrystalline wax, and α-olefin wax with an oxygen-containing gas in a conventional manner.
The reaction product of 0 to 60 W/KOH/9, that is, the above-mentioned waxes, can be oxidized by the usual method with an oxygen-containing gas such as oxygen or air. Preferably. The reaction temperature is 100-20
0°0, preferably at 120 to 170"C.The above oxidation reaction is preferably carried out using a catalyst, such as a transition junction of manganese, cobalt, etc. Manganese acid, manganese phosphate, potassium permanganate, cobalt naphthenate, cobalt phosphate, etc. are used, and in addition to these, ordinary oxidation catalysts can also be used.

As for the degree of oxidation, the acid value of the reaction product is 1O-p-KO
If H/Q is not reached, the emulsion will become unstable,
Furthermore, if the acid value is higher than 607·KOH/g, the antirust ability of the emulsion will be reduced. Specific examples of the nonpolar wax include microcrystalline wax, paraffin wax, polyethylene wax, and α-olefin wax.

In the present invention, it is essential to use the polar wax and the non-polar wax in combination, and as shown in the comparative example, it can be seen that there is a synergistic effect on rust prevention. The mixing ratio of the wax oxidation product and natural wax is such that the mixed wax acid value is 4~a o rr9゛KOH/
p (7) 6 in the range means the acid value is 4 q・KOH/li
The average particle diameter of the emulsion is 20 times or more, resulting in poor emulsion stability, and the emulsion with a ratio of less than 80 KOVg tends to gel. Further, if the mixed wax is added by less than 10 weights, the antirust ability will be insufficient, and if it is more than 50 weights, it will gel, which is not preferable.

Among the properties required for the emulsion-type rust preventive agent of the present invention, sag resistance and permeability are contradictory properties, and the means to improve sag resistance is generally to increase non-volatile content such as wax, or wax oxidation. This is achieved by increasing the viscosity by increasing the amount of amine salt in the product, but the permeability decreases. In addition, the permeability can be improved by increasing the amount of amine violet or by adding alcohols to improve leveling, but on the other hand, the sagging property decreases. As a result of various studies, the present inventors added a water-bathable polymer compound of 0.5 cm or less to increase the viscosity to 400 to 1600 cp, preferably Visoo.
It has been found that when it is set to ~1200 Cp, it is possible to have both sagging properties and permeability.

The amount of usable water-soluble polymer compound is 1t10,000 molecules.
The following polyacrylic acid, alkali salts of polyacrylic acid,
Polyacrylic acid oxyesters JN re-methacrylic acid, alkali salts of polymethacrylic acid, polymethacrylic acid oxyesters, molecular weight greater than or equal to 10.000, molecule f
Polyethylene glycol with i20,000 or less, molecule J
Polyvinyl alcohol with an IE of 100,000 or less, polyethyleneimine with a molecular weight of 500,000 or less, carboxymethyl cellulose and its alkali salts with a molecular weight of 250,000 or less, molecular weight l
Examples include inbutylene-maleic anhydride copolymer alkali salts with a molecular weight of 0,000 or more, polyethylene oxide with a molecular weight of 5,000,000 or more, and the addition cap is 0.5 or less, preferably 0.01 to 0.51, to form an emulsion. Total viscosity increase,
Improves dripping properties during application.

In addition, a polymer compound is used as a film modifying material to form a film after application of the emulsion type rust preventive agent of the present invention and to prevent the film from sagging when heated to about 80°C. is a polymer compound that is liquid at room temperature and non-water bathable, such as α-olefin oligomers with a molecular weight of 8,000 or less, polyethylene, polypropylene, polybutene, polyisobutylene, and molecule 1111 with a molecular weight of 4,000 or less.
0000 or less liquid 1.2= or 1.4-polybutadiene, liquid chloroprene rubber, liquid polypentadiene molecule j412000 or less, polyoxyethylene polyoxypropylene glycol, polypropylene glycol,
Liquid polyamide with molecules 11,700 to 5,000, molecules t
Polymethacrylic acid esters having a weight of 80,000 or less can be used, and the addition cap is in the range of 0 to 10 weight tqk.

Further, 7-lephenol or higher alcohol to impart leveling properties to the cedar hxa film, and dioctyl sebacate to impart cold resistance to the film are also used as necessary.

The 11 amine used is an alkylamine having 8 to 18 carbon atoms, an alkanolamine morpholine, etc., and the hexaamines include hexylamine, trimethylamine, laurylamine stearylamine, monoethanolamine, jetanolamine, triethanolamine, N, N-dimethylethanolamine, N,N-diethylethanolamine, N,N
-Diimpropylethanolamine, N,N-dibutylethanolamine, N-(β-aminoethylethanolamine, N-methylethanolamine, N-methyljetanolamine, morpholine, etc.) kill in a degraded manner.

Next, in order to concretely explain the present invention, the present invention will be described with reference to Examples and Examples, but the scope of the claims of the present invention is not limited to the specific examples illustrated here.

Leprosy Example 1 Powdered potassium permanganate 1O-2 mol/ky tt in polyethylene wax 1OJc9 with molecule ji 2000
, txl 150°C, normal pressure F, air was blown into the reaction mixture for 7 hours, and after removing low-boiling oxides, it was filtered to obtain an oxide having an acid content of 42 and a saponification value of 60. This oxide 5If
9 to microcrystal wax 15 to 9 to 180”C
and then add 0.7 kg of laurylamine) to 30
Stir and mix. In a separate container, water 1512, carboxymethyl cellulose Na salt 1.5 ~ and propylene glycol 0.119 were uniformly stirred and mixed, heated to 90°C or higher, and the molten wax was gradually added dropwise to the emulsion type barrier. Manufactured a rust agent.

Examples 2 to 6 Six tanks of emulsion-type rust preventives were produced in the same manner as in Example 1 under the conditions shown in Examples 2 to 6 of the first group.

Comparative Examples 1 to 8 Emulsion-type rust preventives for two oaks were produced in the same manner as in Example 1 under the conditions shown in Comparative Examples 1 and 2 in Table 1. Further, a conventional solvent-type rust preventive agent was manufactured using the composition ratio shown in Comparative Example 8 in Table i1.

In order to clarify the performance of the emulsion type rust preventive agent of the present invention, it was tested using the following test method, and the results are shown in Table 2.

Rust prevention test: Reduces the amount of rust generated after 6 months of exposure according to JIS K2246.

The degree of rust occurrence is 0.1NIO111~25.25~5
0, and divided into 51 to 100, respectively A class, B class, 0
It was indicated as grade, D grade and E grade.

Salt water spray Conforms to JISK2246. However, the degree of rust occurrence after 600 hours after coating with a film thickness of 150±20μ was shown.

The film thickness at the time of measurement was 50μ.

- Lower part of sagging test plate (SPOO rod 210 x 300 am) 200
Mask U and spray the rust preventive agent of the present invention at a pressure of 5 vc.
A film thickness of 150 μm was applied under m2 conditions, and then the masking was removed and the length of the sag was measured after standing vertically in a constant temperature room at 50° C. for 80 minutes. The viscosity of the rust preventive agent before spraying is 800 centimeter voice (B type accuracy it 60 rpm
).

Two permeability test boards (5 pcc Hazuki 70
1trLt of the rust preventive agent of the present invention was dropped onto the 1st part bent outward at an angle of about 60 degrees (position), and after standing vertically for 24 hours, the bent plate was removed and the penetration length was measured.

The rust preventive agent of the present invention was sprayed on a drying test board (SPOCm210X100IIJI) at a pressure of 5'9/cta2 and a film thickness of 150μ.
A coating of ±20μ was applied and left undisturbed for 30 minutes at room temperature. If the coating did not feel sticky when touched with a finger, it was judged to be acceptable, and if it was sticky, it was judged to be unsatisfactory.

Spray the present invention ±20μ rust preventive agent onto a water resistance test plate (5pcc rod 210Xil 100mm) at a pressure of 5 kg/cra2, film thickness 1) 11
After application, the sample was left to stand for 24 hours, and then immersed in tap water at 20''C for 72 hours, and changes in the state of membrane rupture were visually observed.

As explained above, the wax emulsion-type rust preventive agent for the car body of the East car is made of an oxidized mixed wax of 10 to 50 weight aS, which has been acclimatized to petroleum wax, and an organic -/'min of 10 to 50% heavy aS, which is more than the nominal equivalent to the acid value of the mixed wax. water bathing polymer compound 0.5
Layering: The film modifier θ ~ 10 coulum, residual water, etc., has excellent rust prevention ability, dripping property, and permeability, and has great industrial utility value.

[Brief explanation of the drawing]

51JJ1 Figure (4) is a graph showing the relationship between the production method (direct method) of the rust preventive agent of the present invention and particle size distribution, and Figure 41 (B) is a graph showing the IA manufacturing method (inversion method) of the rust preventive agent of the present invention and the particle size distribution. Graph showing the relationship with the distribution, Figure 2 (4), (B), (C)
, (D) and [Yes]) are diagrams showing the relationship between emulsion particle size and rust prevention power, permeability, -thickness, drying property, and water resistance, respectively, of the present invention. Figure 2 (A) Hirameku L-nin (μU thing rice! 1 company f) (C) CD) (E) Imo 4υ#L Oψno 1400 Procedural amendment November 19, 1980 1, Incident Indication of Showa 5 (Patent Application No. 2, Year I) No. 4791 No. 2, Name of Investigation: Wax Emulsion Type Rust Preventive Agent for Small Bodies 3, Relationship between the person making the amendment and the case: Patent, Ending [Applicant (399) Nissan Motor Co., Ltd. Daido Chemical Industry Co., Ltd. 5゜6 Subject of amendment Detailed explanation column of the invention in the old specification, drawing 7, contents of amendment (as attached) l Specification No. 4, line 8, 10.05~ 5.5μ” to “0.
1 to 5.5 μ'' and ``removal'' in line 19 of the same page to ``gradually''. 2. Figures 1 (A) and (B) in the drawings are corrected to the attached corrected figures Figures 1 (A) and (B). Figure 1 (A) ('B)

Claims (1)

[Claims] L Petroleum wax is oxidized with an oxygen-containing gas at a temperature of 100 to 200°C, resulting in a wax oxidation product with an acid value of 10 to 60 rI9/KOVg-, and natural wax is mixed to create a wax with an acid value in the range of 4 to 80 n9/KOH/9. 10 to 50% by weight of the mixed wax mixed together, plus 0.5% by weight or less of an organic amine with an acid value of 4 or less and a water-soluble polymer compound based on the acid value of the mixed wax, and a film modifier as required. θ〜
A wax emulsion type rust preventive agent for car bodies, which is characterized by consisting of 10% of its weight and the remainder being water.