JPS58125450A - Applied can having excellent sulfuration blackening denaturation resisting property - 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 The present invention relates to a coating plate with excellent resistance to sulfurization and blackening.
In more detail, the present invention relates to a painted iron that prevents the metal material of the can from becoming black due to sulfurization due to the reaction of the resin protective coating on the inner surface of the painted iron with hydrogen sulfide.

Conventionally, in food canning in which various agricultural products, livestock products, marine products, or processed products thereof are filled into cans made of tin-plated steel plates (tin plate), the round surface of the can turns black, which is called sulfide island change. Corrosion is known to occur. This sulfide blackening is caused by the decomposition of some of the sulfur-containing ino acids contained in food proteins, etc. mentioned above, generating trace amounts of mercaptan in hydrogen sulfide, which reacts with metal tin to form tin sulfide. It is said that there is.

In order to prevent sulfide blackening of tin cans, it is common practice to paint the surface of the tin with an organic resin paint to create what is called an internally coated tin can. Prevention is not complete, and it is recognized that considerable sulfide blackening still occurs, especially in processed areas.

Some attempts have already been made to eliminate this sulfide blackening of tin cans with internal coatings. One such attempt was
One method is to mix zinc oxide into the paint to absorb the generated hydrogen sulfide in the form of zinc sulfide, and the other is to mix aluminum flakes into the paint to completely remove the tin plating layer. This is what they are trying to hide. However, when such pigments are mixed into the protective coating of metal materials for iron making, the workability of the material itself becomes extremely poor.
The desired objectives have not yet been achieved.

According to the present invention, when a quinone aldehyde resin or a quinone phenol aldehyde resin is used as at least a part of the film-forming component of the inner surface protective coating for cans, the quinone skeleton in the resin becomes hydrogen sulfide or mercaptan. It has been found that sulfide blackening can be effectively prevented without deteriorating the flavor characteristics of the contents of the can.

That is, according to the present invention, in a painted can provided with a protective resin coating on the inner surface, the lip protective resin coating contains a quinone aldehyde resin or a quinone phenol aldehyde resin as at least a part of the coating film forming components. , the protective film has a quinonic carbonyl group of 10 mm (equivalene)/100
Provided is a coated can with excellent sulfurization resistance and blackening resistance, which is characterized by containing R-resin at a concentration higher than that of R-resin.

As already mentioned above, the present invention is based on the finding that the quinone skeleton incorporated into the molecular chain of the resin effectively absorbs and reacts with hydrogen sulfide or mercaptan.

FIG. 1 of the accompanying drawings shows the changes in the concentration of hydrogen sulfide over time when granules of various resins are filled in a container with a constant volume of hydrogen sulfide. Moreover, FIG. 2 shows the results of nine cases in which methyl mercaptan was filled in place of hydrogen sulfide and the same test was conducted. According to these results, even when known epoxy resins and resol phenol aldehyde resins are used, some absorption of hydrogen sulfide and monothyl mercaptan occurs, but when the quinone aldehyde resin or i-quinone resin according to the present invention is used,・When phenol/aldehyde resin is used, the resin of the present invention such as hydrogen sulfide or methyl mercaptan is coated, and fluorescent X-ray analysis of the coated lI tube, which absorbs 1A of water sulfide, shows that the commonly used phenol/epoxy It was found that it contained a large amount of sulfur element compared to resin. When this paint film was stored under high-temperature vacuum and subjected to a similar fluorescent X-ray analysis after the funeral, it was found that it contained more than 10 times as much sulfur as a normal paint. It is predicted that not only this, but also some of the reaction occurred.

In the O-coated can of the present invention, the reaction mechanism between the quinone skeleton incorporated in the resin and hydrogen sulfide or expanded mercaptan has not yet been fully elucidated, but nuclear magnetic resonance apparatus using a model material According to the analysis results, several types of quinonic carbonyl groups are generated after reacting with hydrogen sulfide, etc., and the formation of hydroxyl groups is also observed according to the analysis of infrared absorption spectra. , this reaction is estimated to be as shown in the following equation.

According to the present invention, the gm*m coating film present on the inner surface of the iron quickly absorbs hydrogen sulfide or mercaptans generated from the contents of the can, and reacts with the hydrogen sulfide or mercaptans produced by metal materials such as roundings and tinplate. can significantly suppress sulfide blackening. Moreover, the reaction with hydrogen sulfide and mercaptans produces only water bulk and hydrocarbons as by-products, and the flavor retention of the contents is also good. An additional advantage is that the coated metal material has excellent processability into one piece because it is not blended.

Conventionally, in the Todoroki industry, much research has been conducted to develop paints with excellent sulfurization resistance and thermal modification resistance.

However, most of these studies aim to prevent sulfide blackening of metal materials by improving the barrier properties (1-breakability) of the coating film itself, and in this case, hydrogen sulfide etc. are consumed. Even if the amount is extremely small, the new problem of degrading the flavor of the contents due to its unique odor has to be solved. . In contrast, in the present invention, hydrogen sulfide, etc. generated from the contents of the can are quickly absorbed into the protective coating film and fixed by reaction in the bottom coating film, thereby preventing sulfide blackening. At the same time, the problem of flavor deterioration of the contents is also solved.

In the present invention, the pupil-retaining coating film on the inner surface of the chisel has a quinonic carbonyl group t, 10<requivalent/100, and a resin or more, and a special #c50 to 950 mm equivalent/100.
It is also an important feature to contain the resin at a high concentration. Conventionally, the reason why coating films containing resol-type phenol aldehyde resins exhibit a unique golden coloration is because part of the phenol skeleton in this coating resin has been changed to a quinone skeleton. It is said that However, the concentration of quinonic carbonyl groups in conventionally used resol-type phenolic aldehyde resins is as low as 5 mIvalene)/10 (HF resins, and these O11 fatty acids Figures 1 and 2 As shown, the reactivity with hydrogen sulfide etc. is also low.

In the present invention, by setting the concentration of the quinonic carbonyl group within the above-mentioned range, hydrogen sulfide etc. generated from the contents can be quickly captured in the coating film.

In this specification, the concentration of a quinonic carbonyl group is determined by redox titration using the oxidizing property of a monocyclic polyhydric phenol represented by the following formula. Alternatively, the S degree can also be determined from the characteristic absorption of the quinonic carbonyl group in the infrared absorption spectrum.

The protective resin coating film in the paint can of the present invention is made of quinone aldehyde resin or quinone phenol aldehyde resin so that the moldiness of the quinonic carbonyl group is within the above-mentioned range when the final protection III coating is used. It can be obtained by using it as a film-forming component.

This quinone aldehyde resin is obtained by condensation polymerization of a monocyclic phenol and an aldehyde under conditions known per se, and oxidizing the resultant as necessary. On this occasion,
If a combination of polyhydric phenol and monohydric phenol and/or bisphenols is used, quinone, phenol,
An aldehyde resin is obtained.

As the monocyclic polyhydric phenol, in the following formula, R represents a hydrogen atom, a carboxyl group, a hydroxyl group, an alkyl group, a ξ) group, a nitro group, a sulfonyl group, a cyano group, or a halogen atom. Hydrolic phenols are preferred, and it is particularly desirable for the 2@O phenolic hydroxyl group in the above general formula (5) to be in the para position for the production of the resin.

Suitable examples of the heptanenol of the above general formula (3) include hydroquinone, catechol, methylhydroquinone, pyrogallol, etc., with hydroquinone and methylhydroquinone being particularly preferable. The polyhydric phenol used is preferably difunctional or more polyfunctional with respect to aldehyde, but -functional phenols can also be incorporated into the polymer chain in the form of polymer chain terminals.

When producing quinone aldehyde resin, the above general formula (
The polyhydric phenol 5) can be used alone or in combination with other phenols. Examples of phenols that can be used in combination include monocyclic-valent phenols and nine-polynuclear phenols in which one phenolic hydroxyl group is bonded to one ring. As a monocyclic monovalent phenol, ℃ is a trifunctional phenol, for example, in the formula, R3 is a hydrogen atom, and 9 is a monovalent hydrocarbon group or an alkoxy group. , Kamo-cresol, Kamo-ethylphenol, 3.5-xylenol, Hino-methoxyphenol, etc.; difunctional phenols, such as R, where R1 has the above-mentioned meaning, R is a hydrogen atom, 1
difunctional phenols represented by a valent hydrocarbon group or an alkoxy group, in which two of the three groups Ex are hydrogen atoms and one is a hydrocarbon or alkoxy group; -Cresol, p-cresol, p-tart-butylphenol, p-ethylphenol, 2,5-xylenol, 2
．． 5-xylenol, c-t-detoylphenol,
p-cyclohexylphenol, p-phenyl phenol, nol, etc. - Natural phenols, for example, in the above general formula (2), one of 5@01RtO is a hydrogen atom and two are hydrocarbon groups or alkoxy Examples of such phenols include 2.4-xylenol and 2.6-xylenol. On the other hand, polycyclic phenols include tetrafunctional phenols, such as a direct bond or a divalent bridging group, especially an alkylidene group having 10 or less carbon atoms, -〇-1-S-1-SO- 1, especially 2,2-bis(4-hydroxyphenyl)furopane [bisphenol A], 2,2-bis(4-hydroxyphenyl, J'L/)butane [bisphenol B] , 1.1-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)methane [bisphenol F], 4.4'-dihydroxydiphenyl, and 4.4'-dihydroxydiphenyl ether.

As the aldehyde, formaldehyde is preferred, but it goes without saying that other aldehydes such as acetaldehyde, propionaldehyde, etc. can be used.

When producing resins, the condensation of phenols and aldehydes mentioned above is carried out using alkaline catalysts such as ammonia, caustic soda, hydroxide! It is advantageous to carry out the reaction in the presence of magnesium, calcium hydroxide, etc. In other words, condensation polymerization in the presence of an alkaline catalyst not only yields a resol-type resin that is convenient for coating film formation, but also allows the oxidation reaction shown by the following formula to be easily carried out in an air atmosphere under alkaline conditions. Therefore, there is an advantage that a resol-based quinone aldehyde resin or a resol-based quinone phenol aldehyde resin can be easily obtained without any special oxidation treatment. Monocyclic polyhydric phenols incorporated into ceramics and resins are not completely converted to quinones. This is because these monocyclic phenols are converted to quinones even under the baking hardening conditions of the coating film.

Further, the above-mentioned nine phenols and aldehydes can be condensed and polymerized in the presence of an acidic catalyst such as oxalic acid, hydrochloric acid, phosphoric acid, etc., and used as a Nogelac m resin.

Further, in producing the resin, the aldehyde is preferably used in an amount of 0.7 to 3.0 moles per phenol ring, and the molecular weight of the resin is preferably in the range of 300 to 1,500. Furthermore, 0.0% of total phenols.
It is desirable that 5 to 95 moles of monocyclic polyhydric phenol occupy 1 to 100 moles of phenol. That is, trees derived solely from monocyclic polyhydric phenols tend to be somewhat brittle in nature, and have the disadvantage of poor paintability and processability, but they can be combined with other phenols such as bisphenols. Depending on the number of uses, paintability and workability can be improved.

The above-mentioned quinone aldehyde resin or quinone phenol aldehyde resin may be treated with known modifiers, such as fatty acids, polymerized fatty acids, resin acids, rosins, drying oils, alkyd resins, etc., as long as their essence is not lost. It can be used alone or modified with F12 or more.

In the present invention, quinone aldehyde resin or quinone phenol aldehyde resin can be used alone as a coating for the inner surface of a chisel.
From the standpoint of corrosion resistance, etc., it is often desirable to use it in combination with other film-forming components. Such resins include resol type phenolic resin, epoxy resin,
One type or 21!1 of vinyl acetal (butyral) resin, phenoxy resin, acrylic resin, xylene resin, etc.
The above combination pipes can be mentioned. Epoxy resin is particularly preferred, and quinone aldehyde resin or quinone phenol aldehyde resin and epoxy resin are mixed in a ratio of 5:9.
It is preferable to use them in combination at a weight ratio of 5 to 95:5, especially 20:80 to 80:20.

It also contains novolac amount quinone aldehyde resin.

Kino/phenol aldehyde resin has self-curing properties to some extent, but it is inferior to Resol M, so when using the novolac type, regular Resol 11 phenol aldehyde resin is used.
It is also possible to use aldehyde resins in combination as curing aids.

These resins are applied to the metal can material in the form of a solution dissolved in an organic solvent. As a solvent, aromatic hydrogen chloride solvents such as xylene and toluene; various ketones such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone;
Various cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; examples include dia-7ton alcohol and isophorone;
As long as it can be dissolved, it is not limited to the above-mentioned item 94,
Any organic solvent can be used. These organic solvents are generally used in an amount such that the solid content (non-volatile content) is 20 to 50%. Catalysts, driers, lubricants, lubricants, anti-pinhole agents, or other known ingredients can be added according to the formulation.

For acid-curing resins, as a catalyst, in addition to usual acid catalysts such as phosphoric acid, phosphoric acid amine salts, and p-toluenesulfonic acid, so-called Lewis acids can also be used. The catalyst resin component can be used in an amount of 0.2 to 5X.

In addition, lead, cobalt,
Salts of higher fatty acids such as zinc and manganese, resinates and naphthenates can also be used as drying agents.

Furthermore, in order to provide lubricity during processing of the coated metal material, lubricants known per se such as aliphatic hydrocarbon lubricants such as liquid paraffin, synthetic paraffin, petroleum wax, and petrolatum; organopolysiloxanes and the like are used. Silicones; higher fatty acids such as stearic acid; amides such as higher fatty acid amide, ethylenebis fatty acid amide, fatty acid jetanolamide; fatty acid esters such as stearic acid %-budel, hydrogenated rosin methyl ester; hydrogenated edible fats and oils; Natural waxes such as montan wax, carnauba wax, beeswax, wood wax, and lanolin; propylene glycol alginate, etc. can be blended, and these lubricants can be blended in an amount of 30X or less, especially 20% or less per resin. .

As the plasticizer, per se known plasticizers such as phthalic acid diester, dibasic fatty acid diester, epoxy substitute, etc. may be used as desired.

As the pinhole prevention agent, silicone resin, surfactant, vinyl butyral resin, etc. can be used.

Of course, this paint number contains zinc oxide, magnesium oxide,
Pigments or fillers such as titanium dioxide, alba flake pigments, and tin powder can also be blended.

The above-mentioned nine coating compositions can be applied to the surface of metal materials for cans such as tin-plated steel plates and surface-treated steel plates by dipping coating, spray coating,
It can be applied by electrostatic coating, electrophoretic coating, brush coating, roller coating, various coating methods, etc. The application rate of this paint is between 2 and 100 r/indr2, especially 3 r/d2, on a dry matter basis, so that an optimum combination of corrosion resistance and processability is achieved.
It is desirable to set it in the range of 20 f/s” to 20 f/s.

Baking of the coating film can generally be carried out at a temperature of 150 to 250° C. for 1 to 20 minutes.

The coated metal material is subjected to various processes known per se, such as side seam forming processing, drawing processing, deep drawing processing, ironing processing, etc.
Various processes such as lunge processing, bending processing, neck-in processing, bead processing, curl processing, crimping processing, stamp processing, punching molding, press processing, etc. Shape. Of course, this coated metal material can be subjected to a plurality of different types of processing to form it into a desired cylinder or the like.

Of course, instead of painting the metal material before forming, it is also possible to paint the inner surface of the cylinder formed by drawing or drawing-sealing by spraying or the like.

The inner surface coated iron according to the present invention is useful as a can for preserving various vegetables, fruits, fruit juices, marine microcrystals, livestock products, etc.

The invention is illustrated by the following example.

Example 16 Quinonic carbonyl group t480 millivalene)/1
A paint consisting of SO:SO of chino/aldehyde resin with 0C1 resin and epoxy resin (Epicote φ1009) was applied to electric tinplate and baked at 200°C for 7 minutes to give a coating thickness of 5 cm. Using this, we made a 6-piece can with an inner diameter of 86mm and a can height of 45EII.
Filled with 0.5tlI solution of cysteine as contents 11
After retorting at 5°C for 90 minutes, the sulfurization resistance was examined.

As a control product, resole phenol resin consisting of bisphenol A and formaldehyde: eboxy resin = 50:
No. 50 was coated on an electroplated tin plate to a thickness of 5 μm, and then tested by filling it with the same cysteine solution. It was found that the product of the present invention is excellent in sulfide blackening.

Example Z Quinonic carbonyl group t-440 milliequivalent 7
A paint made of SO:SO of quinone phenol aldehyde resin and epoxy resin containing 100F resin was applied to electric tinplate and baked at 200°C for 7 minutes to produce a coated plate with a coating thickness of 5 sm. In the same manner as in Example 1, a model solution was filled in a can and the resistance to sulfurization and blackening was examined.

As a control product, the phenol component of the raw material is bisphenol A.
and p-cresol 080:20 A paint consisting of a 50:50 mixture of a phenolic resin and an epoxy resin (Ebicoatna 1009) was applied to a fully electroplated tin plate.
After iron making, a model liquid was filled and a comparative test was conducted.

It was found that the product of the present invention is excellent in terms of resistance to sulfurization and blackening.

The results of Examples 1 and 2 are shown in the table below.

Table 1 The numbers in the sulfurization blackening resistance table indicate the evaluation of each test result based on the following criteria.

5... Sulfur black discoloration None 4... β Slight appearance 6... l Slightly I 2... I Clear 1... I Appears on the entire surface Example 3゜ Nine-quinone phenol used in Example 2・Electroplated tinplate <ET> and Tin Frissol (TFS) are used as paints containing 50:50 aldehyde resin and epoxy resin.
This coating was applied to give a coating thickness of 5 μm. Using this painted board, a can with a height of 45 and an inner diameter of 83 Ij was manufactured, and the contents were used for boiled cod and seaweed crab tests. Heat sterilization conditions are 110℃-60 minutes and 110℃-
90 minutes.

As a control product, the phenolic components are bisphenol A and p
- resol type phenolic resin consisting of cresol 80:20 and epoxy resin 80:20.50:5 respectively
A material coated with a paint consisting of 0 was used. Comprehensive bonding properties such as sulfur black discoloration resistance, flavor pupil retention, etc.

Table 2 shows the test results. The product of the present invention was comprehensively superior to the control product.

Table 2 The letters in the sulfurization resistance table indicate the overall number of sulfurization resistance and flavor retention, with the best one being 5 and the lower the number, the worse the performance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the change in hydrogen sulfide concentration over time when a paint resin is clouded in a container to generate a certain amount of hydrogen sulfide. FIG. 2 is a diagram similarly examining the change over time of methyl mercaptan. The curves A to D in the figure are as follows. A: Used as a control, which only generated hydrogen sulfide. B: Epoxy resin as paint resin (Epicote φ10
09) as a friend. Contains C-niresol type phenolic resin. D: Contains quinone aldehyde resin. Patent applicant Kishi Moto Introducing procedural amendment (voluntary) April 26, 1980 Director General of the Japan Patent Office Shima 1) Haruki Tono1, Incident indication 4IR Ken 57-48 No. 2, Name of the invention Excellent sulfide blackening resistance 3. Relationship with the case of the person making the amendment Address of the patent applicant? Fil J1 Prefecture Yokohama City Kanazawa Ward Todoroki A4459m26 Name Kishimoto Sho 4, generation
Mr. 105 Address: Atagoyama Attorney Building 5, 1-6-7 Atago, Minato-ku, Tokyo, No date of amendment order 1) The second line from the bottom of No. 4 of the specification states, "Filled with hydrogen sulfide." is corrected to ``Hydrogen sulfide is generated to a constant concentration.'' (2) In the first line of page 5, replace "filling" with "generating".
I am corrected. that's all

Claims (1)

[Scope of Claims] (1) In a painting iron having a protective resin coating on the inner surface, the armpit resin coating contains quinone aldehyde resin or quinone phenol aldehyde resin as at least a part of the coating film forming components. and the protective coating film contains quinonic carbonyl groups at a concentration of 10 mEquivalent/100F resin or more. ■ The quinone aldehyde resin or quinone phenol aldehyde resin has the following formula, where R is a hydrogen atom, a carboxyl group, a hydroxyl group, an alkyl group, an abano group, a nitro group, a sulfonyl group, a cyano group,
Represents a halogen atom. The coating iron according to claim 1, which is obtained by polycondensation of a phenol containing a polyhydric phenol represented by the following formula and an aldehyde component, followed by oxidation. (3) The protective resin coating film has a content of 5 to 90% per quinone aldehyde resin or quinone phenol aldehyde resin.
A coating plate according to claim 1, which contains 0% by weight of other film-forming resins.