JP2002020655A - Heat-resistant ink for marking - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resistant ink for marking not only excellent in fast curing property but also remarkably excellent in heat resistance and applicable for marking of a flaw detection point or the like without any problem when various metal articles are continuously manufactured. SOLUTION: The heat-resistant ink for marking comprises at an appropriate ratio (a) a straight silicone resin, (b) a modified silicone resin, (c) an amino-based crosslinking agent, (d) a colorant, (e) a curing catalyst and (f) a volatile solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marking ink which is fast-setting and excellent in heat resistance. Marking flaw detection parts detected by non-destructive flaw detection methods such as wire rods to facilitate detection in the downstream process, or when manufacturing multiple products on one production line, as a kind of intermediate part The present invention relates to a marking ink which is used for marking dots, lines, characters, figures, and the like when performing sorting, lot management, and the like, and which is excellent in fast curing and excellent in heat resistance.

[0002]

2. Description of the Related Art Marking inks are used to apply identification marks to surfaces of various metal products, synthetic resin products, and rubber products (including intermediate products such as plates, bands, pipes, and wires). Liquid color materials are the most commonly used, and metal materials manufacturers mark flaws detected by flaw detection tests on plates, strips, pipes, and wire rods, and select sorting and repair locations in the next process. This is a marking used for clarification or sorting such as lot management.

[0003] In such marking, marking ink is adhered to a flaw detection portion, and the flaw detection portion is extracted at a quality control portion on the downstream side to prevent shipment of defective products, thereby ensuring quality reliability. This is an important step.

[0004] Marking inks used in such applications are a) that they can be reliably and promptly adhered to flaw detection parts in response to a marking signal, and b) when the material to be marked moves on a line, In the case where the mark is transferred or wound after marking such as a band-shaped mark-receiving material, the mark is not transferred to the non-mark portion in the wound state,
C) When applied to a material to be marked which may be wound in a state where it has not been sufficiently cooled after heat treatment, such as a metal band, for example, the material is softened and melted at the winding temperature. D) The substrate should be excellent in heat resistance so that the mark will not be transferred to the substrate. D) In ultrasonic flaw detection, etc., water often adheres to the surface of the material to be marked. To easily adhere to the surface.

[0005] The most widely used marking ink at present is an ink in which an alkyd resin is used as a main curing component, and a modified silicone resin, a pigment and a volatile solvent such as acetone are mixed with the alkyd resin.

[0006]

However, the above-mentioned marking ink is excellent in quick-hardness and heat resistance as compared with ordinary marking ink, but at a curing speed of about ten and several seconds at most. Approximately 60-95 ° C., which cannot be said to satisfy the demands of consumers who demand higher speed for improving productivity.

[0007] Therefore, in order to adapt to recent high-speed continuous production and adaptation to use in a high temperature state, it is required to further improve rapid hardening and heat resistance. The present invention has been made in view of such circumstances, and its purpose is to have a quick-hardening property that can be sufficiently adapted to high-speed continuous operation, and to soften even when the marked material is in a considerably high temperature state. -To provide a high heat resistant marking ink that does not melt.

[0008]

The heat-resistant ink for marking according to the present invention, which can solve the above-mentioned problems, includes:
(A) straight silicone resin, (b) modified silicone resin, (c) amino-based cross-linking agent, (d) coloring agent, (e) curing catalyst and (f) volatile solvent containing a gist The preferable content ratio of these components (means mass% unless otherwise specified, the same applies hereinafter) is as follows: (a) 2% or more and 20% or less of straight silicone resin, more preferably 5% or less.
% To 15%, (b) 0.2% of modified silicone resin
% Or more, 20% or less, more preferably 0.5% or more,
0% or less, (c) the amino-based crosslinking agent is 0.3% or more and 3% or less, more preferably 0.5% or more and 2% or less, and (e) the curing catalyst is 0.02% or more and 0.2% or less. % Or less, more preferably 0.05% or more and 0.1% or less.
% Or more and 95% or less, more preferably 80% or more and 90% or less.
% Or less. (d) The content of the coloring agent is not particularly limited since it varies depending on the type thereof, but is usually 2% or more and 20% or less, more preferably 4% or more and 10% or less.

The curing catalyst is mainly used for curing the amino-based crosslinking agent, and its content is desirably 2% or more and 20% or less based on the amino-based crosslinking agent. Further, the ink of the present invention has a nonvolatile content of 3% or more and 30% or less, more preferably 5% or more and 20% or less, in order to increase fast-curing properties while ensuring storage stability, handling properties and marking workability. It is desirable to adjust the amount of the volatile solvent to be used.

In the above-mentioned ink according to the present invention, an amino-based cross-linking agent is a very important component for improving the quick-setting property and heat resistance. Among them, those using a polymethylolglycoluril compound as the amino-based cross-linking agent include: It is preferable because it shows more excellent performance in quick setting and heat resistance.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The rapid-hardening heat-resistant ink for marking according to the present invention comprises (a) straight silicone resin, (b)
Modified silicone resin, (c) amino-based crosslinking agent, (d) coloring agent,
It is characterized by containing (e) a curing catalyst and (f) a volatile solvent. Hereinafter, the action and type of each of these components, and a preferable blending ratio will be described in detail.

(A) Straight silicone resin The straight silicone resin is a component which contributes to the improvement of the heat resistance of the coating film in the fast-curing heat-resistant ink of the present invention. It is desirable that the content is 2% or more and 20% or less, more preferably 5% or more and 15% or less. By the way, if the content ratio is less than 2%, it is difficult to form a coating film having adhesion to the material to be marked, and if it exceeds 20%, the drying property (quick-setting property) of the coating film tends to deteriorate. come.

The straight silicone resin is an organopolysiloxane having a hydrocarbon group as a main organic group, and may have a hydroxyl group in the molecule.
Examples of the hydrocarbon group include aliphatic and aromatic hydrocarbon groups. Among them, an aliphatic hydrocarbon group having 1 to 5 carbon atoms and an aromatic hydrocarbon group having 6 to 12 carbon atoms are preferably used.

Specific examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, vinyl, allyl, propenyl,
Butenyl group, pentenyl group and the like, and having 6 to 6 carbon atoms.
Specific examples of the 16 aromatic hydrocarbon groups include a phenyl group, a methylphenyl group, an ethylphenyl group, a butylphenyl group, a tertiary butylphenyl group, a naphthyl group,
Examples thereof include a styryl group, an allylphenyl group, and a propenylphenyl group. These can be used alone, and two or more of them can be appropriately selected and used in combination as needed.

The straight silicone resin is usually prepared by hydrolyzing and condensing a silane compound such as a chlorosilane compound or an alkoxysilane compound having a hydrocarbon group described above, or by adding tetrachlorosilane or tetraalkoxysilane to the silane compound. It can be obtained by hydrolyzing the mixture and co-condensing.

Examples of the chlorosilane compound include methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, methylethyldichlorosilane,
Examples include vinylmethyldichlorosilane, vinyltrichlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, methylphenyldichlorosilane, vinylphenyldichlorosilane, and the like. Examples of the alkoxysilane compound include methyltrimethoxysilane, dimethyldiethoxysilane, and trimethylmethoxysilane. , Vinylmethylmethoxysilane, vinyltributoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane,
Examples thereof include methylphenyldipropoxysilane and vinylphenyldimethoxysilane.

(B) Modified Silicone Resin The modified silicone resin is a component that contributes to the improvement of the heat resistance of the coating film in the rapid-setting, heat-resistant ink of the present invention.
In order to effectively exhibit such an effect, it is desirable that the content be contained so that the content ratio in the ink is 0.2% or more and 20% or less, more preferably 0.5% or more and 10% or less. By the way, if the content ratio is less than 0.2%, the ink coating tends to have insufficient adhesion to the mark-receiving material, and if it exceeds 20%, the drying property of the coating deteriorates and the quick-setting property becomes insufficient. A tendency arises.

The modified silicone resin is an organopolysiloxane containing an organic group other than a hydrocarbon group,
For example, a methoxy group-containing silicone resin, an ethoxy group-containing silicone resin, an epoxy group-containing silicone resin, a hydroxyl group-containing silicone resin, an alkyd resin-modified silicone resin, an acrylic resin-modified silicone resin, a polyester resin-modified silicone resin, an epoxy resin-modified silicone resin, and the like. These can be used alone, or two or more of them can be used in combination as needed.

These modified silicone resins have a hydroxyl group contained in the straight silicone resin as described above,
A method of reacting an organic compound having a functional group (a carboxyl group, an acid anhydride group, a hydroxyl group, an aldehyde group, an epoxy group, a chloride group, etc.) capable of reacting with the hydroxyl group, a straight silicone having an unsaturated group such as a vinyl group A method of copolymerizing a resin and a compound having an unsaturated double bond, a method of hydrolyzing and condensing or co-condensing a modified silane compound obtained by reacting the silane compound with another organic compound, and the like. it can.

(C) Amino-based cross-linking agent The amino-based cross-linking agent is used in the fast-curing heat-resistant ink of the present invention to impart fast-curing properties by its own polycondensation or crosslinking reaction with the above-mentioned modified silicone resin and to provide heat resistance. It is a main component for providing the ink, and in order to effectively exert such an effect, the content ratio in the ink should be 0.3% or more and 3% or less, more preferably 0.5% or more and 2% or less. Is desirably contained. By the way, if the content ratio is less than 0.3%, the quick-hardness and heat resistance of the ink tend to be insufficient, while if it exceeds 3%, the pot life is shortened, or the ink is apt to gel and the handleability is poor. A tendency to occur.

As specific examples of the amino-based cross-linking agent, particularly preferred are initial condensates such as a melamine resin, a urea resin, a benzoguanamine resin and a glycoluril resin.
Among these, polymethylol compounds having two or more methylol groups in the molecule and lower alkoxylated compounds thereof are recommended as preferred. The present inventors have confirmed through experiments that, among others, polymethylolglycoluril resin exhibits an excellent effect as a curing agent, and can increase the quick-curing property and heat resistance of the ink to a higher level, and particularly against metal materials. Is preferable because it gives an ink having excellent adhesion.

The above polymethylol glycoluril resin is represented by the following general formula:

[0023]

Embedded image

Is a polycondensable resin having a bicyclic structure represented by the formula: wherein R is hydrogen or an alkyl group having about 1 to 3 carbon atoms, and all Rs are preferably hydrogen.
The object of the present invention can be sufficiently achieved even when a part or all of them are substituted with an alkyl group. This glycoluril resin cures quickly in the presence of a curing catalyst, and releases a small amount of formalin during the curing reaction.
Since it shows excellent heat resistance after curing and also has excellent adhesion to metal materials, it exhibits exceptionally excellent performance as a curing agent for the marking ink according to the present invention.

(D) Colorant The colorant is a component that is blended for the purpose of coloring the marking ink, and an inorganic or organic colorant is arbitrarily selected and used. Specifically, all pigments and dyes used for general inks and paints can be used, but the most common inks of the present invention for the purpose of marking are dispersion stability such as titanium white and zinc white. It is a fine-grained white inorganic pigment excellent in water resistance. Depending on the type (ground color) of the material to be marked, the effect of the mark may not be effectively exhibited with white ink. In such a case, a colorant such as carbon black or an organic dye may be used in combination. Should be colored. The amount of these coloring agents varies depending on the type, and therefore cannot be determined uniformly. In short, the amount is not particularly limited as long as it can give the ink a color suitable for a mark.

(E) Curing catalyst The curing catalyst is mainly used for curing an amino-based crosslinking agent, and its content is 2% or more and 20% or less, more preferably 5% or less, based on the amino-based crosslinking agent. % To 15
% Is desirable. If it is less than 2%, the curing speed at the time of marking will be slow and it will be difficult to obtain the quick-curing property as intended in the present invention. If it exceeds 20%, the pot life as the ink will be short and the handling will be adversely affected. come. In addition, the dispersion stability of the ink may be reduced, and it may be difficult to form a good coating film.

Specific examples of the curing catalyst include acidic alkyl phosphates, amine salts of aromatic sulfonic acids, aromatic sulfonic acids, and the like. Of these, aromatic sulfonic acids are particularly preferred.

(F) Volatile Solvent The volatile solvent is a component that is indispensable for providing paintability as a marking ink, and it is essential that the volatile solvent be volatile to provide quick curing. The marking ink of the present invention has a nonvolatile content of 5% or more and 30% or less, more preferably 10% or less, in order to increase the fast-curing property while ensuring storage stability, handleability, marking workability and the like.
As described above, it is desirable to adjust the amount of the volatile solvent to be in the range of 20% or less. By the way, when the non-volatile content of the ink is lower than 5%, it takes a long time to dry the coating film, which may impair the quick-curing property.
If it exceeds 0%, the storage stability tends to decrease and the marking stability tends to be impaired.

Although the type of the volatile solvent is not particularly limited,
Preferred are aliphatic hydrocarbons such as hexane and cyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; ketones such as acetone, methyl ethyl ketone and cyclohexanone; alcohols such as methanol and ethanol; ethers such as dimethyl ether and diethyl ether. Esters such as ethyl acetate and ethyl acetoacetate; and petroleum-based low-boiling solvents such as kerosene and light oil.

These solvents may be used alone, or may be used as a mixture of two or more solvents depending on the solubility with other components. Particularly preferred among these volatile solvents are (a) straight silicone resin, (b) modified silicone resin, (c) excellent solubility in amino-based cross-linking agents, etc., and highly volatile acetone And ketone solvents such as methyl ethyl ketone, and aromatic solvents such as toluene and xylene.

The essential components constituting the marking ink according to the present invention are as described above. In addition, in order to enhance the adhesion of the marking film to the material to be marked, an appropriate amount of an adhesion improving component, For example, it is also effective to include gum rosin, ester gum, terpene resin, petroleum resin, or a hydride thereof, and a small amount of a plasticizer, dibutyl phthalate to give the mark an appropriate flexibility and suppress cracking and falling off. , Dioctyl phthalate,
Epoxidized oil, tricresyl phosphate, rosin derivatives and the like can also be blended. However, these plasticizers often impair the quick-hardening property and heat resistance. Therefore, even if they are blended, it is desirable to minimize the amount thereof.

The method of preparing the ink for marking using each of the above-mentioned raw material components is not particularly limited. However, usually, the above-mentioned raw materials are mixed in an arbitrary order, and are optionally mixed with a disperser, a ball mill, a sand mill, a roll mill, a homogenizer, a paint shaker, etc. What is necessary is just to mix uniformly using the said apparatus.
At this time, if a curing catalyst is blended from the beginning, the crosslinking reaction by the amino-based crosslinking agent proceeds during mixing, which results in thickening or gelling, which may impair marking workability. It is desired. Also, when selling as a marking ink, only the curing catalyst is divided and provided as a two-part ink, and if a curing agent solution is added immediately before use, there is no danger of gelling or thickening during storage. It is preferred.

[0033]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and the present invention is not limited thereto. Modifications may be made and all of them are included in the technical scope of the present invention.

Incidentally, the evaluation methods of the rapid hardening property and heat resistance adopted in the following examples are as follows.

[Rapid Hardness Evaluation Method] A test ink was applied to the surface of an aluminum plate (20 ° C.) as a material to be marked to a thickness of 1.5 mil with an applicator.
The sample is left in an atmosphere of% RH, and the time until ink does not adhere to the surface with a finger is measured.

[Heat Resistance] The aluminum plate coated with the test ink is heated by a heater, and the temperature at which the coating film softens is measured by a contact sensor.

Example 1 "SH806A" (trade name, manufactured by Dow Corning Toray Silicone Co., Ltd.) as a straight silicone resin, "KR216" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) as a modified silicone resin, and "Symel 11" (trade name, manufactured by Mitsui Cytec Co., Ltd.)
70 ", trade name" Chrome Fine Red 6820 "manufactured by Dainichi Seika Co., Ltd. as a coloring agent, trade name" Catalyst 4040 "manufactured by Mitsui Cytec Co., Ltd. as a curing catalyst, and acetone as a solvent. These are shown in Table 1. The ink for marking is prepared by mixing uniformly in a ratio with a paint shaker. However, the curing agent was dissolved in a small amount of isopropyl alcohol and finally blended.

The obtained ink was applied to a surface of an aluminum plate having a thickness of 0.3 mm at a thickness of 1.5 mil, and the quick-hardness was examined and the heat resistance was evaluated by the method described above. The results are as shown in Table 1, and it can be confirmed that the colored state of the mark is good, and that both the fast curing property and the heat resistance are very excellent.

Example 2 The amino-based crosslinking agent was changed to "Cymel 325" (trade name, manufactured by Mitsui Cytec Co., Ltd.), and the curing catalyst was changed to "Catalyst 296-9" (trade name, manufactured by Mitsui Cytec Co., Ltd.). An ink was prepared in the same manner as in Example 1 except that the ink was slightly changed as shown, and the quick-setting property and heat resistance were evaluated.
The results are as shown in Table 1, and it can be confirmed that the colored state of the mark is good, and that both the fast curing property and the heat resistance are very excellent.

Comparative Example 1 An ink was prepared in exactly the same manner as in Example 1 except that the amino-based crosslinking agent and the curing catalyst were omitted, and the rapid curing property and heat resistance were examined in the same manner. The results are as shown in Table 1. It can be seen that the colored state of the mark is good, but the quick-hardness and heat resistance are significantly inferior to those of Examples 1 and 2.

[0041]

[Table 1]

Comparative Example 2 As a modified silicone resin, "KR2" (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.)
No. 16, "phthalic resin 926-80A" manufactured by Hitachi Chemical Co., Ltd. as an alkyd resin as a curable component, and a black pigment "ANC-C-91" manufactured by Toyo Ink as a colorant.
4 ", and using acetone as a solvent at a ratio shown in Table 2, an ink was prepared in the same manner as in Example 1, and the performance was evaluated.

Comparative Example 3 Silicone alkyd resin (trade name "KR5206", manufactured by Shin-Etsu Chemical Co., Ltd.) as a modified silicone resin, "Phthalkid resin 926-80A", manufactured by Hitachi Chemical Co., Ltd., as an alkyd resin as a curable component, and a colorant An ink was prepared in the same manner as in Example 1 above, using black pigment “ANC-C-914” manufactured by Toyo Ink Co., Ltd., and acetone as a solvent in the ratio shown in Table 2, and the performance was evaluated.

Comparative Example 4 A silicone epoxy resin (trade name "ES-1001N") manufactured by Shin-Etsu Chemical Co., Ltd. as a modified silicone resin, a "phthalic resin 926-80A" manufactured by Hitachi Chemical Co., Ltd. as an alkyd resin as a curable component, colored A black pigment “ANC-C-914” manufactured by Toyo Ink Co., Ltd. was used as an agent, and acetone was used as a solvent. These were used in the ratio shown in Table 2 to prepare an ink in the same manner as in Example 1, and evaluated the performance. did.

Comparative Example 5 A trade name "Beccosol ET-3061-P" manufactured by Dainippon Ink Co., Ltd. as a short oil alkyd resin, and a trade name "Super Beckamine L-121-60" manufactured by Dainippon Ink Inc. as a butylated melamine resin. ", The same phthalkid resin as described above, and the same" ANC-C-91 "as a black pigment as described above.
Ink was prepared in the same manner as in Example 1 above, using "4" and acetone as a solvent at the ratios shown in Table 2, and the performance was evaluated.

Comparative Example 6 The above-mentioned "Beccosol ET-" was used as a short oil alkyd resin.
3061-P ", the above-mentioned" Super-Beckamine L-121-60 "as a butylated melamine resin, the same phthalkid resin as above, the above-mentioned red pigment" Chrome Fine Red 6820 "as a coloring agent, and acetone as a solvent. These were used at the ratios shown in Table 2 to prepare inks in the same manner as in Example 1, and the performance was evaluated.

The performance evaluation results of Comparative Examples 2 to 6 are collectively shown in Table 2. These marking inks, which are considered to be fast drying and excellent in heat resistance, also have a fast curing property in Table 1. And the heat resistance is up to 95 ° C., which is far below the heat resistance of the ink of the present invention.

[0048]

[Table 2]

Reference Examples 1 to 8 In accordance with the method described in Example 1, marking inks having the formulations shown in Table 3 below were prepared, and their performances were evaluated in the same manner. Table 3 shows the results.

[0050]

[Table 3]

In Table 3, Reference Example 1 is an example in which the blending amount of the straight silicone resin is too large than the preferred range, and Reference Example 2 is an example in which the modified silicone resin is too large in the preferred range. poor. On the contrary, Reference Example 3 is an example in which the blending amount of the straight silicone resin is slightly smaller, and Reference Example 4 is an example in which the modified silicone resin is slightly insufficient.
In any case, the adhesion of the ink coating film is insufficient. Reference Examples 5 and 6
Is an example in which the blending amount of the amino-based crosslinking agent is slightly insufficient or too large relative to the suitable range, and the heat resistance is slightly insufficient or the ink state is slightly poor. Reference Example 7 is an example in which the curing catalyst is slightly insufficient with respect to the preferred range, and the heat resistance is slightly poor. Reference Example 8 is an example in which the curing catalyst amount is too large in the preferred range. There is a problem.

[0052]

The present invention is configured as described above.
By mixing (a) straight silicone resin, (b) modified silicone resin, (c) amino crosslinking agent, (d) coloring agent, (e) curing catalyst and (f) volatile solvent in the appropriate ratio, Thus, it has become possible to provide a marking ink exhibiting excellent performance in terms of fast-setting property and heat resistance as compared with the marking ink of the invention.

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Claims (3)

[Claims] 1. (a) a straight silicone resin, (b) a modified silicone resin, (c) an amino-based crosslinking agent, (d) a colorant, (e)
A fast-setting, heat-resistant ink for marking, comprising a curing catalyst and (f) a volatile solvent. 2. The ink has a content of (a) a straight silicone resin of 2 to 20% by mass, (b) a content of a modified silicone resin of 0.2 to 20% by mass, and (c) amino crosslinking. The content of the agent is 0.3 to 3% by mass, the content of the curing catalyst (e) is 0.02 to 0.2% by mass, and the content of the volatile solvent is 70 to 95% by mass. Item 2. The heat-resistant ink for marking according to Item 1. 3. The heat-resistant ink for marking according to claim 1, wherein the amino-based crosslinking agent is a polymethylol glycoluril compound.