JPS6216233B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a marking ink composition, and particularly to a marking ink composition suitable for marking the surfaces of various molded products containing silicone or fluororesin. Marking inks are usually manufactured by blending pigments, plasticizers, and organic solvents with organic solvent-soluble synthetic resins. These synthetic resins include vinyl chloride-vinyl acetate copolymer, acrylic acid-
Thermoplastic resins such as vinyl acetate copolymers and thermosetting resins such as phenolic resins, epoxy resins, and alkyd resins are also used. However,
This marking ink is also used to mark the surface of various molded products, but this molded product is especially a silicone resin molded product, a molded product containing silicone, or even a molded product containing fluororesin. In some cases, even if a thermosetting ink is used, the wettability of the ink is insufficient, resulting in only a weak marking, and furthermore, the marking itself becomes unclear. Therefore, when marking this type of molded product, prior to marking, the surface of the molded product must be cleaned with a solvent, chemically treated such as etching, blasted, or physically treated with sandpaper. However, this method is difficult to process, is not completely effective, and has significant economic disadvantages, so this countermeasure is desired. . This imprintability can be improved by adding a silicone polymer to thermoplastic materials, but thermoplastic materials have a disadvantage in solvent resistance. The present invention relates to a marking ink composition which solves these disadvantages, and which contains a mixture of a reactive linear silicone polymer and a branched silicone polymer or a reaction product thereof. It is characterized by being added in an amount of 0.05 to 10% by weight. That is, as a result of various studies on marking inks that can easily and clearly mark molded products containing silicone or fluororesin, the present inventors have found that a line that is reactive with conventionally known marking inks has been developed. When a branched silicone polymer and a branched silicone polymer are added,
It was discovered that the wettability of the marking ink was improved and the lack of adhesive strength to the molded product was solved, and as a result, marking on the surface of molded products containing silicone or fluororesin could be done easily and clearly. They confirmed that heat curing is better in terms of adhesion to the base material, and conducted research on the composition and amount of silicone polymers that should be added to marking inks, and completed the present invention. . The marking ink that is the main ingredient of the marking ink of the present invention may be a conventionally known marking ink, and examples thereof include epoxy resin, phenolic resin, alkyd resin,
Examples include urethane resins, acrylic resins, and polyester resins, but for use in molded products containing silicone or fluororesin, phenolic resins, epoxy resins, and alkyd resins are preferred due to their excellent adhesion to the base material. It is preferable that the main material is a type of thermosetting resin. The silicone polymer added to the marking ink described above must be a mixture of a reactive linear silicone polymer and a branched silicone polymer, or a reaction product thereof. This reactive linear silicone polymer has the general formula and this R ¹ is a hydrogen atom or a methyl group,
Bonded to alkyl groups such as ethyl, propyl, and butyl groups, alkenyl groups such as vinyl and allyl groups, aryl groups such as phenyl and tolyl groups, cycloalkyl groups such as cyclohexyl groups, or carbon atoms of these groups. Unsubstituted or substituted monovalent hydrocarbon groups, hydroxyl groups, methoxy groups, ethoxy groups, such as chloromethyl groups, fluoropropyl groups, cyanomethyl groups, etc., in which part or all of the hydrogen atoms have been substituted with halogen atoms, cyano groups, etc. Same or different monovalent organic groups selected from hydrocarbon groups having hydrolyzable groups other than halogen atoms such as alkoxy groups, propenoxy groups, oxime groups, and acetoxy groups, amino groups, and epoxy groups;
R ² is a hydrogen atom or an unsubstituted or substituted alkyl group or alkenyl group mentioned above, or a C1-5 unsubstituted or substituted group in which part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group, etc. An atom or group selected from monovalent hydrocarbon groups, where n is an integer of 3 or more, and examples thereof include the following. (m and n are integers _of 3 or more) In addition, the branched silicone polymer used here has R ¹ _a R ³ _b SiO _0.5 units (R ¹ is the same as above, R ³ is an amino group or Hydrocarbon group having an epoxy group, a
is 0 to 3, b is 3 to 0, and a+b=3) and SiO ₂ units may be used, but if this R ¹ _a R ³ _b SiO _0.5 unit is too _small , it will easily gel. If too much is used, ^the desired resin cannot be obtained, and if it is too much, the resin becomes less reactive, which is _{disadvantageous} for adhesion to ^the _{base material .} unit and SiO ₂ unit in molar ratio of 0.5 to
It is recommended that the ratio be in the range of 2.0:1. Such a silicone resin can be obtained, for example, by cohydrolysis of trimethylchlorosilane represented by (CH ₃ ) ₃ SiCl and tetraalkoxysilane represented by Si(OR) ₄ , and the silicone resin obtained in this way has ≡Si(OH) group, ≡Si
The R ¹ _a R 3 b SiO _0.5 unit may contain a reactive group such as an (OR) group, and the following are examples of the R 1 a R ³ _b SiO _0.5 unit.

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[Formula] The linear silicone polymer and branched silicone polymer having the above-mentioned reactivity may be added to the marking ink as they are, but they may also be added after reacting in advance. good. If the mixing ratio of linear silicone polymer and branched silicone polymer is 2:1 or more, the reaction product will have a low crosslinking density and poor solvent resistance. If the ratio is below, the wettability of the added marking ink will decrease and the adhesive strength will also become weak, so it is preferable to set the ratio in the range of 0.5 to 2.0:1. The marking ink composition of the present invention is made by adding a linear silicone polymer and a branched silicone polymer having the above-mentioned reactivity, or a reaction product thereof, to a marking ink. The amount of addition is based on the marking.
If it is less than 0.05% by weight, the composition will be repelled by the surface of the molded product and the marking will have weak adhesive strength, and if it is more than 10% by weight, the ink itself will have weak strength and marking will be easy. Since the marking ink tends to peel off and its solvent resistance deteriorates, it is preferably in the range of 0.05 to 10% by weight, particularly in the range of 5% by weight, based on the marking ink. The marking ink and silicone polymer may be mixed by simply stirring and mixing them in a container, but from the viewpoint of dispersibility, it is preferable to use a mixer such as a three-roll mixer. Furthermore, during this mixing, the silicone polymer may be added after being dissolved in an organic solvent such as toluene or xylene, which has the advantage of being able to adjust the viscosity of the marking ink composition. It will be done. It is optional to add a curing catalyst for the silicone polymer described above to this marking composition, such as a known condensation catalyst or an epoxy ring-opening catalyst. Inhibitors and various inorganic fillers may be added. Since the marking ink composition of the present invention thus obtained contains the above-mentioned silicone polymer, it has good wettability. This composition is said to be useful for marking the surface of products, and this composition is particularly applicable to marking ink compositions whose main ingredient is a thermosetting resin such as a phenolic resin, an epoxy resin, or an alkyd resin. Good. Next, examples of the present invention will be given, and the physical property measurements in the examples are the results of measurements made by the following method. Adhesion: The marking condition was examined after performing a tape peel test 10 times. Solvent resistance: After marking, the molded product was washed with trichlorethylene vapor for 10 minutes and the state of the marking was examined. Ink wettability: The repellency of the marking ink when marked on the surface of the molded article was examined. (Judgment criteria) ◎Excellent, 〇Good, △Acceptable, ×Example Examples 1 Commercially available epoxy resin marking ink Markem 7224 [product name manufactured by Markem Corporation], phenolic resin marking ink Markem 7261 [product manufactured by Markem Corporation] 3% by weight of the following silicone polymer 1 was added to alkyd resin marking ink Bonmark Silver [trade name, manufactured by Toka Shiki Kagaku Kogyo Co., Ltd.] and thoroughly mixed with three rolls to form a marking ink. This is used to mark the surface of an epoxy resin molded product containing silicone, and after curing by heating at 150°C for 1 hour, the adhesive strength, solvent resistance, and ink wettability of this marking are determined. When I looked into it, I found that the first
The results shown in the table were obtained. (Silicone polymer 1) Dimethylpolysiloxane raw rubber containing terminal hydroxyl groups
Obtained by condensing 50 parts by weight, 10 parts by weight of dimethylpolysiloxane oil containing terminal hydroxyl groups with a viscosity of 10,000 cS, and 40 parts by _weight of a silicone resin consisting of 37 mol% of (CH ₃ ) ₃ SiO _0.5 units and 63 mol% of SiO ₂ units. silicone polymer

[Table] Example 2 The silicone polymer used in Example 1 was added to Markem 7261, a phenolic resin marking ink, in the amount shown in Table 2, and thoroughly mixed using a triple roll to prepare a marking ink composition. This was used to mark the surface of an epoxy resin molded product containing silicone, and after curing by heating at 150°C for 1 hour, the adhesion, solvent resistance, and contact angle of this marking were examined. The results shown in Table 2 were obtained. Note that this contact angle was measured at 25°C by dropping marking ink onto the surface of the molded product.

[Table] Example 3 Epoxy resin marking ink Markem
Add 3% by weight of the following mixture of silicone polymers 2, 3, and 4 to 7224 and thoroughly mix with a triple roll to make a marking ink composition, and use this to coat the surface of an epoxy resin molded product containing silicone. After hardening by heating at 150℃ for 1 hour, the adhesion, solvent resistance,
When the wettability of the ink was examined, the results shown in Table 3 were obtained. (Silicone polymer 2) (Silicone polymer 3) (Silicone polymer 4) 5 mol% units, (CH ₃ ) ₃ SiO _{0.5 units} 30 mol%,
60 parts by weight of a silicone resin consisting of 65 mol% SiO ₂ units.

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Claims (1)

[Scope of Claims] 1. The marking ink is characterized by being made by adding 0.05 to 10% by weight of a mixture of a reactive linear silicone polymer and a branched silicone polymer or a reaction product thereof. Markin ink composition. 2. The marking ink composition according to claim 1, wherein the marking ink contains a phenolic, epoxy, or alkyd thermosetting resin component. 3 A reactive linear silicone polymer has the general formula (Here, R ¹ is selected from a hydrogen atom, an unsubstituted or substituted monovalent hydrocarbon group having 1 to 5 carbon atoms, a hydroxyl group, a hydrolyzable group other than a halogen atom, and a hydrocarbon group containing an amino group or an epoxy group. ^R2 is the same or different atoms or groups selected from hydrogen atoms or unsubstituted or substituted monovalent hydrocarbons, n is an integer of 3 or more) , the branched silicone polymer has R ¹ _a R ³ _{b SiO 0.5 units} (R ¹ is the same as above, R ³
is a hydrocarbon group containing an amino group or an epoxy group, a is 0 to 3, b is 0 to 3, a + b = 3)
This ^{R 1} _{a R 3} ^b _{SiO 0.5} unit and
The marking ink composition according to claim 1, which is a silicone resin having a molar ratio with SiO ₂ units of 0.5 to 2.0:1. 4. The marking ink composition according to claim 1 or 3, wherein the blending ratio of the reactive silicone polymer and the branched silicone polymer is 0.5 to 2:1 (weight ratio).