JPH04161468A - marking ink composition - 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 (Field of Industrial Application) The present invention relates to a marking ink composition, and particularly to a marking ink composition useful for marking silicone rubber surfaces with no gloss and no surface tackiness. The present invention relates to an ink composition.

(Prior Art) Recently, there has been a demand for marking the surfaces of tubes, covered electric wires, swimming cassops, key tops of office automation equipment, rubber contacts, etc. made of silicone rubber materials with designs, letters, etc. As a composition for performing such a marking treatment, for example, a composition in which organopolysiloxane and organohydrodiene polysiloxane are blended in a predetermined ratio is known (Japanese Patent Publication No.
2-14642).

However, in recent years, there has been an increasing demand for molded products, such as rubber contacts, whose marking surfaces have been subjected to matte treatment. Marking ink compositions based on silicone oil, resin, etc. have a glossy surface when cured, and are not suitable for producing molded articles having a surface without rips. The above-mentioned special public service No. 52-14642
Also in the marking ink composition disclosed in the publication, the marking surface (cured product surface) has gloss.

(Problem to be solved by the invention a) Currently, methods such as adding inorganic fillers such as silica, diatomaceous earth, and calcium carbonate, using a large amount of solvent, and polishing the surface of the cured product are used to eliminate the gloss of the marking surface. It is being done.

However, the addition of inorganic fillers, for example, has the problem of significantly lowering the abrasion resistance of the marking ink and inhibiting coloring due to the added powder. If a large amount of solvent is used, there is a problem of environmental pollution due to solvent removal, and when the surface of the cured product is polished, there is a problem of restrictions due to the shape of the molded product.

Therefore, it is an object of the present invention to provide a marking ink composition which effectively solves the above-mentioned problems and which is particularly capable of effectively forming markings with excellent abrasion resistance and without burrs on the surface of a molded article. do.

(Means for Achieving the Object) The marking ink composition of the present invention has the following average compositional formula [■]: (1) (a) R, SiO [I] where R is a -valent hydrocarbon is a group, a is a number from 1.98 to 2.01, - has at least two alkenyl groups in the molecule, and has a temperature of 25 °C
100 parts by weight of an organopolysiloxane having a viscosity of 300 cst or more at
)SiO,, □ unit (wherein R1 is an alkyl group,
R2 is an alkenyl group), (R') 3
5 io + /□□Unit (R')z(R”)SiO+
The total amount with 7□ units is 0 per 1 mole of Sing units.
．． Organopolysiloxane in the range of 6 to 1.2 mol and having an alkenyl group content of 1 to 3% by weight 10
~20 parts by weight, (C) The following average composition formula [■], R'JcSiOi, L, i(n) In the formula, R3 is a -valent hydrocarbon group, and b is 1.0 to 2. 1, C is a number from 0.5 to 1.0, and b + c = 1.5 to 2.6, - at least 3 in the molecule; contains an SIH bond,
and organohydrodiene polysiloxane in an amount such that the total number of alkenyl groups in components (a) and (c) is 3 moles or more per mole of alkenyl groups in components (a) and (c); Powder 50-15
0 parts by weight, (el R material), and (f) a catalytic amount of platinum or a platinum-based compound.

Component (5) The organopolysiloxane of component (a) is used as a base polymer in the present invention, and has the above-mentioned average composition formula [I], that is, RIISiO,4,L
CI] (wherein R and a are as described above).

In this average composition formula (I), a is 1.98 to 2.0
1, and examples of the -valent hydrocarbon group R include alkyl groups such as methyl, ethyl and propyl groups, aryl groups such as phenyl and tolyl groups, alkenyl groups such as vinyl and allyl groups, Cycloalkyl groups such as cyclohexyl groups, and groups in which some or all of the hydrogen atoms bonded to carbon atoms of these groups are substituted with halogen atoms, cyano groups, etc., such as chloromethyl groups, trifluoropropyl groups, cyanoethyl groups, etc. can be exemplified. Among these groups, those having 1 to 10 carbon atoms are preferred.

Furthermore, this organopolysiloxane needs to have at least two of the above-mentioned alkenyl groups in one molecule, so that it can be crosslinked to form a cured product. As such an alkenyl group, a vinyl group is particularly suitable.

Further, this alkenyl group may be present either at the end of the molecular chain or in the middle thereof.

Furthermore, from the viewpoint of workability, etc., this organopolysiloxane has a viscosity at 25°C of 300 cSt or more, particularly in the range of 300 to 100,000 cSt.

In the present invention, specific examples of the organopolysiloxane as component (a) include, but are not limited to, the following.

CHs C1 (:l CHl l 1 1 (In the formula, m, n, p are positive integers, and are numbers such that the viscosity is within the above range.) These organopolysiloxanes have a viscosity as described above. Two or more types can be used in combination as long as they are within the range.

Formation (6) In the present invention, the organopolysiloxane as component (c) is used to improve the adhesion and strength of the marking film obtained from the composition of the present invention.

As mentioned above, this organopolysiloxane is SiO
□Unit, (R')3SiO+7z unit and (R')z
(R'') consists of SiO+z□ units (in the formula, R' is an alkyl group, and R2 is an alkenyl group).This alkyl group R1 has a number of carbon atoms such as a methyl group, an ethyl group, a propyl group, etc. Examples include lower alkyl groups of 10 or less, preferably methyl groups. Examples of alkenyl groups include vinyl groups, allyl groups, propenyl groups, and particularly preferably vinyl groups.

In the organopolysiloxane of component (B), (R
')zsiO+7z unit and (R')z(R”)SiO+
The total amount of z□ units is 0 per 1 mole of SiO□ units.
．． It is necessary that the amount is in the range of 6 to 1.2 mol, and the alkenyl group (R1) content is 1 to 3% by weight.

The organopolysiloxane of component (b) is contained in an amount of 1% per 100 parts by weight of the organopolysiloxane of component (a).
It is blended in an amount of 0 to 20 parts by weight, particularly 10 to 15 parts by weight. If the amount is less than 10 parts by weight, the adhesion and strength of the marking film obtained from the composition of the present invention will decrease, and if it exceeds 20 parts by weight, the marking film will have poor flexibility and may peel off. It becomes easier.

The above-mentioned organopolysiloxanes (components) can be produced by methods known per se, for example, by cohydrolyzing silicon tetrachloride, trimethylchlorosilane and dimethylvinylchlorosilane, or by cohydrolyzing silica hydrosol and hexamethyldisiloxane. Alternatively, it can be easily produced by mixing trimethylchlorosilane and dimethylvinylchlorosilane and performing cohydrolysis-collinear combination equilibration.

Component (6) In the present invention, the organohydrodiene polysiloxane used as component (C) acts as a crosslinking agent, and the 35iH group in its molecule is the component (a).
By addition reaction with the alkenyl group contained in the organopolysiloxane (b), a cured product in the form of a rubber elastic body is formed.

This organohydrodiene polysiloxane has the above-mentioned average compositional formula [■], that is, R"bHcSiO1,000 (II), where R3 is a -valent hydrocarbon group, and b is 1.0 to 2.1. , C is a number from 0.5 to 1.0, and b + c = 1.5 to 2.6, where the -valent hydrocarbon group As R3, among those exemplified for R in the above average compositional formula (1), groups excluding alkenyl groups can be mentioned.Also:;S
At least three iO groups must exist in the molecule in order to form a good crosslinked structure with the organopolysiloxanes of components (a) and (b).

Examples of such organohydrodiene polysiloxanes include H5iOzz□, (CH3)H3iO.

(CH3) A siloxane unit having a 5i-H bond such as zH5io+7z, SiO□, CH35i03z□
, (CH3)zsio.

(CH3)(CaHs)SiO, (CHi)3sio+
Examples include those consisting of siloxane units such as z□, and specific examples include, but are not limited to, copolymers of methylhydrodiene polysiloxane and dimethylhydrodiene polysiloxane, and methylhydrodiene polysiloxane. Copolymers of and methylphenylpolysiloxane, methylhydrodienepolysiloxane, copolymers of dimethylpolysiloxane and methylphenylpolysiloxane, and the like are preferably used.

These organohydrodiene polysiloxanes contain 1
The species can be used alone or in combination of two or more, and the amount used is as follows;
The amount is set to be at least mol, preferably from 3 to 20 mol.

As a result, a flexible cured product is formed.

In the present invention, it is possible to eliminate the gloss (gloss) on the surface of the cured product obtained from the composition of the present invention, reduce the sticky feeling (tank feeling) on the surface, and impart abrasion resistance to the cured product. For application, the average particle size is 50 μm or less, preferably 20 μm
+ or less spherical powder is used. The average particle size of the powder is 5
If it exceeds 0 μ■, the mechanical strength of the resulting marking film (cured film) will be impaired, and for example, the film will have poor abrasion resistance. Furthermore, it is difficult to manufacture a powder with an extremely fine average particle size, and no further effect can be obtained, so the average particle size of the powder is 0.1μ-
In particular, it is preferable that the thickness is 0.2μ or more. Further, it is preferable that the particle shape is substantially spherical.

The material of this powder is arbitrary as long as its average particle size is within the above range, such as various inorganic powders, fluororesins, polyester resins, polyamide resins such as nylon, and plastic powders such as polyolefin resins such as polypropylene. However, in the present invention, polymethylsilsesquioxane having a softening temperature of 150° C. or higher or a spherical metal oxide is most preferably used. As a result, the gloss of the cured film of the marking ink composition can be effectively erased, the sticky feeling on the surface can be reduced, the abrasion resistance can be significantly improved, and the adhesion to silicone rubber molded products can be significantly improved. becomes possible.

The above polymethylsilsesquioxane can be obtained by, for example, hydrolyzing methyltrialkoxysilane, orthoalkyl silicate, or a partial hydrolyzate thereof in an aqueous solution containing an alkaline earth metal hydroxide or an alkali metal carbonate. It can be obtained by condensation, or by hydrolysis and condensation in an aqueous solution of amine or ammonia (JP-A-63-77940, JP-A-63-103).
No. 812, JP-A No. 63-295637). Further, this polymethylsilsesquioxane may contain an organic group such as a vinyl group, for example, JP-A-63
Surface-modified polymethylsilsesquioxane disclosed in Japanese Patent Application Laid-Open No. 02-163127 and the like can also be used.

Further, spherical metal oxides can be obtained, for example, by blowing oxygen into silicon or aluminum vapor at high temperatures (JP-A-62-260712, JP-A-63-7).
(See Publication No. 4911).

Here, spherical powder refers to particles whose shape is independently spherical or approximately spherical, and as a guideline, the difference between the horizontal and vertical diameters of the particles is within ±40%.

In the present invention, the above-mentioned powder is blended in an amount of 50 to 150 parts by weight, particularly 50 to 100 parts by weight, per 100 parts by weight of the organopolysiloxane of component (a).

If the amount is less than 50 parts by weight, the desired effect will not be achieved, and if the amount is more than 150 parts by weight, the composition will become hard and processability will deteriorate, and the resulting cured film will have poor mechanical properties. The adhesive strength with silicone rubber molded products also decreases.

Ingredients Since the composition of the present invention is used for marking molded products such as silicone rubber, it contains a pigment as an essential component, and various colors can be applied to the composition using this pigment. The amount of the pigment to be blended is determined depending on the desired degree of coloring, degree of hiding, etc. It is preferably 0 to 100 parts in terms of physical properties.

Examples of such pigments include inorganic pigments such as ultramarine, hengara, titanium white, titanium yellow, carbon blank, iron oxide, zinc white, and chrome green; Examples include organic pigments such as nin green, phthalocyanine green, and verison renodo; metal powder pigments such as aluminum powder, bronze powder, copper powder, and tin powder; and phosphorescent pigments containing zinc sulfide compounds as a main component. These pigments are appropriately selected and used in consideration of the color tone, saturation, etc. of the object.

However, in the present invention, 3S contained in the above-mentioned component (C)
A curing catalyst is used to accelerate the addition curing reaction between the iH group and the alkenyl groups contained in components (a) and (b). The curing catalyst used is platinum or platinum compounds, which are known per se as curing catalysts of this type. Specifically, platinum blanks, chloroplatinic acid, complexes of chloroplatinic acid and olefins such as ethylene and propylene, and alcohol modified chloroplatinic acid disclosed in U.S. Pat. No. 3,220,972. is exemplified.

The amount of these catalysts to be used may be a so-called catalytic amount, for example, in an amount of about 10-' to 10-' mole per mole of alkenyl group in terms of platinum.

±91 bal [1] If necessary, a catalyst activator may be added to the composition of the present invention within a range that does not impair the purpose of matting the cured film. Examples of the catalyst activator include benzotriazole, alcohol derivatives having a triple bond, and triphenyl phosphite.

Marking In The marking ink composition of the present invention can be easily obtained by uniformly mixing the above-mentioned components using a kneading machine such as a mixer or a roll. Although there are no particular restrictions, - For boat fishing, it is preferable to mix component (C) organohydrodiene polysiloxane or component (f) curing catalyst immediately before use.

In actual use of this composition, for example, it is diluted appropriately using an organic solvent such as toluene, n-hexane, methanol, etc., and the required amount of curing catalyst (component) is added. Then, select the desired tube,
It is sufficient to mark the surfaces of coated electric wires, key tops of OA equipment, etc. in the form of desired patterns, letters, etc., and then heat and harden the markings.

Heat curing is usually performed at a temperature of 100 to 250°C for 30
It lasts for about 2 seconds to 2 hours.

(Example) The present invention will be explained using the following examples. In each example, parts are as follows:
All parts are by weight, and viscosities are measured at 25°C.

The following formula on Uragan charcoal, CHz C) 13 CH3 ] 11 CI (2 engineering C) I-5i (O-5→-,0-Si C
Dimethylpolysiloxane (viscosity: 5,0OOcSt) 5 where the molecular terminal is blocked with a dimethylsilyl group, represented by H=CHzCH3GHz CH3 (m=positive integer)
00 parts Dimethylsiloxane raw rubber whose both ends are blocked with dimethylsilyl groups and whose vinyl group content is 0.15 mol% of the total number of organic groups (viscosity: 5 million cst) 106BSiOz
unit, (Ct(3)zsio+7□unit and (CH3
) z (CL・CH)SiO+z□ unit, S
For 1 mole of iO2 unit, (CH:l) zsiO+z
□Unit and (CH3) Z (cllz=cH)SiO+
, z□ units in a total amount of 1 mol, and a vinyl group content of 2% by weight. 10 parts of polysiloxane, particle size: 0.3μ
70 parts of spherical powder consisting of methylsilsesxyloxane (black)
30 parts 2% by weight of chloroplatinic acid (calculated as Pt) 2-
Ethylhexanol solution
A mixture consisting of 1 part ethynylcyclohexanol and 1.4 parts was uniformly blended using a triple roll, and then diluted with toluene to obtain a marking ink composition (Example 1).

Further, a marking ink composition was obtained in the same manner as above except that the spherical powder was mixed in an amount of 35 parts (Example 2).

Next, after each of the compositions obtained above was stored for the period shown in Table 1, the following formula, CH3H (CH3) zsi+0-Si+n, +0-5i)lI, was added per 100 parts of these compositions.
(CHx) 3CH3CH.

Organohydrodiene polysiloxane 10 represented by
After uniformly mixing the parts, apply it to a vulcanized and hardened silicone rubber plate to a thickness of 30 to 50 μm, and heat at 200°
C. for 300 seconds.

The resulting cured film was measured for gloss, and evaluated for adhesive feel (tank feel) and abrasion resistance, and the results are shown in Table 1.

The glossiness was measured using a glossy needle IG-310 manufactured by Horiba under conditions of an incident angle of 60° and a light receiving angle of 60°.

Furthermore, abrasion resistance was evaluated by repeatedly applying friction with a cotton cloth and determining the number of times of friction when the cured film peeled off.

In Example 1, a cured film was formed in the same manner as in Example 1 without using the spherical powder of methylsilsesquioxane, and the gloss of the film was measured ( Comparative example 1
).

In addition, 70 parts of diatomaceous powder ± (average particle size lOμ-) was used in place of the spherical powder used in Example 1, a cured film was formed in the same manner as in Example 1, and the gloss of the film was measured. (Comparative Example 2).

The results are shown in Table 1.

Example 1 IH-1 Instead of the spherical powder of methylsilsesquioxane used in Example 1, methylvinylsilsesquioxane (average particle size 1.2 μM, vinyl group content 0.5 mol%) was used.
) were blended in 70 parts (Example 3) and 35 parts (Example 4) to form a cured film in the same manner as in Example 1, and the glossiness of the film was measured.

The results are shown in Table 2.6 Table 2 (Component (d): Methyl vinyl silsesquioxane with average particle size of 1.2 μ-) Blend amount per 100 parts by weight of dimethylpolysiloxane 1” 1 L-group Instead of the spherical powder of methylsilsesquiosane used in Example 1, spherical silica (average particle size 30 μm) was used.
1 (manufactured by Micron Co., Ltd.), 70 parts (Example 5) and 35 parts (Example 6) were blended to form a cured film in the same manner as in Example 1, and the glossiness of the film was measured. I did it.

The results are shown in Table 3.

Table 3 (Component (d): Spherical silica with average particle size of 30μ11) Compounding amount per 100 parts by weight of dimethylpolysiloxane (Effects of the invention) According to the present invention, there is no gloss or sticky feeling, and there is no abrasion resistance. A marking ink composition capable of forming a cured film with excellent properties has been provided.

Furthermore, the composition of the present invention can form a cured film exhibiting excellent adhesion, particularly to silicone rubber molded articles.

Claims (1)

[Claims] (1) (a) The following average composition formula [I], RaSiO_(_4_-_a_)_/_2 [I] In the formula, R is a monovalent hydrocarbon group, and a is 1.98 to 2. (b) SiO_2
unit, (R^1), SiO_1_/_2 unit and (R
^1)_2(R^2)SiO_1_/_2 units (in the formula,
R^1 is an alkyl group and R^2 is an alkenyl group), and the total amount of (R^1)_3SiO_1_/_2 units and (R^1)_2(R^2)SiO_1_/_2 units is 0.6 to 1 per mole of SiO_2 units.
．． 2 moles, and the alkenyl group content is 1 to 2 moles.
10 to 20 parts by weight of organopolysiloxane which is 3% by weight, (c) the following average composition formula [II], R^3_bH_cSiO_(_4_-_b_-_c_)
/_2 [II] In the formula, R^3 is a monovalent hydrocarbon group, b is a number from 1.0 to 2.1, and c is a number from 0.5 to 1.0. and b + c = 1.5 to 2.6, contains at least 3 SiH bonds in one molecule, and the alkenyl group in the components (a) and (b) (d) spherical powder with an average particle diameter of 50 μm or less 50 to 15
(e) a pigment; and (f) a catalytic amount of platinum or a platinum-based compound.