JPS60173068A - Lowly foaming water ink composition - Google Patents

Abstract

PURPOSE:To provide water ink which can retain lowly foaming properties even under high temperature or high shearing conditions, containing a water ink compsn., an oxyalkylene group-contg. organopolysiloxane, a dimethylpolysiloxane, silica filler and a surfactant. CONSTITUTION:A water ink compsn. consists of 100pts.wt. water ink compsn. (A) and 0.1-10pts.wt. silicone antifoaming agent compsn. (B) consisting of 100pts.wt. oxyalkylene group-contg. organopolysiloxane (i) of formula I [wherein Y is a 3-30C alkyl, etc.; G is oxyalkylene of formula II (wherein R<1> is a 2- 10C bivalent hydrocarbon group; A is H, etc.; Q is a 1-5C oxyalkylene; p is 1- 100); a, b are each 0, 1, 2; c is 1, 2, 3; l is 20-200; m+2a=2-100; n+2b=2- 50], 2-200pts.wt. dimethylpolysiloxane (ii) having a viscosity of 100-1,000,000 at 25 deg.C, 0.1-40pts.wt. silica filler (iii) and 0.1-40pts.wt. surfactant (iv).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides low foaming aqueous ink compositions, particularly those capable of retaining low foaming properties even under severe conditions of high temperature or high shear. The present invention relates to a water-based ink composition that has good stability and is free from problems such as repelling.

Regarding water-based printing ink compositions, being suitable for printing operations during printing, drying, and post-processing by a printing press is considered to be an important factor for printing suitability. Due to the constant high shear force applied by the rotating rolls, the ink may overflow from the vat due to foaming due to the water-based ink composition.
Workability is often significantly impaired due to ink supply problems.

Therefore, this type of ink composition is printed with an antifoaming agent added! A method has been adopted to prevent foaming during the process, and for this purpose, emulsion-type antifoaming agents in which dimethylpolysiloxane is dispersed in water using a surfactant are widely used.

This is because if the liquid to be treated is at a high temperature or a high shear force is applied, the emulsion will be destroyed and the antifoaming effect will be reduced.In some cases, foaming may be promoted, and furthermore, the emulsion may separate during long-term storage. The water repellency of dimethylpolysiloxane after separation causes repellency, which has the disadvantage of deteriorating printing quality. Therefore, it has been proposed to use an organopolysiloxane modified with polyoxyalkylene groups (see US Pat. No. 3,233,986), but this has the disadvantage of having a small antifoaming effect. - Attempts have been made to improve the antifoaming effect by using a combination of such modified siloxanes and diorganopolysiloxanes such as dimethylpolysiloxane (see JP-A-53-34854), but water-based inks, etc. Since the organic substance in the system and dimethylpolysiloxane have poor affinity when added to the system, they eventually separate and cause cissing. In addition, in order to eliminate such drawbacks,
Attempts have been made to introduce hydrocarbon groups into dimethylpolysiloxane to improve its affinity with the resin components in water-based inks and maintain good dispersion in water. A self-emulsifying antifoaming agent in combination with siloxane has also been proposed (see Japanese Patent Laid-Open No. 149.388/1988), but although it is improved in terms of repellency, it has the disadvantage of poor antifoaming durability. Ta.

The present invention relates to a low-foaming ink composition that solves these disadvantages, and is comprised of: A) Ink composition 100
Parts by weight, B) a) General formula [In the formula, Y is a group selected from unsubstituted or substituted alkyl groups having 3 to 30 carbon atoms, aralkyl groups, ester groups, and alkoxy groups, G is the formula -R' -0 -Q -A ＼R1 has 2 to 10 carbon atoms
Divalent hydrocarbon group - Q is a group selected from a hydrogen atom, an alkyl group, an acyl group, and an isocyanate group - Q has 1 to 5 carbon atoms
oxyalkylene 2Lp is an oxyalkylene group represented by (an integer of 1 to 100).

a-b is 0.1 or 2- c is 1-2 or 3 and a
+ b + c = 3, east is an integer from 20 to 200 0m
is m + 2 the number for which a is 2 to 100 - n is n + 2b
is 2 to 50, (n+2 b )/i=0.01
~i,oo) oxyalkylene group-containing organoborisiltetraxane 100! 1 mouth) 2 to 200 parts by weight of dimethylpolysiloxane with a viscosity of 100 to 1,000,000 cS at 25°C, c) 0 silica fillers
．． 2) 0.1 to 10 parts by weight of a silicone antifoam composition comprising 1 to 4 parts by weight of ON, and 2) 0.1 to 40 parts by weight of a surfactant.

To explain this, the present inventors have solved the various disadvantages mentioned above. As a result of extensive research on aqueous ink compositions that exhibit low foaming properties even under high temperatures or high shear, we found that an alkyl group that has an affinity with the organic group in this composition can be used as an antifoaming agent to be added to aqueous ink compositions. - When using an antifoam composition containing a polyoxyalkylene group into which an aralkyl group, an ester group, an alkoxy group, etc. have been introduced, mixed with a modified loxane, finely powdered silica, and a surfactant, this antifoam composition may be heated at high temperatures.
Even under high shear forces, the emulsion does not break down, and no cissing or oil spots occur (.

The present invention was completed by confirming that the aqueous ink compositions containing the compound exhibit excellent defoaming persistence and foam-breaking properties and exhibit excellent printability.

The water-based ink composition as component A) constituting the low-foaming ink composition of the present invention may be a known one or one that is generally commercially available. Vehicles for this aqueous ink composition include natural or processed materials such as starch-dextrin-glue-casein-shellac, gum arabic, rosin-rosin ester, etc.
Cellulose derivatives such as ethyl cellulose, phenolic resin, rosin-modified phenolic resin, maleic acid resin, modified maleic acid resin 1 petroleum resin, vinyl resin, acrylic resin, polyamide resin, epoxy resin-alkyd resin,
An aqueous solution of a synthetic resin such as polyvinyl alcohol, an aqueous alkali solution, or an emulsion can be used alone or in combination, and the aqueous ink composition contains dyes as colorants, inorganic or organic pigments, etc. as colorants, and wax as necessary. It is composed of a plasticizer, a stabilizer, a thickener, a dispersant, a filler, a solvent, and others.

Further, as described above, the antifoaming agent composition as component B) constituting the composition of the present invention includes a) polyoxyalkylene-modified organopolysiloxane, a) dimethylpolysiloxane, and /.) a silica-based filler.

2) A surfactant, and each of these must be as follows. The oxyalkylene group-modified organopolysiloxane as component (a) is represented by the general formula, where Y is a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group-tυtecyl group,
Alkyl groups such as octadecyl groups.

Aralkyl groups such as styryl group, α~methylstyryl group, 2-phenyl ethyl group, 2-phenyloctyl group, formula R20 I I+ -OH-0H-0-OR3 \, R and R are hydrogen atoms or carbon an ester group represented by the formula -○R (R is an alkyl group having 3 to 3 o carbon atoms); Formula -R1-0-%-A
In the oxyalkylene group represented by this R or ethylene group,
A divalent hydrocarbon group having 2 to 10 carbon atoms, consisting of an alkylene group such as a propylene group or a butylene group, an arylene group such as a phenylene group, or an alkaline group such as a 7-enethylene group;
Q is an oxyalkylene group having 1 to 5 carbon atoms, A is a hydrogen atom or a methyl group, an ethyl group, a propyl group, a butyl group,
It is considered to be a hydrocarbon group having 1 to 20 carbon atoms such as a vinyl group, phenyl group, acetyl group, or propynyl group, or an acyl group or an incyanate group, and a and b in this formula are 0.1 or 3. c is 1°2 or 3. a+b
+c=3 is required. Note that if the value of y in this formula is set to 10 or less, the antifoaming properties of this composition will be poor.

If it is more than 300, the dispersibility becomes poor and the antifoaming property decreases, so it should be made to be 10 to 300, and 1 m
If the value is too small, the affinity with the organic groups present in the ink will not be sufficiently exhibited, and if it is too large, the antifoaming properties will be reduced. Since the group shown is a group that imparts hydrophilicity to this organopolysiloxane, n+2b is from 2 to
The number must be in the range of 50, and
Regarding +2b, if there are too many oxyalkylene groups, this oxyalkylene-modified organopolysiloxane becomes water-soluble and loses its antifoaming properties, so this is (n+
2 b )/i is required to be in the range of 0.01 to 1.00. Furthermore, if the molecular weight of the polyoxyalkylene group of the organopolysiloxane represented by this formula is less than 100, it will have poor hydrophilicity and poor dispersibility, and if it is more than 6,000, the viscosity will increase. It is preferable to set it in the range of 100 to 6,000 because the workability will change.

The polyoxyalkylene-modified organopolysiloxane for this glaze is expressed by the following formula:

1 →O, H60 meeting 0-0H3゜ (-aH2tO(O□H40% H- Yl is the same as above G2 is the same as above Y2...-0H20I (206H5+OH.

■ 10H20HO6H,'.

3H7 10H20H20HOH206H,.

-0H20H20, H404H,.

G2 is the same as above -OHOHO○0OH3- Oh.

1 -OH0ROOOOH.

2 2 5 C2H3 10L-1-0R(d)00)1.

2 4 9 G2 is the same as above ? ...-003B,,-004H,.

-00(OH8), 02H,.

100□, Hs7. Examples include compounds represented by -00H206H, which can be synthesized by conventionally known methods. compounds and unsaturated olefins of butene, hexene, and octene, styrenes substituted with alkyl groups such as styrene, α-methylstyrene, and α-butylstyrene as aralkyl groups, methyl acrylate, and methyl methacrylate as ester groups.

It can be produced by addition reaction with unsaturated esters such as butyl oleate in the presence of a platinum catalyst. Also, when introducing this alkoxy group,
organopolysiloxane having mi81H bonds, n-glopanol, n-butanol, in-butanol, n-
Alcohols such as amyl alcohol, cyclohexanol, and stearyl alcohol may be dehydrogenated in the presence of a zinc dust catalyst.

Next, dimethylpolysiloxane as component 0) is a main component for imparting defoaming durability to the composition of the present invention, and it may be either linear or monobranched. Any terminal may be used as long as it is capped with a trinotylsilyl group-monohydro-tetraoxydimethylsilyl group or the like. This viscosity should be as low as possible from the viewpoint of dispersion and prevention of cissing, but from the viewpoint of sustained defoaming, it is better to have a high viscosity of 100 to 1,000.000a.
However, from the viewpoint of compatibility with the polyoxyalkylene-modified organopolysiloxane as the above-mentioned component (a) and affinity with the organic substance contained in the dispersion medium, it should be at least 500 aS or more, and the dispersion From the viewpoint of performance, it is preferable to set it to 300,000 aS or more. Incidentally, if the blending ratio of component (1) to component (a) is too low, antifoaming performance will not be fully exhibited, and if it is too high, hydrophobicity will become strong and dispersibility and stability will deteriorate.

Since it may cause repellency, it is necessary to use 2 to 200 parts by weight per 100 parts by weight of component a), but from the viewpoint of dispersibility and antifoaming properties, it is preferably 5 to 100 parts by weight.

In addition, the unfinished silica filler used as component (c) is a known one (both wet silica and dry silica can be used). Examples include silica treated with silyl groups, specifically Aerosil (trade name of Nippon Dexa Co., Ltd.) and Nibusil (trade name of Nippon Silica Co., Ltd.).

Examples include Cabosil (trade name manufactured by Cabot) and Santocel (trade name manufactured by Monsando Chemical Co., Ltd.). In addition,
This silica unfinished filler has a specific surface area of 5 orr by BET method? /g or more is preferable, but
If this blending ratio is too high or too low, the antifoaming performance will not be fully exhibited, and if it is too high, the system will thicken, causing problems in handling. It is required to be 0.1 to 40 parts by weight.

Note that the surfactant as the second component is as described above)
This is to improve the dispersibility of dimethylpolysiloxane as a component, and this addition results in less cissing and oil spots in the composition.

Both cationic and anionic types can be used. However, from the viewpoint of antifoaming and dispersion effects.

This is preferably a nonionic surfactant, and more preferably a hydrophilic surfactant and a lipophilic surfactant are used in combination, but if the HLB is 3 or less, it will not function as a dispersion stabilizer. If the HLB is 19 or more, antifoaming properties will decrease, so use a hydrophilic surfactant with an HLB of 8 to 20 and HL.
A lipophilic surfactant whose B is 2 to 7 and whose HLB is 3 to 1.
It is preferable to mix it so that it is in the range of 9. Such surfactants include sorbitan fatty acid ester, glycerin fatty acid ester, and sucrose fatty acid ester.
Examples include higher fatty acid esters of polyoxyethylene compounds, higher alcohol esters, alkylphenol condensates, alkyl quaternary ammonium salts, higher alkyl sulfonates, etc., and the blending ratio of these is 100% of component (a) as described above. It is necessary to set it to 0.1-40 parts by weight per military part.

This antifoaming agent composition can be obtained by uniformly mixing predetermined amounts of the above-mentioned components 1) to 2) using a mixer such as a homomixer, but the order of mixing is not particularly limited. 40 to 1 if necessary during mixing.
It may be heated to a temperature in the range of 50°C.

The low-foaming aqueous ink composition of the present invention combines the above-described aqueous ink composition as component A), the silicone antifoam composition as component B), and other auxiliary agents added as necessary. It can be obtained by uniformly mixing or kneading together with a diluent in a roll mill, ball mill, attritor sand mill, desilver, homo mixer, etc. The amount of the antifoaming agent composition to the ink composition is the same as that of the aqueous ink composition. Generally speaking, the amount of antifoam composition is 0.1 to 10 parts by weight, preferably 0.1 to 5 parts by weight, per 100 parts by weight of the ink composition, although it varies somewhat depending on the other components and the type of antifoam composition. It should be a heavy transmission department.

Next, examples of the present invention will be given, and parts in one example are parts by weight.
The viscosity is a value measured at 25°C, and is an antifoaming test of this water-based ink composition.

The defoaming test using a printing press and the repellency test were conducted using the following methods.

(Defoaming test) Water-based ink composition obtained by adding 0.3% by weight of the silicone-based defoaming agent composition prepared in Examples and Comparative Examples to the water-based ink composition in a tall beaker of 1.00 (Il) 200g of stuff
7.000 in a homomixer for low viscosity.
The amount of foaming (foam height) was measured by stirring at rotational speeds of r, p, m, and then left in a constant temperature bath at 40°C for one week, and the same method was used again to generate the foam. The amount of foam was measured.

(Anti-foaming test using a printing machine) Flexographic color printing was carried out using an aqueous ink composition obtained by adding 0.3% by weight of the silicone antifoaming agent composition prepared in Examples and Comparative Examples to an aqueous ink composition. After printing with a printing press, changes in the specific gravity of this ink were measured and evaluated as follows.

◎ ... No bubbles at all O... Some bubbles remain in the corners of the ink vat △ ...
Bubbles cover the surface of the ink vat ×...There are so many bubbles that they overflow from the ink vat and cannot be sucked up with a pump (cissing test) The silicone antifoam composition obtained above was added to 0.3 m 9%.
The added aqueous ink composition was spread on water-repellent liner paper using a -0,151n71 wire bar, and the degree of repellency after drying was observed and evaluated as follows.

◎ ・・・ Same as blank (no antifoaming agent added) ○ ・・
・ Some repellency is present, but it is the same as the blank △ ... Many repellents are present × ... Examples where there are countless repellents Water-based ink Fes Jonkryl 62 [trade name manufactured by Johnson Co., Ltd. ), 15 parts of Joncryl 89 (trade name manufactured by the same company), 5 parts of Impropanol, 4 parts of polyethylene wax, and 26 parts of water were added to 100 parts of an aqueous 7 Lexo ink composition obtained by uniformly mixing the following: 0.3% by weight of the silicone antifoam compositions a) to e) prepared in the above manner.
Added.

When this was subjected to an antifoaming test using a printing press and a repellency test, the results shown in Tables 1 and 2 below were obtained.

[Silicone antifoam composition a)) 1 dimethylpolysiloxane having a viscosity of 5.00008 and having both ends blocked with trimethylsilicate/l/ groups per 100 parts of an oxyalkylene group-containing organopolysiloxane represented by the formula %. 45 parts, fine powder silica nibsil ■N3 (trade name manufactured by Nippon Silica Co., Ltd.) 5 parts, polyoxyethylene sorbitan monooleate ()'-80 (trade name manufactured by Kao Atlas Co., Ltd., HLB = "15.0 ), and 5 parts of Nrubitan Monostearate Span 60 (product name manufactured by Kao Atlas Co., Ltd. - HLB = 4.7) were added, and these were thoroughly mixed with a homomixer to obtain antifoam composition a). Had made.

[Silicone-based fljJ foaming agent composition b)] Formula G...Same as Example 1 Y"-...-cH20H(OHs)0.HI.

1 for 100 parts of oxyalkylene group-containing organopolysiloxane represented by 1 45 parts of dimethylpolysiloxane with a viscosity of 10,000 as, which is capped at both ends with trimethylsilyl groups, and 5 parts of fine powder silica Erosil 200 (trade name manufactured by Nippon Erosil Co., Ltd.). Polyoxyethylene oleyl ether Emulgen 420 (product name manufactured by Kao Atlas Co., Ltd.)
10 parts were added, heated to 60° C., and mixed uniformly with a homomixer to prepare antifoam composition b).

[Silicone antifoam composition C)) 1 dimethylpolysiloxane having a viscosity of 1,500 as and having both ends blocked with monohydroxysilyl groups per 100 parts of an oxyalkylene group-containing organopolysiloxane represented by the formula % formula %) 27 parts, 3 parts of Erzil 200 (above), and polyoxyethylene sorbitan monooleate Tween 8o
(Supra) 2 parts were added and thoroughly mixed with a homomixer to prepare antifoam composition C).

[Silicone antifoam composition d)...Comparative product] Formula G is a composition containing 100 parts of the same oxyalkylene group-containing organopolysiloxane shown above with a viscosity of 300 as, in which both ends are blocked with trimethylsilyl groups. Dimethylpolysiloxane 4
5 parts and 35 parts of finely powdered silica nibsil N2 were added thereto and thoroughly mixed using a homomixer to prepare an antifoam composition d).

[Silicone defoamer composition e)...Comparative product] 100 parts of the same oxyalkylene-modified organopolysiloxane used in the above-mentioned defoamer composition d), with both ends blocked with trimethylsilyl groups. viscosity 1,000 a
45 parts of dimethylpolysiloxane (s) and 5 parts of finely powdered silica Erosil 200 (mentioned above) were added and mixed uniformly with a homomixer to prepare antifoam composition e).

Table 2 Defoaming test using printing machine

Claims (1)

[Scope of Claims] 1. A) Water-based ink composition 100 parts by weight B) i) General formula [In the formula, Y is an unsubstituted or t-substituted alkyl group having 3 to 30 carbon atoms, an aralkyl group, an ester group, A group selected from alkoxy groups, G is the formula -R1-0-Q-A, R1 is a divalent hydrocarbon group having 2 to 10 carbon atoms, and A is a hydrogen atom, an alkyl group, an acyl group, or an incyanate group. selected group, Q is an oxyalkylene group having 1 to 5 carbon atoms, p is an integer of 1 to 100), &-b is 0,1
or 2. c is 1, 2 or 3 and a+b+c=3- A
is an integer from 20 to 200. 1m is a number such that m+2a is 2 to lOO. n is a number where n+2b is 2 to 50, (n+2b)/ma=
100 parts by weight of an organopolysiloxane containing an oxyalkylene group represented by 0.01 to i, oo,); 2 to 200 parts by weight of dimethylpolysiloxane having a viscosity of 100 to 1.000,000 cs at 25°C; c) 2) A silicone antifoaming agent composition comprising 0.1 to 10 parts by weight of a silica unfinished filler and 0.1 to 40 parts by weight of a surfactant. Foamy water-based ink composition.