Metal surface processing agent

Abstract

An object is to provide a metal surface treatment agent which can be coated by screen printing, and can be effectively used for metal surface treatment at the time of forming a rubber-metal complex excellent in water resistance and heat resistance, and the object can be solved by a metal surface treatment agent which comprises an organometallic compound, silica, magnesium silicate hydrate, and an organic solvent represented by the following general formula (I):
RO(CH2)2OHGeneral formula (I)
[wherein R represents an alkyl group having 3 or more carbon atoms or an aryl group.]

Claims

1. A metal surface treatment agent for coating a metal surface to be coated with rubber compound, the metal surface treatment agent comprises an organotitanium compound, silica, magnesium silicate hydrate and an organic solvent represented by the following general formula (I): and the magnesium silicate hydrate is an organic modified magnesium silicate, and the organic modified magnesium silicate is contained in an amount of 4 to 19% by weight based on a total weight of starting reagents;
RO(CH.sub.2).sub.2OHGeneral formula (I) wherein R is selected from the group consisting of a propyl, a butyl, a phenyl, a benzyl, a tollyl and a xylyl, and wherein the organic solvent is contained in an amount of 50% to 70% by weight based on a total weight of starting reagents, and wherein the metal surface treatment agent has a viscosity measured at a temperature of 25 C. using a B type viscometer at 60 rpm of 100 mPas or more.

2. The metal surface treatment agent according to claim 1, wherein solid content concentrations of the organotitanium compound and the silica are both 0.01 to 20% by weight.

3. The metal surface treatment agent according to claim 1, wherein the solid content concentration of the metal surface treatment agent is 4 to 35% by weight.

4. The metal surface treatment agent according to claim 1, wherein the metal surface treatment agent has a viscosity ratio V.sub.6/V.sub.60 which is a ratio of the viscosity V.sub.6 at 6 rpm to a viscosity V.sub.60 at 60 rpm is in the range of 2-10.

5. A metal surface treatment agent for partially coating a surface by screen printing, the metal surface treatment agent comprises an organotitanium compound, silica, an organic modified magnesium silicate hydrate thickener present in an amount of 4 to 19% by weight based on a total weight of starting reagents, and an organic solvent present in an amount of 50% to 70% by weight based on a total weight of starting reagents, the organic solvent represented by the following general formula (I):
RO(CH.sub.2).sub.2OHGeneral formula (I) wherein R is selected from the group consisting of a propyl, a butyl, a phenyl, a benzyl, a tollyl and a xylyl, wherein the solid content concentration of the metal surface treatment agent is 4 to 35% by weight, and wherein the metal surface treatment agent has a viscosity measured at a temperature of 25 C. using a B type viscometer at 60 rpm of 100 mPas or more.

Description

EXAMPLES

(1) Examples of the present invention are explained. The present invention is not limited by such Examples.

Example 1

(2) Organotitanium compound (TC-401 available from Matsumoto Fine Chemical Co., Ltd.; solid content: 45%) . . . 11.1% by weight Colloidal silica (PL-2LPGME available from Fuso Chemical Co., Ltd.; solid content: 25%) . . . 16.6% by weight Thickener: Sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified magnesium silicate hydrate) . . . 7% by weight Organic solvent: Butyl Cellosolve (CH.sub.3(CH.sub.2).sub.3O(CH.sub.2).sub.2OH) (ethylene glycol monobutyl ether available from GODO Co., Ltd.; boiling point: 171 C.) . . . 65.3% by weight

(3) In this Example, an organotitanium compound (TC-401 available from Matsumoto Fine Chemical Co., Ltd., in which a titanium chelate is adjusted to 45% by an organic solvent of isopropyl alcohol was used. When the organotitanium compound is formulated with 11.1% by weight in the metal surface treatment agent, then, the solid content of the organotitanium compound becomes 11.10.45=4.995% by weight. On the other hand, as the silica, silica (PL-2 LPGME available from Fuso Chemical Co., Ltd.) in which colloidal silica is adjusted to 25% by an organic solvent of propylene glycol methyl ether acetate was used. When it is formulated with 16.6% by weight in the metal surface treatment agent, the solid content of the silica becomes 16.60.25=4.15% by weight. Accordingly, a solid content ratio of the organotitanium compound and the silica used in the present Example becomes 54:46.

(4) The above-mentioned respective components were charged in a preparation tank, mixed and stirred by a stirrer, whereby a metal surface treatment agent which has been adjusted to the whole solid content concentration of 15 to 20% by weight was obtained.

(5) With regard to the obtained metal surface treatment agent, its physical properties were evaluated according to the following methods.

(6) <Evaluation method> The respective physical properties were measured by the following methods, and the measurement results were shown in Table 1.

(7) (1) Viscosity By using a B type viscometer, viscosities V.sub.6 and V.sub.60 (mPa.Math.s) at a rotation speed of the rotor at 6 rpm and at 60 rpm were measured at 25 C. Also, a viscosity ratio (V.sub.6/V.sub.60) of V.sub.6 and V.sub.60 was obtained to evaluate the thixotropy property.

(8) (2) Evaluation of Coating Property by Screen Printing

(9) The obtained metal surface treatment agent was coated on a stainless steel plate (SUS301H) by screen printing with single-sided coating weight (a film amount) of 800 mg/m.sup.2, and the coating property at that time was evaluated by the following criteria: : No bleeding, hang down, bubble, etc. : Bleeding, hang down and bubble were generated in some extent : The case where bleeding, hang down and bubble were not generated and the case where they were generated are mixed x: Remarkable bleeding, hang down and bubble were generated

(10) (3) Evaluation of Adhesiveness

(11) The obtained metal surface treatment agent was coated on a stainless steel plate (SUS301H) by screen printing with a single-sided coating weight (a film amount) of 800 mg/m.sup.2, dried at room temperature or warm air, and then, subjected to baking processing in an oven at 200 C. for 2 minutes.

(12) Thereafter, with an unvulcanized rubber compound of a fluororubber compound comprising the following formulation composition is mixed the below mentioned vulcanization accelerator by an open roller to obtain a rubber composition, and the resulting composition is dissolved in a methyl ethyl ketone-methanol (volume ratio: 9:1) mixed solvent so that the solid content concentration thereof becomes 25% by weight by using a rotary type stirrer to prepare a rubber solution (a viscosity by a BH type viscometer with a rotor No. 4 and a rotation speed of 4 rpm: 2.5 Pa.Math.s).

(13) Thereafter, the above-mentioned rubber solution was coated on the stainless steel plate onto which the metal surface treatment agent has been coated. After the solvent was dried, vulcanization is carried out in an oven at 220 C. for 3 minutes to obtain a test piece as the rubber-metal complex.

(14) <Fluororubber Compound Formulation Composition> Fluororubber (Viton A-200 available from Du Pont Kabushiki Kaisha) . . . 100 parts by weight MT carbon black (N990) . . . 20 parts by weight White carbon (Nipsil ER available from Tosoh Silica Corporation) . . . 10 parts by weight Magnesium oxide (Magnesia #30 available from Kyowa Chemical Industry Co., Ltd.) . . . 5 parts by weight Earthy graphite (A-0 available from Nichiden Carbon Co., Ltd.) . . . 30 parts by weight Vulcanizing agent (Curative #30 available from Du Pont Kabushiki Kaisha; bisphenol AF 50% by weight, Fluororubber (Viton E-45) 50% by weight) . . . 10.7 parts by weight Epoxy group-containing silane coupling agent (SH-6040 available from Dow Corning Toray Co., Ltd.) . . . 1.0 part by weight Epoxy-modified phenol resin (Epiclon N695 available from DIC Corporation) . . . 34.5 parts by weight

(15) <Vulcanization Accelerator> Vulcanization accelerator (Curative #20 available from Du Pont Kabushiki Kaisha; quaternary phosphonium salt: 33% by weight, Fluororubber (Viton E-45) 67% by weight) . . . 5.8 parts by weight

(16) With regard to the test piece thus obtained, evaluation of adhesiveness was judged by the method according to the cross-cut adhesion test (JIS K 5400:1959) with five grades based on the following criteria.

(17) <Evaluation Standard> 5 . . . A rubber remaining ratio of the rubber layer is confirmed with naked eyes, and a material with the rubber remaining ratio of 100% 4 . . . A material of 95% or more and less than 100% 3 . . . A material of 85% or more and less than 95% 2 . . . A material of 65% or more and less than 85% 1 . . . A material of less than 65%

(18) Also, with regard to the test piece thus obtained, after subjecting to air heating under the conditions of at 200 C. for 70 hours, the same cross-cut adhesion test was carried out to evaluate heat resistance of adhesion.

(19) Further, with regard to the test piece thus obtained, after dipping in water under the conditions of at 100 C. for 70 hours, the same cross-cut adhesion test was carried out to evaluate water resistance of adhesion.

Example 2

(20) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing an amount of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) from 7% by weight to 10% by weight and changing an amount of the solvent from 65.3% by weight to 62.3% by weight, evaluated in the same manner, and the results were shown in Table 1.

Example 3

(21) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing an amount of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) from 7% by weight to 5% by weight and changing an amount of the solvent from 65.3% by weight to 67.3% by weight, evaluated in the same manner, and the results were shown in Table 1.

Example 4

(22) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing an amount of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) from 7% by weight to 15% by weight and changing an amount of the solvent from 65.3% by weight to 57.3% by weight, evaluated in the same manner, and the results were shown in Table 1.

Example 5

(23) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 5% by weight of sepiolite (PANGEL B40 available from Kusumoto Chemicals, Ltd.; organic modified) and changing an amount of the solvent from 65.3% by weight to 67.3% by weight, evaluated in the same manner, and the results were shown in Table 1.

Example 6

(24) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 7% by weight of sepiolite (PANGEL B40 available from Kusumoto Chemicals, Ltd.; organic modified), evaluated in the same manner, and the results were shown in Table 1.

Example 7

(25) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 10% by weight of sepiolite (PANGEL B40 available from Kusumoto Chemicals, Ltd.; organic modified) and changing an amount of the solvent from 65.3% by weight to 62.3% by weight, evaluated in the same manner, and the results were shown in Table 2.

Example 8

(26) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 7% by weight of sepiolite (PANGEL HV available from Kusumoto Chemicals, Ltd.; non-modified), evaluated in the same manner, and the results were shown in Table 2.

Example 9

(27) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 10% by weight of sepiolite (PANGEL HV available from Kusumoto Chemicals, Ltd.; non-modified) and changing an amount of the solvent from 65.3% by weight to 62.3% by weight, evaluated in the same manner, and the results were shown in Table 2.

Example 10

(28) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing amounts of the organotitanium compound from 11.1% by weight to 22% by weight, the colloidal silica from 16.6% by weight to 0.4% by weight and the solvent from 65.3% by weight to 70.6% by weight, and evaluated in the same manner. In this case, the solid content ratio of the organotitanium compound and the silica used in Example 10 becomes 99:1. The results were shown in Table 2.

Example 11

(29) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing amounts of the organotitanium compound from 11.1% by weight to 2.2% by weight, the colloidal silica from 16.6% by weight to 36% by weight and the solvent from 65.3% by weight to 54.8% by weight, and evaluated in the same manner. In this case, the solid content ratio of the organotitanium compound and the silica used in Example 10 becomes 10:90. The results were shown in Table 2.

Example 12

(30) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing 65.3% by weight of the solvent Butyl Cellosolve (ethylene glycol monobutyl ether available from GODO Co., Ltd.; boiling point: 171 C.) to 65.3% by weight of Phenyl Cellosolve (C.sub.6H.sub.5O(CH.sub.2).sub.2OH) (ethylene glycol monophenyl ether available from GODO Co., Ltd.; boiling point: 245 C.), evaluated in the same manner, and the results were shown in Table 2.

Comparative Example 1

(31) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing an amount of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) from 7% by weight to 0% by weight and changing an amount of the solvent from 65.3% by weight to 72.3% by weight, evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 2

(32) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing an amount of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) from 7% by weight to 3% by weight and changing an amount of the solvent from 65.3% by weight to 69.3% by weight, evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 3

(33) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing an amount of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) from 7% by weight to 20% by weight and changing an amount of the solvent from 65.3% by weight to 52.3% by weight, evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 4

(34) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 5% by weight of sepiolite (PANGEL HV available from Kusumoto Chemicals, Ltd.; non-modified) and changing an amount of the solvent from 65.3% by weight to 67.3% by weight, evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 5

(35) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 20% by weight of sepiolite (PANGEL HV available from Kusumoto Chemicals, Ltd.; non-modified), and changing an amount of the solvent from 65.3% by weight to 52.3% by weight, evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 6

(36) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 5% by weight of castor oil series thickener (THICKENER 4040 available from SAN NOPCO Limited, 100% hydrogenated castor oil), and changing an amount of the solvent from 65.3% by weight to 67.3% by weight, evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 7

(37) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 7% by weight of castor oil series thickener (THICKENER 4040 available from SAN NOPCO Limited, 100% hydrogenated castor oil), evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 8

(38) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 7% by weight of the sepiolite (PANGEL B20 available from Kusumoto Chemicals, Ltd.; organic modified) to 10% by weight of castor oil series thickener (THICKENER 4040 available from SAN NOPCO Limited, 100% hydrogenated castor oil), and changing an amount of the solvent from 65.3% by weight to 62.3% by weight, evaluated in the same manner, and the results were shown in Table 3.

Comparative Example 9

(39) A metal surface treatment agent was formed in the same manner as in Example 1 except for changing from 65.3% by weight of the solvent Butyl Cellosolve (ethylene glycol monobutyl ether available from GODO Co., Ltd.; boiling point: 171 C.) to 65.3% by weight of Ethyl Cellosolve (C.sub.2H.sub.5O(CH.sub.2).sub.2OH) (ethylene glycol monoethyl ether available from GODO Co., Ltd.; boiling point: 135 C.), evaluated in the same manner, and the results were shown in Table 3.

(40) TABLE-US-00001 TABLE 1 (% by weight) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Metal Organotitanium compound TC-401 11.1 11.1 11.1 11.1 11.1 11.1 surface (solid content: 45%) treatment Colloidal silica PL-2L-PGME 16.6 16.6 16.6 16.6 16.6 16.6 agent (solid content: 25%) <Solid content ratio (Organotitanium compound: Colloidal 54:46 54:46 54:46 54:46 54:46 54:46 silica)> Thickener Sepiolite PANGEL B20 7 10 5 15 (organic modified) PANGEL B40 5 7 (organic modified) PANGEL HV (non-modified) Castor oil type thickener Thickener 4040 Solvent Butyl Cellosolve Boiling point: 171 C. 65.3 62.3 67.3 57.3 67.3 65.3 Phenyl Cellosolve Boiling point: 245 C. Ethyl Cellosolve Boiling point: 135 C. Viscosity mPa .Math. s (60 rpm) 350 740 250 50000 540 780 mPa .Math. s (6 rpm) 1575 3330 700 260000 1836 3120 V6/V60 4.5 4.5 2.3 5.2 3.4 4 Evaluation of Initial 5 5 5 5 5 5 adhesion Heat resistance 200 C. 70 h 5 5 5 5 5 5 Water resistance 100 C. 70 h 5 5 5 5 5 5 Evaluation of screen coating

(41) TABLE-US-00002 TABLE 2 (% by weight) Example Example 7 Example 8 Example 9 Example 10 Example 11 12 Metal Organotitanium compound TC-401 11.1 11.1 11.1 22 2.2 11.1 surface (solid content: 45%) treatment Colloidal silica PL-2L-PGME 16.6 16.6 16.6 0.4 36 16.6 agent (solid content: 25%) <Solid content ratio (Organotitanium compound: Colloidal 54:46 54:46 54:46 99:1 10:90 54:46 silica)> Thickener Sepiolite PAMGEL B20 7 7 7 (organic modified) PAMGEL B40 10 (organic modified) PANGEL HV 7 10 (non-modified) Castor oil type thickener Thickener 4040 Solvent Butyl Cellosolve Boiling point: 171 C. 62.3 65.3 62.3 70.6 54.8 Phenyl Cellosolve Boiling point: 245 C. 65.3 Ethyl Cellosolve Boiling point: 135 C. Viscosity mPa .Math. s (60 rpm) 1000 150 200 320 290 820 mPa .Math. s (6 rpm) 4700 375 560 900 725 3690 V6/V60 4.7 2.5 2.8 2.8 2.5 4.5 Evaluation of Initial 5 5 5 5 5 5 adhesion Heat resistance 200 C. 70 h 5 5 5 5 5 5 Water resistance 100 C. 70 h 5 5 5 5 5 5 Evaluation of screen coating

(42) TABLE-US-00003 TABLE 3 (% by weight) Comparative Comparative Comparative Comparative Comparative example 1 example 2 example 3 example 4 example 5 Metal Organotitanium compound TC-401 (solid content: 11.1 11.1 11.1 11.1 11.1 surface 45%) treatment Colloidal silica PL-2L-PGME 16.6 16.6 16.6 16.6 16.6 agent (solid content: 25%) <Solid content ratio (Organotitanium compound: Colloidal 54:46 54:46 54:46 54:46 54:46 silica)> Thickener Sepiolite PANGEL B20 3 20 (organic modified) PANGEL B40 (organic modified) PANGEL HV 5 20 (non-modified) Castor oil type thickener Thickener 4040 Solvent Butyl Cellosolve Boiling point: 171 C. 72.3 69.3 52.3 67.3 52.3 Phenyl Cellosolve Boiling point: 245 C. Ethyl Cellosolve Boiling point: 135 C. Viscosity mPa .Math. s (60 rpm) 10 50 Mixing is 50 Mixing is mPa .Math. s (6 rpm) 10 60 impossible 115 impossible V6/VS0 1 1.2 2.3 Evaluation of Initial 5 5 5 adhesion Heat resistance 200 C. 70 h 5 5 5 Water resistance 100 C. 70 h 5 5 5 Evaluation of screen coating X X X Comparative Comparative Comparative Comparative example 6 example 7 example 8 example 9 Metal Organotitanium compound TC-401 (solid content: 11.1 11.1 11.1 11.1 surface 45%) treatment Colloidal silica PL-2L-PGME 16.6 16.6 16.6 16.6 agent (solid content: 25%) <Solid content ratio (Organotitanium compound: Colloidal 54:46 54:46 54:46 54:46 silica)> Thickener Sepiolite PANGEL B20 7 (organic modified) PANGEL B40 (organic modified) PANGEL HV (non-modified) Castor oil type thickener Thickener 4040 5 7 10 Solvent Butyl Cellosolve Boiling point: 171 C. 67.3 65.3 62.3 Phenyl Cellosolve Boiling point: 245 C. Ethyl Cellosolve Boiling point: 135 C. 65.3 Viscosity mPa .Math. s (60 rpm) 100 350 740 500 mPa .Math. s (6 rpm) 440 1575 3330 2250 V6/VS0 2.2 4.5 4.5 4.5 Evaluation of Initial 5 5 5 5 adhesion Heat resistance 200 C. 70 h 5 5 5 5 Water resistance 100 C. 70 h 1 1 1 5 Evaluation of screen coating X

(43) <Evaluation> When Example 1 and Comparative example 9 are compared to each other, it can be understood that coating property by screen printing is markedly worsened since the carbon number of the alkyl group represented by R in the general formula (I) is less than 3 when Ethyl Cellosolve which is an organic solvent represented by C.sub.2H.sub.5O(CH.sub.2).sub.2OH is formulated in an amount of 50% by weight or more. This can be considered that a low boiling point would be affected as compared with that of the organic solvent in which the carbon number of the alkyl group represented by R in the general formula (I) is 3 or more.

(44) When Examples 1, 2 and 3 and Comparative examples 6, 7 and 8 are compared to each other, it can be understood that the coating property by screen printing can be solved by formulating a large amount of a castor oil series thickener as 7 to 10% by weight in place of using magnesium silicate (sepiolite) as a thickener, but its water resistance of the adhesion is inferior when the rubber-metal complex is formed.

(45) With regard to the amount of the organic modified sepiolite, when Examples 1, 2, 3 and 4 and Comparative examples 1, 2 and 3 are compared to each other, it can be understood that if the amount of the organic modified sepiolite is less than 4% by weight, a viscosity is too low so that screen printing could not be carried out, while if it exceeds 19% by weight, the metal surface treatment agent itself cannot be mixed, whereby it cannot be utilized as a metal surface treatment agent.

(46) With regard to the amount of the inorganic modified sepiolite, when Examples 8 and 9 and Comparative examples 4 and 5 are compared to each other, it can be understood that if the amount of the non-modified sepiolite is less than 6% by weight, a viscosity is too low so that screen printing could not be carried out, while if it exceeds 19% by weight, the metal surface treatment agent itself cannot be mixed, whereby it cannot be utilized as a metal surface treatment agent.

(47) From the results as mentioned above, it could be certified that the metal surface treatment agent according to the present invention has good coating property by screen printing, and the rubber-metal complex prepared by using the metal treatment agent of the present invention is excellent in water resistance and heat resistance, and the adhesiveness is not vulnerable to the external environment.