JPS5818950B2 - paint composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition suitable for use in coating rubber and synthetic resin products.

Generally, natural rubber (NR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), isobutylene-impropylene copolymer rubber (IIR), PolJ chloroprene rubber (CR), acrylonitrile-butadiene copolymer rubber (NBR), polyisoprene rubber (IR)
, synthetic rubbers such as ethylene-propylene rubber (EPDM, EPT), cotton, rayon, acrylonitrile-butadiene-styrene copolymer resin (ABS), polystyrene (PS), etc., have very poor abrasion resistance.

In addition to these, resin paints such as nylon, epoxy resin, acrylic resin, acrylic ethylene resin, and BR, CR
, If a rubber-based paint such as SBR is applied and abrasion occurs,
(A) Due to the lack of adhesion with rubber/synthetic resin products and fibers, problems occur in which the base material and paint peel off during wear.

Furthermore, (B) the paint itself has no abrasion resistance, so its abrasion resistance is poor.

A number of countermeasures have already been attempted to address these drawbacks.

For example, methods for improving (N) include (1) polishing the surface with a wire brush, sandpaper, etc.;
2) oxidize the surface by exposing it to ozone, (3) irradiate it with ultraviolet rays, (4) treat it with iodized incyanate, (5) immerse it in concentrated sulfuric acid, (6) oxidize it with organic monocarboxylic acid and phosphoric acid. There are methods such as treatment with a mixed solution, (7) treatment with aldehydes, and (8) treatment with alkyl hypochlorite.

However, these conventional processing methods have the following problems in (1): (1) It is easy to cause uneven polishing, @ There is an occupational health problem due to the generation of dust, and (2),
O causes deterioration of the vulcanizate, in (3) above, in addition to the O mentioned above, there is a danger of handling ○ processing agent, in the previous statement α4), in addition to the above ○, ■ Special processing agent is required. , O
The treatment process is complicated, ■ The equipment is expensive, and the above (
5), (6), (7), and (8), the above θ○○
There were problems such as θ■, and it was not necessarily suitable for obtaining coating film adhesion.

In addition, improvements to the above (B) include (1) polybutadiene and incyanate-based paint containing both terminal hydroxyl groups, (2) N-methoxymethylated nylon paint, and (3) epoxy resin and polyaminoamide-based paint. , (4) chloroprene rubber-based paint, (5) styrene-butadiene copolymer rubber paint, (6) acrylic-ethylene modified airsion paint, etc. may be used.

However, in (1) and (2) above, these conventional paints do not have heat resistance and the coating film fuses during wear.
In the case of 3), there was no cold resistance, and in the case of (4), there were problems such as weak adhesion of the coating film to the base material, and it was not necessarily suitable for obtaining abrasion resistance.

In view of the above, the present invention provides a coating composition used for coating rubber and synthetic resin products, which provides a coating film with excellent abrasion resistance and coating properties without impairing the material properties of these objects. An object of the present invention is to provide a coating composition that has sufficient adhesion to the surface of a coated object.

The gist of this invention is a urethane polymer 100 having an incyanate group or a hydroxyl group at the end obtained by reacting a mixture of a polyester diol and a polyether diol with a diincyanate and further reacting a low molecular weight diol. The coating composition contains 10 parts or more of silicone oil per part (solid content).

The present invention will be explained in detail below.

First, examples of polyether diols, polyester diols, diisocyanates, low molecular diols, silicone oils, and solvents used in the present invention are as follows.

Polyether diols: polyoxypropylene glycol, polyoxyethylene glycol, polytetramethylene oxide glycol, etc.

Polyester diols: polyethylene adipate, polybutylene adipate, polyethylene butylene adipate, polydiethylene adipate, ■6-hexanediol, adipic acid ester of diethylene glycol, etc.

Diisocyanate: 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, (1), 5-naphthalene diisocyanate, toluene diisocyanate, etc.

Low molecular diols: ethylene glycol, propylene glycol, phthanediol, bentanediol, hexanediol, heptanediol, octanediol, diethylene glycol, triethylene glycol, dithioglycol, dipropylene glycol, neopentyl glycol, 2-ethyl-2-fi -7” thiruto 3=propanediol, 2,2,4-trimethyl-1,3-bentanediol, etc.

Silicone oil: dimethyl silicone oil, methyl chloride silicone oil, methylhydrogen silicone oil, methylphenyl silicone oil, etc.

Solvent: Benzene, toluene, xylene, ethylbenzene, trichlorethylene, ethylene chloride, dimethylformamide, dimethyl sulfoxide, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, impropyl acetate, acetic acid n
-Butyl, anisole, tetrahydrofuran, etc.

Next, the method for preparing a coating composition of the present invention includes appropriately selecting and using the above-mentioned diol, diisocyanate, and solvent;
After reacting in dry nitrogen gas at 50 to 130°C for 60 to 360 minutes to synthesize a urethane prepolymer having an incyanate group at the end, 50 to 1
A urethane polymer was obtained by reacting at 30°C for 10 to 60 minutes.

At least 10 parts of silicone oil is added to 100 parts of this urethane polymer (solid content), and carbon black and a solvent are added as appropriate to adjust the viscosity to a level suitable for coating.

Here, if the amount of silicone oil is less than 10 parts, the wear resistance will be poor.

In this case, if necessary, molybdenum disulfide,
Glass fibers, carbon fibers, polyvinylidene fluoride, poly(47tethylene), polyethylene, silicon oxide, etc. can be added.

As shown in the examples below, when the coating composition of the present invention thus obtained is applied to an object, the coating film forms on the surface of the object without impairing the material properties of the object. It has excellent adhesion with other materials and exhibits excellent abrasion resistance.

Note that silicone oil is sometimes used as a smoothing agent and as a foam stabilizer when foaming urethane, but in either case, the amount of silicone oil added is very small.

It is generally said that coating compositions containing a large amount of silicone oil, such as the coating composition of the present invention, do not have good adhesion, but the coating composition of the present invention has excellent adhesion as shown in the examples below. has.

EXAMPLES Hereinafter, the effects of the present invention will be confirmed with reference to Examples, but the present invention is not limited to these Examples.

The objects to be coated (I) and (II) used in the Examples are vulcanized products under the following conditions.

(I) Ethylene-propylene terpolymer 100
70 parts carbon black, 35 parts mineral oil, 7 parts zinc white
parts, stearic acid 2 parts, vulcanization accelerator 2 parts, sulfur 1.5 parts
Ethylene-
Propylene rubber vulcanizate.

(II) Ethylene-propylene terpolymer 100
1 part, 30 parts of polyhydroxypolybutadiene with 98% or more hydrogenated double bonds, 70 parts of carbon black, 35 parts of mineral oil, 7 parts of zinc white, 2 parts of stearic acid, 2 parts of vulcanization accelerator, 1 part of sulfur. .5 parts of rubber compound at 160°C
Ethylene-propylene rubber cured Wa that was vulcanized for 0 minutes
J.

The method for preparing the test pieces for each example and control example was to clean the surface of the object to be coated in (I) or (6) above, then apply the paint as appropriate using a method suitable for the object to be coated, and then warm it up to room temperature. Create by drying at 180°C.

At this time, the temperature is preferably 80 to 150°C.

If the temperature is below 80°C, the curing time will increase and
If the temperature is 50° C. or higher, there is a risk of thermal aging of the object to be coated or the paint.

Further, it is preferable to select the drying temperature depending on the material of the object to be coated.

In addition, the abrasion resistance test was conducted under the following conditions, and the abrasion resistance was evaluated by wear loss.

Testing machine: Tipa complete rotary breather (manufactured by Toyo Seiki Seisakusho Co., Ltd.) Test conditions: Wear wheel...H-22, load...1kg Wear rotation speed...60 rpm Sample size...100x100mm Number of wear...1000 times Example 1 Polypropylene oxide glycol (molecular weight approximately 2000
) 120 parts, polyethylene adipate (molecular weight approximately 200
After reacting 44 parts of 0'), 100 parts of 4,4'-diphenylmethane diisocyanate, and 264 parts of trichloroethylene at 80°C in dry nitrogen gas for 3 hours, 24.8 parts of 6-hexanediol and 17 parts of dimethylformamide were reacted.
0 parts was added thereto and the reaction was carried out at 80° C. for 20 minutes in dry nitrogen gas to obtain a urethane polymer.

100 parts of the obtained urethane polymer, 30 parts of carbon black, 100 parts of toluene, 40 parts of dimethylformamide, and 20 parts of polydimethylsiloxane (dimethylsilicone oil) (viscosity: about 10,000 cst) were mixed to prepare a paint.

This paint was applied to the object to be coated (I) and cured at 100° C. for 2 minutes to prepare a test piece.

Example 2 Urethane polymer 100 prepared in the same manner as Example 1
10 parts of carbon black, 80 parts of toluene, 50 parts of dimethylformamide, and 30 parts of polydimethylsiloxane (viscosity: about 100,000 cst) were mixed to prepare a paint.

It was applied to the object to be coated (I) and cured at 100° C. for 5 minutes to prepare a test piece.

Example 3 Polypropylene oxide glycol (molecular weight approximately 2000
) 140 parts, polyethylene adipate (molecular weight approximately 200
Example 1
After reacting in the same manner as above, using 24.2 parts of 1,6-hexanediol and 246 parts of dimethylformamide,
A urethane polymer was synthesized in the same manner as in Example 1.

100 parts of the obtained urethane polymer, 30 parts of carbon black, 100 parts of benzene, 50 parts of dimethylformamide, polydimethylsiloxane (viscosity about 10 cSt)
30 parts were mixed to prepare a paint.

This paint was applied to the object to be coated (a river, and cured at 100°C for 5 minutes to prepare a test piece.

Example 4 Polypropylene oxide glycol (molecular weight approximately 2000
), 140 parts of polyethylene butylene adipate (molecular weight approximately 2000), 100 parts of 4,47-diphenylmethane diisocyanate, and 300 parts of trichloroethylene in the same manner as in Example 1, and then 189 parts of 4-butanediol. A urethane polymer was synthesized in the same manner as in Example 1 using 246 parts of dimethylformamide.

100 parts of the obtained urethane polymer, 10 parts of carbon black, 100 parts of toluene, 50 parts of dimethylformamide, polydimethylsiloxane (viscosity about 60,000 cst)
A paint was prepared by mixing 35 parts.

This paint was applied to the object to be coated (I[) and cured at 100° C. for 5 minutes to prepare a test piece.

Example 5 Polypropylene oxide glycol (molecular weight approximately 2000
) 60 parts, polybutylene adipate (molecular weight approximately 2000
), 100 parts of 4,4'-diphenylmethane diisocyanate, and 300 parts of trichlorethylene in Example 1.
After reacting in the same manner as ethylene glycol 12
．． A urethane polymer was synthesized in the same manner as in Example 1 using 2 parts of dimethylformamide and 300 parts of dimethylformamide.

100 parts of this obtained urethane polymer, 5 parts of carbon black, 100 parts of toluene, 5 parts of dimethylformamide
0 parts, polydimethylsiloxane (viscosity approximately 1000 cs
t) 30 parts were mixed to prepare a paint.

This paint was applied to the object to be coated (I) and cured at 100° C. for 5 minutes to prepare a test piece.

Example 6 Polypropylene oxide glycol (molecular weight approximately 2000
), 60 parts of polyethylene/butylene adipate (molecular weight approximately 2000), 100 parts of 4,4'-diphenylmethane diisocyanate, and 300 parts of trichlorethylene in the same manner as in Example 1, and then ethylene glycol 12, A urethane polymer was synthesized in the same manner as in Example 1 using 2 parts of dimethylformamide and 300 parts of dimethylformamide.

100 parts of the obtained urethane polymer, 30 parts of carbon black, 100 parts of toluene, 50 parts of dimethylformamide, polydimethylsiloxane (viscosity approximately 100,000 cst),
) were mixed to prepare a paint.

This paint was applied to the object to be coated (I) and cured at 100° C. for 5 minutes to prepare a test piece.

Control example 1 "Idemitsu Seal AB-700WJ (trade name, liquid polybutadiene, manufactured by Idemitsu Petrochemical Co., Ltd.) 100 copies, 4.4'
- A paint was prepared by mixing 10 parts of diphenylmethane diisocyanate.

This paint was applied to the object to be coated (I) and cured at room temperature to prepare a test piece.

Control example 2 [Idemitsu Seal AB-100J (trade name, liquid polybutadiene, manufactured by Idemitsu Petrochemical Co., Ltd.) 100 copies, 4.4/-
A paint was prepared by mixing 10 parts of diphenylmethane diisocyanate.

This paint was applied to the object to be coated I) and cured at room temperature to prepare a test piece.

Control Example 3 Torezin M-20J (trade name: N-methoxymethylated nylon, 70% methanol solution, manufactured by Teikoku Kagaku Sangyo Co., Ltd.) was applied to the coated object (I) and cured at room temperature to prepare a test piece.

Control example 4 100 parts of "Araldai" PZ820J (trade name epoxy resin, manufactured by Nippon Ciba Geigy Co., Ltd.), [Hardner H
A paint was prepared by mixing 100 parts of 2J (trade name: Polyaminoamide, manufactured by Nippon Ciba Geigy Co., Ltd.).

This paint was applied to the object to be coated (①) and cured at room temperature to prepare a test piece.

Control example 5 [Araldai] GY250j (trade name epoxy resin, manufactured by Nippon Ciba Geigy Co., Ltd.) 100 parts, "Hardner H
A paint was prepared by mixing 30 parts of 2J (trade name: Polyamide Amide, manufactured by Nippon Ciba Geigy Co., Ltd.).

This paint was applied to the object to be coated (①) and cured at room temperature to prepare a test piece.

Control Example 6 Bond G2J (trade name: chloroprene rubber, 74% toluene solution, manufactured by Konishi Co., Ltd.) was applied to the coated object (I) and cured at room temperature to prepare a test piece.

Control Example 7 "Diabond 5o1o, J (trade name: SBR manufactured by Nogawa Chemical Co., Ltd.) was applied to the object to be coated (I) and cured at room temperature to prepare a test piece.

Control Example 8 "Diabond DA-830AJ (trade name: acrylic resin emulsion non-volatile content 70%, manufactured by Nogawa Chemical Co., Ltd.) was applied to the object to be coated (I) and cured at room temperature to prepare a test piece.

Control Example 9 Penguin Cement 138J (trade name: acrylic ethylene modified emulsion, non-volatile content: 55%, manufactured by Sunstar Chemical Co., Ltd.) was applied to the object to be coated (I) and cured at room temperature to prepare a test piece.

Control example 10 “Diabond DA700EJ (product name: polyurethane,
(manufactured by Nogawa Chemical Co., Ltd.) was applied to the object to be coated (I) and cured at room temperature to prepare a test piece.

Table 1 shows the test results of the above, Examples, and Control Examples.

Claims (1)

[Claims] 1 A mixture of polyester diols and polyether diols is reacted with diincyanate,
A coating composition characterized in that 100 parts (solid content) of a urethane polymer having an incyanate group or a hydroxyl group at the end obtained by reacting a low-molecular diol with 10 parts or more of silicone oil is blended.