JPH03252477A - Coating composition - Google Patents

Abstract

PURPOSE:To obtain the title composition capable of providing a coating film having excellent abrasion resistance by blending a specific polyurethane with a fluororesin, silicone oil, polyether silicone and halogenating agent at definite ratios. CONSTITUTION:The aimed composition obtained by blending (A) 100 pts.wt. polyurethane consisting of a polyol, triethanolamine and a polyisocyanate and having molar ratio of polyol: triethanolamine of 1:0.05-2.0 and molar ratio of hydroxyl group: isocyanate of 1:1.5-7 with (B) 2-100 pts.wt. fluororesin, (C) 5-200 pts.wt. silicone oil, (D) polyethersilicone having amounts capable of providing molar ratio of hydroxyl group: isocyanate group of 0.7-1.3:1 and (E) 0.002-20 pts.wt. halogenating agent such as N-bromophthalic imide.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating composition suitable for coating rubber products, synthetic resin products, etc.

[Conventional technology]

Conventionally, natural rubber (NR), styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), isobutylene-isoprene copolymer rubber (IIR), chloroprene rubber (CR), acrylonitrile-butadiene copolymer rubber (NBR), isoprene Rubber (IR), ethylene-
For surface coating of synthetic rubber such as propylene-diene copolymer rubber (EPDM), ethylene-propylene copolymer rubber (EPM), cotton, rayon, ABS, PS, etc., nylon-based, epoxy-based, acrylic-based, acrylic-ethylene Copolymer resin paints or rubber paints such as BR, CR, and SBR are used.

[Problem to be solved by the invention]

The conventional resin-based paints and rubber-based paints have problems in that they have poor adhesion to coated objects such as rubber, synthetic resins, and fibers, and the resulting paint films have poor abrasion resistance.

An object of the present invention is to solve the above-mentioned problems and provide a coating composition that provides a coating film surface with excellent abrasion resistance and good adhesion between the coating film and the object to be coated.

[Means to solve the problem]

In order to achieve the above object, the coating composition of the present invention includes:
It is composed of polyol, triethanolamine, and polyisocyanate, and the molar ratio of polyol:triethanolamine is 1:0.05 to 2.0, and the hydroxyl group (-O
H): The molar ratio of isocyanate groups (-NCO) is 1:
For 100 parts by weight of polyurethane having a polyurethane content of 1.5 to 7,
2 to 100 parts by weight of fluororesin, 5 parts of silicone oil
~200 parts by weight, polyether silicone in an amount such that the molar ratio of hydroxyl group (-OH):isocyanate group (-NCO) is 0.7 to 1.3:l, and halogenating agent to 0.
．． 002 to 20 parts by weight is adopted.

[Detailed explanation of means]

First, the polyurethane used in the present invention will be explained.

Polyols include polyoxypropylene glycol (PPG), propylene oxide adduct of glycerin, propylene oxide adduct of trimethylolpropane, propylene oxide adduct of pentaerythritol, triethylene glycol (TG), addition of propylene oxide to sucrose. Examples include compounds such as The above polyoxypropylene glycol has a number average molecular weight of 8
A value in the range of 00 to 6000 is preferred.

The amine is triethanolamine, and a crosslinking reaction occurs with monoethanolamine and jetanolamine.
It is unsuitable because polyurethane gels.

Polyisocyanate is a compound having a plurality of isocyanate groups, such as 2.4-Mu lylene diisocyanate TDI), 65/35 (2,4=ratio of tolylene diisocyanate and 2,6-tolylene diisocyanate, hereinafter the same) ) Tolylene diisocyanate, 80/20
Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), dianisidine diisocyanate, tridene diisocyanate, hexamethylene diisocyanate, metaxylene diisocyanate,
1,5-naphthalene diisocyanate (NDI), hydrogenated 4,4'-diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, hydrogenated 2,4-)lylene diisocyanate, hydrogenated 65/35 tolylene diisocyanate, hydrogenated 80/20 tri Diisocyanate, isophorone diisocyanate (IPDI), 4.4' 4
'-triphenylmethane triisocyanate, tris(
p-isocyanate phenyl) thiophosphate, etc. are used.

The molar ratio of the polyol:triethanolamine is 1:
It is 0.05 to 2.0. If this ratio is less than 0.05 or more than 2.0, the adhesion of the resulting coating film to the object to be coated will be greatly reduced.

Further, the molar ratio of hydroxyl group (-0H) in the polyol to isocyanate group (-NCO) in the polyisocyanate is 1:1.5 to 7, and the isocyanate group is blended in excess with respect to the hydroxyl group.

When this ratio is less than 1.5 or more than 7, the adhesion of the resulting coating film to the object to be coated decreases, and may not adhere properly.

Fluororesins include tetrafluoroethylene resin,
Tetrafluoroethylene-hexafluoropropylene copolymer resin, trifluorochloroethylene resin, vinylidene fluoride resin, etc. are used. The blending ratio of this fluororesin is in the range of 2 to 100 parts by weight per 100 parts by weight of the polyurethane. If the proportion is less than 2 parts by weight, the abrasion resistance will not improve, and if it exceeds 100 parts by weight, it will be difficult to apply the coating composition.

As the silicone oil, dimethyl silicone oil, methyl chloride silicone oil, methyl hydrogen silicone oil, methylphenyl silicone oil, fluorosilicone oil, etc. are used. The blending ratio of this silicone oil is 5 parts by weight based on 100 parts by weight of the polyurethane.
~200 parts by weight. If the blending ratio is less than 5 parts by weight, it is impossible to improve the abrasion resistance, and even if it is blended in an amount exceeding 200 parts by weight, the effect of improving the abrasion resistance does not change, but instead the adhesion deteriorates. .

The polyether silicone is a polymer having a hydroxyl group and a siloxane bond, and for example, one having the following structural formula can be used.

This polyether silicone is made by reacting a copolymer of ethylene oxide and propylene oxide with silicone, but it may also be made by reacting a homopolymer of ethylene oxide or propylene oxide with silicone. The polyether silicone preferably has a hydroxyl value of about 45 to 60, and this polyether silicone functions as a curing agent for the polyurethane and also contributes to improving wear resistance.

The molar ratio of hydroxyl groups in the polyether silicone to isocyanate groups in the polyurethane is in the range of 0.7 to 1.3:1. When this molar ratio is less than 0.7, the adhesion of the resulting coating film to the object to be coated decreases, and it is also impossible to improve the abrasion resistance. Moreover, when it exceeds 1.3, the adhesion of the coating film to the object to be coated decreases.

As a halogenating agent, N-promsuccinimide (N
BSI), acid imide halogen compounds such as N-bromphthalimide, isocyanuric acid halides such as trichloroisocyanuric acid (TCIA) and dichloroisocyanuric acid, halogenated hydantoins such as dichlorodimethylhydantoin, and alkyl hypohalides.

The above-mentioned alkyl hypohalides are normal, secondary or tertiary alkyl hypohalides, particularly stable tertiary alkyl chlorides and bromides, such as tertiary butyl hypobromide, tertiary amyl hypobromide, etc. is preferred, and halogen-substituted alkyl hypochlorides such as dichloro, trichloro or fluoromethyl hypochloride can also be used.

The halogenating agent is used in an amount of 0.002 to 20 parts by weight per 100 parts by weight of the polyurethane.

If the blending ratio is less than 0.002 parts by weight, the degree of halogenation is small, so there is little improvement in adhesion, and if it exceeds 20 parts by weight, the stability of the coating composition deteriorates.

In the present invention, a solvent may be added if necessary. Examples of this solvent include benzene, toluene, xylene, ethylbenzene, trichloroethylene, ethylene chloride, dimethylformamide, dimethyl sulfoxide,
Examples include methyl ethyl ketone, athene, methyl isopropyl ketone, methyl isobutyl ketone, methyl acetate, ethyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, anisole, and tetrahydrofuran.

The blending ratio of this solvent is 10 parts by weight in 100 parts by weight of the coating composition.
A range of 90 parts by weight is preferred. If the blending ratio is less than 10 parts by weight, the solid content will be relatively high and the viscosity of the coating composition will increase, making coating work difficult and likely resulting in a decrease in adhesion; if it exceeds 90 parts by weight, On the other hand, the proportion of solids becomes low and the film thickness of the coating composition becomes thin, which is not preferable as a coating material.

The coating composition of the present invention is prepared, for example, as follows. First, the polyol, triethanolamine, polyisocyanate, and a necessary solvent are appropriately selected and mixed, and the mixture is reacted at 80° C. for 3 hours in dry nitrogen gas to prepare a polyurethane having isocyanate groups.

Next, based on 100 parts by weight of this polyurethane, 2 to 100 parts by weight of fluororesin, 5 to 200 parts by weight of silicone oil, and polyether silicone are added in an amount such that hydroxyl group: incyanate group = 0.7 to 1°3:l. Halogenating agent 0. A coating composition is obtained by adding 2 to 20 parts by weight of OO and further adding a solvent to adjust the viscosity to a level suitable for coating.

In this case, a part of the fluororesin may be replaced with molybdenum disulfide, glass fiber, carbon fiber, polyethylene, silicon oxide, calcium carbonate, magnesium carbonate, clay, or the like.

[Effect]

By adopting the above method, the coating composition improves the abrasion resistance of the resulting coating film surface due to the characteristics such as the lubricity of silicone oil and polyether silicone and the low coefficient of friction of fluororesin, and also improves the abrasion resistance of the resulting coating film surface. The oxidizing agent halogenates the object to be coated and improves the mutual intermolecular force,
It is composed of a polyol, triethanolamine, and polyisocyanate in a predetermined proportion, and by blending an excess of isocyanate groups, the adhesion to the coated object is improved due to effects such as hydrogen bonding due to the polyurethane having a specific structure having isocyanate groups.

[Examples 1 to 12 and Comparative Examples 1 to 6] Examples embodying the present invention will be described below in comparison with comparative examples. In addition, on each side, parts represent parts by weight.

First, the object to be coated is the following vulcanizate.

That is, the vulcanizate contains 100 parts of EPDM, 70 parts of carbon black, 35 parts of mineral oil, 7 parts of zinc oxide, and 2 parts of stearic acid.
1 part of sulfur, 2 parts of vulcanization accelerator, and 1.5 parts of sulfur.
It was vulcanized at 60°C for 30 minutes.

In addition, the wear resistance test was conducted by the following method, and the wear resistance was evaluated based on the amount of wear loss.

That is, Test machine: Taper type rotary abrader (manufactured by Toyo Seiki Seisakusho Co., Ltd.) Test conditions: Wear wheel, H-22, Load: 1 kg Wear rotation speed: 60 rpm Sample size: 100+no+X100n+m Number of wear, 1
000 times Next, polyol (PO), triethanolamine (TEA), and polyisocyanate (PI) shown in Table 1 below were used.
) were mixed in trichlorethylene and reacted at 80° C. for 3 hours in a nitrogen gas atmosphere to synthesize polyurethane. The obtained polyurethane had a solid content of 83% and a trichlorethylene content of 17%.

The abbreviations in Table-1 represent the following meanings.

PPG 3000: Polyoxypropylene glycol with a number average molecular weight of 3000 PPG 100 Polyoxypropylene glycol with a number average molecular weight of 1000 PPG 2000: Polyoxypropylene glycol with a number average molecular weight of 2000 TG 3000: Triethylene glycol with a number average molecular weight of 3000 TG 1000: Triethylene glycol TG 2000 with a number average molecular weight of 1000: Triethylene glycol with a number average molecular weight of 2000 MDI: 4,4'-diphenylmethane diisocyanate NDI: 1.5-naphthalene diisocyanate XDI:
Xylylene diisocyanate IPDI: Isophorone diisocyanate Next, based on 100 parts by weight of the solid content of the above various polyurethanes, Table 2 below
A coating composition was obtained by blending predetermined amounts of the fluororesin, silicone oil, polyether silicone (PESj), and halogenating agent shown in .

This coating composition was applied to the object to be coated and heated at 80°C for 20 hours.
The above-mentioned abrasion resistance test was conducted on the dried product. The results are shown in Table 4 below.

Table-2 The abbreviations in Table-2 represent the following meanings.

Fluororesin refers to tetrafluoroethylene resin.

DMS i represents dimethyl silicone oil.

(1) One with a viscosity of 10,000 centistokes (C3t) (
2): Viscosity of 60,000 cSt (3): Viscosity of 100,000 C3t Polyether silicone has the following hydroxyl value.

(a) 56, (b) 48, (C) 4.7,
(d) 59, (e) 46, (f) 52,
(g) 51 , (h) 50, (i) 49 The halogenating agent represents the following.

TCIA: l-lichloroisocyanuric acid NBSI:
N-promsuccinimide t-BHC: tertiary butyl hypochloride In addition, as a comparative example, a coating composition as shown in Table 3 was prepared, applied to the object to be coated in the same manner, dried, and then subjected to an abrasion resistance test. The results are shown in Table 5 below.

Above table be.

The meaning of the abbreviation 3 is the same as in Table 2 above.Table 5 As can be seen from Table 4 above, the paint compositions of each example had abrasion loss of 3.
The amount is extremely small at 4 to 6.3 mg. The reason why the coating compositions of each example exhibit such excellent wear resistance without impairing the material properties of the coated object is due to the lubricity of silicone oil and polyether silicone, and the low coefficient of friction of fluororesin. It is presumed that this is based on small characteristics.

In addition, the coating composition of each example is composed of a predetermined amount of polyol, triethanolamine, and polyisocyanate, and the halogenating agent halogenates the coated object to improve mutual intermolecular force. It exhibits excellent adhesion to vulcanized rubber, which is the object to be coated, due to hydrogen bonding caused by polyurethane.

On the other hand, as can be seen from Table 5, the coating compositions of each comparative example either gelled or the abrasion loss was 894.2 to 3951.
It is large at 6 mg and has poor wear resistance.

〔Effect of the invention〕

The coating composition of the present invention has the effect that the resulting coating film surface has very good abrasion resistance, and the adhesion between the coating film and the object to be coated is excellent.

Claims (1)

[Claims] 1. Consisting of polyol, triethanolamine and polyisocyanate, the molar ratio of polyol:triethanolamine is 1:0.05-2.0, and the hydroxyl group (
-OH): molar ratio of isocyanate group (-NCO) is 1
:1.5-7 for 100 parts by weight of polyurethane,
2 to 100 parts by weight of fluororesin, 5 parts of silicone oil
~200 parts by weight, polyether silicone in an amount such that the molar ratio of hydroxyl group (-OH):isocyanate group (-NCO) is 0.7 to 1.3:1, and 0 halogenating agent.
．． A coating composition containing 2 to 20 parts by weight of 0.002 to 20 parts by weight.