JPS61138638A - Coating composition for surface-treatment of polymeric elastomer - Google Patents

Abstract

PURPOSE:To provide the titled composition containing curable polyurethane composed of a polyvalent isocyanate and a polyol, a curable silicone, a tackifier, and a silicone oil, and capable of forming firmly bonded coating film having excellent slipperiness, water-repellency, sound-proofing property and abrasion resistance. CONSTITUTION:The objective composition can be produced by compounding (A) a curable polyurethane composed of a combination of a polyvalent isocyanate and a polyol, (B) a curable silicone, (C) a tackifier, and (D) a silicone oil, as film-forming elements. The component C is e.g. a chlorinated EPT having a chlorine-content of 10-30% which may be grafted with an amino-coatining acrylic monomer, and the component D is e.g. dimathyl silicone oil etc. preferably having a viscosity of 10,000-10,000,000cst. The amounts of the components B, C and D are 1-1,000pts. (wt.), 5-300pts. and 3-150pts. per 100pts. of the component A, respectively.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention provides a one-coat treatment to the surface of the object to be painted made of an elastic polymer material, particularly non-polar rubber, etc. adhesion, lubricity, water repellency, soundproofing,
The present invention relates to a coating composition for surface treatment that provides surface properties with excellent non-sticking properties, non-freezing properties, and abrasion resistance.

(Prior art and its problems) Weather strips and glass runs used in automobiles,
Furthermore, the conditions required for weather strips used in building satchels include not only weather resistance and heat resistance, but also non-freezing properties, water resistance, abrasion resistance, slipperiness, and many other properties. Ru.

For example, weather stripping for automobiles is used for the sliding surface between a window glass and a door, or for the contact surface between a door and a body paint plate, and the material used for the weather strip is strip rubber, vinyl chloride, or the like.

In order to provide lubricity and water repellency to the surface of this weather strip, hardening silicone or silicone oil is applied as shown in Japanese Patent Laid-Open No. 19813/1983.

However, these hardening silicones or silicone oils are I! ! It is easily rubbed off or wiped off by rubbing and has no lasting effect.

In other words, these silicones alone have no adhesion to objects to be coated, and are also brittle as coatings.

In order to improve such drawbacks, for example, special special open 55
-160063 Publication, JP-A-55-157661, JP-A-55-157660, ¥f gap 5-
Publication No. 157662 and Utility Model Application No. 164819 @
As disclosed in the publication, there is also a method in which the above-mentioned silicone oil is blended into a urethane paint to impart toughness to the formed coating film due to the adhesion of the urethane paint.

However, although this urethane-silicone oil composition has lubricity and water repellency on the surface, the silicone oil component was washed away during the weather resistance test and the water repellency and lubricity quickly disappeared. It was found that it could be stored away.

Therefore, it slides as it is used! ! There have been problems such as poor sliding on surfaces, poor rainwater repellency, freezing especially in winter, and the inability to use window glass.

Furthermore, these two-component coating compositions have poor adhesion, particularly to non-crosslinked polymeric elastomers such as EPT rubber.

(Means for Solving the Problem) The present inventors have improved the adhesion to the object to be coated and the weather resistance, which were drawbacks of conventional surface treatment/coating compositions of this type, and have achieved long-term use. Abrasion resistance and slipperiness.

As a result of intensive research into paint compositions that impart water repellency, non-sticking properties, and non-freezing properties, we have found that by blending curable silicone, adhesion promoter, and silicone oil with curable polyurethane, the above-mentioned conventional problems can be solved. We have discovered that this can be solved, and have arrived at the present invention.

(Structure of the Invention) The gist of the present invention is to use a curable polyurethane paint consisting of a combination of a polyvalent isocyanate and a polyol, a curable silicone, an adhesion promoter, and a silicone oil as coating film forming elements. This is a coating composition for surface treatment of an elastomer polymer, which is characterized in that it substantially contains:

Here, the curable polyurethane paint is a urethane prepolymer obtained by reacting a polyester polyol or a polyether polyol or a blend thereof having a hydroxyl group at the terminal, and a diisocyanate with a blend of both at the terminal, and a low-molecular diamine. Alternatively, it is composed of a urethane polymer having an amino group or a hydroxyl group at the terminal obtained by chain extension reaction of a low-molecular diol, and a diisocyanate.

In addition to the above combinations, CJ... C6 saturated low molecular weight diol, C4, C, s- dicarboxylic acid, and a terminal synthesized from the above saturated low molecular weight diol and dicarboxylic acid, and low molecular weight trifunctional polyol and dicarboxylic acid. A urethane paint consisting of a urethane polyol having a hydroxyl group at the end obtained by reacting a polyester having a hydroxyl group with an isocyanate and a urethane prepolymer having an isocyanate group at the end may be used.

Here, the isocyanate is MDI.

TDl, HDl, IPDl, NDI, XDI.

Examples include polyfunctional isocyanates such as TMP adducts, water adducts, and trimers of H6M DI, H+z X DI, and (Desmodur) R, RF, and RU.

As the curable silicone, a curable polyorganosiloxane composition having the composition shown in Japanese Patent Publication No. 56-19812 or another composition can be selected.

Adhesives include modified EPT and modified PP.

It consists of one type or a combination of two or more types selected from the group of modified PE, NR or NR modified product, OR or CR modified product, and organic acid.

As an example, modified EPT may include, for example, halogenated EPT.
More specifically, it is chlorinated EPT containing 110 to 30% of chlorine 1f or chlorinated EPT grafted with an amino group-containing acrylic monomer or a hydroxyl group-containing acrylic monomer.

In addition, as the amino group-containing acrylic monomer, N-methylolacrylamide, methacrylamide, acrylamide, N-n-butoxymethylacrylamide, N-
Examples include 1,1 dimethyl-3-oxobutylacrylamide.

In addition, as a hydroxyl group-containing acrylic monomer,
2-hydroxylethyl methacrylate.

Examples include 2-hydroxypropyl methacrylate, trimedylolpropane trimethacrylate, N-medyllol acryl 7mide, and 3-chloro 2-hydroxypropyl methacrylate.

As for other modified products, those obtained by partially grafting an acid- or base-containing acrylic monomer to a halogenated or halogen-modified product are used in accordance with EPT.

Further, as a special example, an organic acid such as trichloroisocyanuric acid can be used.

The viscosity of the silicone oil varies depending on the degree of polymerization, but preferably has a viscosity of 10,000 centistokes to 10,000 centistokes.
Examples include dimethyl silicone oil and methyl chloride silicone oil with centistokes of io, ooo, and ooo.

The composition consisting of the above combinations can be appropriately selected from among the combinations that are industrially inexpensive and most readily available.

In addition to the above-mentioned main components, the present invention includes additives such as a catalyst 9 promoter, dyes, pigments, and solvents or diluents such as toluene and MEK.

Note that the above-mentioned catalysts include dibdeltin diacetate, dibutyltin dilaurate, dibutyltin octoate, and tributyltin octoate.

Dioctyltin acetate, mercaptantin.

Dioctyltin oleate and the like are used. These catalysts accelerate the reaction when the composition is turned into a paint.

Next, the blending ratio of the composition can be set as follows.

Curable polyurethane 100 (polymer part: same below): curable silicone 1-1000, adhesion promoter 5-300: silicone oil 3-150.

The reason for this limitation will be explained. That is, 1 to 1000 parts of curable silicone to 100 parts of curable polyurethane.
The reason why 1 part is added is because if it is less than 1 part, the formed coating will lose its lubricity and water resistance, and if it exceeds 1000 parts, the function of the urethane paint as a binder will be impaired. be.

Therefore, the blending ratio of the curable silicone should be within the above-mentioned range, although it varies depending on the degree of lubricity imparted to the surface of the object to be coated.

In addition, if the adhesion promoter is less than 5 parts, the composition as a whole will not have sufficient adhesion to the surface to be painted;
If it is more than 0 parts, layer separation occurs during coating, making it difficult to obtain a uniform coating film.

Therefore, preferably 20 to 100 parts of the adhesion promoter per 100 parts of the curable polyurethane paint gives good results.

The blending ratio of silicone oil depends on the blending amount of the curable silicone, but if it is less than 3 parts, the composition as a whole will not have sufficient abrasion resistance for the object to be coated;
If the amount exceeds 100 parts, the stability of the composition deteriorates, so the amount is limited to 3 parts to 200 parts per 100 parts of curable polyurethane. Further, in order to maintain compatibility with the curable silicone, it is preferably 10 to 50% of the curable silicone.

The coating composition of the present invention can be applied to a brush within its usable life.

It is applied to the surface of the polymeric elastic material by spraying or the like.

Examples of elastomer polymers include commonly used strip rubber and PVC, and E
Examples include non-polar polymeric elastomers such as PT rubber and EPDM rubber.

(Effects of the Invention) When the coating composition of the present invention is coated on an object to be painted, it firmly adheres to the object to be painted, and the surface of the object to be painted has abrasion resistance, lubricity, water repellency, non-stick properties and Provides non-freezing properties.

In particular, when this coating composition is applied to the surface of a non-polar polymeric elastomer such as EPT rubber or EPDM rubber, the adhesion is significantly higher than when coating with other surface treatment coating compositions. is improved.

This is because the adhesion promoter has good compatibility with the polyurethane resin and good compatibility with the non-polar surface of the object to be coated.

Furthermore, the curable silicone is compatible with the polyurethane resin, and is dispersed and retained on the surface layer of the coating film. At the same time, the silicone oil, which is compatible with the curable silicone, is separated into the curable silicone in a state that stands out on the coating surface. Therefore, it is presumed that as a result of being retained, desirable characteristics such as lubricity are imparted.

Therefore, the coating composition of the present invention also has the advantage of simplifying the coating process without requiring any pre-treatment or post-treatment when coating the surface of a non-polar polymeric elastomer.

(Explanation of Examples) Examples will be described below.

First, as the urethane polyol used, an amine chain-extended ester urethane was used.

The method for producing this urethane polyol is as follows.

100 parts by weight of toluene and 22 parts by weight of isophorone diincyanate to ioo<m parts of a polyester polyol obtained from butanediol and adipic acid with a molecular ff of 12,000.
．． 2 parts by weight are added and reacted for 2 hours at 100-110°C in NZ gas using dibutyltin dilaurate as a catalyst. Next, after cooling to 50°C, 3 parts by weight of ethylenediamine is added, and the reaction is further continued at 70 to 80°C for 1 hour. After the reaction is completed, the mixture is diluted with toluene and a small amount of iPA so that the solid content becomes 30% to obtain a urethane prepolymer.

Next, the following graft copolymer was used as the modified EPT.

Chlorinated EPT (degree of chlorination 20w% > 100 parts, N-
20 parts of methylol acrylamide is dissolved in 500 parts of toluene, and 0.5 parts of benzoyl oxide is added at a temperature of 90 to 100°C, and the mixture is reacted for about 3 hours to obtain a graft copolymer with a polymerization rate of about 50%.

Dilute this to 10% with toluene.

Next, as for the curable silicone, the commercially available product name ■Toshiba Shi IJ:+-:zlYSR3022:Touch WYC■
Shin-Etsu Silicone@Ks709: Catalyst C-PS ■Toray Silicone@@5RX290: Catalyst SR242AC was used.

Examples Urethane polyol 333 Partially curable silicone YSR3022130 Catalyst YX6831 13 Silicone oil 20 Polyisocyanate
60 Halogen 7 EPT 40 Toluene 500 The coating composition prepared as above was sprayed onto the surface of an untreated automobile weather strip and dried at room temperature.

Comparative Example 1 A paint consisting of a single curable silicone disclosed in Japanese Patent Publication No. 56-19813 was prepared and applied to the surface of a weather strip under the same conditions as in the example.

Comparative Example 2 Urethane polyol 333 Partially curable silicone KS70.9 130 Catalyst C-PS-513 Polyisocyanate 60 Halogenated EP
T40 toluene
A paint having a composition of 500 or more was prepared and applied to the weatherstrip surface under the same conditions as in the example.

In this comparative example, the silicone oil component in the example was removed.

The results of measuring the surface conditions of the weatherstrips obtained in the above Examples and Comparative Examples 1.2 are shown in the table below.

The measurement items are wear resistance and contact angle.

Adhesive strength and actual vehicle test. Regarding wear resistance and contact angle, the initial state and the temperature of 63±3°C in the weatherometer.
The state after weathering for 100 hours is shown.

In addition, as test conditions for abrasion resistance, the surface was coated with a No. 800 sand vapor according to the JIS standard for 1 stroke.
At 20 am+, the cycle was 30 cycles/l1in, and the number of strokes required until the surface became peeled was examined.

The contact angle was measured by a droplet method, and the contact angle of a water droplet dropped on the surface was measured.

Adhesive strength was determined by bonding surface-treated sponges together, tensile speed 20 Q5, 1/1n, 180 degrees (Peel
) Measured by peeling.

In addition, as a result of the actual vehicle test, in this example there was no squeaking sound at all, whereas in comparative example 1 there was a moderate level of 4. The squeak sound and the small squeak sound in Comparative Example 2 were identified as significant differences.

*: Sponge material failure ◎: Silicone cohesive failure As is clear from the above results, the paint composition according to the present invention as a coating film forming element has poor wear resistance compared to Comparative Example 1. Improve dramatically.

Furthermore, it was found that it was superior to Comparative Example 2 in wear resistance and in actual vehicle tests. It can be inferred that this is because the sample of this example contains silicone oil compared to Comparative Example 2, and this silicone oil component effectively functions to further improve surface smoothness.

Claims (1)

[Claims] An elastic polymer characterized by substantially containing a curable polyurethane consisting of a combination of a polyvalent isocyanate and a polyol, a curable silicone, an adhesion promoter, and a silicone oil as film-forming elements. Paint composition for body surface treatment.