JPS61138639A - Coating composition for surface-treatment of polymeric elastomer - Google Patents

Abstract

PURPOSE:To provide the titled composition containing a curable polyurethane composed of polyvalent isocyanate and a polyol, a curable silicone, a takifier, a powdery component, and a silicone oil, and capable of forming a firmly bonded coating film having excellent slipperiness, antifreezing property, etc. 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, (D) a powdery component and (E) a silicone oil, as film-fomring elements. The component C is e.g. a chlorinated EPT which may be grafted with an amino-containing acrylic monomer, and the component D is e.g. nylon powder having particle diameter of 0.1-200mu. The component E is e.g. a dimethyl silicone oil etc. having a viscosity of 10,000-10,000,000cst.

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) Self! Weather strips and grass runs used in i11 tunnels, and weather strips used in building satsui.
The strips are required to have many properties such as not only weather resistance and heat resistance, but also non-freezing properties, water resistance, abrasion resistance, and lubricity.

For example, a weather strip for an automobile is used between the active surface between a window glass and a door, or 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 curable silicones or silicone oils are easily rubbed off or wiped off by friction and do not have a 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, Japanese Patent Laid-Open No. 55
-160063, JP 55-157661, JP 55-157660, JP 55-1
As disclosed in Japanese Utility Model Publication No. 57662 and Japanese Utility Model Application Publication No. 56-164819, 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. be.

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, with use, the slide against the sliding surface becomes worse, the water repellent effect of rainwater becomes worse, and especially in winter, it freezes, making it impossible to open and close the window glass.

Furthermore, these two-component coating compositions have poor adhesion, particularly to non-polar 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 weather resistance, which were drawbacks of conventional surface treatment coating compositions of this type, and have achieved long-term durability. Abrasive, slippery.

As a result of intensive research into paint compositions that impart water repellency, non-sticking properties, and non-freezing properties, we found that curable silicone, adhesion promoter, and particle size of 0.1μ to 200μ compared to curable polyurethane.
It has been discovered that the above problems can be solved by blending powder and silicone oil, and the present invention has been achieved.

(Structure of the Invention) The gist of the present invention is that a curable polyurethane consisting of a combination of a polyvalent isocyanate and a polyol, a curable silicone, an adhesion promoter, and a particle size of 0.1 μ to 200 μ This is a coating composition for surface treatment of a polymeric elastomer, characterized in that it substantially contains powder and silicone oil as coating film-forming elements.

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 composition, a hydroxyl group at the terminal is synthesized from a C3...C6 saturated low molecular diol, Ca, Cs dicarboxylic acid, the saturated low molecular diol and dicarboxylic acid, and a low molecular trifunctional polyol and dicarboxylic acid. You may use the urethane paint which consists of the urethane polyol which has a hydroxyl group at the terminal, and the urethane prepolymer which has an isocyanate group at the terminal, which is obtained by reacting the polyester having the above with an isocyanate.

Here, the isocyanate is MDI.

TDI, HDI, IPDl, NDI, XDI.

H6MD I, Hn XD I TMP adduct,
Examples include polyfunctional isocyanates such as water adducts and trimers, as well as Desmodur R, RF, and RtJ.

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 selected from the group of modified PE, NR or NR modified product, OR or OR modified product, and organic acid. As an example, modified EPT is, for example, halogenated EPT, more specifically chlorinated EPT with 10 to 30 percent chlorine, or chlorinated EPT grafted with an amino group-containing acrylic monomer or a hydroxyl group-containing acrylic monomer. be.

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-Human Oxylethyl methacrylate.

Examples include 2-hydroxypropyl methacrylate, trimethylolpropane trimethacrylate, N-methylol acrylamide, 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 triclo-O cyanuric acid can be used.

In addition, as a powder with a particle size of 0.1μ to 200μ,
It includes inorganic and organic pigments, and further includes synthetic or silicon carbide or oxide powders, metal soap powders, nylon powders, fluororesin powders, and sulfide powders.

More specifically, carbide powders include powders such as titanium carbide, zirconium carbide, barium carbide, niobium carbide, tantalum carbide, chromium carbide, molybdenum carbide, silicon carbide, and tungsten carbide, and oxide powders include aluminum oxide.

Uses powders such as titanium oxide and silicon oxide.

Nylon powders include nylon 66, nylon 610, nylon 6, and nylon 11. Use powder such as nylon 12.

As the fluororesin powder, powder such as polytetrafluoroethylene, polychlorotrifluoroethylene, or tetrafluoroethylene-hexafluoropropylene copolymer is used, and as the sulfide powder, powder such as molybdenum disulfide is used.

The viscosity of the silicone oil varies depending on the degree of polymerization, but preferred examples include dimethyl silicone oil and methyl chloride silicone oil having a viscosity of io, ooo centistokes to io, ooo, ooo centistokes.

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 catalysts and promoters, dyes, pigments, and solvents or diluents such as toluene and MEK.

Note that the above-mentioned catalysts include dibutyltin 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 (parts by weight: the same below): Curable silicone 1-1000: Adhesive agent 5-300: Powder with a particle size of 0.1 μm to 200 μm 0.01-100: Silicone oil 3-200.

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 repellency, and if it exceeds 1,000 parts, the function of the urethane paint as a binder will be impaired. .

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

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 be able to provide sufficient abrasion resistance to the object to be coated, and if it exceeds 200 parts, the composition will deteriorate. Since the stability of the product deteriorates, 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.

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, separation may occur during forming into a paint, making it difficult to obtain a uniform coating film.

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

The blending ratio of the powder will vary somewhat depending on the type and particle size of the powder, but if it is less than 0.01 part per 100 parts of curable polyurethane, there will be no cleanliness and durability;
Beyond this point, the coating film has no flexibility and no followability with the adherend. Therefore, it is preferably in the range of 0.01 to 30 parts per 100 parts of curable polyurethane.

The reason why the particle size is limited to 0.1 μm to 200 μm is as follows. In other words, if the particle size of the powder is less than 0.1μ, it will not be effective in reducing the yP and friction coefficient, and problems will occur.On the other hand, if the particle size exceeds 200μ, the coating film will not be able to hold the powder and the powder will separate. This may cause a problem in that the effect of imparting lubricity is lost. Therefore, it is limited to the above range, and is more preferably 1 μ to 100 μ.

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 resistance, 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 EPD-1 Rubber, it is more effective than when other surface treatment coating compositions are applied. The adhesion is significantly 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.

In addition, the curable silicone is dispersed and held in the polyurethane paint on the surface layer side of the coating film, and the powder is dispersed and held in the curable silicone in a state where it stands out on the coating surface, thereby providing desirable properties such as lubricity. It is presumed that this is the case.

Furthermore, speaking only about powder, the following will be considered.

(b) When microscopically inspecting the glass surface using rIA, there are small irregularities that are hit by the powder particles exposed on the surface, so overall the contact surface between the glass surface and the paint film is smooth. (b) The glass surface and the coating surface are relative g! When moving, the resin alone will be pulled toward the glass and wear out, but since the contact surface with the glass is in countless point contact with hard or slippery powder, No wear,
It also becomes slippery.

Further, the present invention also has the following effects. For example, a weather strip for a window frame is integrally formed into a frame shape by joining the four corners of an extruded body formed by molding or the like. In this case, the molded product has a different gloss at the extruded portion and a corner portion, giving the molded product the appearance of being spliced. However, by subjecting the surface of the molded article to one-coat treatment with the composition according to the present invention, the entire surface becomes semi-glossy, and there is no difference in gloss between the corner portion and the extruded portion. Therefore, the appearance performance of the product is also improved and the product looks good.

Furthermore, the coating composition of the present invention has the advantage of simplifying the coating process without requiring 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 22.2 parts by weight of isophorone diisocyanate were added to 1 part of polyester polyol obtained from butanediol and adipic acid with a molecular ff of 12,000, and the mixture was heated in N2 gas at 100 to 110°C for 2 hours using dibutyltin dilaurate as a catalyst. react. 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 J8 colorant.

To 100 parts of chlorinated EPT (degree of chlorination 20% by weight), N-
20 parts of methylol acrylamide was dissolved in 5'00 parts of toluene, the temperature was raised to 90-100°C, 0.5 parts of benzoyl peroxide was added, and the mixture was reacted for about 3 hours, resulting in a graft copolymer with a polymerization rate of about 50%. get.

Dilute this to 10% with toluene.

Next, as for the curable silicone, commercially available product names: *Toshiba Silicone *YSR3022: Catalyst YC *Shin-Etsu Silicone *KS709: Catalyst c-ps *Toreshi UD
- (tlsRX290: Touch WSR242AC was used.

Example 1 Urethane polyol 333 Partially curable silicone YSR3022130 Catalyst YC683113 Silicone oil 20 Fluorine resin powder 10 Polyisocyanate
60 halogenated E PDM 40 (
~ Run 1 500 MEK
The coating composition prepared as above 500 was spray applied to the surface of an untreated automobile weather strip and dried at room temperature.

Example 2 Urethane polyol 333 Partially curable silicone KS709 130 Catalyst C-PS-513 Nylon powder 5 Silicone oil 20 Polyisocyanate
60 halogenated EPT 40 toluene 500MEK
A coating composition adjusted to a composition ratio of 500 or more was applied by spray to an untreated automobile weather strip and dried at room temperature.

Example 3 Urethane polyol 333 Partially curable silicone 5RX290 130 Catalyst 5RX242AC13 Molybdenum disulfide powder 5 Silicone oil 20 Polyisocyanate
60 halogenated EPT 40 toluene 500MEK
A coating composition having a composition ratio of 500 or more was spray applied onto a weather strip in the same manner as in Example 1, and dried at 70°C.

Comparative Example 1 A paint consisting of a single curable silicone disclosed in Japanese Patent Publication No. 19813/1983 was prepared and applied to the surface of a weather strip under the same conditions as in Examples 1 to 3.

Comparative Example 2 As shown in Japanese Unexamined Patent Publication No. 55-157662, a coating composition consisting of urethane + silicone oil + fluororesin was prepared according to the publication, and this was applied to Examples VA1 to 3.
Spray applied under the same conditions.

Comparative Example 3 A coating composition consisting of a combination of urethane + fluororesin + polyamide resin disclosed in Japanese Utility Model Publication No. 56-1648 was prepared according to the same publication, and weatherstripped in the same manner as Examples 1 to 3. spray applied to the surface.

The results of measuring the surface conditions of the weatherstrips obtained in Examples 1 to 3 and Comparative Examples 1 to 3 are shown in the table below.

Note that the measurement items are abrasion resistance, contact angle, and adhesive strength. Regarding wear resistance and contact angle, the initial state and
The state after being weathered for 100 hours at 63±3°C in a weatherometer.

In addition, as for the abrasion resistance: Jt test conditions, the surface was sandpapered with No. 800 sandpaper according to JIS standards.
The number of strokes required until the surface peeled off was examined under conditions of 120ae+ and a cycle of 30 cycles/10.

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 at a tensile rate of 200 ael/min, 180 degrees (Peel
) Measured by peeling.

*: Sponge material failure ◎: Silicone cohesive failure ΔNi Interfacial peeling between strip rubber and paint film As is clear from the above results, the paint composition of the present invention as a paint film forming element has poor wear resistance. The properties and adhesive strength are dramatically improved. Moreover, compared to Comparative Examples 2 and 3, the weather resistance is excellent.

Claims (1)

[Claims] It is characterized by substantially containing curable polyurethane consisting of a combination of polyvalent isocyanate and polyol, curable silicone, adhesion promoter, powder, and silicone oil as coating film forming elements. A coating composition for surface treatment of elastomer polymers.