JPS61155432A - Coating composition for surface treatment of polymeric elastomer - Google Patents

Abstract

PURPOSE:To obtain a coating composition which, when applied to the surface of a polymeric elastomer such as an object, especially, a nonoplar rubber, can improve the adhesion, lubricity, water repellency, resistance to freezing, abrasion resistance, etc., of the elastomer, by using a curable polyurethane, a curable silicone and a tackifier as the principal components of the coating composition. CONSTITUTION:A curable polyurethane comprising a polyisocyanate and a polyol, a curable silicone (e.g., YSR3022, a product of Toshiba Silicone Co.) and a tackifier are used as the principal components of a coating. It is preferable to use atackifier which is the most suitable for an object as said tackifier. When the object is an olefinic elastomer such as EPDM, PP or EPT rubber, halogenated EPT, halogenated PE or the like can be used. When the object is a diene rubber suchas SBR rubber, CR, modified CR, an organic acid such as trichloroisocyanuric acid or the like can be used. The mixing ratio of said coating components is preferably such that 1-1,000pts.wt. curable silicone and 5-300pts.wt. tackifier are used per 100pts.wt. curable polyurethane.

Description

Detailed Description of the Invention (Technical Field of the Invention) This invention provides a one-coat treatment on the surface of an object to be coated made of an elastomer polymer, particularly non-polar rubber, etc.
The present invention relates to a coating composition for surface treatment that firmly adheres to the surface of an object to be coated and has excellent lubricity, water repellency, soundproofing, 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.

As an example, weather stripping for automobiles is used between the vibrating surface between a window glass and a door, or at 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 JIE rubbing, and their effects do not last long.

In other words, these silicones alone do not have adhesion to objects to be coated, and 1119 is also brittle.

In order to improve such drawbacks, for example, Japanese Patent Application Laid-open No. 55
-160063, JP 55-157661, JP 55-157660, JP 55-1
As disclosed in Publication No. 57.662 and Japanese Utility Model Application No. 56-164819, the aforementioned silicone oil was blended with urethane paint to impart toughness to the formed coating film due to the adhesion of the urethane paint. There are some things.

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.

As a result, as they are used, they become less slippery on stratified cooling surfaces, become less effective at repelling rainwater, and freeze, especially in winter, resulting in inconveniences such as the inability to open and close window glass.

(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 extensive research into paint compositions that impart water repellency, JE adhesion, and anti-freeze properties, we found that by blending curable silicone with curable polyurethane and adding an adhesion promoter as a third component, we were able to achieve the above properties. The inventors have discovered that the objects can be achieved, and have arrived at the present invention.

(Structure of the Invention) The gist of the present invention is as follows: A curable polyurethane paint consisting of a combination of a polyvalent isocyanate and a polyol, a curable silicone, and an adhesion promoter substantially containing as coating film forming elements. This is a coating composition for surface treatment of an elastomer polymer, which is characterized by:

Here, the curable polyurethane In 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 both blends 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 end obtained by chain extension reaction of a low-molecular diol, and a diisocyanate.

In addition to the above composition, a saturated low molecular weight diol of Cj...C6, a dicarboxylic acid of C4, Cs, and a hydroxyl terminal synthesized from the saturated low molecular weight diol and dicarboxylic acid, and a low molecular weight 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 a polyester having a group with an isocyanate.

Here, the isocyanate is MDI.

TDl, HDI, IPDI, NDI, XDI.

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

As the curable silicone, a curable polyorganosiloxane composition having the composition shown in Japanese Patent Publication No. 19812/1983 or another composition can be selected.

For adhesion application 1 to 1, it is preferable to select the one most suitable for the object to be coated, such as T-.

(1) When the object to be coated is an olefin rubber such as EPDM, PP, or EPT rubber, halogenated EPT, halogenated PP, or halogenated PE.

NR or NR modified product, CR or OR modified product.

(2) When the object to be coated is a diene rubber such as SBR rubber, a CR or OR modified product, NR or NR modified product, or an organic acid such as tric-O-loysocyanuric acid.

One type or two or more types selected from the above group are used in appropriate combinations depending on the object to be coated.

In addition to the above-mentioned main components, the present invention also includes additives such as catalysts and accelerators, dyes, pigments, and base coating film forming elements such as toluene and M.
Contains solvents or diluents such as EK.

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. The above catalyst is the urethane mentioned above! ? Accelerates the reaction of adhesives, curable silicones, and adhesion promoters when they are turned into paints.

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

Curable polyurethane 100 (parts by weight: same below): Curable silicone 1-1ooo: Adhesion promoter 5-300.

The reason for this limitation will be explained. That is, 1 to 1000 parts of curable silicone to 100 parts of curable polyurethane.
If this is less than 1 part, the r! This is because the i-film loses lubricity and water repellency, and if it exceeds 1000 parts, the function of the urethane paint as a binder is 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.

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, good results can be obtained by adding 20 to 100 parts of the adhesion promoter to 100 parts of the curable polyurethane paint.

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 8-molecular elastic material to be coated by spraying or the like.

(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, ift property, water repellency, non-stick properties and Provides non-freezing properties.

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, it is presumed that when the curable silicone is dispersed and held in the polyurethane paint, it provides desired properties such as cohesion and lubricity that stand out on the surface of the object to be coated.

Therefore, 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 the object to be coated.

(Explanation of Examples) Examples will be described below.

First, the urethane polyol used is (A)
Ester urethane with amine chain extension, (B) ester urethane with 081m extension, (C) ether urethane with OH chain extension, and (D) blend of ester urethane + ether urethane were used.

The manufacturing method for each urethane polyol is as follows.

(△) Amine-based extended ester urethane molecule 12000
Polyester polyol obtained from butanediol and adipic acid 100! Add 100 parts by weight of toluene and 22.2 parts by weight of isophorone diisocyanate to the amount,
1 in Nλ gas using dibutyltin dilaurate as a catalyst.
React at 00-110°C for 2 hours. Next, cool to 50"C, add 3 parts of ethylenediamine, and then cool to 70"C.
Continue the reaction at 80°C for 1 hour. After the reaction, the solid content is 3
Dilute with toluene and a small skewer of IPA to make it 0%,
Use urethane prepolymer.

(B) OH chain extended ester system 9.9 Recall, polyester polyol made from adipic acid 100! 53 parts by weight of diphenylmethane diisocyanate, 150 parts by weight of toluene, and 53 parts by weight of MEK were added to 9 parts by weight using dioctyltin oleate as a catalyst.
React for 2 hours at 0'C. Thereafter, 10 parts by weight of 1,4-butanediol was added, and the reaction was continued for an additional hour.
Dilute to 30% with EK to obtain a urethane prepolymer.

(C) 112.5 parts of toluene and 112.5 parts of MEK112.5 to 100 parts of OH chain extended ether system
12.5 parts of diphenylmethane diisocyanate is added to the mixture diluted with 12.5 parts of diphenylmethane diisocyanate, and the mixture is reacted at 90 to 100° C. for 4 hours in N2 gas using Merno J-butane tin as a catalyst. The reaction cotton was diluted with toluene and MEK so that the solid content was 30% to obtain a urethane prepolymer.

(D) Ester urethane + ether urethane blend 50 parts of a polyester polyol made from butanediol, ethylene glycol, and adipic acid with a molecule ff of 12,000 and 50 parts of polypropylene glycol with a molecule of 12,000 are dissolved in 100 parts of MEK, and 2・Add 8.7 parts of 4-tolylene diisocyanate and react with 4-tolylene diisocyanate at 80 to 90°C in Nz gas using dibutyltin dilaurate as a catalyst.
Time reacts. Dilute with MEK so that the solid content of the reaction mixture becomes 30% to obtain a urethane prepolymer.

Next, the following graft copolymers were used as the modified EPDM and NR graft polymers.

(E-1) 100 parts of chlorinated EPDM (degree of chlorination 20%), N
- 20 parts of methylol acrylamide was dissolved in 500 parts of toluene, the temperature was raised to 90 to 100°C, 0.5 parts of benzoyl peroxide was added, and the mixture was reacted for about 3 hours to form a graft copolymer with a polymerization rate of about 50%. obtain. Dilute this to 10% with toluene.

(E-2) 100 parts of salt (PP, degree of chlorination 20 weight, 11%).

10 parts of acrylamide and 10 parts of 2-hydroxyl methacrylate were added, this mixture was dissolved in 500 parts of toluene, and after heating to 90-100°C, benzoyl peroxide 0
．． A graft copolymer with a polymerization rate of about 50% is obtained by adding 5 parts and reacting for about 3 hours. Add this with toluene
Dilute to 0%.

(E-3> In 100 parts of NR (degree of chlorination 20% by weight), 30 parts of N-methylolacrylamide was dissolved in 400 parts of toluene,
After raising the temperature to 90 to 100°C, 0.7 part of benzoyl peroxide is added and reacted for about 4 hours to obtain a graft copolymer with a polymerization rate of about 60%.

Dilute this to 10% with toluene.

In addition, as the curable silicone, commonly available commercially available product name: ■Toshiba Silicone■ YSR3022 Catalyst YC6
831 ■Shin-Etsu silicone tel KS709 catalyst C-
PS-5 ■Toray Silicone■ 5RX290 Catalyst 5RX242AC was used.

Example 1 Urethane polyol 333 Partially curable silicone (YSR3022>130 catalyst (Y
C683) 1.3 polyisocyanate
60 halogenated EPDM (E-1)
40 toluene 500MEK
The coating composition prepared as above 500 was sprayed onto the surface of untreated EPDM rubber and dried at room temperature.

Example 2 Urethane polyol 333 Partially curable silicone (KS709) 130 Catalyst (C-
PS-5) 1.3 polyisocyanate
60 chlorinated PP (E-2> 30 toluene 500MEK
A paint adjusted to a composition ratio of 500 or more was spray applied to the surface of untreated PP rubber and dried at room temperature.

Example 3 Urethane polyol 333 partially curable silicone (SRX290) 130 catalyst (YC6
83) 1.3 polyisocyanate
6ONR graft polymer (E-3) 45 toluene 500MEK
500 total A coating composition having a composition ratio of 1569.3 parts or more was treated with E in the same manner as in Example 1.
It was spray applied onto the surface of POM rubber and allowed to dry at room temperature.

Example 4 Urethane polyol 333 partially curable silicone (YSR3022) 130 catalyst (Y
C683) 1.3 polyisocyanate
60 trichloroisocyanuric acid 1m
10 toluene 500MEK
500 ethylene acetate
A coating composition having a composition ratio of 100 parts or more in total was spray applied to the surface of untreated SBR rubber in the same manner as in Example 1, 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 Examples 1 to 4.

Comparative Example 2 As shown in JP-A-55-157662, a coating composition consisting of urethane + silicone oil + fluororesin was prepared according to the publication, and this was sprayed under the same conditions as Examples 1 to 4. I covered it.

Comparative Example 3 Consists of a combination of urethane + fluororesin + polyamide resin shown in Japanese Utility Model Application Publication No. 56-1648. A crude coating material was prepared according to the same publication, and it was spray applied to the surface of a weather strip in the same manner as in Examples 1 to 4.

The results of measuring the surface conditions of the weatherstrips obtained in Examples 1 to 4 and Comparative Examples 1 to 3 are shown in the table below.

The measurement items were abrasion resistance, contact angle, and adhesive strength. Regarding wear resistance and contact angle, the initial state and
Shows weather resistance for 100 hours at 63±3°C in a weatherometer.

In addition, as test conditions for wear resistance, the surface was coated with a No. 800 sand vapor according to the JI 3 standard, with a stroke of 120 m and a cycle of 30 cycles/1n, and the number of strokes required until the surface peeled off. Inspected.

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

The adhesive strength was measured by bonding surface-treated sponges together at a tensile speed of 200 m/l 1 lin, 180 a (Peel
) Measured by peeling.

*: Sponge material failure, O: Silicon cohesive failure △ Interfacial peeling between Nistrip 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 durability. Abrasion resistance is dramatically improved.

In addition, the contact angle does not change at all between the initial state and after weathering.
Furthermore, the adhesive strength is so strong that the sponge material to which it is attached is destroyed, and the results are significantly superior to those of conventional coating compositions.

Claims (1)

[Claims] Surface treatment of an elastomer polymer, characterized in that it substantially contains a curable polyurethane consisting of a combination of a polyvalent isocyanate and a polyol, a curable silicone, and an adhesion promoter as coating film forming elements. Paint composition for use.