JPS61225222A - Surface treatment of polymer elastomer - Google Patents

Abstract

PURPOSE:To impart excellent surface properties such as excellent lubricity, water repellency, soundproofness and abrasion resistance to the surface of a polymer elastomer, by pretreating the surface of this elastomer and coating it with a surface treating agent containing a curable polyurethane and a curable silicon. CONSTITUTION:A curable polyurethane is prepared by reacting a polyisocyanate (e.g., diphenylmethane diisocyanate) with a polyol. A surface treating agent for imparting lubricity and water repellency is prepared by using the above curable polyurethane and a curable silicon (e.g., curable polyorganosiloxane) as film forming components and adding, if necessary, a silicon oil, a particulate product (e.g., titanium dioxide or nylon powder). This surface treating agent is applied to the surface of a polymer elastomer (e.g., automobile weather strip) which has been subjected to pretreatment for imparting adhesiveness (e.g., solvent washing and buffing).

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention provides properties such as smoothness, water repellency, soundproofing, non-sticking properties, non-freezing properties, and The present invention relates to a surface treatment method for imparting surface properties with excellent wear 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 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 Application Publication 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 friction 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) Therefore, the present inventors developed a conventional method of this type in order to impart lubricity, water repellency, non-stick property, and non-freeze property to the surface of the elastic body to be treated over a long period of time. After conducting a pre-treatment process to impart adhesion to the surface of the elastomer to be treated, we found that a material that substantially contains curable polyurethane and curable silicone as at least film-forming elements It has been discovered that the above-mentioned conventional problems can be solved by applying a surface treatment agent, and the present invention has been achieved.

(Structure of the Invention) The gist of the present invention is to provide a first step for imparting adhesiveness to the surface of an elastic body to be treated, a curable polyurethane consisting of a combination of a polyvalent isocyanate and a polyol, and a curable polyurethane consisting of a combination of a polyvalent isocyanate and a polyol. This is a method for surface treatment of an elastomer polymer, comprising a second step of applying a surface treatment agent substantially containing silicon at least as a coating film forming element.

Here, the first step is as follows: a. Cleaning with an organic solvent by wiping with a cloth or washing with paper, adhesive, modified EPT, modified PP, and modified PE.

Primer treatment using one or a combination of two or more selected from the group of NR or NR modified product, CR or CR modified product, acid treatment using C3 organic acid, physical treatment such as puffing, sandblasting, etc. Examples include ultraviolet treatment, corona discharge treatment, plasma treatment, etc., and the method can be selected as appropriate depending on the material of the elastic body to be treated.

As an example of the primer treatment, modified EPT may be treated with, for example, halogenated EPT, more specifically with a chlorine content of 10 to 3.
0% chlorinated EPT or chlorinated EPT,
It is a product obtained by grafting an amino group-containing acrylic monomer and 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-Human Oxylethyl methacrylate.

Examples include 2-hydroxypropyl methacrylate, trimethylolpropane trimethacrylate, N-methylol acrylamide, and 3-chloro02-human0xypropyl 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.

Here, in addition to containing a curable polyurethane paint and a curable silicone as coating film forming elements, the surface treatment agent used in the second step specifically includes the following three combinations.

(1) Surface treatment agent whose main components are curable polyurethane paint, curable silicone, and silicone oil.

(2) Curable polyurethane paint, curable silicone,
A surface treatment agent whose main component is powder with a particle size of 0.1μ to 200μ.

(3) curable polyurethane paint, curable silicone,
A surface treatment agent whose main ingredients are silicone oil and powder with a particle size of 0.1μ to 200μ.

Among these, curable polyurethane paints include polyester polyols or polyether polyols having hydroxyl groups at the terminals, or blends thereof, and urethane prepolymers obtained by reacting both blends at the terminals with diisocyanates, and low-molecular diamines or It consists of a urethane polymer having an amino group or hydroxyl group at the end obtained by chain extension reaction of a low-molecular diol, and a diisocyanate.

In addition to the above combinations, a hydroxyl group at the terminal is synthesized from a C3...C6 saturated low-molecular diol, a C4, C5 dicarboxylic acid, the above 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, HDl, IPD・I, NDI, XDI.

Polyfunctional isocyanates such as HeMDl, H12XDI TMP adduct, water adduct, trimer, etc.
(modur) R, RF, and RU can be exemplified.

Further, as the curable silicone, a curable polyorganosiloxa 2 composition having the composition shown in Japanese Patent Publication No. 56-19812@ or another composition can be selected.

In addition, as a powder with a particle size of 0.1μ to 200μ,
It includes inorganic and organic pigments, and further includes metal 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, a powder such as polytetrafluoroethylene, polychlorotrifluoroethylene, or tetrafluoroethylene-hexafluoropropylene copolymer is used, and as a sulfide powder, a powder such as molybdenum disulfide is 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 of 1G, Goo, 000 centistokes, and methyl chloride silicone oil.

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 each composition in the combinations (1) to (3) above can be set as follows.

(1) Curable polyurethane 100 (same below 2 parts by weight)
: Curing silicone 1~i ooo : 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 the amount is less than 1 part, the formed coating film will lack lubricity and water repellency, and if it is more than 1000 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 have sufficient abrasion resistance for the object to be coated, and
If the amount exceeds 100 parts, the stability of the composition deteriorates, so the amount is limited to 3 parts to 150 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.

(2) Curable polyurethane 100: Curable silicone 1~
iooo: Powder 0 with a particle size of 0.1μ to 200μ
．． 01-100.

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 the amount is less than 1 part, the formed coating film will lack moisture and water repellency, and if it is more than 1000 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 the powder varies depending on the type and particle size of the powder, but the blending ratio of the curable polyurethane
If it is less than 0.01 part based on
If it exceeds 0 parts, the coating film will not have flexibility and will not follow the adherend. Therefore, it is preferably in the range of 0.01 to 100 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, problems will occur as it is not effective in reducing the *m coefficient, and conversely, if the particle size exceeds 200μ, the coating film will not be able to hold the powder, and the powder will separate and slip. A problem arises in that the effect of imparting sex is lost. Therefore, it is limited to the above range, and is more preferably 1 μ to 100 μ.

(3) Curable polyurethane 100: Curable silicone 1~
iooo: Powder 0 with a particle size of 0.1μ to 200μ
．． 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 the amount is less than 1 part, the formed coating film will lack lubricity and water repellency, and if it is more than 1000 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.

The blending ratio of the powder varies 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 lubricity 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 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.

(Effect of the invention) When the surface of the elastic body to be treated is treated according to the present invention,
The surface of the treated elastic body is imparted with lubricity, Ml aqueous property, abrasion resistance, adhesion resistance, and anti-freezing property. In particular, this invention
When applied to the surface of a non-polar polymeric elastomer such as rubber or EPDM rubber, the adhesion is significantly improved compared to other surface treatment methods.

This is because adhesiveness is extremely effectively imparted to the surface of the elastic body to be treated in the first step, and the surface treatment agent in the second step has good compatibility with the non-polar surface of the elastic body to be treated. to cause.

Furthermore, in the second step, by containing curable silicone and silicone oil in the surface treatment agent, the curable silicone is compatible with the polyurethane resin and is dispersed and retained on the surface layer side of the coating film. At the same time, it is presumed that the silicone oil, which is compatible with the facilitative silicone, is dispersed and held in the curable silicone in a state in which it stands out on the surface of the coating film, thereby providing desirable properties such as lubricity.

Furthermore, by including the powder, the curable silicone is dispersed and retained in the polyurethane paint on the surface layer side of the coating film, and the powder is dispersed and retained in the curable silicone in a state that stands out on the coating surface, resulting in smoothness. It is presumed that this provides desirable properties such as sex and other desired properties.

Referring to powder only, the following is considered.

(b) Microscopic observation of the glass surface reveals small irregularities, which are touched by powder particles exposed on the surface, so overall the contact surface between the glass surface and the paint film is a smooth paint film surface. (b) When the glass surface and the coating surface move relative to each other, the resin component alone will be pulled toward the glass side and wear out, but the surface in contact with the glass will be Since there are countless points of hard (or slippery) powder in contact with each other, there is no wear during relative movement, and it becomes easy to slip.

(Explanation of Examples) Examples will be described below.

In this embodiment, an automobile weather strip is used as the elastic body to be treated. First, the surface of the weather strip was subjected to a brimer treatment using modified EPT.

The modified EPT was prepared by dissolving 100 parts of salted EPT (degree of chlorination: 20% by weight) and 20 parts of N-methylolacrylamide in 500 parts of toluene, and after raising the temperature to 90 to 100°C, 0.0% of benzoyl peroxide was added. 5 parts were added and reacted for about 3 hours to obtain a graft copolymer with a polymerization rate of about 50%. This was diluted to 10% with toluene and used.

Next, as the slippery/water-repellent surface treatment agent, (1) a curable polyurethane paint and a surface treatment agent whose main components are curable silicone, (2) a curable polyurethane paint, and a curable silicone,
Surface treatment agent containing silicone oil as a main component (3) Curing polyurethane paint, curable silicone,
Surface treatment agent containing powder as a main component (4) Curable polyurethane paint, curable silicone,
Surface treatment agents (1) to (4) containing silicone oil and powder as main components were prepared and sprayed onto the surface of the pretreated weather strip under the same conditions, and dried at room temperature. Ta.

The urethane polyol used was an ester urethane with an extended amine chain.

The method for producing this urethane polyol is as follows.

Add 1 part of toluene to 100 ml of polyester polyol obtained from butanediol and adipic acid with a molecular weight of 12,000.
00 weight 1 part and isophorone diisocyanate 22.2
Parts by weight are added, and the mixture is reacted at 100 to 110° C. for 2 hours in N2 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. When the reaction is complete, add toluene and a small amount of IP to make the solid content 30%.
Dilute with A to obtain a urethane prepolymer.

Next, as the curable silicone, commercially available product names ■Toshiba Silicone■YSR3022: Catalyst YC01M IJ Corn ft1lKs709: ViC-PS■Tore Series]-:z(tlsRX2901!ISR24
2AC was used.

Specific adjustment of the surface treatment agents (1) to (4) is as follows.

For surface treatment agent (1) 1Q1 Urethane polyol 333 Partially curable silicone KS709 130 tactile 11 [c-PS-513 Polyisocyanate 60 Toluene
500 total 1536 parts Surface treatment agent (2) 1 Urethane polyol 333 parts Curable silicone YSR3022130 Catalyst YX6831 13 Silicone oil 20 Polyisocyanate
60 toluene 500 total
1556 parts Urethane polyol for surface treatment agent (3) 333 parts Curable silicone YSR3022130 Catalyst YC683113 Fluororesin powder 50 Polyisocyanate 60 Toluene
500MEK 5
00 total 1586 part order 2 urethane polyol 333 part curable silicone (KS709) 130 catalyst C-PS-513 nylon powder 50 polyisocyanate 60 toluene
500MEK 500 total
1586 parts Na3 Urethane polyol 333 parts Curable silicone 5RX290 130 Catalyst 5RX242AC13 Molybdenum disulfide powder 100 Polyisocyanate 60 Toluene
500MEK 500 total
1636 Part Surface Treatment Agent (4) Order 1 Urethane Polyol 333 Part Curable Silicone YSR3022130 Catalyst YC683113 Silicone Oil 20 Fluororesin Powder 10 Polyisocyanate
60 toluene 500MEK
500 total 1566
Part Na2 Urethane polyol 333 Part Curable silicone KS709 130 Catalyst C-PS-513 Nylon powder 5 Silicone oil 20 Polyisocyanate
60 toluene 500MEK
500 total 1561
Part 3 Urethane polyol 333 Part curable silicone SR x 290 130 Part 1 [5RX242Ac 132 Molybdenum sulfide powder 5 Silicone oil
20 Polyisocyanate 60 Toluene 500MEK
500 total 1561 parts Comparative Example 1 A paint consisting of a single curable silicone disclosed in Japanese Patent Publication No. 19813/1981 was prepared and treated under the same conditions as each of the surface treatment agents (1) to (4) of the Examples. Applied to the weatherstrip surface.

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 mixed with each of the surface treatment agents (1) to 1 in Examples. Spray coating was performed under the same conditions as in (4).

Comparative Example 3 A coating composition consisting of a combination of urethane + fluororesin + polyamide resin disclosed in Japanese Utility Model Application Publication No. 56-1648 was prepared according to the same publication, and this was treated with each of the surface treatment agents (1) to ( Spray coating was applied to the surface of the weather strip in the same manner as in 4).

The results of measuring the surface conditions of the weatherstrips obtained by each of the surface treatment agents (1) to (4) of the above Examples 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 test conditions for abrasion resistance, the surface was coated with a No. 800 sand vapor according to the JIS standard for 1 stroke.
The number of strokes required until the surface peeled off was examined under a distance of 20 m and a cycle of 30 cycles/sin.

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 is determined by bonding surface-treated sponges together.
□ Tensile speed: 200 m+/1 lin, Measured by 180 degree (peel) peeling.

*: Sponge material failure ◎: Silicone cohesive failure ∆ Interfacial peeling between strip rubber and paint film As is clear from the above results, the materials surface treated according to the present invention did not contain the surface treatment agents (1) to (1) in Examples.
Along with 4), the abrasion resistance and adhesive strength are dramatically improved compared to each comparative example. Moreover, the weather resistance is excellent compared to Comparative Example 2.3.

Claims (1)

[Claims] A pretreatment step for imparting adhesion to the surface of the elastomer to be treated; and a curable polyurethane consisting of a combination of a polyvalent isocyanate and a polyol, and a curable silicone substantially containing at least as coating film forming elements. 1. A method for surface treatment of an elastomer polymer, comprising the step of applying a water-repellent surface treatment agent.