JPS63110263A - Method for treating surface - Google Patents

Abstract

PURPOSE:To provide the surface of a substrate with surface characteristics such as water repellency, by using a surface treating agent comprising an alkylsilyltriisocyanate and an acidic phosphate ester to coat the surface of a substrate with a cured coating film exhibiting an excellent adhesivity to the substrate. CONSTITUTION:(A) An alkyl or phenyltriisocyanate of formula: R<1>Si(NCO)3 (R<1> is monovalent alkyl, phenyl, etc.) and (B) an acidic phosphate ester of formula (R<2> is monovalent alkyl or halogenated alkyl; n is 1 or 2) are compounded at a ratio A:B of 100:1-20. Subsequently, a substrate such as paper, rubber or plastic is treated with a surface treating agent consisting essentially of the above-produced compsn. The component A is preferably methylsilyltriisocyanate or the like and the component B is e.g. monooctyl acid phosphate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for treating the surface of a substrate with a curable composition containing an alkyl or silyl triisocyanate and an acidic phosphoric acid ester as main components. In particular, it provides a method for imparting surface properties such as water repellency, slipperiness, heat resistance, non-viscous properties, and stain resistance by applying it to the surface of substrates such as paper, rubber, plastic, metal, and glass. It is.

[Conventional technology and its problems]

In recent years, with the development of electronic equipment, requirements for performance such as slipperiness and heat resistance of magnetic tapes, thermal printing materials, etc. have become increasingly sophisticated, and there is a need for methods that can meet these requirements. These methods can be roughly divided into two directions. One is to change the base material itself to a heat-resistant base material such as polyimide or polysulfone. However, these base materials are expensive, and it is difficult to obtain thin films necessary for high functionality. The other method is to modify polyester film, which is the most commonly used base material. There are several methods for this, each of which has its own drawbacks.

■ A method has been developed in which fine particles of silica or calcium carbonate are added during polyester production to roughen the surface and improve slipperiness. However, these methods have problems in increasing the functionality of the magnetic tape by making the film thinner and smoother.

■ A method has been developed to improve slipperiness and heat resistance by introducing polysiloxane into the main chain of polyester.
This method has a problem with the adhesion of the magnetic film or ink layer.

■ Methods of applying silicone resins, epoxy resins, melamine resins, fluororesins, etc. to the surface of polyester substrates have been developed, but these methods have properties that aim to improve slipperiness, heat resistance, etc. However, the adhesion of the resin film to the base material was incompatible.

Among these, silicone resins have relatively excellent slipperiness, heat resistance, and adhesion to substrates, but each method can be roughly divided into the following based on the curing method. It has problems.

Method A: Polydiorganosiloxane with hydroxyl group at the end of 5
A solution containing a t-H bond-containing polyorganosiloxane and/or an organoalkoxysilane, and further containing an organic tin compound and an organic solvent.

A solution whose main components are a polyorganosiloxane having two or more vinyl groups in one molecule, a polyorganosiloxane containing a 5L-H bond, a platinum compound, and a solvent.

C. An organic solvent solution of an oligomer obtained by hydrolyzing and condensing an alkyl silicate.

2. Aminosilane, acetoxysilane, oximesilane, polydiorganosiloxane with a hydroxyl group at the end,
A solution containing any silane compound having a hydrolyzable group such as isopropenyloxysilane or isocyanatosilane, and further containing an organic tin compound and an organic solvent.

Problem A requires a curing temperature of 120 to 150° C., making it difficult to apply to biaxially stretched polystyrene films, thin biaxially stretched polyester films required for high functionality, and the like. Also, although rubber etc. harden, their adhesion is low.

This method requires a curing temperature of 120 to 150°C, and is difficult to apply to biaxially oriented polystyrene films, thin biaxially oriented polyester films required for high functionality, and the like. Furthermore, in the case of rubber, platinum compounds often lose their activity due to the vulcanizing agents and vulcanization accelerators in the rubber, and thus do not cure.

C. cures at a relatively lower temperature than C.41, but has lower adhesion to the substrate.

Second, although it cures at room temperature, it has low adhesion to the substrate.

Other known methods include using methods (1), (c), and (2) in combination with auto-machine resin, or curing silicone resin modified with machine (a) resin using methods (a), (b), (c), and (2). However, although these improve adhesion, they result in a decrease in heat resistance.

Note that amines and organic tin compounds are known as curing catalysts for alkyl or silyl triisocyanates.
Both have poor composition stability and are difficult to use. Also, the adhesion is poor.

The present invention solves the two problems of the prior art,
The object of the present invention is to provide a surface treatment method for maintaining adhesion to a substrate in a simple manner and providing a surface with slipperiness, heat resistance, non-adhesion, etc.

[Means and effects for solving the problem] The present inventors have developed a curable composition containing an alkyl or phenylsilyl triisocyanate and an acidic phosphoric acid ester as main components, which can be used to cure paper, rubber, plastic, metal 1, and glass. The present invention has been completed by discovering a method for imparting surface properties such as excellent adhesion, water repellency, slipperiness, heat resistance, non-stickiness, and stain resistance to the surface of such materials.

That is, the present invention provides at least one alkyl or phenylsilyl triisocyanate represented by R] is a monovalent alkyl group, a halogen-substituted alkyl group, or a phenyl group (wherein R2 is a monovalent alkyl group, a halogen-substituted alkyl group, or a phenyl group); group, n is 1 or 2
) at least one acidic phosphoric acid ester represented by (1) and (2) in a weight ratio of 100:1 to 20.
The present invention relates to a surface treatment method characterized in that the surface of a substrate is treated with a surface treatment agent whose main component is a composition blended with.

To explain the present invention in detail, the alkyl or phenylsilyl triisocyanate (1) used in the present invention is methylsilyl triisocyanate, ethylsilyl triisocyanate-1, propylsilyl triisocyanate triisocyanate, perfluoroalkyl triisocyanate, etc. Silyl triisocyanates (e.g. CF (CF ) CH CH S L (NC
O) a) is exemplified.

Methylsilyltriisocyanate and phenylsilyltriisocyanate are convenient because of their easy availability of raw materials.

As the acidic phosphoric acid ester (2) used in the present invention, R2 is a methyl group, ethyl group, propyl group, butyl group, octyl group, isodecyl group, tridecyl group, or fluoroalkyl group (e.g. CF3(CF2)5CH2CH2-
) and the like are exemplified.

If the blending ratio of (1) and (2) is less than 1 part (2) per 100 parts (1) by weight, it will take a long time to cure at room temperature, which is not practical. Moreover, if it is more than 20 parts, the stability is poor and it is difficult to handle, so the range of 1 to 20 parts is used.

The surface treatment agent used in the present invention can be used as a mixture thereof.
However, it may be diluted with an organic solvent. Solvents include n-hebutane, petroleum hydrocarbons, toluene,
Examples include xylene, 1.111-lichloroethane, acetone, dioxane, diglyme, ethyl acetate, butyl acetate, cellosolve, and acetate.

Isopropyl alcohol, cellosolve, and butanol can also be used if stability in daily doses is not required.

The processing method of the present invention is as follows.

Components (1) and (2) are blended and diluted with the above solvent if necessary.

The obtained treatment agent is applied to the surface of a substrate such as paper, rubber, plastic, metal, glass, etc. by a method such as dip coating, spin cord, spray coating, brush coating, knife coating, or roll coating.

When a solvent is used, the solvent is removed by drying at room temperature or by heating.

The curing temperature and time vary depending on the film thickness and the solvent used, but in the case of a film thickness of 1 μm or less, it hardens in 30 seconds to 1 minute at room temperature. In the case of 1μ to 100μ, it hardens in several minutes to several hours. Although it is possible to cure at room temperature, in industrial applications it is often more convenient to heat to evaporate the solvent.

The composition according to the present invention is composed of the compounds listed in (+) and (2), but in addition to these, it also has smoothness,
In order to further improve non-viscosity, heat resistance, etc., SiN
Any substance that reacts with CO bonds and becomes a component of a film that becomes substantially integrated may be used in combination. For this purpose,
Examples include carboxylic acids having a perfluoroalkyl group, alcohols having a perfluoroalkyl group, α-ω dihydrooxydimethylpolysiloxane, and α-hydroxydimethylpolysiloxane. These are suitably less than 10% of the total of (1) and (2), which are the main components of the present invention.

If it exceeds 10%, the adhesion with the base material will be adversely affected and it is not suitable.

〔Effect of the invention〕

The surface treatment method of the present invention provides a cured film with excellent adhesion to the substrate compared to the conventional treatment method using a silicone composition, and has particularly good heat resistance, slipperiness, non-adhesion, and silicone for film formation. A cured film with excellent adhesion can be produced even on rubber, plastic, etc., for which sufficient adhesion could not be obtained with the composition. Furthermore, since the method of the present invention can be processed at room temperature and in a short time, it is possible to process oak wood with low heat resistance and large substrates that are difficult to heat treat. Provides good water repellency, slip properties, heat resistance, non-stick properties, and stain resistance.

The present invention is concerned with imparting slipperiness to natural rubber and synthetic rubber, anti-blocking treatment, improving the slipperiness of polypropylene molded products, imparting non-adhesiveness to biaxially oriented polystyrene, magnetic tape, biaxially oriented thermal printing materials, and polyester films. back coat, polyethylene laminate paper, glassine paper,
It exhibits excellent properties when applied to coated paper to make it non-adhesive, the glass of existing public phone booths, the painted surface of telephones to prevent stickers, and sandblasting glass, stainless steel plates, and artificial marble to prevent stains.

The reason why the treatment method of the present invention exhibits low-temperature processability and excellent adhesion is not clear, but it is thought to be as follows.

In other words, low-temperature curability is determined by the fact that silyl isocyanate has significantly greater reactivity with moisture than silane compounds such as alkoxysilane, acetoxysilane, and aminosilane, and that the silyl isocyanate produced at that time is due to the catalytic action of acidic phosphoric acid ester. This is thought to be due to condensation at low temperatures.

Excellent adhesion to the base material can be considered as follows.

For materials such as paper, metal, and glass, where several molecules of water are adsorbed on the surface, silyl isocyanate reacts with the adsorbed water,
C-OH%M-OH which produces silanol and this silanol is the main body of the substrate.

This is thought to be due to a direct bond with a functional group such as 5iOH.

In the case of rubber, film, etc., it is thought that silyl isocyanate diffuses between the molecular chains of the rubber, film, etc., and then reacts to improve adhesion.

The present invention will be specifically explained below with reference to Examples.

〔Example〕

Example 1 8 parts of methylsilyl triisocyanate, butyl acid phosphate ((CH3CH2CH2CH20)2P(O)OH and C
0.4 part of a mixture of H3CH2CH2CH20P(O)(OH)2 in a weight ratio of 1=1), 70 parts of ethyl acetate, and 5 parts of cellosolve acetate were mixed.

This solution was diluted to a silane compound concentration of 5% using toluene.

This liquid was mixed into chloroprene rubber (abbreviated as CR), biaxially oriented polypropylene film with a thickness of 5 μm (abbreviated as OPP), biaxially oriented polystyrene with a thickness of 100 μm (abbreviated as OPS), and biaxially oriented polyester with a thickness of 6 μm (abbreviated as PET). ), glass (
G) was spray coated, heated at 90° C. for 30 seconds, and then left at the lowest temperature for one day.

Example 2 6 parts of methylsilyl triisocyanate, 2 parts of phenylsilyl triisocyanate, 0.
8 parts of ethyl acetate, 70 parts of ethyl acetate, and 10 parts of diglyme were mixed. This solution was prepared using n-hexane with a silane compound concentration of 5%.
The material of Example 1 was treated in the same manner as in Example 1.

Comparative Example 1 100 parts of αω dihydroxypolydimethylsiloxane represented by the average formula HO[(CH3)25iO]4oooH was dissolved in 200 parts of toluene, and polymethylhydro represented by the general formula %S i (CH3)3 3.5 parts of dienesiloxane, 6 parts of dibutyltin dilaurate, and 2 parts of γ-aminopropyltriethoxysilane were added and mixed uniformly, and further diluted with toluene to prepare a solution containing 5% polysiloxane. This was spray coated onto the material of Example 1, heated at 100° C. for 10 minutes, and left at room temperature for 10 minutes.

Comparative Example 2 Average formula CH-CH(CH3) 2S iO[(CH3) 2S
in) 5000 ((CH3)(CH24CH)Sin
) 100 parts of polymethylvinylsiloxane raw rubber represented by 5t(CH3)2CH-CH2 was mixed with 30 parts of toluene.
0 parts, add 4 parts of polymethylhydrodiene siloxane represented by the general formula (% formula %) Si (CH3)3 and 5 parts of octatool solution containing 2% chloroplatinic acid to uniformly dissolve, and then add toluene. A solution containing 5% polysiloxane was prepared. After spray coating the material of Example 1 using this,
The mixture was heated at 0° C. for 10 minutes and left at room temperature for 1 day.

Comparative Example 3 60 parts of methyltrimethoxysilane, 50 parts of water, 1.
5 parts were stirred while cooling in a water bath, and 100 parts of isopropyl alcohol and 25 parts of acetic acid were added and mixed with stirring.
It was left at room temperature for 7 days.

This solution was mixed with methyl cellosolve: methyl ethyl ketone-1:
1 (by weight) to prepare a solution with a solid content of 5%. This was spray coated on the sample of Example 1, heated at 100° C. for 10 minutes, and left at room temperature for 1 day.

Comparative Example 4 8 parts of methylsilyl triisocyanate, 0.4 parts of dibutyltin dilaurate, 70 parts of ethyl acetate, 5 parts of cellosolve acetate, and 8 parts of average formula % formula % were uniformly mixed. This solution was diluted to a silane compound concentration of 5% using toluene. The material of Example 1 was treated in the same manner.

Comparative Example 5 8 parts of methylsilyl triisocyanate, 0.4 parts of tri-n-butylamine, 70 parts of ethyl acetate, and 5 parts of cellosolve acetate were uniformly mixed. This liquid was diluted to a silane compound concentration of 5% using toluene. The material of Example 1 was treated in the same manner.

The performance of the substrate treated as described above was evaluated by the following test method. The evaluation results are shown in Table 1. The slip properties and water repellency are also shown for untreated glass for reference.

■) Slip property: Using a surface-treated glass plate, the slip property was evaluated by setting the coefficient of dynamic friction of the coating film to 1 (11).

HEIDON-14 type manufactured by Shinto Kagakusha was used.

2) Water repellency: The same test piece as used in the slip test was used. Water repellency was evaluated by measuring the contact angle of the coating film with water.

It was measured by a droplet method using a model CA-A manufactured by Kyowa Interface Science.

3) Heat resistance: A hot-melt ink consisting of paraffin wax and carbon black was hot-melt coated on the non-coated surface of the PET film.

Place the surface-treated surface on the thermal head side and stack it on the receiver paper, then use a commercially available GIII facsimile (Fujisoku FACOM
6401540), and observed the state of dirt on the thermal head and the clarity of the print after printing. ○: Thermal head did not leak, the print was clear. ×: The thermal head was stained and the print was unclear. did.

4) Density: Chloroprene rubber (CR), O
f"P, OPS, PET, and glass (G) surface-treated products were pressure-bonded with adhesive tape (Tiban, Polyester Chive). After standing at 50°C for 10 minutes, the live pipe tape was peeled off, and the peeled tape was crimped onto a stainless steel plate, and
After a minute, the dry blue tape was peeled off at an angle of 180°, and the residual contact force (g/2.5 cm) was measured.

5) Stability: The surface treatment composition was stored in a sealed glass bottle, and one day later, the presence or absence of precipitation and the presence or absence of an increase in viscosity were observed.

As is clear from Table 1 above, Examples 1 and 2 had good adhesion and slipperiness to various materials, water repellency, and heat resistance. Moreover, Example 1.2 shows that the stability of the processing agent is good.

Comparative Examples 1 and 2 were poor in adhesion to various materials and heat resistance, and thickening of the processing agent was observed after one day.

Comparative Example 3 shows poor adhesion to various materials and poor heat resistance.

Comparative Example 4 is poor in adhesion to various materials, heat resistance, and stability of the processing agent.

Comparative Example 5 has good heat resistance, but has problems in adhesion to various materials and stability of the processing agent.

From the above, it is clear that the treatment method of the present invention exhibits low-temperature processability and excellent sealing properties, and has good stability, making it an excellent treatment method.

Claims (1)

[Claims] 1. (1) General formula R^1Si(NCO)_3 (where R
^1 is at least one alkyl or phenylsilyl triisocyanate represented by a monovalent alkyl group, a halogen-substituted alkyl group, or a phenyl group), (2) general formula (R^2O)_nP(OH)_3_-_n
(However, R^2 is a monovalent alkyl group, a halogen-substituted alkyl group, and n is 1 or 2). 100:1-2
1. A surface treatment method characterized by treating a substrate with a surface treatment agent whose main component is a composition blended with 0.