JPS6248773A - Heat-resistant coating material - Google Patents

Abstract

PURPOSE:The titled novel heat-resistant coating material, obtained by dispersing or dissolving a polymetallocarbosilane and inorganic filler in an organic solvent and capable of giving coating films having improved corrosion and impact resistance and flexibility. CONSTITUTION:A heat-resistant coating material obtained by dispersing or dissolving (A) a polymetallocarbosilane consisting of (i) carbosilane linking units expressed by formula I (R1 and R2 are lower alkyl, phenyl or H and (ii) metalloxane linking units expressed by formula II (M is Ti, Zr, Cr or Mo and, as necessary, respective elements partially have lower alkoxy group or phenoxy group), preferably 1:1-10:1 ratio of the total number of linking units of the components (A) to (B) and having 400-50,000 number-average molecular weight and (B) an inorganic filler, e.g. oxide, borate or phosphate, in an organic solvent. The compounding ratio of the component (B) is preferably 10-90pts.wt. based on 100pts.wt. component (A).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel heat-resistant coatings containing polymetallocarbosilanes. More specifically, the present invention relates to a novel heat-resistant paint containing a polymetallocarbosilane and a filler.

(Prior Art) Paints containing polyorganosiloxane as a vehicle and various pigments added thereto are known as heat-resistant paints that prevent corrosion and deterioration of metal and non-metallic base materials at high temperatures. This polyorganosiloxane paint has excellent heat resistance compared to conventionally known organic polymer paints such as polyester and polyimide, but even so, in an air atmosphere at a high temperature of over 400°C, the paint film does not coat the base material. Peel it off.

Furthermore, with the development of industry, coating materials that can prevent oxidation and corrosion of metal or non-metallic base materials that are exposed to high temperatures exceeding 1000°C, such as aircraft parts, steel manufacturing, or the furnace body and surrounding parts of metal smelting furnaces, are being developed. Demand is increasing.

Japanese Patent Publication No. 59-12746 discloses that polycarbosilane containing carbon and silicon as skeleton components and a small amount of metal elements is coated on a metal material and then heated to 800-200% in a non-oxidizing atmosphere.
A method for producing a heat-resistant metal material is described in which polycarbosilane is converted to silicon carbide by heating and firing at 000°C. Japanese Patent Application Laid-Open No. 55-84370 discloses that a coating composition containing ceramic or metal powder added to a semi-inorganic compound containing polycarbosilane is applied to a metal or non-metal material, and then heated for 400 minutes in a non-oxidizing atmosphere. ~20
A method for obtaining a heat-resistant coating film by heating to 00°C and baking is described.

However, the temperature of this polycarbosilane at 1000℃ (in air)
The firing residual rate in is approximately 30% (based on weight,
Due to the thermal decomposition of polycarbosilane during baking, a large volumetric shrinkage occurs.

For this reason, the adhesion of the coating film to the substrate becomes insufficient in the case of baking. When baking is performed in an oxidizing atmosphere such as air, most of the coating film peels off from the base material.

Furthermore, the heat resistance of the resulting coating film is approximately 400° C. in air, which is comparable to the heat resistance temperature of conventional polyol and nosiloxane paints.

(Problems to be Solved by the Invention) The present invention provides a heat-resistant paint that has a high firing residual rate in air, can be baked in air, and has a high heat resistance temperature in air. The present invention aims to effectively prevent oxidation and corrosion of metal or nonmetallic substrates even under high temperature conditions.

(Means for Solving the Problems) The present invention is a heat-resistant paint made by dissolving or dispersing polymetallocarbosilane and Kuroiso filler in an organic solvent.

The polymetallocarbosilane used in the present invention is the following (A)
of carbosilane bonding units and less than one of the following (B
), (A): +5i-CH2+- (However, R5 and R2 may be the same or different and independently represent a lower alkyl group, phenyl group or hydrogen atom) (B) : -+M-〇≠ (However, M represents at least one element selected from the group consisting of Ti, Zr, Cr, and V Mo, and in some cases, at least one part of each element is a side chain group. (having at least one lower alkoxy group or phenoxy group) (A) and (B) a polymer in which each bonding unit is randomly bonded in the main chain skeleton; is bonded to each element of the bonding unit of (B) via an oxygen atom, whereby the polycarbosilane moiety obtained by the chain of bonding units of (A) is bonded to each of the elements of the bonding unit of (B). It is a polymer cross-linked by bonding units of (A>) to the total number of bonding units of (B) in the range of 1 to 10:1 and has a number average molecular weight. is 400 to 50,000.

The above-mentioned polymetallocarbosilane is a polymer mainly composed of a carbosilane bonding unit and one or more metalloxane bonding units, in which the carbosilane and metalloxane bonding units are randomly bonded in the main chain skeleton.
Or, at least a portion of the silicon atoms of the carbosilane bonding unit are bonded to each of the above elements of the metalloxane bonding unit via an oxygen atom, whereby a polycarbosilane moiety obtained by a chain of carbosilane bonding units is bonded to the metalloxane bonding unit. It is a crosslinked polymer.

The inorganic filler used in the present invention is at least one selected from the group consisting of oxides, borates, phosphates, silicates, silicides, borides, nitrides, and carbides; For example, it is as follows.

Boron, magnesium, aluminum, silicon, calcium, titanium, vanadium, chromium, manganese, zinc,
Zirconium, molybdenum, cadmium, tin, antimony, barium, tungsten, lead, bismuth oxides, carbides, nitrides, silicides, borides, lithium, sodium, potassium, magnesium, calcium, zinc borates, phosphates Contains salts, silicates, etc.

These may be used alone or in combination if necessary.

A coating obtained by applying the above-mentioned coating material consisting of polymetallocarbosilane and an inorganic filler to a metal or non-metallic base material, and then heating and baking the coating at 200 to 2000°C in an oxidizing or non-oxidizing atmosphere. The inventors have discovered that the film has better adhesion to underlying metal and non-metal substrates and has superior heat resistance than the coating film made of polycarbosilane, and has thus arrived at the present invention.

Even when the polymetallocarbosilane used in the present invention is heat-treated at 1000° C. for 10 hours or more in an air atmosphere, the weight loss on heating is only 10 to 15% by weight. For this reason, shrinkage and cracking due to weight loss of the baked coating film are less likely to occur, and the baked coating film formed is dense.Also, since polymetallocarbosilane contains metals, When baked onto the surface of the base material, the metal carbide or metal oxide of the M11 element forms a strong bond between the coating film and the metal base material, forming a dense protective film layer that does not peel off even at temperatures above 1000°C. do. Similarly, on ceramic and glass surfaces, the ultrafine particles function as a binder and form a strongly bonded coating film.

Furthermore, when an inorganic filler is added to this polymetallocarbosilane, it adheres more firmly to the base material than a coating formed from polymetallocarbosilane alone, improves heat resistance, and has visibility. A coating film is obtained.

To 100 parts by weight of this polymetallocarbosilane, 10 to 900 parts by weight or 50 to 500 parts by weight of an inorganic filler is added. Addition of an inorganic filler 8 results in poor adhesion to the convex drinking knife and the To 1-Kan no Tojo Sui Dissipating Dish Mutt Yushaku 1, and if the amount exceeds 900 parts by weight, the flexibility of the coating film decreases.

A coating material is obtained by dissolving or dispersing this polymetallocarbosilane and an inorganic filler in a suitable solvent such as benzene, toluene, or xylene.

This paint is applied to a metal base material or a non-metal base material such as glass, ceramic, refractory brick, etc. by brushing, roll coater, spray gun, dipping, etc., and then dried and baked.

A coating amount of 20 to 100 g/m2 is generally desirable.

If it is 20 g/m'', pinholes will occur and the anticorrosion property will be reduced. On the other hand, if it is more than 100 g/l112, the coating film will easily crack during baking, which is not preferable.

The baking temperature is preferably 150° C. or higher, but if the uncoated object is placed in a usage environment of 150° C. or higher after painting, there is no need to provide a baking step. A baking temperature of 150° C. or lower is not preferable because the strength of the coating film is low and both hardness and impact resistance are poor.

The baked coating film thus obtained has excellent heat resistance, and at the same time exhibits good corrosion resistance, impact resistance, and flexibility.

Next, an example will be described. In addition, in the reference examples and examples, % and parts indicate weight % and parts by weight unless otherwise specified.

(Reference Example 1) 2.52 g of anhydrous xylene and 400 g of sodium were placed in a No. 51 three-lough flask, heated to the boiling point of xylene under a nitrogen gas stream, and dimethylnochlorosilane 11 was added dropwise over 1 hour. After the dropwise addition was completed, the mixture was heated under reflux for 10 hours to form a precipitate. This precipitate was filtered and washed first with methanol and then with water to obtain polydimethylsilane 42 as a white powder.
0. I got it.

400 g of the above polydimethylsilane was transferred to a 3-meter tube equipped with a gas inlet tube, a stirrer, a cooler, and a distillation tube. Pour the mixture into a three-lens flask and stir under a nitrogen stream (50 ml/f).
A colorless and transparent slightly viscous liquid of 3501r was obtained in the distillation receiver by heat treatment at 420°C. The number average molecular weight of this liquid is determined by vapor pressure osmosis method (VP
It was 470 when measured by O method).

Additionally, measurements of far-infrared absorption of this material revealed that mainly +S
It was confirmed that it was an organosilicon polymer consisting of i -CH2+ bond units and +5i-8i+- bond units, and having a hydrogen atom and a methyl group in the silicon side chain.

(Reference Example 2) Next, this organosilicon polymer 40. Weigh out 20g of titanium tetraisopropoxide and add 400mj of xylene to this mixture! was added to form a mixed solution consisting of a homogeneous phase, and a reflux reaction was carried out under a nitrogen gas atmosphere at 130° C. with stirring for 1 hour. After the reflux reaction was completed, the temperature was further raised to distill out the solvent xylene, and then the temperature was increased for 10 minutes at 300°C.
Time polymerization was performed to obtain an organometallic crosslinked polymer containing silicon and titanium. The number average molecular weight of this polymer is VPO
It was 1165 when measured by the method.

From gel permeacytane chromatography and infrared absorption spectra, the polymer obtained here shows that the 5i-H bonds in the organosilicon polymer have partially disappeared, and the silicon atoms in this part are the titanium atoms of titanium tetraisopropoxide. through an oxygen atom, so that some of the organosilicon polymers have 0-Ti(QC-H7)* groups in their side chains,
In addition, part of the organosilicon polymer was polytitanocarbosilane crosslinked with +Ti-0← bonds, and the reaction rate and/or crosslinking rate at the Si H bonding portion in this polymer was 44.5%. . +Si CH2 ← bonding unit → 5i-8i of the organosilicon polymer part of this polymer
It was confirmed that the ratio of the total number of ← bond units to the total number of -〇 -T 1 (OC, H,) and -Ti O- bond units was about 6:1.

The above reaction product is dissolved in xylene so that the solid content is 50%.
A solution of

(Reference Example 3) Instead of titanium tetraisopropoxide, which is one of the starting materials in Reference Example 2, tetrainpropoxide, chromium trimethoxide, or molybdenum tri-7e/oxide is used. Ua 1. s
i ze II U ll-w no a ll-
J/ F -4'7 4F II h +
|+ Mocarposilane or polynorconocarbosilane was obtained. The reaction conditions and operating method are substantially the same as fj# Example 2.

[Example 1] 50wt xylene of polytitanocarbosilane of Reference Example 2
A heat-resistant paint was obtained by mixing 8,150 parts of % solution and 50 parts of talc. Apply this paint to an 11-thick stainless steel plate (SUS30).
After coating 4) with a bar coater to a thickness of about 50μ,
Bake in the oven for 1 hour at 0°C.

This baking-painted steel plate was heated to
After heating for a period of time, the coating film was removed from the oven and slowly cooled in the air. No peeling or cracking occurred in the coating film, and it showed good adhesion to the metal substrate.

[Example 2] 40 parts of a 50% xylene solution of the polynorconocarbosilane of Reference Example 3 and 60 parts of tungsten trioxide were mixed to obtain 1 (thermal paint).

A temporary titanium film with a thickness of 0.5111 m was dipped into this paint and applied, and then baked in an oven at 200°C for one hour.

Heat cycle test (
The test was repeated three times (1 hour at room temperature - 1 hour in a 1000°C oven), but no cracking or peeling of the coating occurred.

[Example 3] A heat-resistant paint was obtained by mixing 60 parts of the polyzyl core carbosilane solution of Reference Example 3 in 50% xycin and 40 parts of aluminum oxide. This paint was applied with a brush to a 1 mm thick stainless steel plate (SUS304) and then baked in an oven at 250°C for 1 hour.

This baking-painted steel plate was heated at 1000°C for 10 hours in the open air, and then slowly cooled in the air.
Although it was bent with a radius of curvature R, no peeling of the coating occurred.

[Example 4] 30 parts of the 50% xylene solution of the polychromocarbosilane of Reference Example 3 and 70 parts of talc were mixed to obtain a heat-resistant paint.

After applying this paint to a thickness of about 30 μm on an 11-thick stainless steel plate (SUS304) using a bar coater,
Bake it in the oven for 1 hour.

This baking-painted steel plate was heated at 1000° C. for 10 hours in an open environment. Then, it was taken out from the open air and slowly cooled in the air, but no peeling of the paint film was observed.

[Comparative Example 1] A 50% by weight xylene solution of the polytitano of Reference Example 2 was coated on a 11I11 thick stainless steel plate (
It was coated on SUS304) to a thickness of approximately 50 μm, and then baked in an oven at 200° C. for 1 hour.

This baked-coated steel plate was heated in an oven at 1000°C for 10 hours, then taken out from the open air and slowly cooled in the air. During this cooling process, the coating film peeled off.

[Comparative Example 2] A coating material was obtained by mixing 5 parts of a 50% by weight xylene solution of the polyzyl core carbosilane of Reference Example 3 and 95 parts of silicon dioxide. A titanium plate having a thickness of 0.5III was dipped in this paint, coated, and then baked in an oven at 200°C for 1 hour.

This baking-painted steel plate was heated in an oven at 1000° C. for 10 hours, then taken out from the oven and slowly cooled in air. Next, when this painted steel is bent with a radius of curvature of 2OR,
The coating peeled off from the substrate.

1 other person

Claims (4)

[Claims] (1) A heat-resistant paint characterized by dispersing or dissolving polymetallocarbosilane and an inorganic filler in an organic solvent. (2) Polymetallocarbosilane consists of the carbosilane bond unit shown below (A) and at least one metalloxane bond unit shown below (B), (A): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R_1 and R_2 may be the same or different and independently represent a lower alkyl group, a phenyl group, or a hydrogen atom) (B): -(M-O)- (However, M is a group consisting of Ti, Zr, Cr, and Mo. at least one element selected from the group consisting of (A) and (B) each of the above (A) and (B). A polymer in which the bonding units are randomly bonded in the main chain skeleton, and/or at least a portion of the silicon atoms in the bonding unit (A) are connected to each of the elements in the bonding unit (B) via an oxygen atom. is a polymer in which the polycarbosilane moiety obtained by the chaining of the bonding units of (A) is crosslinked by the bonding units of (B), and the total number of bonding units of (A) to the ( The heat-resistant paint according to claim 1, wherein the ratio of the total number of bonding units in B) is in the range of 1:1 to 10:1 and the number average molecular weight is 400 to 50,000. . (3) Claim 1, wherein the inorganic filler is at least one selected from the group consisting of oxides, borates, phosphates, silicates, silicides, borides, nitrides, and carbides. Heat-resistant paint as described. (4) The heat-resistant paint according to claim 1, wherein the inorganic filler is contained in an amount of 10 to 900 parts by weight based on 100 parts by weight of the polymetallocarbosilane.