JPS5837062A - Heat-resistant powder composition - Google Patents

Abstract

PURPOSE:To provide a heat-resistant powder compsn. which forms a coating film with an excellent surface smoothness and is suitable for powder coating of the surface of metal substrates, prepared by dispersing and blending a silicone resin, a polyester resin, a low-melting glass and a high-melting inorganic substance homogeneously. CONSTITUTION:The compsn. is prepared by dispersing and blending homogeneously 5-50wt% silicone resin, 5-50wt% polyester resin, 20-80wt% low-melting glass (e.g., borosilicate glass or lead glass) and 0.2-15wt% high-melting inorganic substance (e.g., alumina or titanium dioxide) by powder blend process, kneading-crushing method, etc. The silicone and polyester resins serve as binders and fluidizing agents which flow within a baking temperature range of the powder coating and form a smooth coated surface, while the low-melting glass and high-melting inorganic substance form strong ceramic film.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a powder composition useful as a maintenance coating or insulation coating for various electric crosspieces, etc. by powder coating the surface of a metal base material, and a powder composition particularly excellent in heat resistance. 1. Ordinary coating powders are single or composite powders of synthetic resins, so they can only be used in equipment that is used at temperatures below the decomposition temperature of At high temperatures, the resin maintains an excellent coating without decomposing, and even when the temperature rises abnormally due to overload current, even if the resin decomposes, the insulation remains intact! ! A paint that retains the A film may be a mixture of resin powder and an inorganic powder, and a known alternative is a composite powder that is a mixture of an epoxy resin powder and an inorganic powder.

If the epoxy*m decomposes, this composite body cannot form a film with an inorganic powder wheel, and the properties of the epoxy resin four-body coating film were only slightly improved.

Also, silicon/resin powder can be used instead of epoxy resin powder.
There is also a composite powder made by combining this and other inorganic powders, but while silicone IIM is said to withstand higher temperatures than epoxy resin, its mechanical strength and adhesion to the substrate are poor. Besides being inferior to epoxy resins, there is no essential difference between silico/resin and epoxy resins in that the Fi coating collapses above the decomposition temperature.

As a result of pursuing this point, the present inventors developed a composite powder consisting of silicone resin, epoxy resin, low-melting point glass powder, and high-melting point inorganic fine powder. It has been found that the coating can be constructed and still perform the function of a protective or insulating coating.

Although the composite powder consisting of the above four compositions has excellent performance in itself (as described above), it has the disadvantage that the coating film is poor in smoothness.

As a result of studies on this point, the present invention has developed a composite powder consisting of four components: silicone resin, polyester resin, low-melting point glass powder, and high-melting point inorganic fine powder, which has excellent insulation and preservation properties at normal operating temperatures. However, it was discovered that the coating changes to a ceramic film at a high temperature above the decomposition temperature of the resin, and that the smoothness of the coating film is extremely excellent.

In particular, a preferred formulation of the present invention is a composite powder composition consisting of 5-50% by weight of silicone resin, 5-50% by weight of polyester resin, 20-80% by weight of low-temperature glass powder, and 0.2-15% by weight of high-melting point inorganic material. It is a thing.

Next, to explain the composition of the composite powder that constitutes the present invention, the silico/resin and polyester resin flow in the baking temperature range of normal powder coatings and function as flow agents to obtain a smooth painted surface. In addition, low-melting point gases have the ability to act as a hardener on fine powders and inorganic fine powders.In particular, silicone resins provide heat resistance to the coating film and prevent it from becoming brittle when the temperature rises. and heat resistance. Forms an excellent insulating skin for tubes.

In this formulation, if the silico/resin is less than 5% by weight, I! IJ [the effect of preventing embrittlement is insufficient], on the contrary, it is 50% heavier.

For example, there is a risk that cracks may occur in the ceramic insulation film formed due to high temperatures, and the adhesion of the film may deteriorate. ' This silico/resin includes methyl silicone resin, methylphenyl silico/resin alone or in mixture, as well as alkyd resin-modified dolicon resin, epoxy-modified silicone resin, phenol resin-modified silicone resin, and melamine resin-modified silico/resin. Copolymers of resins and unmodified silicone resins, or silicone/resin and methyl methacrylate,
A copolymer of a polymerizable monomer such as acrylonitrile and O may also be used, and in that case, it is desirable that the O content of the silicone resin component is at least 30- or more.

Furthermore, S Todoroki and T Mori, B, At, P, Ge, As
, 8b, etc., which have t-1 or more O elements and oxygen in their skeletons, or Ti, B, AJ! ,P,Ge,
It is possible to use a structure having 111 or more elements such as As and 8b, oxygen, and carbon in the skeleton.

Polyester resin decomposes and disappears at the decomposition temperature of the resin at abnormally high temperatures, etc., but if it is less than 5 weight, the initial 111
If the smoothness and adhesion of the polyester resin is insufficient and the temperature exceeds 50 weight St, the polyester resin will decompose due to abnormally high temperatures, and the film will undergo too much thermal decomposition, resulting in rapid embrittlement. This may cause the film to peel off from the base material.

Low-melting glass fine powder (glass frit) softens and flows at a temperature of about 400°C, at which epoxy resins and silicopane resins decompose, and maintains adhesion to the base material, and also contains the aforementioned silicone resin decomposition products ( 8) to form a high melting point ceramic film. Examples of the low melting point glass include borosilicate glass having a melting point of 300 to 600° C., lead-containing glass, and phosphoric acid glass. Ninth, Oo, N1N15Pe, N1N15Pe,
Metal oxides and compounds such as TI, Zr, Os, Mo, etc.

Alternatively, it is desirable to use a mixture of one or more of these elements, such as a borate, a composite oxide containing one of these elements, and other compounds.

In addition, the low point glass fine powder used here is 2.
More than one type of glass can be used in combination. Since low melting point glass plays an important role in producing a strong ceramic film of rQK in which the resin decomposes due to abnormal temperature rise, 20 to 80% by weight is preferable, and if it is less than 20% by weight, the Heat resistance is poor, and if it exceeds 80% by weight, the smoothness, adhesion, etc. of the film will deteriorate.

High melting point inorganic fine powder has a high g
In process A, it is necessary to prevent peeling from the base material due to cracking due to shrinkage of the coating film and to form a strong ceramic film, so the preferred range is 0.2 to 1511. be. If the amount added is more than 15% by weight, the strength of the ceramic''** decreases, and if it is less than 0.2% by weight, large cracks are likely to occur when the temperature is increased.

In addition, this high melting point inorganic fine powder is interposed between the polyester resin, silicone resin, and low melting point glass fine powder, and has the effect of suppressing the mutual reaction between t and improving the smoothness of m conversion.

As the high melting point inorganic fine powder, one having a melting point at least higher than that of the low melting point glass fine powder, usually 6,000° C. or more, preferably soo C. or more, is used. Specifically, Al7Na (k'sOs) + silica (840m), beryllia (BeQ), zirconia (ZrOl), magnesia (MgO), tin fluoride (TlOs), ff
Ferric acid (FeO, FoOs), Nororiku titanate A
(BMTI-01, Titanium Shun Calcium (0aTiO
s) s Titanium lead (PbTlOs), Zirnia
:/ (Zr8104), Jini Core Knowledge Barium (Ba
(Zr0m), xf7fi a) (Mg8+O, talc containing, FL-, montmorillonite, bentonite, kaolin, mica, xeronitrite (BN silicon nitride, others to *') Ztsuku-based aging-resistant coloring IR family etc. are used. In addition, these inorganic fine powders are treated with modified silanes such as silyl peroxide or alkyl titanates in silane-based processing agents having t-containing vinyl groups, epoxy groups, alkyl atom groups, alkoxy groups, aroxy groups, halide atoms, etc. Even if the surface is treated with organic titanium-based substances such as phosphate esters, organic titanium compounds such as phosphoric acid esters, and organic titanium compounds such as phosphoric acid esters, etc., to make it compatible with or reactive with silicon-based materials. In other words, this type of surface treatment makes it easy to smooth the coating film by heating it during powder coating, and it also improves the adhesion between the inorganic powder and the silicone resin), and it creates a strong coating. A film is obtained.

In addition, the inorganic fine powder may be a composite powder in which the particle surface is coated with polyester resin, silicone resin, or a V = @ fat that is compatible with these resins, and in this case, the smoothness of the coating film is also improved. is improved, and adhesion to the substrate is also improved.

In the present invention, since polyester resin is used for the silicone resin, it can be said that the adhesion to the base material is slightly lower than that of epoxy resin, but in practical terms, the adhesion to the silicone resin is good, and the adhesion to the base material is good. fF, which has little reactivity with other materials, has excellent fluidity of the coating film and is easy to form a smooth mat.

Heat-resistant powder O can be produced by various methods such as powder blending method, kneading and pulverization method, transfer flow method, and spray drying method. 80 each if combined
Desirably less than 100 kg. (9) When using the kneading and pulverizing method, the transfer flow method, the spray drying method, etc., it is appropriate that the final particles be 80 meshes or less.

The painting method is electrostatic painting or spray painting.12
0~250℃@1. All you have to do is heat it to 1 layer, and there is only one layer of paint! The layer may be formed in multiple layers, and the coating temperature is 140℃.
After attaching the base material KIIIA at a certain level.

Post-heating may be performed at about 200°C to 250°C.

When further smoothness of the film surface is required, the heat-resistant powder according to the present invention is coated on the base material to form an inner layer coating, and then Nixy resin, polyester resin, silicone resin, It can have a double coating structure protected by an outer layer of a mixture of two or more types of 111 or Fi of resin powder such as polyimide resin, polyamide resin, or phenol resin.

Note that the exterior paint film is originally intended to improve the smoothness of the paint film on the inner layer paint film, but when the temperature rises, decomposition gas from the inner heat-resistant paint film may become difficult to degas, so If this happens, there is a risk of flaking due to blistering of the paint film, but if the outer device 1E film uses degradable Yoshishima resin,
Even if *m has poor decomposability, adding a large amount of high-melting point inorganic substances will make it easier to degas the decomposed gas and prevent the above-mentioned peeling phenomenon of the heat-resistant coating film on the inner layer when the temperature rises. It can be prevented.

In addition, in the case of double coating as in O above, the thickness of the inner layer heat-resistant m film is preferably 20 to 700 mm, and a more preferable range is 1
00 to 4004 m, if the thickness of the IIL metal is too thin, the electrical insulation properties at high temperatures will deteriorate; if it is too thick, decomposed gases may desorb, cause blistering or peeling, and deteriorate the mechanical and electrical properties. spoil.

Next, an example of OX of the present invention will be described.

Example 1 Methylphenyl silicone resin (Toshiba Silico Co., Ltd. @ Y
B2168) powder with a particle size of 100 mesh or less, and polyester resin (GV-100 manufactured by Toyobo Co., Ltd.)
) 42) Powder with a particle size of 100 mm or less and a weight of 16 mm,
A powder composition was obtained by uniformly mixing 48 weight of low-melting point glass powder (lead-based) with grains of 1180 mesh or less and a melting point of 450°C and 3 weight of ngara with an average particle diameter of 1 μm in a l-luminium. The powder composition was spray-painted onto a steel plate preheated to 1200°C and fused to form a 30011ahOg film with a thickness of 30011ahOg.

Example 2 Methylphenyl silicone 1tJDi () II Shiba”
+): 23 weight of powder of YR3168 manufactured by Xun Co., Ltd. with particle size of 30 mesh or less, 11 weight of powder of polyester resin (GV-100 manufactured by Toyobo Co., Ltd.) of particle size of 113 G mesh or less, and 1 particle size of 80 mesh or less, Low melting point glass powder CII system with a melting point of 450°C) 63 weight and 1 average particle size lμSO
After uniformly mixing Red Red Garla 3 weight with a TV electric shock absorber, kneading with a heated roll at 60° C., and pulverizing to 80 mesh or less with a pulverizer to obtain a powder composition. The powder composition was spray-coated and fused onto a steel plate preheated to 200°C to form a coating film with a thickness of 300#.

Example 3 Methi-7 brown silicone resin (Toshiba Siri-・Gyast
20 weight of powder of ssn O grains of 11,100 mesh or less, 10 weight of powder of polyester resin (Toyobo JlQV-100) with particle size of 10 G mesh or less, and particle size of 80
A powder composition was obtained by uniformly mixing 67 weights of low-melting point glass powder (lead-based) with a melting point of 450° C. below mesh and 3 weights of red iron oxide having an average particle size of 1 μm in a T-sail mill. The O powder composition is spray-painted onto a steel plate preheated to 200°C and fused to form a heat-resistant inner layer with a thickness of 300 μm, and on top of this is an epoxy resin powder of 100 mesh or less. (V-PET ”1340 manufactured by Dainippon Toyo Co., Ltd.
A base material t' having an inner layer coating film was preheated to 200° C. using H), and was coated by a spray method and fused to form an outer layer coating film with a thickness of 150 μm.9.

Example 4 Methyl silicon 'IHMC Toshiba Silicon Co., Ltd.gYiL-
3370) powder with a particle size of 20 mesh or less, 36% by weight,
Polyester *mc GV-100 manufactured by Toyobo Co., Ltd.) Particle size 20 mesh or less 0 @ End 17 Weight 9! , low melting point glass (
A powder consisting of 44% by weight of a powder with a particle size of 80 mesh or less and 3% by weight of a red iron oxide particle with a particle size of 1/2 (phosphoric acid) (phosphoric acid) was mixed uniformly in a V-type mixer, and then heated to 60°C. The mixture was kneaded for 7 minutes using controlled heated rolls, and then ground to 80 mesh or less in a non-marine mill to obtain a heat-resistant powder composition. This powder composition'1230℃
Spray paint and fuse to a preheated steel plate to a thickness of 300mm.
#2) A coating film was formed.

Example 5 After forming the coating film according to Example 4, an epoxy resin of 100 mesh or less (Dainippon Toyo Co., Ltd. gV-PITφ
After preheating the substrate at 230 DEG C. using 1340H), a 150 .mu.m thick Ok film was formed by spraying and fusing.

In order to compare with the above-mentioned example, all the following comparative samples were prepared.

Comparative Example 1 Epoxy resin powder (V-PFfTφ13 manufactured by Dainippon Toyo Co., Ltd.
40H) was electrostatically coated on a steel plate and heated at 200°C for 30 minutes to form a coating film with a thickness of 250 μm. Comparative Example 2 Methylphenyl; 4V Sucon resin (Toshiba Crycon Co., Ltd.
fJYR3168) powder with a particle size of 100 mesh or less 4
A powder composition was obtained by uniformly mixing 5 weight of low melting point glass powder (lead-based) with a particle size of 100 mesh or less and a melting point of 450°C (lead-based) 52 weight n* and 3 weight of glass/glass with an average particle size of 1 μm in a Zeel mill. I also got things. The powder composition 't'' was spray-painted onto a steel plate preheated to 200°C and fused to a thickness of 250 μm.
The entire coating was formed.

The results of performance comparison tests of the coating films shown in the above Examples and Comparative Examples are as follows.

(Note) 0 Good △ Average

Patent Applicant Fujikura Electric Cable Co., Ltd. Agent Patent Attorney Mamoru Takeuchi Procedural Amendment (Voluntary) May 27, 1980 Haruki Shimada, Commissioner of the Japan Patent Office Display of the Case 1982 Patent Application No. 134555 λ Name of Invention Heat Resistant Relation to the famous case involving powder composition 3.111i1E Patent applicant address 5-1 Kiba-chome, Koto-ku, Tokyo Name (5
1g) Fujikura Electric Wire Co., Ltd. Kinsha ff Representative: Katsuo Kawamura 4, Agent: 101 Address: Nanbu Building, 2-15-13 Uchikanda, Chiyoda-ku, Tokyo) (75 papers) 1. Specification No. 1 member Iris 19~ In line 20, the description "for each machine's remaining electrical equipment, etc." has been changed to "for various electrical equipment, etc."
Press J.

2-BAJl] On page 1, line s13, reel is corrected to "GC."

Claims (1)

[Scope of Claims] (υ A heat-resistant powder composition (phantom silicone resin 5 ~50 weight, polyester resin 5~50 weight, low melting point glass 20~80 weight, and high melting point inorganic material 04~15 weight), each component being uniformly dispersed. Heat resistant powder composition (a) silico/resin, polyester *m, low melting point glass, and high melting point inorganic material are each individually powdered and crushed O heat resistance as described in claims 1 and 2 powder composition