JPH0459079A - Heat-resistant precoated metallic sheet and its production - Google Patents

Abstract

PURPOSE:To obtain an excellent heat-resistant precoated metallic sheet by coating the surface of the aluminum-plated metallic sheet or aluminum sheet with one or >=2 kinds among a group consisting of silane coupling agents and then applying a heat-resistant coating resin having S atom thereto. CONSTITUTION:One or >=2 kinds selected from a group consisting of the silane coupling agents having a mercapto group such as 3- mercaptopropyltrimethoxysilane and/or an epoxy group such as 3- glycidoxypropyltrimethoxysilane are applied to the surface of the aluminum- plated metallic sheet or aluminum sheet and dried. PES, PPS, etc., alone or a heat-resistant coating resin having S atom and mixed with tetrafluoromethylene resin, a copolymer resin of propylene hexafluoride, etc., are applied thereto and baked. The heat-resistant precoated metallic sheet obtained by this method has excellent adhesion as well as heat resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat-resistant pre-coated metal plate that has excellent heat resistance and coating adhesion and is used for home appliances, containers, automobiles, etc., and a method for manufacturing the same.

Conventional technology Polyether sulfone resin (hereinafter referred to as PES), polyphenylene sulfide resin (hereinafter referred to as PPS),
Polyamide-imide resin (hereinafter referred to as FAI) or silicone resin has excellent heat resistance and flame retardancy, so it has been widely used as a pre-coated metal plate paint for heat-resistant coatings, either alone or in combination with other heat-resistant resins. It is used.

On the other hand, stainless steel, aluminized steel plate, aluminum plate, tin-free steel, etc. are used as the base plate for heat-resistant coating.

However, coated metal plates made from these resins and coated original plates do not necessarily have sufficient adhesion between the primary and secondary coatings. Therefore, in order to improve the damage resistance, (1) pretreatment such as chromate treatment, phosphoric acid chromate treatment, and composite chemical resistant treatment is performed (for example, Patent II/(5)
9-+9+767+3. Special! Qil? l 63-243
952, or special application\(i l-2973841zu).

(2) Physically polishing the metal plate surface.

A's noi? ), has been taken.

Problems to be Solved by the Invention However, although the methods (1) and (2) above improve the primary adhesion, the secondary adhesion is insufficient, and the method (2) without further pretreatment improves the primary adhesion. This method significantly reduces water resistance.

The present invention has been made in order to solve these problems, and has the following objects: 1-1 to provide a heat-resistant precoated metal plate having excellent heat resistance and coating film density, and a method for manufacturing the same;
target

Means for Solving the Problem Regarding silane coupling agents, O
The R group (me, xino, (, ethoxy group'v) undergoes hydrolysis and forms an oxysan bond (M-0-5i) with the inorganic surface.
・Functional groups such as groups, amine groups, etc. (or organic functional groups) can crosslink elastic materials and organic materials by reacting with resins and organic materials.

For example, in the field of glass fiber-reinforced plastics, by treating the surface of the glass fibers with a silane coupling agent, it is possible to crosslink glass [1 and plastics and increase the strength (Journalof Co11oids).
and Interface, Vol. 86.
No, I.

March 19f12).

Therefore, the present invention was completed by applying and optimizing this silane coupling agent technology. That is, a layer made of one or more selected from the group consisting of silane coupling agents having a mercap group and/or an epoxy group is formed on an aluminum coated metal plate or an aluminum plate, It is a heat-resistant precoated metal plate characterized in that a heat-resistant resin layer containing S atoms is further formed on L of the layer, and is made of a silane camping agent that has a mercapto group and/or an epoxy group. One or two types of inserts selected from the group -1- are applied to an aluminum coated metal plate or an aluminum plate surface of 1m, and after drying, a heat-resistant resin paint containing S atoms is applied on top of it and baked. This is a method for producing a heat-resistant pre-coated metal plate characterized by the following:

The invention will now be explained in detail along with its functions.

Effect of the present invention: Coating film density of heat-resistant pre-coated metal plate) I+1
In order to improve this, we considered applying a silane camping agent and conducted an experiment. As a result, if a silane coupling agent layer of 41 constant was formed on the surface of a specific metal plate and a specific resin layer was further formed on the surface of the metal plate, it was found that
．． It was found that the sex of

That is, aluminum coated metal plate or alumina 1, plate 1 - [comercaptono 1 (and/or epoxyno 1
Apply a silane coupling agent to (IIJL),
The present invention was completed based on the fact that a coated board coated and baked with a paint containing S-Haronyo has excellent paint film adhesion and heat resistance of +1.

As a silane coupling agent having mercap 1, (I), 3-mercaptopropyl i.lime[xysilane], as a silane coupling agent having an epoxy group, 3-glycidoxypropyl trimethoxysilane. There are 2-(3.4~epoxycyclohexyl)ethyl[・rime)-xysilane.

The silane coupling agent layer can be formed by diluting the silane coupling agent with a solvent, applying the diluted silane coupling agent to the aluminum surface, and drying the diluted silane coupling agent. Examples of organic solvents used for silane coupling agents include methanol, ethanol, inpropanol, acetate, benzene, i.luene,
For xylene, etc., most organic solvents and alcohol/wood mixed solutions can be used, and the amount of silane coupling agent deposited is 10 to 150 mg as Si adhesion.
/m' is suitable, preferably 10-30mg/m2
It is. If it exceeds 150 mg/m', it cannot be expected that the crosslinking effect of the silane coupling agent will be improved; on the contrary, it will be weakened, and moreover, it is not economical. Also,
There is no effect at doses below 10 mg/m'.

Further, when two or more types of silane coupling agents are mixed, the mixing ratio is not particularly limited.

As for the coating method of JllIM, roll coating, spraying, and deimping methods are applicable, and the drying time is 41 minutes if the solvent can be released, and the temperature is between 200° and 200°. It is carried out in the temperature range of C.

The drying force υ is not limited to 4 yen, but is 1. The appropriate method may be selected, such as drying in an equipped hot air oven or drying in an induction heating furnace.

PE5 is a heat-resistant resin containing a force, s a; <-f.
PPS, etc., and these may be used alone or in combination with other resins. The resins mixed at that time include:
Polytetrafluoroethylene resin (PTFE), tetrafluoroethylene resin, hexafluoropropylene co-crosslinked resin (FEP: l'9
Fluorinated olefin resin fragrance, in this case on the coating film;
Wakatake・In addition to heat resistance, it has excellent non-viscous properties and lubricating properties.
'can do. Furthermore, if only film adhesion and heat resistance are required, FAI etc. are available. The mixing ratio of these resins is preferably adjusted according to the following conditions.

Paints made of resin such as
Any method such as 1. or Flow Co. 1. can be applied to metal plates, and it is preferable to apply the coating so that the dry coating thickness is usually in the range of 7 to 40 gm from the viewpoint of heat resistance, corrosion resistance, and pressure resistance. (Japanese Patent Application Laid-open No. 191767-1989). Further, the curing stage I may be determined depending on the properties of the resin and required performance, and may be set at a plate temperature of 150 to 5000 C for 20 to 300 seconds.

Tables 1 (Part 1) to (Part 4) of Examples list the performance test results of samples when coating was performed with the /<- coater based on each manufacturing condition. Here, we attempted to clean the surface of an aluminum coated steel plate or aluminum plate by degreasing it with a weak alkali. After that, it was immersed in a treatment solution prepared by dissolving the above-mentioned silane coupling agent in ethanol, taken out and dried at room temperature, and then coated with various paints.
It was coated to a film thickness of 0 to 12 m, and finally baked and burned at a board temperature of 270°C.

The types of pretreatment in Table 1 are as follows.

5i-A ・3-mercap] ・Propyl trime I
・Xysilane 5i-B: 3-crisitoxypropyl trimethoxysilane Si-C ・3-glycidoxypropyl methyldimethoxysilane Si-D: 2-(3.4-epoxycyclohexol)ethyltrime[・xysilane Si -E・3-Mercaptopropyl・[・Rime I
・Methyl silane in 3-glycidoxypropyl] ・Mixed xysilane at 11 for 1 night Polishing: Lightly polish the metal plate surface with a commercially available nylon scrubber made by 3M ■ Chromate: 11 parr force rising stock Coating type chromate treatment for pre-coated steel sheets [Z M-R 1415A, 120mg/m'
J mercap] group and/or an epoxy group, S i =1, ? The adhesion of 10 to 150 kg/m'
Excellent heat resistance, -water+11 (Examples 1 to 42),
On the other hand, the silane force, the pulling agent Si, 1 right-H-, 1
If exceeds 150mg/m' and IOmg/m? If the amount is less, the adhesion will be significantly reduced (Comparative Examples 1, 2,
3, 4, 13, 14, 21, 22).

If chromate or polishing is used for treatment,
It can be seen that the water resistance and polishing are poor compared to J1 Hayabusa (Comparative Examples 5, 6, 7, 8910, 15, 16, 1).
7, 18, 18, 20, 23, 24). Moreover, in the case of no treatment, the adhesion was poor, and the water resistance of J1 was always poor (Comparative Examples 11 and 12).

(The following is a blank space) The test methods for the physical properties shown in Table 1 are as follows. In other words, for the three cases from ■ to (3),
) to (3) were tested, and in addition, water resistance (4) was tested.

(1) The following items: 1: The painted board has not been added anything.

Tested at.

■Secondary physical properties: Tested after being immersed in boiling water for 2 hours.

■Heat resistance: Tested after heating the pressurized product in a 300°C atmosphere for 200 hours.

(D A board 1-J Eriksen NT cutter,
100 pieces of substrate II were placed on the surface of the sample, extruded to 7 mm using an Erichsen tester, and then taped to evaluate the @shape condition.

○: No peeling was observed.

Δ: Peeling occurs in 1 or more out of 100 pieces - less than 5 pieces.

X: Peeling occurs in 5 or more of too many pieces.

(2) DuPont opposition? : Place the sample under an I/2" steel ball, drop a 500 g weight onto it from a height of 50 cm, tape it, and evaluate the peeling condition on both the gate and convex surfaces.

〇 - No peeling observed at all.

Δ: Some peeling is observed.

×: Completely peeled off.

(3) Bending: Holding 0 and 2 plates of the same thickness as the sample, perform a 180 degree mountain rod test, tape one bent part, and evaluate the peeling situation.

○: No peeling observed at all.

Δ: Some peeling is observed.

×: Completely peeled off.

(4) Water resistance - The sample was left in an atmosphere of 49°C and 188% RH for 240 hours, and the appearance of the flat part was evaluated.

O: No abnormality × Abnormalities such as niblisters are observed.

Effects of the Invention The heat-resistant precoated metal plate obtained by the present invention has excellent adhesion in addition to heat resistance.

Claims (2)

[Claims] (1) A layer made of one or more selected from the group consisting of silane coupling agents having mercapto groups and/or epoxy groups is formed on an aluminized metal plate or an aluminum plate, A heat-resistant precoated metal plate further comprising a heat-resistant resin layer containing S atoms formed on the layer. (2) After applying one or more selected from the group consisting of silane coupling agents having mercapto groups and/or epoxy groups to the surface of an aluminized metal plate or aluminum plate and drying, A method for producing a heat-resistant precoated metal plate, which comprises applying and baking a heat-resistant resin paint containing S atoms on the surface of the metal plate.