JPH0351201B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold release agent for metal thermal spraying. More specifically, the present invention relates to a mold release agent for metal thermal spraying that has excellent metal adhesion and is easy to demold when metal thermal spraying is performed.

When molding a resin molded product using a mold, a metal film is formed on the mold in advance by metal spraying, and then the metal film is backed up using a resin molding material to integrate the metal film and the resin molded product. A method has been proposed for manufacturing a metal-resin composite in which a metal film and a resin molded product are integrated by pressing and then demolding. If this method is followed, a metal-resin composite with a metal layer firmly attached to the surface can be manufactured easily and with good dimensional accuracy, and the resin molded product can be endowed with various physical properties such as wear resistance, electrical conductivity, and heat resistance. It is considered to be a very useful method because it can be done. However, when performing metal spraying on a mold, if no mold release agent is used on the mold surface, a problem tends to occur in that the sprayed metal hardly adheres to the mold surface. Furthermore, as already proposed, if a solution of polyvinyl alcohol is applied as a mold release agent and then dried, followed by metal spraying, the adhesion of the sprayed metal will be slightly improved, but There are problems such as the deposited metal film peeling off during the work, or the fact that the sprayed metal does not adhere well to mirror-finished molds. Currently, the development of a mold release agent that allows easy molding is awaited.

The present inventors conducted various studies in view of the current situation, and as a result, arrived at the present invention. That is, the present invention contains 0.001% by weight or more of water-soluble polymer A selected from the group consisting of nonionic polymers, anionic polymers, and zwitterionic polymers, and 0.001% by weight or more of cationic polymer B, with the remainder being The present invention provides a mold release agent for metal thermal spraying which is mainly composed of a solvent C in which a water-soluble polymer A and a cationic polymer B are dissolved or dispersed.

The water-soluble polymer A used in the present invention is one or more water-soluble polymers selected from the group consisting of nonionic polymers, anionic polymers, and zwitterionic polymers, and the mold surface after solvent C has evaporated. It suffices if it remains in the Examples of such water-soluble polymer A include natural water-soluble polymers such as starch, gum arabic, dextran, gelatin, and casein; semi-synthetic water-soluble polymers such as cellulose-based viscose, methyl cellulose, ethyl cellulose, and dialdehyde starch;
Polyvinyl alcohol, sodium polyacrylate, polyethylene oxide, copolymer containing dimethylaminoethyl methacrylate and methacrylic acid, copolymer containing N,N-dimethylaminopropylacrylamide and acrylic acid, bisphenol type Examples include synthetic water-soluble polymers such as a resin obtained by reacting an epoxy resin with diethylenetriamine and then reacting with chloroacetic acid, and a resin obtained by reacting polyacrylic acid with ethyleneimine and then neutralizing it with acetic acid. Among them, polyvinyl alcohol is particularly preferred as the water-soluble polymer A used in the present invention.

The cationic polymer B used in the present invention is
It is a water-soluble or water-dispersible polymer that is composed of polyalkylene polyamines such as polyethyleneimine and polypropyleneimine and/or derivatives thereof, and has cationic nitrogen in the molecule. Examples of derivatives of polyalkylene polyamines include polycarboxylic acids, polyglycidyl compounds such as epoxy resins, polyisocyanate compounds such as urethane prepolymers, polymers containing chloromethyl groups and/or hydroxymethyl groups, and Examples include those obtained by reacting at least one of polyhaloalkanes and/or epihalohydrins and/or polyepihalohydrins.

Any of these polymers can be synthesized by a conventional method. These polymers may be used as they are, or a part of the cationic nitrogen contained in these polymers may be salted with an inorganic or organic acid such as hydrochloric acid, nitric acid, phosphoric acid, formic acid, or acetic acid. It can also be used as a quaternary ammonium salt.

As the cationic polymer B, one or more of these polymers can be used.

Solvent C is a solvent that can completely or mostly dissolve or disperse water-soluble polymer A and cationic polymer B, and after applying a mold release agent to the mold, the solvent is heated at room temperature or heated. It transpires at a certain temperature. Therefore, solvent C
may be appropriately selected depending on the temperature of the mold to be coated. For example, water, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone,
Can be used alone or in combination of two or more solvents from among vinegar ethyl ester, vinegar butyl ester, ethylene glycol, propylene glycol, diethylene glycol, methyl cellosolve, dimethyl sulfoxide, etc., and a low temperature mold is used. When using a high-temperature type, it is desirable to use a low-boiling point solvent, and when using a high-temperature type, it is desirable to use a high-boiling point solvent.

The amount of water-soluble polymer A in the resulting mold release agent is
It is 0.001% by weight or more. In addition, the amount of cationic polymer B is 0.001% by weight in the mold release agent obtained.
That's all.

If the amount of water-soluble polymer A is small (less than 0.001% by weight), the strength of the release agent layer formed after solvent C evaporates will be weak, and the sprayed metal will likely peel off, which is undesirable. .
There is no particular restriction on the upper limit of the amount used, but as the amount used increases, the viscosity increases, so it may be used within a range that does not make the work difficult.

If the amount of cationic polymer B is less than 0.001% by weight, the adhesion of the sprayed metal will be poor, causing problems such as almost no metal film being formed or the metal film peeling off during the spraying process. It is easy to do and not desirable. Cationic polymer B
There is no particular restriction on the upper limit of the amount used, and it is used within a range until work becomes difficult due to thickening as the amount used increases.

In order to obtain the mold release agent for metal thermal spraying of the present invention from water-soluble polymer A, cationic polymer B, and solvent C, these components may be mixed using a conventional mixing method and apparatus, and the mixing order may be particularly limited. There are no limitations.

Moreover, other additives can be used in the mold release agent for metal thermal spraying of the present invention as necessary. For example, it is also possible to add a water-soluble coloring agent for coloring.

When using the mold release agent for metal thermal spraying of the present invention, the mold release agent is applied onto the mold surface by means such as a brush, sponge, or spray, and then dried to form a film on the mold surface. That's fine. Moreover, it is also possible to apply a mold release agent generally used for mold release of resin molded products to the mold surface in advance so that the mold release agent can be easily applied uniformly onto the mold surface. If a film of the mold release agent for metal spraying according to the present invention is formed on the mold surface in this manner and then metal spraying is performed on the film, the adhesion of the sprayed metal will be good and it will not peel off during the spraying process. Alternatively, it is possible to form a good metal film without causing problems such as falling off. In addition, it is easy to back up the metal film obtained in this way with a resin molding material, integrate the metal film and the resin molded product, and then remove the resulting metal-resin composite from the mold. can be done.

The mold release agent of the present invention remaining on the mold surface or the metal surface of the metal-resin composite after demolding can be easily removed by washing with water.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Note that all parts in the examples indicate parts by weight.

Example 1 50 parts of polyvinyl alcohol (Gohsenol GH-23, manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.) was mixed with 400 parts of water at 90°C.
After dissolving in 50% of methanol, cool to room temperature and add 200% of methanol.
50 parts of ethyl acetate and polyethyleneimine (manufactured by Nippon Shokubai Chemical Co., Ltd., Epomin P-1000)
5 parts were added and mixed to obtain a mold release agent for metal thermal spraying (hereinafter referred to as mold release agent (1)). This mold release agent (1) was applied thinly to the surface of a flat FRP mold using a brush and left to dry at room temperature for 30 minutes. Next, zinc was sprayed to a thickness of about 100 microns using an arc spraying machine (TAFA, USA, 375EFS), and a good metal coating was obtained. Next, unsaturated polyester resin (manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd.),
A resin composition prepared by adding and mixing 1.0 part of a 55% dimethyl phthalate solution of methyl ethyl ketone peroxide to 100 parts of Epolack G-773PTMY) and a glass mat (manufactured by Nittobo Co., Ltd., MC-450A) were used to apply the usual method on the metal film. According to the instructions, the materials were laminated to a thickness of approximately 5 mm using the hand lay-up method, and then left to harden at room temperature. Next, when the metal layer was demolded together with the hardened FRP, it could be easily demolded and the surface condition was good.

Comparative Example 1 In the same flat FRP mold used in Example 1,
When zinc was directly sprayed under the same conditions as in Example 1 without using a mold release agent, the sprayed zinc did not adhere.

Comparative Example 2 50 parts of the same polyvinyl alcohol used in Example 1 was dissolved in 400 parts of water at 90°C, cooled to room temperature, mixed with 200 parts of methanol and 50 parts of ethyl acetate, and mixed with a mold release agent (hereinafter referred to as A mold release agent (referred to as mold release agent (2)) was obtained. The mold release agent (2) was placed in the same mold as used in Example 1.
After coating under the same conditions as in Example 1, drying;
Next, zinc was sprayed under the same conditions as in Example 1, but the sprayed metal film peeled off from the mold during the spraying process.

Claims (1)

[Claims] 1. 0.001% by weight or more of a water-soluble polymer A selected from the group consisting of nonionic polymers, anionic polymers, and zwitterionic polymers, and a cation consisting of polyalkylene polyamine and/or its derivatives. 0.001% by weight of polymer B
A mold release agent for metal thermal spraying containing the above, with the remainder mainly consisting of a solvent C that dissolves or disperses a water-soluble polymer A and a cationic polymer B. 2. The mold release agent for metal thermal spraying according to claim 1, wherein the water-soluble polymer A is polyvinyl alcohol.