JPH0523309B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to improvements in filling and sealing voids in metal materials having voids, such as cast products, sintered metals, aluminum alloys, etc., in order to improve their properties. The present invention relates to a resin impregnating agent composition for metals. [Prior Art] In order to obtain the necessary airtightness when metal materials with voids such as cast products, sintered metals, and aluminum alloys are used as mechanical parts that contain gas or liquid, such as automobile engine parts. Various impregnating agents have been used. Regarding the type of impregnating agent, in contrast to inorganic water glass, which has traditionally been widely used, resin impregnating agents have recently attracted attention due to their pore-sealing effect and processability, and acrylic-based ones are now the mainstream. There is. Acrylic resin impregnation agents mainly contain polymerizable monomers, and various curing agents are added during the impregnation process.
A processing process is used in which the metal material is impregnated and heated to harden. In such an impregnation process, it is necessary for the resin impregnating agent added with a hardening agent to maintain a stable viscosity for a long period of time, and if gelation occurs, most of these resin impregnating agents In either case, since a three-dimensionally crosslinked thermosetting cured product is obtained, a great deal of damage is caused not only to the resin impregnating agent but also to processing equipment such as an impregnating tank. In addition, some of the metal materials processed with these resin impregnating agents significantly impair the stability (pot life) of the resin impregnating agents to which specific hardening agents have been added, and improvements are needed. Ta. [Problems to be solved by the invention] Hydroquinone, hydroquinone monomethyl ether, 2,4 It is well known that compounds such as dimethyl-6-tertbutylphenol are added as polymerization inhibitors. In these resin impregnating agents mainly composed of acrylic monomers, azo compounds or peroxides are used as curing agents, and in the processing process, heat curing is performed at a temperature corresponding to the decomposition temperature of these curing agents. However, the decomposition temperature of the curing agent is generally 50 to 100℃.
℃, the resin impregnating agent gels at a temperature far lower than the decomposition temperature of the hardening agent due to an oversight in temperature control during the summer processing process, or even if there is no oversight in temperature control. This is a problem that cannot be solved simply by paying attention to the addition of a polymerization inhibitor and temperature control as described above. One possible cause of this is the low temperature decomposition of the curing agent due to the catalytic effect of certain metal ions. Therefore, we have developed a resin impregnating agent that provides stability to prevent gelation or viscosity increase due to many factors, without sacrificing characteristics such as reliability in pore sealing effect and processing productivity. It is necessary to improve the In addition, with impregnating agents whose curing is accelerated by the catalytic effect of metals as described above, there are often accompanying problems such as discoloration of the surface of the metal being impregnated, and the appearance of metal mechanical parts. It is necessary to solve this problem as it may not only damage the process but also reduce the workability of painting etc. [Means for solving the problem] As a result of research, the present inventors have found that for this purpose, it is most effective to coexist in the resin impregnating agent a corrosion inhibitor that adsorbs to the metal surface and suppresses ionization. The present invention was completed based on this discovery. The present invention provides a resin impregnating agent composition containing a vinyl monomer as a main component.
N′,N′tetrakis-(2-hydroxypropyl)
An improved metal resin impregnating composition characterized by containing 0.01 to 5% by weight of a corrosion inhibitor of ethylenediamine and/or benzotriazole and a polymerization inhibitor. The present invention is achieved by incorporating the above-mentioned specific N, N, N', N' tetrakis-(2-hydroxypropyl)ethylenediamine and/or benzotriazole into a resin impregnating agent whose main component is a vinyl monomer. , resin impregnants have a remarkable effect of inhibiting corrosion on target materials such as aluminum, magnesium, and zinc. In addition, the above polymerization inhibitor is added to the resin impregnating agent within a range that does not significantly change the impregnation processing conditions such as heat curing time, and is used in combination with the above corrosion inhibitor. This is the most effective means to ensure the stability of the resin impregnating agent. This is because the metal ionization suppressing effect of the corrosion inhibitor suppresses the increase in the low-temperature decomposition reaction rate of the metal in the hardening agent, and the polymerization inhibitor captures radicals caused by the decomposition of the hardening agent at that temperature. This proves that stabilization of the viscosity behavior of the resin impregnating agent containing vinyl monomer as the main component is achieved through the combined effects of the following. Furthermore, when using a corrosion inhibitor and a polymerization inhibitor as a component of a resin impregnating agent containing a vinyl monomer as a main component, it is necessary to appropriately select the composition ratio to the entire resin impregnating agent. First, the composition ratio of the corrosion inhibitor is determined because it adsorbs to the surface of the metal parts to be impregnated and prevents ionization, and because it is a non-polymerizable compound, it is undesirable for its physical properties to be included in excess in the cured product. A range of 0.01 to 5.0 weight percent of the corrosion inhibitor was determined through experiments. Further, if the polymerization inhibitor is used in excess, it may retard the curing behavior of the resin impregnating agent or cause curing failure, so a suitable composition ratio range is 0.1 to 1.0 weight percent. In addition, known hydroquinone, hydroquinone monomethyl ether, 2,4
Dimethyl-6-tertbutylphenol or the like is used. Vinyl monomers that can be used in the present invention include methyl methacrylate, methyl acrylate,
Acrylates or methacrylates such as 2-ethylhexyl methacrylate, lauryl methacrylate, 2-hydroxypropyl methacrylate, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, aromatic compounds such as styrene, divinylbenzene, etc. Examples include vinyl compounds. Further, as a curing agent (polymerization initiator) for curing the vinyl monomer, benzoyl peroxide, lauroyl peroxide, t-butyl peroxypivalate, dicyclohexyl peroxydicarbonate, diisopropyl peroxydicarbonate, Bis-(4-tert-butylcyclohexyl) peroxydicarbonate, o
-Organic peroxides such as methylbenzoyl peroxide, azobisisobutyronitrile, 2,2'-
Azo compounds such as azobis-2,4-dimethylvaleronitrile and dimethyl 2,2'-azobisisobutyrate are used. [Function] By adding the above-mentioned corrosion inhibitor and polymerization inhibitor that are soluble in the resin impregnating agent mainly composed of vinyl monomers, the ionization of metal ions from the impregnated metal surface is inhibited. The inhibitor suppresses the catalytic effect of metal ions on the decomposition reaction of the curing agent, which is a polymerization initiator, and the polymerization inhibitor suppresses the radicals caused by the decomposition of the curing agent corresponding to the temperature at which the resin impregnating agent is used. The combined effect of trapping stabilizes the viscosity of the resin impregnating agent over a long period of time, and prevents gelation even when the environmental temperature rises. [Example] Next, the effects of the present invention will be explained with reference to Examples. Example 1 A resin impregnating agent containing methacrylic acid ester as a main component and having the following composition ratio was prepared (referred to as a composition). Butyl methacrylate 40 parts by weight 2-hydroxyethyl methacrylate 40 〃 Ethylene glycol dimethacrylate 20 〃 Azobisisobutyronitrile 0.5 〃 Results of measuring the pot life at 35°C by immersing an aluminum piece in the resin impregnating agent of the composition 7
The pot life of the impregnating agent prepared by adding 0.5 parts by weight of benzotriazole and 0.5 parts by weight of hydroquinone monomethyl ether was
It was hot in 40 days. However, when only 0.5 parts by weight of hydroquinone monomethyl ether was added, the pot life was 15 days. However, the pot life was measured by the following method. (1) Fill a test tube with an outer diameter of 8 mm and a length of 18 cm with impregnating agent to a depth of 10 cm, then immerse a metal piece with a length of 3 cm and a width of 5 mm, and cover the top with a polyethylene film. (2) Place the test tube containing the impregnating agent in a constant temperature bath using a temperature controller with an accuracy of 35 ± 0.1℃, and check whether it has hardened every 24 hours. The pot life is defined as the number of days in which gelation is observed in one out of five test tubes. Example 2 A resin impregnating agent having the following composition (referred to as composition) was prepared. 2-Hydroxypropyl methacrylate 80 parts by weight Neopentyl glycol dimethacrylate 20 〃 Benzoyl peroxide 0.5 〃 A zinc piece was immersed in the resin impregnating agent of the composition and heated to 35°C.
The pot life of the impregnating agent was 2 days, but the pot life of the impregnating agent prepared by adding 1 part by weight of N,N,N',N'tetrakis-(2-hydroxypropyl)ethylenediamine and 0.5 part by weight of hydroquinone was 2 days. It was the 15th. but,
The pot life of the impregnating agent containing only 0.5 parts by weight of hydroquinone was 3 days. Furthermore, the surface of the zinc piece immersed in the impregnating agent without a corrosion inhibitor turned black, but no discoloration was observed on the surface of the zinc piece immersed in the impregnating agent containing the corrosion inhibitor. Example 3 An aluminum piece was immersed in an impregnating agent containing 0.005 parts by weight of benzotriazole and 0.5 parts by weight of hydroquinone monomethyl ether, and heated to 35°C.
The pot life was measured to be 16 days, and no effect of benzotriazole was observed. However, the amount of benzotriazole added is 0.02
The pot life of the product was 20 days, indicating that it was effective. Example 4 3, 4, 5 benzotriazole in the composition
6 parts by weight were added, and 0.5 parts by weight of hydroquinone monomethyl ether and aluminum pieces were added to each, and the pot life was as follows.

[Table] In this way, even if the amount of benzotriazole added was increased, the pot life did not change significantly.
Although it was cured by heating at 90°C for 15 minutes, poor curing was observed. However, no curing failure was observed when the amount of benzotriazole added was 5 parts by weight or less. Comparative Example 1 Triethanolamine was added to the composition of Example 1.
An aluminum piece was immersed in an impregnating agent containing 0.5 parts and 1.5 parts by weight, and 0.5 parts by weight of hydroquinone monomethyl ether to each, and the pot life at 35°C was measured. The results are shown below.

[Table] Comparative Example 2 Triethanolamine was added to the composition of Example 2.
Zinc pieces were immersed in impregnating agents containing 0.5 parts and 1.5 parts by weight, and 0.5 parts by weight of hydroquinone in each, and the pot life at 35°C was measured. The results are shown below.

[Table] As is clear from the comparison between Example 1 and Comparative Example 1, and Example 2 and Comparative Example 2, resin impregnation with an excellent pot life can be achieved by using the specific corrosion inhibitor of the present invention. It can be seen that a drug can be obtained.

Claims (1)

[Scope of Claims] 1. A resin impregnating agent composition containing a vinyl monomer as a main component, containing N, N, N', N'tetrakis-(2-hydroxypropyl)ethylenediamine and/or soluble therein. An improved metal resin impregnating composition comprising 0.01 to 5% by weight of a benzotriazole corrosion inhibitor and a polymerization inhibitor. 2. The composition according to claim 1, wherein the vinyl monomer is one or more (meth)acrylic esters.