JPS63172764A - Internal parting agent for polyurethane reaction injection molding - Google Patents

Abstract

PURPOSE:To obtain a parting agent which gives reaction injection molded products having excellent mold release characteristics by the addition of a small amount thereof without detriment to physical properties and coatability, by using an ethylene oxide adduct of a specified satd. aliph. compd. as a component. CONSTITUTION:An internal parting agent consists of one or more members selected from the group consisting of ethylene oxide adducts of satd. aliph. compds. selected from among 12C or higher satd. aliph. carboxylic acids and ester derivatives thereof, satd. aliph. alcohols and satd. aliph. amines. When the amount of ethylene oxide to be added is more than 300pts.wt. per 100pts.wt. satd. aliph. compd., no parting agent capable of imparting satisfactory mold release characteristics to molded products can be obtd., while when the amount is less than 50pts.wt., the molded products have poor coatability. Thus, the preferred amount is 50-300pts.wt. The internal parting agent is used in an amount of 0.1-10pts.wt. per 100pts.wt. raw polyol material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an internal mold release agent used in polyurethane reaction injection molding. [Prior art] Polyurethane reaction injection molding is a method in which highly chemically active raw material solution components for producing polyurethane resin are passed under pressure into a mixing cylinder, and simultaneously injected into a closed mold for reaction curing. This is a method of molding.

This molding method has the advantage of shortening the molding cycle and allowing selection of a variety of molds, resulting in high productivity.
It is also known to have the advantage of being able to produce polyurethane molded products with excellent performance in feel and elasticity.

For this reason, we have expanded our focus from the field of manufacturing substitutes for metal industrial parts (e.g. rollers, gears, bearings, etc.) with the main purpose of simply reducing weight by making full use of the above-mentioned advantages, to the field of manufacturing automotive interior parts. or exterior parts (e.g. bumpers,
Polyurethane reaction injection molding has come to be widely adopted even in the field of manufacturing fenders, etc., and the demand for this molding method is steadily increasing.

However, when implementing the polyurethane reaction injection molding method, molded products made by this method have a high frictional resistance and strong adhesion with the mold surface, so during the molding operation, a relatively short constant cycle is required. At intervals, the mold must be coated with a strong external mold release agent, such as a mixture of wax or soap and a highly volatile organic solvent. However, this method has the risk of igniting the solvent scattered during external mold release agent application, and also contaminates the environment of the molding process itself.
Furthermore, molded products molded using this method have drawbacks such as poor coating when the molded product is painted unless the surface of the molded product is sufficiently washed to remove the adhering mold release agent. In order to eliminate the drawbacks of mold release agents, internal mold release agents have been proposed that are mixed into raw materials for producing polyurethane resins.

As such an internal mold release agent, carboxyl group-functional organopolysiloxanes (Japanese Patent Publication No. 55-1176, Japanese Patent Publication No. 57,
-1532), organopolysiloxane having an alkali metal salt of a carboxyl group in the molecule (JP-A No. 59-1
4991), and further, carboxyl group-containing perfluorocarbons (Japanese Unexamined Patent Publication No. 59-213716).

[Problem that the invention seeks to solve]

However, although such conventional internal mold release agents can improve mold release performance to some extent, they have the disadvantage that the functional groups they contain inhibit the curing reaction during polyurethane resin production, significantly reducing the physical properties and paintability of molded products. be.

Furthermore, when trying to utilize an internal mold release agent as described above, there is the disadvantage that if such a mold release agent is added to the organic isocyanate raw material component, it will rapidly react with the incyanate, and if it is added to the polyol component raw material in advance. If left untreated, the activity of the catalyst in the component will decrease. Therefore, the premix (polyol, catalyst, Problems such as the need to install a new raw material tank exclusively for the internal mold release agent and mix it during injection molding in addition to the two raw material tanks for components (such as mold release agents)
still unresolved.

For this reason, the current situation is that the method of applying an external M type agent to the mold is exclusively used. has become a major obstacle to technological development.

Therefore, an object of the present invention is to overcome the problems occurring in the prior art described above and to provide an internal mold release agent that can be applied to polyurethane reaction injection molding machines that have been widely put into practical use. An object of the present invention is to provide an internal mold release agent for polyurethane reaction molding, which allows reaction injection molded products with excellent mold release properties to be obtained by simply adding the agent without impairing physical properties or paintability. Another object of the present invention is to reduce the number of applications of the external mold release agent when used in combination with an external mold release agent, that is, to improve the molding cycle per application of the external mold release agent.

[Means for solving problems]

The present invention is based on one or more ethylene oxide adducts of saturated aliphatic compounds selected from the group consisting of saturated aliphatic carboxylic acids having 12 or more carbon atoms and their ester derivatives, saturated aliphatic alcohols, and saturated aliphatic amines. An internal mold release agent for polyurethane reaction injection molding.

Next, the present invention will be explained in more detail.

The saturated aliphatic carboxylic acids of the saturated aliphatic compounds used in producing the mold release agent according to the present invention include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, lignoceric acid, cerotic acid, and montanic acid. , merisiliic acid, and the like. In addition, the ester derivatives include the above saturated aliphatic carboxylic acid and aliphatic polyhydric alcohol (for example, 1,4-butanediol, 1
, 6-hexanediol, glycerin, trimethylolpropane, pentaerythritol, etc.) and acede esters with aliphatic alkanol-class amines (e.g., monoethanolamine, impropaturamine, etc.). . Further, examples of the saturated aliphatic alcohol include lauryl alcohol, myristyl alcohol, palmityl alcohol, and stearyl alcohol, and examples of the saturated aliphatic amine include laurylamine and stearylamine. Ethylene oxide adducts of saturated aliphatic compounds and unsaturated aliphatic compounds having less than 12 carbon atoms are not preferred because they have excessively low softening points and do not exhibit excellent mold release properties when used as internal mold release agents.

The internal mold release agent according to the invention is prepared by adding ethylene oxide to the above-mentioned raw materials according to known methods. The addition ratio of ethylene oxide is not particularly limited, but if it exceeds 300 parts by weight per 100 parts by weight of the saturated aliphatic compound, it becomes a mold release agent that is insufficient to impart satisfactory demoldability to the molded product. On the other hand, if the amount does not reach 50 parts by weight, coating defects will occur on the molded product, so it is preferable to add 50 to 300 parts by weight of ethylene oxide per 100 parts by weight of the saturated aliphatic compound.

Even when the internal mold release agent of the present invention is composed of only one type selected from the above-mentioned ethylene oxide adducts, its mold release properties are excellent, but it is better to melt and mix two or more of them to produce molded products. It has been found that the coating properties of the two or more types are excellent, so it is preferable to melt and mix two or more types to be used.

The organic isocyanate used in polyurethane reaction injection molding using the internal mold release agent according to the present invention is not particularly limited, and includes tolylene diisocyanate (TD), 4.
4'-diphenylmethane diisocyanate (MDI),
There are any conventionally known organic incyanates such as prepolymer-modified MDI and carbodiimide-modified MDI.

Polyols usually include diols such as polyethylene ether glycol and polypropylene ether glycol, as well as glycerin, trimethylolpropane,
A polyether polyol prepared by adding propylene oxide and/or ethylene oxide to a polyhydric alcohol such as sorbitol is used, but the present invention is not particularly limited to these, and any conventionally used polyol can be used.

Furthermore, the polyol may contain short chain polyhydric alcohols such as ethylene glyfur and butanediol, and short chain polyamines such as phenylene diamine and 4°4'-diaminodiphenylmethane as chain extenders. As reaction catalysts, tertiary amines such as triethylamine, N-methylmorpholine, triethanolamine, N,N-dimethylethanolamine, and organotin compounds such as diptyltin acetate and diptyltin maleate may also be used, if necessary, with particular limitations. used without being

In addition to polyols, organic incyanates, chain extenders and reaction catalysts, water, blowing agents such as methylene chloride, trifluoromonochloromethane, etc., colorants such as red iron, zinc white, carbon black, milled glass fiber, mica, It is also possible to use one or more types of filling reinforcing agents such as silica filler, and furthermore, silicone foam stabilizers, as required.

Since the internal mold release agent according to the present invention has poor dispersibility in the organic incyanate face used in ordinary polyurethane reaction injection molding, it is preferable to use it by dispersing it in a polyol-based raw material for handling reasons.

When adding the internal mold release agent according to the present invention to a polyol-based raw material liquid, in addition to the method of directly adding and dispersing, a predetermined amount of the internal mold release agent of the present invention can be added in advance to a part of the polyol component. You may also use methods such as adding
It is not particularly limited.

The amount of internal mold release agent used according to the present invention is not particularly limited, but is preferably 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the polyol raw material.
Use parts by weight. If it is less than 0.1 part by weight, the mold release property will not be sufficiently developed, and if it exceeds 10 parts by weight, the paintability of the molded product will deteriorate, and even worse, an excess of the internal mold release agent will leach onto the surface of the molded product, causing the surface to deteriorate. This is not preferable because it may cause staining and deteriorate physical properties.

[Effect]

The internal mold release agent according to the present invention can be mixed in advance with one of the raw materials for polyurethane reaction injection molding, especially the polyol component, and unlike conventional internal mold release agents, there is no need to mix it during injection molding. The paintability of molded products can be improved and the molding cycle can be significantly increased without requiring a separate tank or reducing the polyurethane production reaction.

〔Example〕

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited by these Examples. Parts are by weight unless otherwise specified.

Example 1 50% by weight of a reaction product obtained by adding 250 parts of ethylene oxide to 100 parts of myristic acid and 50% by weight of a reaction product obtained by adding 150 parts of ethylene oxide to 100 parts of monoglyceride of behenic acid were melt-mixed and internal mold release was performed. obtained the drug.

In determining the performance of the internal mold release agent, polypropylene ether glycol 100 having a hydroxyl value of 28
parts, chain extender ethylene glycol 15 parts, 33% by weight
Contains 29.0% effective Woo of a polyol component and an incyanate component, which is a mixture of 0.02 parts of a dipropylene glycol solution of triethylenediamine (0.0 parts, part a, diptyltin urethane) and 1.0 parts of the above internal *a agent. Two components of 1100 parts of carbodiimide-modified MD were reaction injection molded.

To add the internal mold release agent, heat and dissolve a predetermined ratio in the chain extender ethylene glycol, and after cooling, add the predetermined amount of ethylene glycol and other components other than the internal mold release agent. This was done by adding it to the polyol component and stirring.

Molding conditions Reaction injection molding machine: MG120/80 (manufactured by Niigata Iron Works) Discharge pressure 150 Ky/d Discharge speed near 5Z/min Raw materials Temperature: Boriol component: 35℃ Incyanate component: 40℃ Under these molding conditions Internal dimensions 300 m x 4 temperature controlled at 70°C using a regulated reaction injection molding machine
The molded product was placed in an aluminum mold measuring 00 m x 3 m and coated with a polyethylene wax solvent-dispersed external mold release agent (wax content: 2%, wax softening point: 115-120'' C1 solvent; No. 5 naphtha). Density is 1.0~
The urethane composition mixture was injected to give a concentration of 1.11 F-/d and cured by reaction, and 60 seconds after injection, the mold was opened and demolded to produce a panel-shaped polyurethane molded product.

Furthermore, without applying an external mold release agent to the mold, injection of the urethane compounded composition and demolding are repeated, and the number of shots is determined until the mold cannot be easily demolded and a perfect molded product cannot be obtained. The mold release properties of the internal mold release agent were determined by counting the number of mold release agents.

Next, three randomly selected panel-shaped polyurethane molded products were washed with methylene chloride, which is well known to those skilled in the art, and commercially available acrylic urethane paint was applied to a thickness of about 30 μm. Spray paint it like this 10
It was set for 30 minutes and baked at 80°C for 30 minutes to paint. After carefully observing the painted surface, count the number of repellents that occurred and calculate the number of repellents per 1a.
Paintability was determined.

Example 2 200 parts of ethylene oxide to 100 parts of stearylamine
50Jin% of the reaction product added with 50Jin% and 50Jin% of the reaction product added with 200 parts of monoethanolamide of behenic acid.
% to obtain an internal mold release agent.

The performance of the internal mold release agent was evaluated in the same manner as in Example 1.

When the above-mentioned internal M type agent was used, demolding was easy up to at least 30 shots, and the paintability of the molded product was also extremely good. In addition, there was very little dirt on the mold.

Example 3 100 parts of stearyl alcohol and 2 parts of ethylene oxide
Performance was tested in the same manner as in Example 1, except that only the reactant added with 00 parts was used as the internal mold release agent.

Example 4 Performance was tested in the same manner as in Example 1, except that only a reaction product obtained by adding 200 parts of ethylene oxide to 100 parts of behenic acid was used as the internal mold release agent.

Comparative Example 1 Molding was performed under the same conditions as in Example 1 without using an internal mold release agent, and mold release properties were tested.

Comparative Example 2 A commercially available carboxy-functional siloxane internal mold release agent (Dow
An attempt was made to mold under the same conditions as in Example 1 using Q-7119 (manufactured by Hooning Co., Ltd.), but this internal S-type agent
It reacted with the catalyst to form a gelled product, inhibiting the urethane reaction, and the physical properties of the molded article were significantly reduced.

The results of Examples and Comparative Examples are collectively shown in Table 1.

Comparative Example 3 20 parts of ethylene oxide in 100 parts of normal decanol
The molding was performed under the same conditions as in Example 1, except that only the reactant to which 0 part was added was used as an internal mold release agent, and the mold release property was tested.

Comparative Example 4 20 parts of ethylene oxide in 100 parts of oleyl alcohol
The product was molded under the same conditions as in Example 1, except that only the reactant to which 0 part was added was used as an internal mold release agent, and the wi-type property was tested.

Table 1 [Effects of the Invention] As is clear from the above description, when the internal mold release agent according to the present invention is used, the time loss due to external mold release agent application is reduced and productivity is significantly improved.

In addition, the obtained polyurethane molded product is coated with
The conventional method was applied and did not cause poor coating properties such as repellency of the coating film. Furthermore, it can be mixed in advance with the polyol component used in polyurethane reaction injection molding, thus eliminating the need for a separate tank when conventional internal mold release agents are used.

Patent applicant: Kyoeisha Yushigaku Kogyo Co., Ltd.
Hanano Shoji Co., Ltd. procedural amendment (voluntary)

Claims (1)

[Claims] 1. Polyurethane consisting of one or more ethylene oxide adducts of saturated aliphatic compounds selected from the group consisting of saturated aliphatic carboxylic acids having 12 or more carbon atoms and their ester derivatives, saturated aliphatic alcohols, and saturated aliphatic amines. Internal mold release agent for reaction injection molding.