JPS5815593A - Inner mold releasing agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Most polymer molding systems, especially those based on polyurethanes or polyesters, have the disadvantage that objects molded from the systems do not release rapidly from the mold after their molding. This is due to the very strong adhesive properties of the polymers in the composition. A third common method to overcome this strong adhesion to the mold in which the product is molded is to add mold release agent (mold release agent) to the surface of the mold.
e-lease agent,). This, of course, requires an expenditure of both time and effort on the part of the operator. When using a coated mold release agent, the mold release agent accumulates on the surface of the mold to the extent that regular cleaning of the mold is required, resulting in loss of time due to stoppage of operation. We must also recognize that.

In an effort to overcome this drawback, attempts have been made to add demolding agents, such as zinc stearate, directly into the polymer system. However, direct addition of such an internal demolding agent is difficult to obtain a uniform distribution of zinc stearate in the polymer system, so reaction injection molding (
reaction 1 injection mold
d) No success in polyurethane or polyester systems.

Accordingly, it is a constant object of the art to provide internal die cutting agents that are effective for use in polyurethane and polyester systems.

=4- It has been found according to the present invention that an effective demolding agent can be provided which can be successfully achieved by heating a metal salt of a long chain fatty acid with an epoxidized vegetable oil.

Such demolding agents can be added directly into the polyurethane or polyester systems used in reaction injection molding.

A demolding agent composition is easily prepared by heating a mixture of metal salt and epoxidized vegetable oil to about 110 DEG to 140 DEG C. with constant stirring. A preferred temperature range is about 125° to about 135°C. The resulting clear homogeneous solution is cooled and added to the polymer system.

It has been found that polymeric systems containing the above-mentioned die cutting edges easily release from the surface of the mold, in sharp contrast to polymeric systems that do not contain a die cutting agent.

As another advantageous feature of the present invention, the polymer systems containing the demolding agents of the present invention, when used together with polyols and isocyanates in the production of urethanes with the demolding agent as a third component, may be It was also found that the system would gel at a significantly faster rate than the treated system. This indicates that the metal salt-epoxidized vegetable oil compositions of the present invention, when so used, in addition to imparting desirable demolding properties to polymer molding systems, also provide a catalytic effect. It shows.

Although it is contemplated that the internal demolding agent provided by the present invention can be incorporated into any polymer system, it has been found to be particularly advantageous when used with systems based on polyurethane or polyester resins. has been done. Such resins and molding systems based thereon are well known in the art.

The metal salt component of the mold cutting agent of the present invention includes calcium, barium, cadmium and other known metal salts of long chain fatty acid substances and their glycerides, including stearic acid, valmitic acid and oleic acid. It can be any of the known metal salts including. The metal salt component can be a simple salt or a coformed 5alt system of two different metals, such as those described in Example 5 later in this specification.
It can also be. However, particular preference is given to using zinc stearate as metal salt component.

The epoxidized vegetable oil may be any known vegetable oil, such as epoxidized soybean oil and epoxidized linseed oil.

However, particular preference is given to using epoxidized octyl tallate. In the typical practice of the invention, each component is present in a ratio of about 20 to about 50 parts by weight of metal salt to about 50 parts by weight of epoxidized vegetable oil. The preferred range is about 25 to about 40 metal months about 75
~60 epoxidized vegetable oil.

In making the demolding agent, the ingredients can be dry mixed and then heated to a temperature and for a period of time sufficient to produce a homogeneous solution. However, it is sometimes convenient to preheat the epoxidized vegetable oil before mixing it with the metal salt component. The temperature of about 110° to about 140°C is about 1
It can be used for a time period of 5 to about 30 minutes.

By direct mixing according to processes well known in the art for incorporating additives into molding compositions,
A demolding agent is added to the polymer system.

The invention is illustrated by the following examples. It is to be understood that the examples are merely illustrative of the invention and not limiting.

10 parts zinc stearate and 90 parts epoxidized soybean oil are charged into a container, dry blended, and then heated to 125° to 130°C for about 15 minutes with continuous stirring. did. A clear amber solution formed. The solution was then cooled to room temperature, leaving a clear amber solution. This solution was molded into a polyurethane reaction injection molding system, typically RIM 125, sold by Union Carbide Corporation, with 1.5% by weight of S8 in the system.
- Added in an amount sufficient to provide zinc thearate.

Next, 35 parts of zinc stearate and 65 parts of epoxidized octyl tallate were charged into a container and then heated to 25° to 130°C for about 15 minutes with continuous stirring. . A clear amber solution formed. The solution was then cooled to room temperature, leaving a clear amber solution. This solution was added to a polyurethane reaction injection molding system in an amount sufficient to provide 1.5% by weight zinc stearate in the system.

Example 3 30 parts zinc stearate and 70 parts octyl epoxy linseed oil were charged to a vessel and then heated to 125°-130° C. for about 15 minutes with continuous stirring. A clear amber solution formed. The solution was then cooled to room temperature, leaving a clear amber solution. This solution was added to a polyurethane reaction injection molding system in an amount sufficient to provide 1.8% by weight of zinc 9-stearate in the system.

Example 4 - 45 parts zinc stearate and 55 parts vik, an epoxy ester from Viking Chemical Company.
of lex 4.050 was charged into a container and then heated to 125°-130°C for about 15 minutes with continuous stirring. A clear light amber solution formed. The solution was then cooled to room temperature, leaving a clear amber solution. This solution was added to the reaction creation molding system at a rate of 1.5
Sufficient amount was added to provide % by weight zinc stearate.

Example 5 Octyl epoxy sauce (125~
135° C.) with continuous stirring. A clear amber solution formed. This solution is then cooled to room temperature and placed in a polyurethane reaction injection molding system.
Sufficient amount was added to give 5% by weight of mixed stearate.

-0- 25 parts of zinc stearate and 75 parts of epoxidized soybean oil were charged into a container and then continuously stirred at 125° to 13 fl'C for about 15 minutes. Heated. A clear amber solution formed. The solution was then cooled to room temperature, leaving a clear amber solution. This solution was added to a polyurethane reaction injection molding system with 1.8
Sufficient amount was added to provide % by weight zinc stearate.

After molding, articles made from the reaction injection molding compositions containing the demolding agents of Examples 1-6 easily separated from the aluminum pans. Systems using the same polyurethane reaction injection molding compositions but without the die cut edges of Examples 1-6 adhered well to the pan during molding.

The examples below illustrate this.

Example 7 An internal mold release agent was prepared according to the process of Example 2 and incorporated into the urethane reaction injection molding composition 'RIM125''.
('l (added in an amount of 5 parts by weight per 1 part of total composition,
The resulting composition was then applied to an aluminum substrate at a rate of 160 mm.
Cure for 1 minute at °F.

II I M] Similarly, 16 pieces were used for comparison consisting of 25 pieces.
Cure for 1 minute at 0°F.

The peel force required to release the piece from the aluminum substrate was measured with the following results.

−−”■−−− Familiar humubo z”Z nose-like −−
Force a) RIM125 32.4 The above test was repeated using a chromium-plated steel substrate instead of the aluminum substrate.

The following results were observed.

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The significantly superior demolding properties afforded by the use of the demolding agent of the present invention can be easily seen from the results of the tests described in section 2 above.

Patent applicant: Dart Industries, Inc. Patent attorney: Taikichi Odajima 13-

Claims (1)

Claims: An internal mold release agent composition comprising: 1) 5 to 50 parts by weight of a metal salt; and 1) 5 to 50 parts by weight of an epoxidized vegetable oil. 2. The composition according to claim 1, wherein the metal salt is zinc stearate. 3. The composition according to claim 1, which is epoxidized vegetable oil or epoxidized soybean oil.・1. The composition of claim 1, wherein the epoxidized vegetable oil is octyl epoxitalate. 5. The composition of claim 1, wherein the ratio of metal salt to epoxidized vegetable oil is from about 1:10 to about 1:1. 6. The composition of claim 5, wherein the metal salt is zinc stearate, and 1- the epoxidized vegetable oil is epoxidized soybean oil. 7. The metal salt is zinc stearate and the epoxidized vegetable oil is octyl epoxytalate;
A method according to claim 5. 8. In reaction injection molding of polymer systems based on polyurethane or polyester, an internal mold cutter consisting of 0.5-5 parts by weight of metal salt and 1.5-15 parts by weight of epoxidized vegetable oil in the polymer system. A forming method that involves cutting. 9. The method according to claim 8, wherein the metal salt is zinc stearate. 10. The method according to claim 8, wherein the epoxidized vegetable oil is epoxidized soybean oil. 11. The method according to claim 8-2, wherein the epoxidized vegetable oil is octyl epoxytale-1. 12. The ratio of metal salts to epoxidized vegetable oil is approximately 1
9. The method of claim 8, wherein the ratio is from 10 to about 1:1 per month. 13. The method of claim 12, wherein the metal salt is zinc stearate and the epoxidized vegetable oil is epoxidized soybean oil. 14. The method of claim 12, wherein the metal salt is zinc stearate and the epoxidized vegetable oil is octyl epoxytale-1.