JPS60168715A - Production of polyurethane molding - Google Patents

Abstract

PURPOSE:To improve the rate of production of polyurethane moldings by decreasing the number of molding operations, by feeding a reaction mixture comprising an organic polyisocyanate, a polyol, a crosslinking agent, a catalyst and a specified internal releasing agent to a molding die. CONSTITUTION:A polyurethane molding is produced by feeding a reaction mixture comprising an organic polyisocyanate, a polyol, a crosslinking agent, a catalyst and the following internal releasing agent and, optionally, a blowing agent and an aid to a molding die pre-coated with an external releasing agent. Examples of the above releasing agents include fatty acid esters of an HLB (hydrophilic/lipophilic balance) of 10-20, obtained from a reaction among oleyl alcohol, isostearyl alcohol, a higher fatty acid and a glycol, fatty acid ethers of an HLB of 8-15, obtained by a reaction between a higher alcohol and a glcyol, a reaction product between oleic acid and an organic polyisocyanate, or mixtures thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a polyurethane molded product having good mold releasability and a method for manufacturing a polyurethane molded product that can omit the application of a mold release agent to the rows.

Polyurethane molded articles are produced by introducing a reaction mixture consisting of polyisocyanate, a compound containing at least two hydrogen atoms reactive with isocyanate groups, and additives into a completely hermetic mold. The reaction mixture is cured in the mold and removed as a molded article. The mold is made of a material with high thermal conductivity in order to control the reaction temperature, and metal molds are generally used. Usually, in order to prevent polyurethane molded products from sticking to the mold surface, a method of applying a mold release agent such as wax, metal soap, or oil to the mold surface is adopted.

In this case, a thin film with low surface tension is formed between the molded product and the mold surface, and since this thin film does not adhere to either the molded product or the mold surface, the molded product can be easily removed.

However, with this method, a new mold release agent must be applied each time molding is performed, and the old mold release agent remaining on the mold surface must be removed at regular intervals. This requires considerable manpower and time.

Methods of adding compounds with one-way properties to polyurethane resin reaction mixtures have also been investigated.

The mold release agent applied to the mold surface is called an external mold release agent, and the mold release agent added to the polyurethane resin reaction mixture is called an internal mold release agent. The present invention was completed as a result of intensive research into a molding method that can omit the application of an external mold release agent or cleaning the surface of the molding die, reduces operations in the molding process, and contributes to improved productivity. reached.

That is, in the present invention, a reaction mixture consisting of an organic polyisocyanate, a polyol, a crosslinking agent, a catalyst, an internal mold release agent, and, if necessary, a blowing agent and an auxiliary agent, is introduced into a molding die coated with an external mold release agent in advance. In the method for producing polyurethane molded articles, the internal mold release agent is oleyl alcohol, isostearyl alcohol, HLB (hydrophilic-lipophilic balance) obtained by reaction of high m fatty acids with glycol], (l to 200 fatty acids) Polyurethane molding characterized by adding an ether compound having an HLB of 8 to 15 obtained by the reaction of an ester, a high R alcohol and a glycol, a reaction product of an ionic acid and an organic polyisocyanate, or an arbitrary mixture thereof. Furthermore, by using a wax-based mold release agent with a solid content melting point of 100°C or higher as the external mold release agent, after applying the external mold release agent, the introduction of the reaction mixture and the molded product can be carried out. This is a method for producing polyurethane molded products obtained by a molding method in which demolding is repeated two or more times (hereinafter referred to as continuous demolding).The polyol used in the present invention is a polyfunctional hydroxyl group-containing compound such as glycerin or triethanolamine. Compounds containing amino K and hydroxyl groups such as or diaminotoluene containing alkylene oxides such as ethylene oxide and propylene oxide contain 2 to 6 hydroxyl groups in the molecule, and the average molecule Jj Polyether polyols having a molecular weight of 3,000 to 7,000 are effective.

The organic polyisocyanate used in the present invention includes:
Tolylene diisocyanate (hereinafter referred to as TDI), tuphenylmethane diisocyanate (hereinafter referred to as MDI),
Modified polyisocyanates obtained by reacting these polyisocyanates with polyfunctional hydroxyl group-containing compounds or modified by carbodiimidization and mixtures of the above polyisocyanates are used, but particularly preferred polyisocyanates are MDI and modified MDI. The crosslinking agent used in the invention generally includes low molecular weight polyols such as trimethylolpropane, glycerin, ethylene glycol, butanediol, hexanetriol, amino alcohols such as triethanolamine, /p-functional amines, Polyols made by adding alkylene oxides such as ethylene oxide and propylene oxide to amino compounds are used.

As the blowing agent, water or halogenated hydrocarbons are generally used. Various auxiliary agents are used as needed, such as cell regulators, discoloration inhibitors, flowability improvers, and colorants.These substances can be added in advance to the polyol in the required amount, or added to the polyol. It may be added at the same time as the reaction with isocyanate.

As a catalyst for the reaction between polyol and polyisocyanate, tertiary amines such as triethylenediamine and dimethylethanolamine and metal compounds are generally used.

Examples of the internal mold release agent of the present invention include oleyl alcohol, instairifle alcohol, fatty acid esters with an HLB of 10 to 20 obtained by reaction of a high M fatty acid with glycol, and HLB of 8 to 20 obtained by reaction with a higher alcohol. 15 ether compounds or reaction products of oleic acid and organic polyisocyanates or any mixtures thereof are used. These compounds may be added to the polyol component or polyisocyanate in advance, or may be added simultaneously during the reaction of the polyol component and polyisocyanate, and the method of addition is not particularly limited. Furthermore, a known internal mold release agent may be used in combination with these compounds. In addition, the amount of these compounds added is 0.5% by weight (1.0 in the case of a reaction product of oleic acid and organic polyisocyanate) based on the total amount of resin components.
If the mold release property is less than 0.5 to 30 (10 in the case of a reaction product of oleic acid and organic polyisocyanate), the mold releasability is insufficient.
~6.0)% by weight, the mold releasability becomes good as well as the added liquid. In the range of 3.0 to 5.0 (6.0 to 100 in the case of the reaction product of oleic acid and organic polyisocyanate) by weight, the mold releasability is good, but the initial strength (green strength) during polyurethane resin production is ) tends to decrease.

50 (10 for oleic acid and organic polyisocyanate
0) In the range of more than 0% by weight, the green strength decreases significantly. Therefore, the amount of internal mold release agent added is 0.5 to 5.0 (in the case of reaction products of oleic acid and organic polyisocyanate, 1
．． 0-IQ, 0)% by weight, preferably 0.5-3.0(
In the case of a reaction product of oleic acid and an organic polyisocyanate, an amount of 10 to 6.0) i% is suitable.

When a wax-based mold release agent having a solid fraction melting point of 100' CI2 or more was used as an external mold release agent, a remarkable increase in the number of consecutive demoldings was observed when used in combination with an internal mold release agent.

If the solid state melting point of the external mold release agent is lower than 1()0°C, the wax will assume a fluid state due to the reaction heat when the reaction mixture is introduced into the mold. Therefore, the wax easily enters the reaction mixture and migrates from the mold surface towards the molded part.
The mold release effect is not sufficient during the next molding, and the number of consecutive mold removals does not increase.

On the other hand, if the solid content melting point is too high, the applied mold release agent will tend to stick to the molded product whose temperature is slightly higher than the total temperature, and will be taken out together with the molded product during demolding, reducing its contribution to continuous demolding. . Therefore, it is preferable that the external mold release agent has a solid content melting point of 100°C or higher and a temperature that is approximately 50°C higher than the metal temperature. If such an external mold release agent is used, the reaction mixture can be molded. When introduced into a mold, it exhibits a semi-fluid state and does not migrate to the molded product much, remaining on the mold surface and contributing to continuous demolding.

EXAMPLES The present invention will be explained in detail below with reference to Examples, but the present invention is not limited thereto. The numbers in the examples indicate parts by weight.

Example 1 Ethylene oxide and propylene oxide in glycerin
(100 parts of polyether polyol-7 with OH value of 23"f/KOH/f, ethylene glycol/L'
20 parts, 0.1 part of triethylenediamine, 0.1 part of digtylthine dilaurate, 4 parts of oleyl alcohol (hereinafter referred to as A), and 4 parts of Freon 11.

A reaction mixture of a well-mixed polyol component and 116 parts of a 4.4'-MI) I derivative (a mixture of a urethane modified product and a levodiimide modified product) having an isocyanate group content of 26.5% was prepared in advance so that the solid content had a melting point. A wax-based mold release agent (Limurikei B-269 manufactured by Chukyo Yushi Co., Ltd.) (hereinafter referred to as below) was applied with a brush at a temperature of 105° C., and the thickness was α and 3 mm. Approximately 70
After a few seconds, the mold was opened and a sheet-like molded product was obtained. After that, repeat the same operation as above without cleaning the mold surface.
The number of times until the mold could no longer be demolded was determined. After demolding, the molded product was left for one week and the physical properties of the molded product were determined. The results are shown in Table 1.

Example 2 Nipholyoxyethylene sorbitan monolaurate (HL
B=16.7) (Odo AzTW-L manufactured by Kao Soap
Example 1 except that 4 parts of 120) (hereinafter referred to as B) were used.
I went exactly the same way. The results are shown in Table 1.

Example 3] 120 parts of the 4,4'-MDI derivative used in Example 1 was heated to 50°C, and 4 parts of oleic acid was gradually added dropwise thereto to react, resulting in a reaction product with the MDI derivative. (L.J.
, lower C) was obtained. Oleyl alcohol-/I/4 part and 4,4'-MDI derivative 116 used in Example 1
Example 1 except that 124 parts of this reactant was used instead of 1 part.
I went exactly the same way. The results are shown in Table 1.

Example 4] The same procedure as in Example 1 was carried out except that 4 parts of insudaryl alcohol lv (hereinafter referred to as below) was used in place of 4 parts of oleyl alcohol/L/ used in Example 1. The results are shown in Table 1.

Example 5] Polyoxyethylene oleyl ether (HLB=12.0) was used instead of 4 parts of oleyl alcohol used in Example 1.
The same procedure as in Example 1 was repeated except that 2 parts of Emulgen 408 (manufactured by Kao Soap) (hereinafter referred to as E) and 2 parts of oleyl alcohol were used. The results are shown in Table 1.

Example 6] Instead of the oleyl alcohol used in Example 1, oleyl alcohol/l/3.5 parts of halogenated silicone mold release agent S-700 (hereinafter referred to as F) manufactured by Tobitsukumarinckrodt Co., Ltd. f! : The same procedure as in Example 1 was repeated except that 0.5 parts of the following were used. The results are shown in Table 1.

Example 7 Instead of the wax-based mold release agent used in Example 1, 4 parts of a wax-based mold release agent (Chukyo Yumide prototype) (hereinafter referred to as M) with a solid content melting point of 115°C was used. Except for this, the same procedure as in Example 1 was conducted, and the results are shown in Table 1.

Comparative Example] The same procedure was carried out as in Example except that 4 parts of oleyl alcohol used in Example 1 was not used. The results are shown in Table J.

Comparative Example 2] V4 parts of oleyl alcohol used in Example 1 (The same procedure as in Example 1 was repeated except that 0.4 parts of oleyl alcohol was used instead of D. The results are shown in Table 1.

Comparative Example 3] Rimurikei D-18, a wax-based mold release agent with a solid content melting point of 95°C, was used instead of the wax-based mold release agent used in Example 1.
6 (manufactured by Chukyo Yusashi Co., Ltd.) (hereinafter referred to as N), and the same procedure as in Example 1 was carried out. The results are shown in Table 1.

Comparative Example 4] 4 parts of oleyl alcohol-7' used in Example 1 (
i = 10 parts, and the same operation as in Example 1 was performed.
When the mold was opened after 70 seconds and the molded product was taken out, a part of the resin on the surface adhered to the mold, and a molded product with a good appearance could not be obtained. The initial strength development time was 5 minutes or more.

fA441x on Umei Y board? ＞/4 Correspondence to YM Raishoto Procedural Amendment (Voluntary) March 1981: Mr. Kazuo Wakasugi, Commissioner of the Japan Patent Office1, Indication of the case 1982 Patent Application No. 256232, Title of invention Polyurethane molded product Manufacturing method 3, Claims column and Detailed description of the invention column 5, Contents of the amendment (1) Claims column As shown in the attached sheet (2) Detailed description of the invention Amend the column as follows: 〇〇Mei Tsumugisho, page 6, lines 10 to 16, delete “Furthermore, it is a manufacturing method.”
.

0 Specification, page 1, line 9 to page 11, line 10 “External...
・・・・・・Contribute. "Delete 00 Specification No. 1
Page 5, line 5 to line 1 O, Comparative Example 3] is deleted.C. Book, page 15, line 11, Comparative Example 4 is changed to Comparative Example 3. Table 1, page 16 of the specification, Table 1 of Comparative Example 3. Delete a column.

24 Claim 1: A reaction mixture consisting of an organic polyisocyanate, a polyol, a crosslinking agent, a catalyst, an internal mold release agent, and, if necessary, a blowing agent and an auxiliary agent, in a mold coated with an external mold release agent f# in advance. In the method of manufacturing polyurethane molded articles by introducing oleyl alcohol, instearyl alcohol, and high M1 fatty acid togelicol as internal mold release agents, HLB (hydrophilic-lipophilic balance) is 10 to 10. 20 monofatty acid ester, iF++t & HLB obtained by alcohol and glycol tono reaction is 8
15. A method for producing a polyurethane molded article, characterized in that it uses an ether compound, a reaction product of oleic acid and an organic polyisocyanate, or any mixture thereof.

Procedural amendment meeting (method) June 19, 1981 1981 Patent Application No. 25623 3. Person who makes corrections Relationship to the incident: Patent applicant 5. Subject of amendment Specification

Claims (1)

[Scope of Claims] 1. Organic polyisocyanate and polyol are placed in a mold that has been coated with an external mold release agent in advance. A method for manufacturing polyurethane molded articles by introducing a reaction mixture consisting of a crosslinking agent, a catalyst, an internal mold release agent, and, if necessary, a blowing agent and an auxiliary agent. stearyl alcohol, high i
A fatty acid ester with an HLB (hydrophilic-lipophilic balance) of 0 to 20 obtained by the reaction of a fatty acid and a glycol,
H obtained by reaction of higher alcohol and glycol
A method for producing a polyurethane molded article, characterized in that an ether compound having an LB of 8 to 15, a reaction product of oleic acid and an organic polyisocyanate, or any mixture thereof is used. 2. Add organic polyisocyanate and polyol to a mold that has been coated with an external mold release agent in advance. In a method for manufacturing a poly-1-cretane molded article by introducing a reaction mixture consisting of a crosslinking agent, a catalyst, an internal mold release agent, and, if necessary, a blowing agent and an auxiliary agent, the external # molding agent has a solid fraction melting point of 100. 1. A method for producing a polyurethane molded article, which comprises repeating the steps of applying a wax-based mold release agent at a temperature of .degree. C. or above, introducing a reaction mixture and demolding the molded article two or more times. 3 As an internal mold release agent, Oley I real alcohol, isostearyl alcohol-IV, fatty acid ester with HLB of 10 to 20 obtained by reaction of higher fatty acid and glycol, and HLB of 8 to 20 obtained by reaction of higher alcohol and glycol. 15. The method for producing a polyurethane molded article according to claim 2, characterized in that 15 ether compounds, a reaction mixture of oleic acid and an organic polyisocyanate, or any mixture thereof are used.