JPH0741541A - Production of polyurethane and/or polyurea molding - Google Patents

Abstract

PURPOSE:To produce a liquefied polyisocyanate at a relatively low cost by a simpler and easier process and to produce a molding with mechanical and physical characteristics equivalent to those of a molding produced by using MDI. CONSTITUTION:A polyurethane and/or a polyurea molding is produced by reaction injection molding by using a polyisocyanate, an active hydrogen compd., a chain extender, and if necessary other additives under conditions that the polyisocyanate used is one obtd. by modifying polymethylene polyphenylene polyisocyanate contg. 15-60wt.% trinuclear or higher compd. with a monofunctional active hydrogen compd. and that the chain extender used is a nuclearly alkyl-substd. arom. diamine.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Polyurethane and / or polyurea molded products are used for seat cushions, automobile parts, electronic / electrical device parts, etc. according to their physical properties. As parts, interior materials and exterior materials are being applied, and particularly polyurethane and / or polyurea molded products having fine cells are widely used for automobile bumpers, armrests, steering wheels, and the like.

[0002]

BACKGROUND OF THE INVENTION Polyurethane and / or polyurea moldings are produced by introducing a reaction mixture of polyisocyanates, active hydrogen compounds, chain extenders and optionally additives into a mold which can be closed.

Examples of polyisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate (hereinafter referred to as MDI), polyphenyl polymethylene polyisocyanate (hereinafter referred to as polymeric MDI), xylylene diisocyanate, and modified polyisocyanates thereof. However, MDI is widely used for bumpers, armrests, handles, etc., because the strength of the molded product immediately after reaction immediately appears and the physical properties of the molded product are excellent.

Since this MDI is a solid at room temperature, it is usually used by being modified and liquefied. There are two modification methods, urethane modification and carbodiimide modification (or uretoimine modification). It is used by sequentially mixing or mixing polyisocyanates modified by both modification methods. Urethane modification is the reaction of MDI with a small amount of low molecular weight diols, triols, etc.
This is a method of changing the number of isocyanate groups of MDI to several 10% to urethane groups (JP-A-3-74357). The carbodiimide modification (or uretoimine modification) utilizes the reaction in which carbon dioxide gas is desorbed from two isocyanate groups to generate a carbodiimide group, and MDI is heated at a high temperature or reacted in the presence of a catalyst. And
It is shown in Japanese Examined Patent Publication No. 45-7545 and Japanese Patent Laid-Open No. 1212023.

The active hydrogen compound has a molecular weight of 500 to 20.
000, preferably 800 to 15,000, polyether polyol, polymer polyol, polyester polyol, polyether polyamine and the like. The chain extender is a polyhydric alcohol having a molecular weight of 62 to 500, a polyvalent amine, etc., and is disclosed in JP-B-54-17359 and JP-B-1-3.
4527, JP-A-57-74325, JP-B-63-47.
726 and the like.

It is also known to add glass fiber, rock wool, mica or the like as a reinforcing agent or a filler in order to improve the shape retention and dimensional stability of a molded article (Plastic Age, April 1986 issue). 119-126).
There is also known a method in which most of the active hydrogen compound is reacted with polyisocyanate in advance to greatly improve the thermal characteristics such as the heat distortion temperature of the molded product (Japanese Patent Laid-Open No. 3-7721).

[0007]

However, such a production method requires M which is relatively expensive as a polyisocyanate.
Using DI and modifying it for further liquefaction complicates the production process of polyisocyanate, invites a significant increase in costs associated with it, and is a great way to expand the application of molded products to new fields. It is an obstacle.

On the other hand, since polymeric MDI is liquid at room temperature and has a lower cost than MDI, attempts have been made to use it to reduce the cost of molded articles, but the flow of the reaction mixture in the mold has been studied. In addition, the mechanical properties such as elongation at break, tear strength, and wear resistance of the molded product and the change in rigidity due to temperature change, and the physical properties such as sag deformation (heat sag) at high temperature are significantly deteriorated. , Only very small amounts of polymeric MDI have been added as an aid to the liquefaction of MDI, or they have been aware of the loss of these properties and have only attempted to reduce costs.

[0009]

The present inventor has manufactured a liquefied polyisocyanate at a relatively low cost by a simpler manufacturing process, and has a mechanical property and a physical property using MDI. As a result of intensive studies on a method for producing a molded product comparable to a product, the present invention has been completed.

The present invention uses a polyisocyanate, an active hydrogen compound, a chain extender and optionally an additive,
The present invention relates to a method for producing a polyurethane and / or polyurea molded product by a reaction injection molding method.

Polyisocyanate is a binuclear MD
I of 85 to 40% by weight and polynuclear bodies of 3 or more nuclei are 15 to 6
Polymeric MDI containing 0% by weight and having an average functionality of 2.2 to 3.0 is used as a monofunctional active hydrogen compound such as methanol, ethanol, isopropanol (hereinafter, referred to as IP
It is called A. ), 2-ethylhexanol, oleyl alcohol, stearyl alcohol and other aliphatic alcohols, ethylamine, propylamine and other aliphatic amines, N-methyl-N-ethylamine, N-methyl-N-
A modified form of polymeric MDI in which the average functionality is approximately equal to the modified form of MDI by modification with an aliphatic secondary amine such as propylamine, benzyl alcohol, aromatic alcohol such as phenoxyethanol, or a mixture thereof. is there. The modified product of the polymeric MDI is preferably a product obtained by reacting 1000 g of the polymeric MDI with a monofunctional active hydrogen compound [polynuclear compound content of trinuclear or more (wt%) × 0.015 to 0.05] mol. is there. The average functionality is 1.9 to 2.2. In order to further improve the liquid stability at low temperatures or to improve the physical properties of molded articles, such modified products are further urethane-modified with diols, triols, etc., heated at high temperatures, or in the presence of a catalyst. It is also possible to modify with carbodiimide by reacting with.

The chain extender is an aromatic diamine having a nucleus-substituted alkyl group, for example, diethyltoluenediamine (hereinafter referred to as DETDA) or t-butyltoluenediamine. It is also possible to use ethylene glycol (hereinafter referred to as EG), a diol such as 1,4-butanediol, a triol such as trimethylolpropane, a low molecular weight polyol having a molecular weight of 500 or less, and an alkylene oxide adduct of ethylenediamine. is there.

The active hydrogen compound has a molecular weight of 500 to 200.
00, preferably 800-15000, polyether polyols, polymer polyols, polyester polyols, polyether polyamines and the like.

If desired, a catalyst, an internal mold release agent, a foam stabilizer, a foaming agent, a flame retardant, an antioxidant, etc. may be added to the polyisocyanate and / or active hydrogen compound. The addition amount thereof is usually 10 parts by weight or less, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total of the polyisocyanate and the active hydrogen compound. The catalyst is, for example, an organometallic compound such as dibutyltin dilaurate or a tertiary amine such as triethylenediamine. The internal release agent is, for example, an amine solution of a fatty acid metal salt or a silicone compound. The foam stabilizer is, for example, a silicone compound. The foaming agent is, for example, air, a fluorine-containing compound (for example, Freon 11, Freon 123, Freon 141b),
It is a hydrocarbon (eg, pentane, cyclopentane). Further, a reinforcing filler such as glass fiber, rock wool, glass flake, mica, wollastonite, etc., which does not impair the surface clarity of the molded product, may be used together. By introducing these raw materials into a mold that can be closed using a reaction injection molding machine, it is possible to produce a polyurethane and / or polyurea molded article having high elongation at break and tear strength and high heat sag.

[0015]

EXAMPLES The present invention will be specifically described with reference to Reference Examples, Examples and Comparative Examples.

Reference Example 1 1000 g of polymeric MDI having a 50% dinuclear content was heated to 60 ° C. to obtain 71.4 g (1.18 mol) of IPA and polypropylene glycol having a hydroxyl value of 500 mg KOH / g (hereinafter referred to as PPG) 42. 5 g (0.19 mol) were added in two portions with stirring. Furthermore, by reacting at 70 ° C. for 5 hours, the isocyanate content is 2
A 2.2% homogeneous isocyanate mixture was obtained. The viscosity of this liquid at 25 ° C. was 6200 cps.

Reference Example 2 1000 g of polymeric MDI having a binuclear content of 50% was heated to 60 ° C., and 91.7 g (1.52 mol) of IPA was added in two portions with stirring. Furthermore, 5 at 70 ° C
After reacting for a time, a uniform isocyanate mixture having an isocyanate content of 23% was obtained. The viscosity of this liquid at 25 ° C is
It was 2300 cps.

Reference Example 3 1000 g of polymeric MDI having a binuclear content of 45% was heated to 60 ° C., and 142 g (1.09 mol) of 2-ethylhexanol was added in two portions with stirring. Further, the reaction was carried out at 70 ° C. for 5 hours to give an isocyanate content of 2
A homogeneous isocyanate mixture of 800 cps (25 ° C.) at 3.1% was obtained.

Reference Example 4 550 g of polymeric MDI having a dinuclear content of 45% and M
DI of 450 g was mixed to prepare a polyisocyanate having a binuclear content of 70% (polynuclear content of trinuclear or higher is 30%), which was heated to 60 ° C. to obtain 86.3 g of IPA (1.4
(3 mol) was added in two portions with stirring. 7 more
After reacting at 0 ° C. for 5 hours, the isocyanate content was 24.2.
% Homogeneous isocyanate mixture was obtained. 25 of this liquid
The viscosity at ° C was 1200 cps.

Example 1 Trimethylolpropane was mixed with propylene oxide (hereinafter,
It is called PO. ) And ethylene oxide (hereinafter referred to as EO) (PO: EO molar ratio 83:17) are added to obtain a polyether polyol 15200 having a molecular weight of 6000.
Molecular weight of 36 obtained by adding PO to ethylenediamine
400g of 0 polyether polyol, DETDA42
00 g, 20 g of dibutyltin dilaurate and 20 g of 33% dipropylene glycol solution of triethylenediamine were added, and the mixture was stirred for 30 minutes using a stirrer (Satake portable stirrer 525N-1.5) at a rotation speed of 240 / min for polyol. A mixture was obtained. Using a reaction injection molding machine (PEC-MC104R manufactured by Polyurethane Engineering Co., Ltd.), 100 parts of this polyol mixture and the isocyanate mixture having an isocyanate content of 22.2% obtained in Reference Example 1 were used:
Mix and inject into a flat mold at 70 ° C in a weight ratio of 60 for 1 second, and demold after 30 seconds to obtain a width of 300 mm and a length of 700 m.
A molded product having a thickness of 3 mm and a thickness of 3 mm was obtained. This molded product is 120 ℃
After heat-treating for 30 minutes, the physical properties were measured. First result
Shown in the table.

Example 2 Using the same reaction injection molding machine as in Example 1, the polyol mixture shown in Example 1 and the isocyanate mixture obtained in Reference Example 2 were mixed and injected into the mold at a weight ratio of 100: 58. To obtain a molded product. After heat-treating this molded product at 120 ° C. for 30 minutes, the physical properties were measured. The results are shown in Table 1.

Example 3 Using the same reaction injection molding machine as in Example 1, the polyol mixture shown in Example 1 and the isocyanate mixture obtained in Reference Example 3 were mixed and injected into the mold at a weight ratio of 100: 59. To obtain a molded product. After heat-treating this molded product at 120 ° C. for 30 minutes, the physical properties were measured. The results are shown in Table 1.

Example 4 The polyol mixture shown in Example 1 and the isocyanate mixture obtained in Reference Example 4 were injected into a mold using the same reaction injection molding machine as in Example 1 at a weight ratio of 100: 55.5. A molded product was obtained. After heat-treating this molded product at 120 ° C. for 30 minutes, the physical properties were measured. The results are shown in Table 1.

Comparative Example 1 To 1000 g of MDI having a binuclear content of 99%, 151 g of tripropylene glycol (hereinafter referred to as TPG) was added in two batches and reacted in the same manner as in Reference Example 1 to obtain an isocyanate content of 22.8%. To obtain a uniform liquid. The viscosity at 25 ° C. was 700 cps. Using a reaction injection molding machine, the polyol mixture shown in Example 1 and this liquid material
It was injected into the mold at a weight ratio of 00:58 to obtain a molded product. Table 2 shows the results of measuring the physical properties of the obtained molded products.

Comparative Example 2 550 g of polymeric MDI having a dinuclear content of 45% and M
Mix 450g of DI and the content of polynuclear bodies of 3 or more is 3
0% polyisocyanate was prepared and heated to 60 ° C. to obtain 62 g of PPG having a hydroxyl value of 500 mgKOH / g.
(0.27 mol) was added in two portions with stirring.
Further, the mixture was reacted at 70 ° C. for 5 hours to obtain a uniform liquid substance having an isocyanate content of 28%. Viscosity at 25 ℃ is 120
It was cps. The polyol mixture shown in Example 1 and this liquid material were injected into a mold at a weight ratio of 100: 48 using a reaction injection molding machine to obtain a molded product. Table 2 shows the results of measuring the physical properties of the obtained molded products. The rigidity and the elongation at break decreased remarkably only by adding 30% of polynuclear bodies of 3 or more nuclei.

Comparative Example 3 To 15,000 g of a polyether polyol having a molecular weight of 6000 obtained by adding PO and EO (80:20 weight ratio of PO: EO) to trimethylolpropane was added EO and PO (weight of EO and PO) to toluenediamine. Polyether polyol 600 having a molecular weight of 480 obtained by adding a ratio of 46:54)
g, EG2850 g, 45 g of a 32% dipropylene glycol solution of triethylenediamine, 3 g of dibutyltin dilaurate and 900 g of freon 11 were added and stirred to obtain a polyol mixture. This polyol mixture and Comparative Example 1
100: 90 using a reaction injection molding machine with the liquid material obtained in
A molded product was obtained by injecting into the mold at a weight ratio of. 3 at 120 ° C
After heat treatment for 0 minutes, the physical properties of this molded product were measured. The results are shown in Table 2. The heat sag is more than double that of the example.

Comparative Example 4 The polyol mixture shown in Comparative Example 3 and the isocyanate mixture obtained in Comparative Example 2 were mixed with each other using a reaction injection molding machine.
It was injected into the mold at a weight ratio of 0:85 to obtain a molded product. This molded product was heat treated at 120 ° C. for 30 minutes, and the physical properties were measured. The results are shown in Table 2. Although the bending modulus at room temperature increased, the heat sag decreased about 5 times compared with the examples, and the elongation at break also decreased significantly.

Comparative Example 5 150 g (0.67 mol) of EG was added to 1000 g of polymeric MDI having a dinuclear content of 50% in two portions, and the reaction was carried out in the same manner as in Reference Example 1 to obtain an isocyanate content of 22.5.
% Liquid was obtained. The viscosity of this liquid at 25 ° C is 33.0.
It was 00 cps. This liquid could not be used for molding because of its high viscosity.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

EFFECTS OF THE INVENTION Conventionally, when a low molecular weight polyhydric alcohol is used as a chain extender, a polymeric MDI which is not suitable for use as a polyisocyanate because of its excessively high rigidity dependence on temperature is replaced with an aromatic diamine. It has been found that when used as a chain extender, it exhibits few of its drawbacks. In addition, Polymeric MDI is
Due to its high functionality, it has the drawback of impeding the flowability of the reaction mixture and reducing the elongation at break of the molded product.
It has been found that by adjusting the average functionality by reacting a monofunctional active hydrogen compound, a polyisocyanate having a relatively low viscosity and giving a high elongation at break to a molded article can be obtained. Furthermore, not only does it have no adverse effect on the high temperature stability of the molded article that is predicted to be caused by the polynuclear compound containing three or more nuclei contained in the polyisocyanate, but it is also modified by modification with a monofunctional active hydrogen compound. It has been found to give the article higher rigidity. By using a reaction-injection molding method, a polymer MDI modified with such a monofunctional active hydrogen compound and an aromatic diamine chain extender are used.
A molded product having various characteristics comparable to a molded product using DI can be manufactured at a relatively low cost.

Claims (2)

[Claims] 1. A polyisocyanate, an active hydrogen compound,
In a method for producing a polyurethane and / or polyurea molded article by a reaction injection molding method using a chain extender and, if necessary, an additive, a) the polyisocyanate contains 15 to 60 polynuclear compounds having 3 or more nuclei. A polyisocyanate obtained by modifying a polymethylene polyphenyl polyisocyanate containing 1% by weight with a monofunctional active hydrogen compound, b)
A method for producing a polyurethane and / or polyurea molded article, wherein the chain extender is an aromatic diamine having a nucleus-substituted alkyl group. 2. The modified polyisocyanate is a monofunctional active hydrogen compound [polynuclear content of trinuclear or more (wt%) × 0.015 to 0.05] mol per 1000 g of polymethylene polyphenyl polyisocyanate. The method for producing a polyurethane and / or polyurea molded article according to claim 1, wherein the polyurethane and / or polyurea molded article is additionally modified by reaction.