JPS58162623A - Polyurethane moldings and their production - Google Patents

Abstract

PURPOSE:A composition consisting of a specific hexamethylene diisocyanate polymer, a polyol, a foaming agent and a catalyst is made to react in a mold to produce a polyurethane molded product with high-density surface layers. CONSTITUTION:A composition consisting of a hexamethylene diisocyanate polymer containing more than 10wt% of hexamethylene diisocyanate trimer that can form an isocyanurate ring, a polyol such as a polyetherpolyol, a foaming agent such as water and/or halogenated aliphatic hydrocarbon, a catalyst such as a tertiary amine, when needed, a surfactant, colorants, fillers, flame retarders is subjected to casting to produce the objective formed polyurethane within the range of 70 to 140 NCO index. EFFECT:The resultant products have high weathering resistance and heat resistance.

Description

[Detailed description of the invention] The present invention relates to a polyurethane molded article and a method for producing the same.

More specifically, a hexamethylene diisocyanate polymer having incyanurate 19, a polyol, a blowing agent,
A polyurethane molded article having a high-density skin layer, which is produced by reacting a composition consisting of a catalyst and, if necessary, a surfactant, a colorant, and other additives in a mold, to produce polyurethane, and its production. Regarding “waves”.

In recent years, polyurethane molded products with a high-density skin layer have become
For example, it is used in automobile parts such as steering wheels, instrument panels, armrests, headrests, bumpers, spoilers, etc., as well as shoe soles and housings for various devices. However, since aromatic polyisocyanate is usually used as the polyisocyanate, these molded products have the disadvantage of yellowing when exposed to sunlight. For this reason, when manufacturing colored products, the color change is limited to black or brown, where the discoloration is less noticeable.If a light color is required, the paint film protection method is either pre-painting (inmolt foot) or post-painting. Alternatively, a method of adding large amounts of antioxidants and ultraviolet absorbers has been adopted.

However, although the paint film protection method is effective in preventing discoloration, it has drawbacks in terms of process and work, and the additive method has limitations in preventing discoloration.

Therefore, the main object of the present invention is to provide a polyurethane molded article that has a high degree of stability against discoloration due to sunlight etc. even without a protective coating, and a method for producing the same.

Conventionally, polyurethane resins using hexamethylene diisocyanate (hereinafter abbreviated as HDI) are known to have excellent weather resistance, and are usually provided as polyol adducts or biuret modified products of HDI, and are mainly used in paints, Used in the adhesive field.

Methods of using aliphatic or alicyclic polyisocyanates in molded products are disclosed in Japanese Patent Publication No. 54-15599 and Japanese Patent Application Laid-Open No. 56-282.
12, etc., but the method described here uses the polyisocyanate monomer as it is, or uses a prepolymer containing a large amount of the monomer.

Polyurethane molded products are usually manufactured under conditions where the raw materials and molds are heated, so the use of monomers with high vapor pressure poses health and safety problems.

Additionally, when HDI is used in the manner described herein,
Due to its molecular structure, it has drawbacks such as low hardness and poor heat resistance.

The present inventors focused on the excellent color fastness of HDI, and
As a result of repeated research to improve the drawbacks of DI monomer, HD
The inventors have discovered that the incyanurate product I imparts appropriate hardness and excellent heat resistance to molded products, and at the same time further improves discoloration resistance, leading to the present invention.

That is, the present invention provides HDI that forms an incyanurate ring.
A polyurethane having a high-density skin layer characterized by reacting a composition consisting of an HD1 polymer containing 10% by weight or more of a trimer, a polyol, a blowing agent, and a catalyst in a mold to produce a raw polyurethane. This article relates to molded products and their manufacturing methods.

In the present invention, the HDI polymer is prepared by adding tertiary amines, alkyl-substituted ethyleneimines, 13-class alkyl phosphines, acetylacetone metal salts, metal salts of various monoacids, etc. as catalysts to HDI or HDI polyol adducts. It can be obtained by carrying out an incyanurate reaction at 100° C. or lower, using or in combination, and using a co-catalyst if necessary.

In this case, the HDI polyol adduct is obtained by urethanizing a part of MDI using a polyol by a known method.

Bo diol has a molecular weight of 2 to 50 to 3000.
Trifunctional polyols are suitable. For example, diols include ethylene glycol, diethyl ethylene glycol, and 1.3-butanediol (hereinafter referred to as 1°3B).
dihydric alcohols such as 1.4 butanediol, propylene glycol, dipropylene glycol, neopesityl glycol, 1.6 hexane glycol (hereinafter abbreviated as 1.68G), polyester polyols, polyether polyols, etc. can be mentioned.

Triols include trihydric alcohols such as glycerin, trimethylolethane, and trimethylolethane;
Examples include polyester polyols and polyether polyols.

As the polyol, these may be used alone or a mixture of two or more thereof in any proportion may be used.

The reaction can be carried out more easily by using as a cocatalyst a phenolic hydroxy compound, a phenolic hydroxy compound, a phenolic hydroxy compound, a tertiary amine, or the like, if necessary. The incyanurate reaction can be carried out in the presence or absence of a solvent.

The catalyst can be made inactive by using known strong acids such as phosphoric acid, sulfuric acid, etc. as terminators. HD
It was found that by reacting a part of I with a polyol and introducing a urethane bond, incyanurate formation was facilitated, and at the same time, the resulting polymer was found to have further improved compatibility with other resins. The incyanurate reaction solution from the HDI polyol adduct contains unreacted HDI, and by removing them by distillation or extraction, a highly purified incyanurate product can be obtained.

In the present invention, isosifof HDI by the method described above: i
A compound having an incyanate group at the end obtained by forming a l L/-to ring and then reacting it with the above-mentioned polyol or water can also be used as the HDI polymer.

Furthermore, it is also possible to form an incyanurate ring of HDl or an HDI polyol adduct by the method described above, and use a mixture of this and a modified HDI product as the HDI polymer.

Here, the HDI modified product is a urethane modified product or biuret modified product of HDI having an incyanate group at the terminal obtained by reacting HDI with unafoliol or water as described above.

HDI 3Jll forming the incyanurate ring was determined by liquid chromatography to have a trimer molecular weight of 50.
It clearly appears around 4 and can be quantified. In addition to the HDI trimer forming the isocyanurate ring, incyanurate bodies with a higher degree of polymerization exist.

Since the incyanurate reaction according to the method of the present application can be carried out at a low temperature and in a relatively short time, it is difficult to produce polymers with a high degree of polymerization, but trimers forming incyanurate rings are produced. It is possible to limit the amount of polymer incyanurate to several times the molecular weight.

Depending on the manufacturing method, a higher molecular weight isocyanurate may also be included. As a result, when the content of the trimer forming the incyanurate ring becomes less than 10% by weight, the compatibility with polyols etc. decreases, the viscosity increases and it becomes difficult to handle, and the resulting molded product becomes difficult to handle. Tensile properties deteriorate.

In addition, in the present invention, when an incyanurate ring of HDI or an HDI polyol adduct is formed and a mixture of this and the above-mentioned HDI modified product is used as an HDI polymer, the isocyanurate ring in the entire HDI polymer is formed. Even if the content of HDI Sankeitai is lower than 10% by weight,
The heat resistance and hardness of the resulting molded product decrease.

In the present invention, the polyols used together with the HD1 polymer to produce polyurethane molded articles include:
Any compound having two or more hydroxyl groups in one molecule and conventionally used for producing polyurethane molded articles can be used. Examples include polyether polyol, polyester polyol, and polybutadiene polyol.

Two or more of these polyols can also be used in combination.

Polyether polyols include, for example, ethylene glycol
diethylene glycol, triethylene glycol,
trimethylolpropane, glycerin, sorbitol,
Ethylene oxide, propylene oxide using one or more compounds having at least two active hydrogen atoms such as sucrose, bisphenol A1 water, ethylene diamine, tolylene diamine, diphenylmethane diamine, etc. as an initiator.

It is produced by addition-polymerizing one or more of hexamers such as epichlorohydrin, styrene, acrylonitrile, etc. by a known method.

Polyester polyols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1
, 2-propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, tetramethylene glycol, hexamethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, etc. one or more compounds having at least two carboxyl groups, such as mapric acid, maleic acid, succinic acid, divic acid, tartaric acid, cepacic acid, terephthalic acid, etc. It can be produced by a known method using one species or two or more species.

Also included are polyester polyols such as those obtained by ring-opening polymerization of caprolactone.

A chain extender and a crosslinking agent may be used in combination as necessary.

Chain extenders and crosslinking agents used in combination include, for example, engineered ethylene glycol, butylene glycol, diethylene glycol, dibu-pyrene glycol, tripropylene glycol, glycerin, trimethylolpropane, jetanolamine, triethanolamine, tolylene diamine,
It is a low-molecular compound having at least two active hydrogen groups, such as hexamethylene diamine, methylene bis-O-lyp-ruaniline, and the like.

The blowing agent used in the present invention has conventionally been used in the production of polyurethane foams.

You can use everything. For example, water and/or... rogane-substituted aliphatic hydrocarbon blowing agents.

The amount of the blowing agent to be used is determined as appropriate depending on the purpose of use.

The catalysts used in the present invention are all those used in the production of polyurethane.

For example, U.S. Patent No. 3; M, 4,898 and
-15599, tertiary amines, diazabicycloalkenes and their salts, and organometallic compounds.

In carrying out the present invention, various surfactants, coloring agents such as dyes and pigments, reinforcing materials and fillers such as mica and glass fibers, flame retardants, antioxidants, ultraviolet absorbers, and others may be used as necessary. Auxiliary agents and additives can be used.

The polyurethane molded product having a high-density skin layer of the present invention has an NCO index in the range of 70 to 140,
Preferably, it is produced in a range of 90 to 120. In this case, the reaction can be accelerated by heating the raw materials and mold as necessary.

The molded product obtained by the present invention has excellent weather resistance and discoloration resistance, so it can be colored in any desired color tone without any additional treatment such as protection with a coating film, and it also has an isocyanurate ring. Since HD! polymer is used, heat resistance is improved and it can be used in a wide range of applications such as steering wheels, instrument panels, and shoe soles.

The present invention will be further explained in detail with reference to Examples, but the present invention is not limited thereto.

In the examples, all parts and percentages are by weight unless otherwise indicated.

Preparation of HD1 polymer Preparation of incyanurate component Synthesis of incyanurate component Preparation of HD1 polymer A predetermined amount of HDI, polyol, catalyst, and cocatalyst was placed in a 500-capacity laminated glass four-loaf flask equipped with a thermometer, a stirrer, and a nitrogen-sealed tube. The flask was charged at a ratio of 10, the air in the flask was replaced with nitrogen, and the mixture was heated to the reaction temperature shown in Table 1 while stirring.

After reacting at the same temperature for a predetermined period of 10 hours, the NGO content was measured, and the values shown in Table 1 were obtained. The reaction solution was a pale yellow transparent liquid.

Phosphoric acid was added to this reaction solution as a terminating agent, and 1
After stirring for an hour, free HDI was removed by distillation. The obtained liquid is a pale yellow transparent liquid whose NCOCO2 content is HD
I, measurement table of trimer forming incyanurate ring,
Shown in 1.

Preparation 2. Synthesis of modified HDI A predetermined amount of HDI was placed in a 500-d, laminated glass four-loaf flask equipped with a thermometer, a stirrer, and a nitrogen-sealed tube.

Polyols were charged in the proportions shown in Table 1, the air in the flask was replaced with nitrogen, and the mixture was stirred and heated to the reaction temperature shown in Table 1 from r.

The reaction was carried out at the same temperature for the predetermined time shown in Table 1, and the NGO content was measured, and the values shown in Table 1 were obtained. The reaction solution was a pale yellow transparent liquid.

Free HDI was removed from this reaction solution by distillation. The resulting liquid is a pale yellow transparent liquid whose NCO content is free HD.
I, the trimer forming the incyanurate ring was measured and Table 1
It was shown to.

Preparation 3, Adjustment of HDI polymer, etc. The incyanates obtained in Preparation 1 and 2 were used alone or in combination as incyanates for Examples and Comparative Examples. Its NGO content, free MDI.

Table 2 shows the trimers forming the incyanurate ring.

Table 1゜Table 2゜Note I A and G 7 = 3 Blend quality 2. A and G 3 near blend quality 3A and G#)
1:9 Plastic vvv products Examples 1 to 5, Comparative Examples 1 to 4 100 parts of polyether polyol (poly G 845 manufactured by Asahi Glass), 10 parts of ethylene glycol, Freon-1
15 parts, 1 part of TEDA L-33 (manufactured by Toyo Soda), 1 part of dibutyltin dilaurate, Irganox 1010 (
Premix consisting of 0.8 parts (manufactured by Ciba Geigy) and Table 2
The incyanates shown in were heated to 30°C, and each NGO
A mixture having an index of 105 was poured into an open mold to allow free foaming, and then poured into a 5x120x420 snow mold heated to 55°C to obtain a molded product. Table 3 shows the foaming speed during free foaming and the physical properties of the molded product. It was shown to.

The following margin Example 6 100 parts of polyester polyol (N-155 manufactured by Nippon Polyurethane Industries), 10 parts of 1.4-butanediol, 0 parts of water
8 parts, TEDA L-330, 5 parts, dibutyltin dilaurate 0.5 parts, Sanol 144 (manufactured by Ciba Geigy)
A premix consisting of 0.4 parts and HD1 polymer symbol E shown in Table 2 were respectively heated to 50°C and mixed in a ratio of NGO index 98, and the foaming rate and 5X120X
The physical properties of the molded product of No. 420 were as follows.

Cream Time (see), 25 Rise Time (see) 150 Density (Na-) 0.75 Hardness
Degree (C) 70 elongation
(%) 80 Tensile strength (IAI) 13 Weather resistance Note 1) Appearance No abnormality Δ E2.5 Note 1. Sunshine type weatherometer 400 hours H
When the DI modified product (symbol G in Table 2) was used and the other conditions were the same as in Example 6, the foaming rate and physical properties of the molded product were as follows.

Cream Time (see) 28 Quiz Time
(Sec) 165 Density (fAd) 0.75 Hardness
Degree (C) 65 elongation
(%) 90 Tensile strength (IQim) 10.5 Weather resistance Note 1) Appearance Cracking Δ E3,5

Claims (1)

[Claims] Polyurethane is produced by reacting a composition consisting of a hexamethylene diisocyanate polymer containing 10% by weight or more of hexamethylene diisocyanate trimer forming an i11 isone annulate ring, a polyol, a blowing agent, and a catalyst in a mold. A polyurethane molded product having a high-density skin layer, which is characterized by producing. (2) A composition consisting of a hexamethylene diisocyanate polymer containing 10% by weight or more of hexamethylene diisocyanate trimer forming an incyanurate ring, a polyol, a blowing agent, and a catalyst is reacted in a mold to produce polyurethane. A method for producing a polyurethane molded article having a high-density skin layer.