JPS63132920A - Elastic elastomer molder article - Google Patents

Abstract

PURPOSE:To obtain the titled molded article having dense surface and excellent mold-releasability, heat-resistance, etc., and suitable as automobile bumper, etc., by subjecting a mixture of specific aromatic polyisocyanate, long-chain polyol, aromatic polyamine and catalyst to reaction injection molding in a closed mold. CONSTITUTION:The objective molded article can be produced by the reaction injection molding of a mixture of (A) an aromatic polyisocyanate which is liquid at room temperature (preferably 4,4'-diphenyl-methane diisocyanate derivative), (B) a long-chain polyol having a molecular weight of 1,000-12,000 and containing >=50% primary hydroxyl group (e.g. a compound produced by the addition polymerization of an alkylene oxide to a polyhydric alcohol), (C) an aromatic polyamine of formula [R1 is Cl; R2 is methyl, etc.; X is R1, etc.; n is 0-3; R1:OR2=5:95-60:40 (molar ratio)] (preferably a condensation product of o-chloroaniline and o-anisidine with formaldehyde) and (D) a catalyst (e.g. dibutyltin diacetate) in a closed mold.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a polyurethane elastic elastomer manufactured by reaction injection molding technology, and in particular to a highly reactive polyisocyanate, a high molecular weight polyether polyol, and an aromatic polyamine chain extender. This invention relates to an elastic molded article with a dense surface manufactured by reaction injection molding technology.

Polyurethane elastic molded products, which have a dense surface and excellent physical properties, moldability, and appearance, are widely used. Specific examples of reactions include a wide range of products such as automobile plate materials, sports and leisure goods, office equipment housings, furniture, and agricultural equipment. The most commonly used of these are automobile bumpers, fascias, fenders, doors, along side moldings, and the like.The present invention has such a very wide field of application. The aim is to provide materials with higher performance and economical value.

(Prior Art) It is known to mold non-foamed polyurethanes, their fiber-reinforced elastomers or microcellular polyurethane elastomers by reaction injection molding by polyaddition of isocyanates and isocyanate-reactive compounds. The raw materials for these polyurethanes are usually polyisocyanates, polyether polyols and polyester polyols with hydroxyl groups, chain extenders, catalysts and optionally blowing agents, auxiliaries, additives and fibrous inorganic compounds, reaction injection molding. Law is Reaction Injection
Molding (hereinafter referred to as RIM) is a method in which inocyanate and an isocyanate-reactive component mixture are impingement-mixed under pressure (often under high pressure) using a mixing injection machine, and this mixture is filled into a mold and cured, followed by a molded product. This is a method to extract the .

Among these raw materials used, chain extenders are particularly important because they have a great influence on moldability and physical properties. Conventionally, ethylene glycol or 1,4-butanediol has been generally used as a chain extender, but neither of them necessarily provides sufficient performance in terms of moldability and physical properties. Specifically, for example, curing properties, void generation rate, mold releasability, heat resistance, tensile properties, etc. were not sufficient.

(Problem that the invention attempts to solve) Various improvements have been attempted to address these problems.

For example, in JP-A-56-109216, a relatively large amount of an aliphatic amine chain extender is used in combination with ethylene glycol to improve mechanical strength and heat resistance. However, since this method uses ethylene glycol as the main chain extender, it cannot achieve a significant improvement in mechanical strength and heat resistance. The aliphatic amine itself, which has a relatively large value, does not significantly improve curing properties and heat resistance.

Another method is, for example, as disclosed in JP-A-52-77200, in which a small amount of a polynuclear mixed polyamine synthesized as an aromatic polyamine by condensation of aniline and formalin is used in combination with ethylene glycol to improve heat resistance.

Aromatic polyamines have a very large effect on improving heat resistance, but with this method, the high reactivity of the aromatic polyamines used reduces the ability to fill the mold during reaction injection molding, resulting in unsatisfactory molding. The amount of use is limited because it cannot be obtained. Furthermore, since alkanediol is used, no significant improvement in heat resistance can be expected.

Another method is to use halogen-containing diaminobenzene as a chain extender to improve heat resistance, as disclosed in JP-A-58-32626. In this method, the reactivity of halogen-containing diaminobenzene is moderately fast, but
On the other hand, curing is slow (problems remain in molding).

As we have seen above, chain extenders greatly affect the performance of polymers, but most of them are not satisfactory in terms of physical properties and moldability. Further, even if the aromatic diamine has satisfactory physical properties, the reaction is too fast, resulting in problems such as the need for a large injection molding machine.

(Means for Solving the Problems) In order to improve the curing properties, mold release properties, and heat resistance, which are the shortcomings of conventional glycol cured urethane RIM, the present inventors created a product obtained by condensing orthoanisidine and formalin. A patent application was filed for the use of aromatic polyamines as chain extenders (Japanese Patent Application No. 6O-248987).

Although this aromatic polyamine is extremely effective as a countermeasure for the above-mentioned problems, it is necessary to improve its excessive reactivity and its poor compatibility with long-chain molecular polyols due to its high melting point. As a result of further intensive studies to improve this point, it was discovered that it is effective to add orthochloroaniline when condensing orthoalkoxyaniline and formaldehyde, and the present invention was achieved.

That is, the present invention comprises (a) an aromatic polyisocyanate that is liquid at room temperature; (b)
The molecular weight is from 1000 to 12000, and at least 50
% or more of a primary hydroxyl group (c) General formula (where R1 is a chloro group, L is a methyl group, ethyl group, propyl group or isopropyl group, X is R1 or an OR group, and n is a 0 or an integer of 1 to 3, and the molar ratio of R3 and OR is 5:95 to 60:40.] (d) a catalyst, and optionally (e) foaming. This is an elastic elastomer molded product obtained by reaction injection molding a mixture containing a mold release agent, an internal mold release agent, a filler, and other auxiliaries in a closed mold.

In the present invention, e) by mixing orthochloroaniline with 1-soalkoxyaniline, the crystallinity and meltability of the aromatic polyamine obtained by condensation with formaldehyde are reduced. As a result, the compatibility with long-chain molecular polyols is improved. In addition, the presence of orthochloroaniline can reduce the reactivity. Therefore, by changing the mixing ratio of orthoalkoxyaniline and orthochloroaniline, the reaction rate can be adjusted freely, which is an unprecedented advantage.

The aromatic polyamine used as component (c) in the present invention is produced by condensing orthochloroaniline and orthoalkoxyaniline with formaldehyde.

Specific examples of orthoalkoxyaniline include orthoanisidine, orthophenetidine, orthopropoxyaniline, and orthoisopropoxyaniline, of which orthoanisidine is particularly preferred.

The molar ratio of orthochloroaniline to orthoalkoxyaniline is preferably from 5:95 to 60:40, and particularly preferably from 10:90 to 50:50.

The aromatic polyamine produced under these conditions contains 4,
4°-diamino-3-chloro-3°-flukoxydiphenylmethane is present in the largest amount, and 4.4'-
Contains diamino-3,3'-dialkoxydiphenylmethane and 4,4'-diamino-3,3'-dichlorodiphenylmethane. If the molar ratio of orthoalkoxyaniline exceeds this range, the reaction rate will be too fast, and if the molar ratio of orthochloroaniline exceeds this range, the reaction rate will become too slow.

Aromatic polyamine can be represented by the following general formula.

In this general formula, R is a chloro group, %R1 is a methyl group, ethyl group, propyl group, or isopropyl group, and X is R.

or an ORB group, and n represents O or an integer of 1 to 3.

The above-mentioned amine preferably has a ratio of dinuclear (n=o) to trinuclear (n=1 to 3) of 90:10 to 407. 60
(w tχ), because if there are many polynuclear bodies, the reactivity of some of the amino groups will decrease too much.

The aromatic polyamine of component (c) can be obtained, for example, by reacting orthoalkoxyaniline and orthochloroaniline in an aqueous formalin hydrochloric acid solution, followed by rearrangement at high temperature and neutralization with alkali.

The aromatic polyamine is used in an amount of 10 to 70 parts by weight per 100 parts by weight of the long-chain molecular polyol.

Aromatic polyisocyanates used as component (a) in the present invention include, for example, 4,4°-diphenylmethane diisocyanate, 2.4- and/or 2.6-
) lylene diisocyanate, polymethylene polyphenyl polyisocyanate, xylylene diisocyanate, dimers, trimers, carbodiimide modified products, 70-fanet modified products, beureft modified products, prepolymers, etc. of these isocyanates.

Among these aromatic polyisocyanates, preferred isocyanate compounds for the present invention are derivatives of 4,4'-diphenylmethane diisocyanate, which is liquid at room temperature. 4.4°-diphenylmethane diisocyanate and a low molecular weight diol or triol (preferably 70
Urethane group-containing polyisocyanate obtained by reacting polypropylene/glycol having a molecular weight of less than 0: 414゛-diphenylmethane diisocyanate-based diisocyanate containing a carbodiimide group and/or urethane imine group, and examples of preferred polyisocyanates include The following may be mentioned: A modified product made by modifying a mixture of 2.4°- and 4.4°-diphenylmethane diisocyanates as described above: 4,4°-diphenylmethane diisocyanate modified as described above. and a small amount of a polyisocyanate having a higher functionality than the difunctionality of the diphenylmethane type.

Examples of long chain molecular polyols used in the present invention include:
Ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane,
1.3. Hydroxyl value 20 to 800 mg obtained by addition polymerizing alkylene oxide to polyhydric alcohols such as 6-hexanetriol, pentaerythritol, and sorbitol, and/or these polyhydroxy compounds
K OH/g polyether polyol. Additionally, alkanolamines such as jetanolamine and triethanolamine, amines containing two or more active hydrogens such as ethylene diamine, diethylene glycol, ammonia, aniline, tolylene diamine, xylylene diamine, and di-1-minodiphenylmethane, and ethylene oxide. ,
Propylene oxide, butylene oxide, styrene oxide, etc.

Hydroxyl value obtained by addition polymerization of 20 to 800 mg
KOH/g polyether polyols and polytetramethylene ether glycols can also be used.

In addition to the above, higher fatty acid ester polyols, polyester polyols obtained by reacting polycarboxylic acids with low molecular weight polyols, polyester polyols obtained by polymerizing caprolactone, and 0H4i-containing higher fatty acid esters such as castor oil and dehydrated castor oil are also used. can.

Further, polymer polyols obtained by grafting ethylenically unsaturated compounds such as styrene, acrylonitrile, and methyl methacrylate onto the above-mentioned known polyether polyols or polyester polyols, 1.2- or 1.4-polybutadiene polyols, or these. Hydrogenates can also be used. These polyols are 1m
Or a mixture of two or more types is used.

When carrying out the present invention, the amount of each raw material used is such that the equivalent ratio of the NGO group contained in the aromatic polyisocyanate to the active hydrogen contained in the polyol and aromatic polyamine is 0.8 to 1.3. Adjust.

Catalysts used as component (d) in the present invention include organometallic catalysts such as dibutyltin diacetate, dibutyltin dilaurate, tin oleate, tin octoate, and triethylamine, N, N, N', N' tetramethyl -propanediamine, 1,4-diazabicyclo-(2,2,
2) There are amine catalysts such as -octane and pentamethyldiethylenetriamine.

As a blowing agent, trichlorofluoromethane, CC1,F
, CC1, F, methylene chloride, water, nitrogen gas, carbon dioxide gas, etc.

There are many types of internal mold release agents, including silicone-based ones, fatty acid metal salts, fatty acid amide derivatives, and fatty acid ester derivatives.

Fillers include glass fiber, flake glass, mica,
Other auxiliary agents include talc, inorganic compound whiskers, etc., pigments such as carbon, antioxidants, weathering stabilizers, etc.

(Function) In the present invention, the melting point of the aromatic polyamine decreases, the compatibility with the polyol increases, and the reaction rate decreases.

(Example) A mixed stock solution was prepared using the above raw materials, and R1M molding was performed in a mold using an injection molding machine for polyurethane.

Synthesis examples and examples of aromatic polyamines will be described below.

Synthesis Example 1 51.0 g of 0-chloroaniline (
0.4 mol), O-anisidine 197 g (1.6 mol)
, 197.8 g (1.3 mol) of 24% hydrochloric acid was added and mixed, and then 111 g (1.0 mol) of 37% formalin was added dropwise at 30°C or below over 1 hour. After continuing stirring at the same temperature for 1 hour, the temperature was raised to 100°C and maintained at 100°C for 1 hour.

After the reaction, 116 g (1.3 mol) of 45% aqueous sodium hydroxide solution was added and stirred at 80° C. for 30 minutes. The precipitated oil is separated and washed three times with warm water at 80°C. This is 80
Dehydration was performed at °C to obtain 262 g of methylene-crosslinked aromatic polyamine. The yield is 95%. The product is a brown solid with a melting point of 70
~90°C, dinuclear content 82.4%, polynuclear content 17
．． 6%, and the chlorine content was 5.2 wt%. This was designated as aromatic polyamine-1.

Synthesis Example 2 76.5 g of 0-chloroaniline (0,
6 mol), O-anisidine 172 g (1.4 mol)
, 197.8 g (1.3 mol) of 24% hydrochloric acid was added and mixed, and then 111 g (1.0 mol) of 37% formalin was added dropwise at 30°C or below over 1 hour. After continuing stirring at the same temperature for 1 hour, the temperature was raised to 100°C and maintained at 100°C for 1 hour.

After the reaction, 116 g (1.3 mol) of 45% aqueous sodium hydroxide solution was added and stirred at 80° C. for 30 minutes. The precipitated oil is separated and washed three times with warm water at 80°C. This is 80
Dehydration was performed at °C to obtain 263 g of methylene-crosslinked aromatic polyamine. The yield is 95%. The product is a brown solid with a melting point of 70
~90°C, dinuclear content 80.0%, polynuclear content 20
．． 0%, and the chlorine content was 7.8%. This was designated as aromatic polyamine-2.

Polyol A: Polyoxyalkylene diol having a hydroxyl value of 28 gKOH/g and a primary hydroxyl group content of 80%, obtained by addition polymerizing ethylene oxide and propylene oxide to propylene glycol.

Polyol B: A polyoxyalkylene triol with a hydroxyl value of 28 mgKOH/g and a primary hydroxyl group content of 75% obtained by addition polymerization of ethylene oxide and propylene oxide to glycerin.

Isocyanate A...N obtained by reacting diphenylmethane diisocyanate and tripropylene glycol
Prepolymer Isocyanate B with a CO group content of 22%: A repolymer with a NCO group content of 26% obtained by reacting a mixture of diphenylmethane diisocyanate and its carbodiimide modified product with tripropylene glycol.

Examples 1 to 3 Polyol A and polyol B in the amounts shown in Table 1, aromatic polyamine-1 or -2, and dibutyltin dilauret (DBTDL) as a catalyst were mixed to prepare a resin liquid. Isocyanate A or Isocyanate B
I reacted.

Is the reaction injection molding machine LI made by Cincinnati Milacron? ?
1-M15 type was used. The mold is 900X 600X
2. A sheet mold from Sen was heated to 75°C.

Adjust the temperature of the stock solution to 30℃, and make sure that the flow rate ratio of resin solution and isocyanate component is as shown in Table 1! l1
I did it. Dry nitrogen gas was mixed and dispersed in the resin liquid in an amount of 15% by volume. Injection speed 1000 g/s, injection time 2
．． After injecting into the mold for 0 seconds, the mold was demolded for 40 seconds, and the quality of the mold releasability and the elasticity immediately after demolding were compared.

The obtained sheet-like molded product was bent 180 degrees and the time taken until no cracking occurred was measured and the green strength was determined. We also checked the surface condition of the molded product, presence of voids and sound quality, and also cut test pieces from the molded product to determine its tensile strength and
Elongation, notched Izont impact value, bending modulus and heat resistance were measured. For the heat resistance test, a 2 x 15 cm strip-shaped test piece was fixed horizontally at a position 5c11 from one end and left in a constant temperature bath at 120°C for 1 hour. After leaving it
The distance that the other end drooped (thermal droop) was measured and the heat resistance was compared. The results were as shown in Table 2.

Comparative Example 1 A sample was treated in the same manner as in Example except that ethylene glycol was used instead of the aromatic polyamine of the present invention. The stock solutions were formulated as shown in Table 1, and the results obtained were as shown in Table 2.

Comparative Example 2 A sample was treated in the same manner as in Example except that diethyltoluenediamine (DI!TDA) was used instead of the aromatic polyamine of the present invention. The formulations were as shown in Table 1, and the results obtained were as shown in Table 2.

(Effects) As is clear from Tables 1 and 2, as a result of adjusting the reaction rate according to the present invention, the filling property into the mold is improved, the mold releasability, the elasticity immediately after demolding, the voids are improved, and the strength is improved. , Table 1 Table 2 Mitsui Toatsu Chemical Co., Ltd. Procedural Amendment (Voluntary) January 7, 1988

Claims (1)

[Claims] (a) an aromatic polyisocyanate that is liquid at room temperature; (b)
The molecular weight is from 1000 to 12000, and at least 50
% or more of primary hydroxyl groups (c) General formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (However, R_1 is a chloro group, R_2 is a methyl group, ethyl group, propyl group, or isopropyl group, X is R_1 or OR_2 group, n is 0 or an integer of 1 to 3, R_1
and OR_2 in a molar ratio of 5:95 to 60:40. ], (d) a catalyst, and optionally (e) a blowing agent, an internal mold release agent, a filler, and other auxiliaries. Elastomer molding.