JPS604519A - Reactive injection molding - Google Patents

Abstract

PURPOSE:To carry out reactive injection molding at high reaction rate without using a catalyst, by using an active hydrogen compound-containing component consisting of a specific aminated polyether and a reactive inner releasing agent and a polyisocyanate compound-containing component. CONSTITUTION:Two components of (A) an active hydrogen compound-containing component consisting of (a) a high-molecular-weight active hydrogen compound comprising an aminated polyether having about 500-4,000 average molecular weight per functional group obtained by aminating partially or completely hydroxyl group of a high-molecular-weight polyether polyol or a mixture of the aminated polyether and at least one of other high-molecular-weight active hydrogen compounds, having about >=25% average amination ratio, >=about 2.0 average number of functional groups, and about 500-4,000 average molecular weight per functional group, (b) a chain extender, and (c) a reactive inner releasing agent (catalyst) consisting of a carboxyl group-containing organosilicone compound, etc. and (B) a polyisocyanate compound-containing component are blended rapidly, injected immediately to a mold, reacted and cured in the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding polyurethaneurea-based or polyurea-based nidistomer molded articles by reaction injection molding, and in particular, the present invention relates to a method for molding a polyurethaneurea-based or polyurea-based nidistomer molded article by a reaction injection molding method. It relates to the reaction injection molding method used.

Methods for producing molded articles of polyurethanes, polyurethane ureas, and other synthetic resins by reaction injection molding are known. Reaction injection molding is a method in which at least two components that react quickly when mixed with each other are rapidly mixed by impingement mixing, the mixture is filled into a mold, and the mixture is reacted and hardened. The two mutually reactive components are usually liquids, but in some cases they may be slurry-like liquids containing insoluble components such as the filler.

Polyurethane, polyurethane urea, etc. have one component mainly composed of a polyisocyanate compound and the other component mainly composed of an active hydrogen compound having at least two active hydrogen-containing groups. Both are obtained using two components. Hereinafter, in the present invention, an active hydrogen-containing group refers to a functional group containing an active frozen confection that reacts with an incyanate group, and representative examples thereof are a hydroxyl group and an amine group.

In reaction injection molding, non-foamed elastomers and microcellular elastomers such as polyurethane and polyurethaneurea are usually obtained by reacting an active hydrogen compound, which is a combination of a high molecular weight polyol and a low molecular weight polyol or polyamine, with a polyisocyanate compound. Low molecular weight polyols and polyamines are sometimes called crosslinking agents (especially in the case of trifunctional or higher functional compounds), but in the present invention, bifunctional and trifunctional or higher functional compounds are also referred to as chain extenders. In addition, the polyurethaneurea-based or polyurea-based nidistomers in the present invention, including microcellular nidistomers, have a density of about 0.85'/m or more, particularly 0.95'/m or more, and do not contain fillers. In this case, the upper limit is about 1.2 f/cr/l.

In particular, it is about 1.15 t/c4. This microcellular nydistomer is usually obtained using small amounts of blowing agents. The amount of blowing agent used is usually 1 part of a high molecular weight active hydrogen compound.
00 parts by weight, about 15 parts by weight or less, especially 10 parts by weight or less. Furthermore, the difference between microcellular elastomers and ordinary flexible polyurethane foams lies in the difference in their foaming double curtains, and the expansion ratio of microcellular elastomers is usually 2 or less.

The characteristic of reaction injection molding is that the molding time from the injection of raw materials to the removal of the molded product is short. Shortening the time from taking out one molded product to taking out the next molded product, in other words, the molding cycle time -C Currently, the most problematic point is the adjustment of the mold cavity, that is, the cleaning of the mold. The problem is that it takes a long time to apply the coating agent.As a method to shorten the polishing time of the mold, a method using an internal mold release agent has been proposed. By using Jv1, it is possible to simplify the stitching of the Le/1 type and to significantly shorten the molding cycle time.
Waiting. However, it is not effective to repurpose the internal mold release agent conventionally used in injection molding as an internal mold release agent that can be used in reaction injection molding (a unique internal mold release agent is required. Effective internal mold release agents for reaction injection molding that are commercially available are internal mold release agents having functional groups reactive with incyanate groups (hereinafter referred to as reactive internal mold release agents). A silicon compound containing a carboxyl group, such as polysiloxane, is known as a reactive internal mold release agent (for example, Japanese Patent Publication No. 1176/1982 and Japanese Patent Publication No. 58/897).
4) and commercially available reactive internal mold release agents for reaction injection molding are also compounds of this type.

When using an internal heating agent containing a carboxyl group as described in the above-mentioned Japanese Patent Publication No. 55-1176, 1 g
What is important is that interaction between this reactive internal mold release agent and the organometallic compound-based or tertiary amine-based catalyst must be avoided. The carboxy group of the reactive internal mold release agent tends to react with the organometallic compound catalyst to deactivate the catalyst or to react with the tertiary amine threadworm medium to reduce its activity. To avoid this problem, the reactive internal mold release agent must be used separately from the catalyst until the components are mixed during reaction injection molding (or, although this is not the preferred method, It is also possible to use a large amount of catalyst to compensate for the decrease in activity caused by the reactive internal mold release agent.These two solutions are described, for example, in the aforementioned Japanese Patent Publication No. 5B-8974.Commonly used methods is the former method, in which reaction injection molding is carried out using three components: a polyol component containing a catalyst, a polyol component containing a reactive internal mold release agent, and an incyanate component. Most reaction injection molding equipment is of the type that mixes and injects two components, so in order to adopt this method, it is essential to use a new reaction injection molding equipment, and it is not possible to use conventional reaction injection molding equipment. The drawback is that it cannot be done.

The present inventor investigated a reaction injection molding method that uses a reactive internal mold release agent and can be applied to a conventional reaction injection molding apparatus of the type that mixes and injects two components. As mentioned above, it is possible to adopt a method that uses a large amount of catalyst, but since the interaction between the reactive internal mold release agent and the catalyst tends to change over time, it is necessary to keep the activity of the catalyst constant. be in trouble,
This method was inappropriate because it was difficult to vary the reactive internal mold release agent and the catalyst depending on the purpose of use, and there was an economic problem due to the use of a large amount of catalyst. Therefore, in the name of the present invention, we investigated a method using raw materials that can maintain good reactivity even if the catalytic activity is low. A method of increasing the proportion of primary hydroxyl groups in polyols to increase their activity is known.

However, since increasing the proportion of primary hydroxyl groups is a condition normally required for polyols used in reaction injection molding, it is difficult to further increase the proportion of primary hydroxyl groups, and it is also difficult to increase the proportion of primary hydroxyl groups further. Even if almost all of the hydroxyl groups were primary hydroxyl groups, good reactivity could not be maintained without a catalyst. The present inventor investigated aminated polyethers as active hydrogen compounds with higher activity. Aminated polyethers, in which some or all of the hydroxyl groups in polyether polyols are replaced with amino groups, can react at a high rate with incyanate groups without using a catalyst because the amino groups have higher activity than the hydroxyl groups. can react with In addition, it is thought that the amino group reacts with the carboxyl group of the reactive internal mold release agent, but since there are a very large number of bare amino groups compared to the carboxyl group in Z4, the effect on the aminated polyether can be ignored, and the opposite is true. It was confirmed that the effect of the reactive internal 411-type agent was hardly influenced by 41p.

The present invention consists of an active hydrogen compound-containing component containing an aminated polyether, a reactive internal mold release agent, and an incyanate component.
The present invention relates to a method of performing reaction injection molding using the components. This is the gist of the present invention, namely, the production of a molded article of polyurecunurea-based or polyurea-based elastomer by reaction injection molding using two components: an active hydrogen compound-containing component and a polyisocyanate compound-containing component. In the reaction injection molding method, the active hydrogen compound-containing components include a 7R molecular weight active hydrogen compound, a chain extender, and a reactive internal g1 [forming agent as an essential component, and may or may not contain a catalyst, and the high molecular weight active An aminated polyether with an average molecular weight of about 500 to 4,000 per functional group obtained by a hydrogen compound aminating some or all of the hydroxyl groups of a high molecular weight polyether polyol, or the aminated polyether and other high molecular weight activities. It is a mixture with a small amount of hydrogen compounds,
A reaction injection molding method, characterized in that the high molecular weight active hydrogen compound has an average amination rate of about 25 or more, an average number of functional groups of about 2.0 or more, and an average molecular weight per functional group of about 500 to 4,000. It is.

As mentioned above, the reactive internal mold release agent is a compound containing a carboxyl group, preferably an organosilicon compound containing a carboxyl group, in particular a carboxyl group-containing polysiloxane as described in the above-mentioned publication. Of course, two or more of these reactive internal mold release agents may be used in combination, and a reactive internal mold release agent that reacts with a molding agent or an incyanate group that has a functional group reactive with an incyanate group other than a carboxyl group It may be used in combination with internal recess X+lI which does not have a functional group.

Amount of reactive internal ratio type I agent used (other internal klt type %il
(if 1 is used in combination, the total amount) is M molecular weight active limescale compound 1', class ii, other raw material tlj class,
Although it may vary depending on the reaction conditions, h to O type conditions, etc., it is usually 0 parts by weight per 100 parts by weight of the high molecular weight active hydrogen compound.
．． 0.01 to 10 parts by weight, particularly 0.03 to 5 parts by weight, is suitable.

A catalyst may be present in the active hydrogen compound-containing component. That is, it is possible to use a catalyst that does not deactivate the reactive internal catalyst by interaction with the molding agent. In addition, even if there is a catalyst that is deactivated by interaction with the reactive internal mold release agent, unless the deactivated catalyst has a large effect on the reaction, the catalyst (deactivated) will be treated as an impurity. A catalyst (not a catalyst) may also be present. However, in contrast to II, catalysts such as F's compound catalysts, especially organotin compound catalysts, which are easily deactivated by R-type agents during reaction, must be substantially not present in the active hydrogen compound-containing component. is preferred.

Examples of organometallic compound catalysts that are easily deactivated by reactive internal mold release agents include dibutyl smedimalate, dibutyltin dilaurate, stannanooctoate, lead octoate, and other organometallic compound carboxylates and carboxylic acids. There are metal salts. On the other hand, tertiary amine catalysts do not react with the reactive internal mold release agent as easily as the organotin compound catalysts mentioned above, and even if they react, the activity decreases less. Therefore,
The method of the present invention can be carried out using only a tertiary amine catalyst without substantially using an organometallic compound catalyst. In particular, it is possible to use a larger amount of tertiary amine catalyst than is commonly used.

Examples of tertiary amine catalysts include triethylenediamine, triethylamine, N-alkylmorpholine,
Examples include N, N, N', N'-tetraalkylethylenediamine. The amount of catalyst added to the active hydrogen compound component is not particularly limited as explained above, and varies depending on the use of the reactive internal mold release agent (Ei), but the amount of catalyst added to 100 parts by weight of the high molecular weight active hydrogen compound is not limited. Therefore, the amount of the organometallic compound catalyst that does not substantially exhibit catalytic activity after being deactivated after addition, that is, usually 0.3 parts by weight or less, preferably less than 0.03 parts by weight, is suitable, and especially if the amount of the organometallic compound catalyst is (i.e., 0.0% if present).
Xi-kan Gunbu and below are preferred. Suitably, the amount of tertiary amine catalyst added is less than about 5 parts by weight.

As mentioned above, when using a tertiary amine-based catalyst, the interaction between the tertiary amine-based catalyst and the reactive internal pjO type agent may not be negligible, and therefore a larger amount than usual is used. Although it may be appropriate to use a tertiary amine catalyst, the aminated polyneedle described later in the present invention itself has a reaction promoting effect similar to that of a tertiary amine catalyst due to the nitrogen atom of the amino group. are doing.

Therefore, in Kito BIj, there is little point in using a large amount of tertiary amine catalyst. On the other hand, according to studies conducted by the present inventors, the water absorption dimensional stability of polyurethaneurea-based or polyurea-based elastomers obtained using aminated polyethers described below decreases as the amount of tertiary amine catalyst used increases. It has been found that the decrease in
65214). Therefore, in the present invention, it is not preferable to use a tertiary amine-based catalyst in molded products that are subject to water resistance, such as automotive exterior members such as bumper shells.

Therefore, in the present invention, it is more preferable not to add a practically effective amount of a tertiary amine catalyst to the active hydrogen compound component. Therefore, in the present invention, it is most preferable that not only organometallic compounds that are easily deactivated by reactive internal mold release agents but also tertiary amine catalysts are not collectively added to the active hydrogen compound-containing component. In the above method, an organometallic compound catalyst that is easily deactivated by a reactive internal mold release agent, such as an organotin compound catalyst, can be used by adding it to the polyisocyanate compound-containing component. On the other hand, since a tertiary amine catalyst has the effect of promoting the reaction between isocyanate groups, it is usually difficult to use it by adding it to a component containing a polyincyanate compound. The amount of the organic gold-containing compound, which is easily deactivated by reactive internal mold release agents, added to the polyisocyanate compound-containing component is not particularly limited. 1 at 1.0 for 100 parts by weight of tfJ
A distance of 0.3 mm or less is suitable, especially a distance of 0.3 mm or less. Furthermore, when the organic metal compound-based medium in the polyisocyanate compound-containing component is mixed with the active hydrogen compound-containing component, the catalyst is not deactivated due to interaction with the reactive internal ttyt agent. In some cases, the activity may change and there is a risk that the reactivity may become insufficient.
'JZ, 9 (
It is preferable not to include a metal compound type f+s'y #V' which is easily deactivated by a reactive internal mold release agent. In the present invention, the active hydrogen compound-containing component and the polyisoane-1 compound-containing component are used to melt a catalyst other than the catalyst that tends to lose its active ratio due to a reactive internal mold release agent. Needless to say.

The high molecular weight active hydrogen compound is essentially an aminated polyether described below, but may also be a combination of an aminated polyether and another high molecular weight IT active hydration compound.

As other high molecular weight active hydrogen compounds, polyether polyols are most preferred (aminated polyethers with a low amination rate are considered to be essentially a mixture of aminated polyethers and polyether polyols).

In addition, relatively small amounts (usually less than about 30 weight grams) of other high molecular weight polyols may be added to the aminated polyether or mixture thereof and polyether polyol. Typical examples of other high molecular weight polyols are hydrocarbon polymers having two or more hydroxyl groups, such as polybutadiene glycols. In addition, other high molecular weight polyols such as polyester polyols may also be used in combination.

These high molecular weight active hydrogen compounds will be explained below.

First, aminated polyether will be explained. The production method of aminated polyether and its use to produce foam-like synthetic resins such as polyurethane urea foam are known, for example, as described in Japanese Patent Publication No. 4B-11685, Japanese Patent Publication No. 49-28914, Japanese Patent Publication No. 49-28914, Kosho 51-4
It is described in Japanese Patent Application Laid-open No. 8799, Japanese Patent Application Laid-open No. 50-29699, etc. Aminated polyethers can be represented by the general formula (I) as reported.

A: (m+n) valent inishekou residue R: alkylene group m: an integer neo of 1 or more or an integer of 1 or more, where m+n is 2 or more p, q: molecule 1170 months/(m+n) is about 500 to 40
41 by 00 and 1 The number A is an inishekhu residue, water, polyhydric alcohol,
It is a residue obtained by removing a hydrogen atom that can react with ethers from a polyhydric phenol, alkanolamine, mono- or polyamine, or other initiator (details will be described later).

-(-Ro+ and +RO+ are different oxiap
q It may be a random or block polymer of alkylene groups, and when m or n is 2 or more, p or q in each may be different. This aminated polyol is usually A+ (RO←ROH) [x is p
, and q, by aminating a polyether polyol with ammonia, but the method is not limited to this method. Regarding the amination of polyether polyols, in addition to the above-mentioned Japanese Patent Publication No. 48-11685 and Japanese Patent Publication No. 51-48799, for example,
Publication No. 7553, Special Publication No. 16443/1983, scratches,
Publication No. 49-14158, Special Publication No. 49-14159
It is also stated in the publication. In the present invention, the aminated polyether may necessarily be a compound not represented by the above general formula (1). For example, a cyclic ether in which part or all of the cyclic ether is other than alkylene oxide, This includes, for example, halogenated alkylene oxide, styrene oxide, or glycidyl ether.In short, the aminated polyether in the present invention is a polyether polyol in which some or all of the terminal OH groups are replaced with NI (z groups). However, the compound represented by the above general formula <1) is a typical example of aminated polyether, and in the present invention, it is a compound represented by the above general formula (+). Needless to say, it is the most suitable compound.

In the present invention, the average molecular weight of the aminated polyether is from 500 to 4,000 per active hydrogen-containing group. The active hydrogen-containing groups in the aminated polyether are amino groups or amine groups and hydroxyl groups. That is, the above general formula (1)
In the aminated polyether represented by , the molecular weight divided by (m+n) is approximately 500 to 4,000. A more preferred average molecular weight per active hydrogen-containing group is about 1,000 to 3,000. In the aminated polyether of general formula (1), the amination rate is +, X 100
It can be expressed as Amination rate refers to the ratio of terminal amine groups to the total number of terminal amino groups and terminal water groups, and the amination rate of the entire aminated polyether is the average of the amination rate of one molecule of aminated polyether. . Therefore, the entire aminated polyether may contain non-aminated polyether polyol molecules.

Therefore, as described below, aminated polyethers and polyether polyols may be used in combination in the present invention. The amination rate of the aminated polyether itself is required to be about 25-100%, more preferably about 45-95%, still more preferably about 60-90%. Further, when only aminated polyether is used as the active hydrogen compound of the polymer, it is necessary that the average amination rate is as described below.

It is well known to mold polyurecumurea elastomer or microcellular elastomer by reaction injection molding using a low molecular weight aminated polyether as a chain extender, and it is described in JP-A-56-109216. There is.

There, it is described that a synthetic resin is molded by reaction injection molding by reacting a high molecular weight polyether polyol, an aminated polyether with a molecular weight of about 500 or less, and a polyisocyanate compound as an active hydrogen compound component of a low molecular weight polyol. has been done. This low molecular weight aminated polyether is used as a chain extender and has a molecular weight of at least 10,000 (at least 50
00 molecular weight and at least two active hydrogen-containing groups), it has a much lower molecular weight. The use of low molecular weight aminated polyethers does not provide a solution to the problem of the present invention since it requires the use of high molecular weight polyols such as polyether polyols, which in turn necessitates the use of the catalysts mentioned above.

Polyether polyols, which are the raw materials for aminated polyethers, and polyether polyols such as polyethers, which can be used in combination with aminated polyethers, are polyether polyols that are produced by adding plate-like ethers to the initial shake. preferable. As described above, examples of the iniconic acid include water, polyhydric alcohols, polyhydric phenols, alkanolamines, mono- or polyamines, and other compounds. Since water reacts with cyclic ethers to form diols, these diols can be considered as initiators. The number of functional valves of the initiator is preferably 2 or more, particularly 2 to 8, and more preferably 2 to 4. Initial shakes can be used in combination of two or more. Examples of initialization f and V are shown below, but they are not limited to straw.

Polyhydric alcohols: ethylene glycol, glopylene glycol, diethylene glycol.

Chrycerin, trimethylolpropane.

Hexanetriol, diglycerin, bentaerythritol, methyl glycosides.

Dextrose, sorbitol, sucrose.

Polyhydric phenol: phenol-aldehyde initial condensate,
Bisphenol A, Bisphenol F0 Alkanolamine: Monoethanolamine.

Jetanolamine, triethanolamine, diisopropanolamine.

Mono- or polyamines: aniline, diaminodiphenylmethane, tolylene diamine.

Ethylenediamine.

The current ethers added to the above initiator are preferably compounds containing a 3- to 6-membered oxygen-containing ring, such as epoxides containing an epoxy group. Alkylene oxides include, in particular, epoxides having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, butylene oxide, etc. Particularly preferred are propylene oxide and/or butylene oxide, or a combination thereof with ethylene oxide. As other epoxides, compounds having epoxy groups such as halogenated alkylene oxides such as epichlorohydrin, styrene oxides, various glycidyl ethers and glycidyl esters can be used. When two or more types of epoxides are used in combination, they can be mixed and reacted, or they can be reacted sequentially. For example, propylene oxide and ethylene oxide can be used in combination to produce a polyoxyalkylene chain in which oxypropylene groups and oxyethylene groups are randomly and/or block-polymerized.

In particular, the oxyethylene group is preferably present at the terminal portion of the oxyalkylene region. Preferred current ethers other than epoxides are tetrahydrofuran, and its polymer poly(oxytetramethylene) glycol is a preferred polyether polyol in the present invention.

The polyether polyol may be a mixture of two or more polyether polyols. The average molecular weight is preferably about 500 to 4,000, particularly preferably about 1,000 to 3,000 per hydroxyl group. Even if the hydroxyl group of the polyether polyol is changed to an amine group, theoretically, the change in molecular weight can be seen as almost negligible. Therefore, a polyether polyol having almost the same molecular weight range as the aminated polyether is used as a raw material for the aminated polyether. Alternatively, it can be used as a polyether polyol in combination with aminated polyethers. By aminating this polyether polyol with ammonia 60 as in the above-mentioned known example, the aminated polyether of relatively high molecular weight in the present invention can be produced. On the other hand, the polyether polyol that can be used in combination with this aminated polyether may be the same or different species i (1, or the same or different molecular weight polyether polyol as the raw material for the aminated polyether). Polyether polyols can be used. Combining aminated polyethers and polyether polyols is advantageous for several reasons. For example, for aminated polyethers, different molecular weights or...
The physical properties of the synthetic resin obtained by combining the functional groups v and polyether polyol can be easily changed depending on the purpose. Moreover, this combination is advantageous from the viewpoint of adjusting reactivity and economy.

The aminated polyethers and polyether polyols may also contain up to 40 M (J+%) of one polymeric component, such as acrylonitrile, styrene, methacrylate trile.

Methyl methacrylate, butyl acrylate.

Isoprene and other vinyl monomers alone or copolymers are suitable. This polyether polyol containing one integrated component is usually called a polymer polyol,
It is usually obtained by combining vinyl monomers in polyether polyol, and is a composition in which fine polymer particles are stably dispersed in polyether bodiol.

A typical example of another high molecular weight active hydrogen compound that can be used in combination with the amino-containing polyether is a carbonized ice candy yarn polymer having two or more hydroxyl groups. In particular, a combination of an aminated polyether and a hydrocarbon polymer containing a water group, or a combination of an aminated polyether, a polyether polyol, and a hydrocarbon thread polymer containing a hydroxyl group is preferred.

The amount of the hydroxyl group-containing hydrocarbon polymer to be used is about 30 weight-Hs or less, especially about 20 weight-Hs or less, based on the total high molecular weight active hydrogen compound.
It is appropriate to have a diameter of φ or less. Examples of hydroxyl group-containing hydrocarbon polymers include hydroxyl group-containing polybutadiene, polybutadiene copolymers (for example, copolymers of butadiene with acrylonitrile, styrene, and other monomers, and small amounts of these hydroxyl group-containing hydrocarbon polymers), ethylene oxide, propylene, etc. Preferred are metal compounds obtained by adding oxide and other alkylene oxides. The molecular weight is suitably about 500 to 400°0 per hydroxyl group, but is not limited thereto. These hydroxyl group-containing hydrocarbon polymers have high hydrophobicity and are effective in reducing the water absorption of elastomers such as polyurekuneurea, and their use makes it possible to obtain elastomers with a low rate of dimensional change upon water absorption. Further, other high molecular weight active hydrogen compounds that can be used in combination include polyether polyols and polyether ester polyols. Of course, two or more of these high molecular weight active hydrogen compounds can be used in combination, as in the case of aminated polyethers and polyether polyols. ' In the present invention, the high molecular weight active hydrogen compound that essentially includes aminated polyether may be aminated polyether alone or a mixture of it and other high molecular weight active hydrogen compounds, especially polyether polyols. , the average amine specific gravity per molecule should be about 25% or more, the number of functional groups (i.e., both amine groups and hydroxyl groups) should be 2.0 or more, and the molecular weight per functional group should be about 500 to 4000. It is. Therefore, each component does not need to be within this numerical range; for example, an aminated polyether with an amination rate of over 70% and a polyether polymer can be mixed to obtain an aminated polyester with an amination rate of 25 to 70%. . More preferably, the average amount of amination is about 45 to 95, especially about 60
~90%, and the average number of monofunctional groups is 2.0~4. o.

The average molecule per functional group, h (approximately 1000 to 3000), is the average oxyethylene group content in the high molecular weight active hydrogen compound.
There are many cases where this is the case, and the more oxyethylene groups there are in the chain, the greater the rate of dimensional change upon water absorption. Furthermore, when polybutadiene yarn glycol or fillers described below are used, the water absorption dimensional change rate is low even if the oxyethylene group content is relatively high. In general, it is appropriate that the oxyethylene group content be on average 35:IFI or less, particularly 20:IFI or less. In particular, in order to reduce the water absorption dimensional change rate,
You can also do the following:

The chain extender consists of a low molecular weight compound having a molecular weight of 400 or less and a polyamide and/or polyamine compound. Especially molecular weight 20
Low molecular weight polyols of 0 or less are preferred. Suitable low molecular weight polyols include polyhydric alcohols and alkanolamines having 2 or more, especially 2 to 4, hydroxyl groups, and polyols obtained by adding a small amount of alkylene oxide to the above-mentioned polyvalent initiators.

Particularly preferred low molecular weight polyols are dihydric alcohols having 2 to 4 carbon atoms. Suitable polyamines include aromatic diamines having an alkyl substituent and/or a halogen. Preferred specific chain extenders are ethylene glycol, 1°4-7" tanediol, and propylene glycol.

These include diethylene glycol, dipropylene f IJ col, glycerin, trimethylolpropane, jetanolamine, triethanolamine, etc. Ethylene glycol and 1,4-butanediol are particularly preferred. The amount used is 5% based on the total amount with the high molecular weight active hydrogen compound.
~40% by weight, especially 10-30% by weight, is suitable.

The polyisocyanate compound includes aromatic, alicyclic, aliphatic, and other polyisocyanate compounds having at least two isocyanate groups, and modified products thereof. For example, 2.4-) IJ diisocyanate, 2.6-
) lylene diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene polyphenylisocyanate, xylylene diisocyanate, inphorone diisocyanate, methylene-bis(cyclohexyl isocyanate), hexamethylene diisocyanate, and the like. Examples of modified forms include 2μ' form, 3' form, prepolymer type modified form, carbodiimide modified form, primitive modified form, and others. Two or more of these polyincyanate compounds may be used in combination. Particularly preferred polyisocyanate compounds are 4,4'-diphenylmethane diisocyanate and its carbodiimide-modified and prepolymer-type modified products. The usage conditions of polyisocyanate compounds are expressed as isocyanate index of 90~
120, especially 95-110 is suitable.

In the production of elastomers such as polyurethane urea in the reaction injection molding method, it is preferable to use a blowing agent in addition to the reactive internal mold release agent. In the present invention, the use of a blowing agent is not indispensable; even without the use of a blowing agent, a slightly foamed elastomer can be obtained due to the presence of air and water dissolved in the raw materials, and these can be sufficiently removed. This results in a non-foamed elastomer. However, use of a small amount of blowing agent is preferred for reasons such as improving moldability. Although air, water, etc. can be used as the blowing agent, halogenated hydrocarbons with a low boiling point are preferably used.

Specifically, trichlorofluoromethane, dichlorodifluoromethane, methylene chloride, etc. are suitable. The amount of the bone is preferably 15 parts by weight or less, particularly 2 to 10 parts by weight, based on 100 parts by weight of the high molecular weight active hydrogen compound and chain extender.

Furthermore, various additives may be added as optional additive components. Examples include fibrous, plate-like, and powdery fillers, colorants, ultraviolet absorbers, antioxidants, and combustible substances.

Adding a porcelain-like filler to the cavity improves physical properties,
In particular, it has the effect of reducing the water absorption dimensional change rate. this is,
This seems to be to improve the rigidity and strength of the nidistomer. Suitable examples of the filler include glass-grade milled fibers, cut fibers, and wollastonite. It is sufficiently effective when the amount of oil is less than about 3 oi%, especially less than 20 tfit%, based on the entire elastomer. These additives, including the catalysts and blowing agents mentioned above, are usually added to the polymer (51) polyol component, which includes active hydrogen compounds and chain extenders. It can also be added to the cyanate component.

In the reaction injection molding method, the active hydrogen compound-containing component containing the high molecular weight active hydrogen compound and chain extender and the polyisocyanate compound-containing component are rapidly mixed, immediately poured into a mold, and the mixture is allowed to react in the mold. This is done by taking out the molded product after curing. Rapid mixing is usually achieved by collisional mixing of each component, and an after-mixing mechanism may be provided in a portion of the runner to perform remixing. The present invention is used for molding exterior parts of automobiles, especially bumper shells. It is also suitable for molding fenders, front panels, front panels, and other automotive exterior parts. However, the present invention is not limited to these uses.

The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Examples and Comparative Examples Reactivity consisting of the polymer sieve listed in Table 1 below, a total of 83 parts of active hydrogen compound, 17 parts of ethylene glycol, 5 parts of trichlorofluoromethane, and an organosilicon compound containing a carboxyl group. Internal mold release agent (product name 'Q2-
7119", manufactured by Dow Corning, USA), 2 parts by weight, catalyst (dibutyltin dilaurate [amount variable, listed in Table 2])
), and after leaving it for about 10 hours, it was mixed with a polyisocyanate compound (prepolymer type modified diphenylmethane diincyane-1-
:NOO-containing; 1426.0%) and a polyisocyanate compound-containing component (contains NOO; 1426.0%), and a microcelsi-like polyurecunurea elastomer (specific gravity 1.05) is produced by reaction injection molding using a high-pressure foaming method. Manufactured. The discharge pressure of the high-pressure foaming machine is 150 Kg/cdl, and the discharge amount is 40 KL! /min, liquid temperature of each component 35℃, mold size 500X500X3 (flat mold), mold temperature about 70℃,
Molding was carried out under conditions of an incyanate index of 1050. Table 2 shows the type and amount of the high molecular weight active hydrogen compound used and the physical properties of the obtained elastomer. In addition, apart from reaction injection molding, we use raw materials of the same type and composition to create Cream Time (OT), a reactive mixture of an active hydrogen compound-containing component and a polyisocyanate compound-containing component.
Table 2 also shows Yuga, who won against Rice Time (RT).

The physical properties of the obtained elastomer were measured under the following conditions.

Flexural modulus: Based on ASTM-D790 method.

Tensile strength: Based on J-Tech S-630 dumbbell No. 2.

Stretch: JT, S- with 630 dumbbells No. 2.

Heat Zag = 125 cm x 25 parrots x 3 test pieces, one end of which was held horizontally and heated in an oven at 120°C for 1 hour, and the amount of droop at the tip is shown in centimeters.

rSi curing temperature: According to J Engineering S K7216.

High molecular weight active hydrogen compounds Polyethers A to G shown in Table i51 below are aminated polyethers and polyether polyols, and polyether polyols are made by adding propylene oxide to di- or trivalent polyhydric alcohols, It is a polyoxypropylene/oxyethylene polyol obtained by adding ethylene oxide. Aminated polyether is an aminated polyether obtained by aminating the terminal hydroxyl groups of polyoxypropylene oxy and ethylene polyols synthesized in the same manner with ammonia.

Claims (1)

[Scope of Claims] (1) A reaction injection molding method for producing a polyurethaneurea-based or polyurea-based nidistomer molded article by reaction injection molding using two components: an active hydrogen compound-containing component and a polyisocyanate compound-containing component, The active hydrogen compound-containing component contains a high molecular weight active hydrogen compound, a chain extender and a reactive internal isomorphic agent as essential components, and may or may not contain a catalyst, and the high molecular sensitive active hydrogen compound is a high molecular weight polyether. (average molecular weight per functional group obtained by aminating some or all of the hydroxyl groups of a polyol) 11' Aminated polyether of about 500 to 4000, or at least 1 of the aminated polyether and other high molecular weight active hydrogen compound The average amination rate of the high molecular weight active hydrogen compound is about 25 degrees or more, the average number of functional groups is about 2.0 or more, and the average molecular weight of the functional groups is about 500 to 4000. Characteristic reaction injection molding method. (2) Claim 1, characterized in that the reactive internal mold release agent is an organosilicon compound containing a carboxyne group.
Section method. (8) The method according to claim 1, characterized in that an organometallic compound catalyst that is easily deactivated by a reactive internal AT type agent is not substantially added to the active hydrogen compound-containing component. (4) The method according to claim 1, characterized in that a depletingly effective amount of the tertiary amine catalyst is not added per minute of the active hydrogen compound-containing component. (5) The method according to claim 1, wherein the average amination rate of the high molecular weight active hydrogen compound is about 45 or more.