JPS59117521A - Preparation of polyurethane elastomer - Google Patents

Abstract

PURPOSE:To obtain the titled high-quality elastomer having low water absorption properties by injection molding in the same molding time as an existing method, by using a specific polyoxyalkylene polyol as a high-molecular weight polyol. CONSTITUTION:(A) A high-molecular weight polyol consisting of >=80wt% (mixed) polyoxyalkylene polyol having >=2 average hydroxyl group number, <15% average oxyethylene group content, wherein at least 5wt% of it exists at the end part of oxyalkylene chain, <=0.1meq/g average unsaturated group-containing monool component, and 15-60 average hydroxyl value, (B) a polyol component consisting of a chain extending agent as an essential component, and (C) an isocyanate component consisting of a polyisocyanate compound as an essential component are subjected to reaction injection molding, to give unfoamed or micro-cellular polyurethane elastomer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyurethane elastomer using a reaction injection molding method, and particularly to a method for producing a polyurethane elastomer with a small rate of dimensional change upon absorption of water.

It is known to produce polyurethane elastomers such as microcellular elastomers and non-foamed elastomers by reaction injection molding using polyols, chain extenders, and organic polyisocyanates as main raw materials. The production of polyurethane elastomers by reaction injection molding is currently used for molded products in automobile-related fields, including the outer shell of automobile bumpers. It is also being considered for use in automobile fenders, door panels, front panels, and other exterior panels. These exterior members for automobiles, including the outer shell of the bumper, are required to have greater water resistance than interior members. However, the polyurethane elastomer conventionally used for bumper outer shells has had problems with poor water resistance.

The most problematic aspect of conventional polyurethane elastomers has been dimensional changes due to water absorption. That is, the polyurethane elastomer easily absorbs water, and the dimensions change due to water absorption, which tends to cause deformation of the molded product. Conventionally,
In order to avoid dimensional changes due to water absorption, the wall thickness of molded products has been increased. However, it is extremely uneconomical to increase the wall thickness of a molded product solely to cope with dimensional changes due to water absorption. In addition, being limited to thick walls means that the degree of freedom regarding the shape and physical properties of the molded product is reduced. Therefore, in order to essentially solve this problem, it is considered necessary to lower the water absorption of polyurethane elastomers.

When we investigated the cause of the water absorbency of polyurethane elastomers, we found that it is due to the hydrophilicity of the oxyethylene groups in the high molecular weight polyoxyalkylene polyol that is the raw material.

It is believed that the problem of water absorption can be solved if a polyoxyalkylene polyol containing no oxyethylene group can be used. On the other hand, however, the presence of oxyethylene groups is essential for polyoxyalkylene polyols that are suitable for reaction injection molding. That is, the polyoxyalkylene polyol used in reaction injection molding must have high reactivity, and therefore the polyol must have a high proportion of primary hydroxyl groups. It is necessary that the terminal oxyalkylene group of the oxyalkylene polyol is an oxyethylene group. Typical polyoxyalkylene polyols are high polymers having oxyethylene groups at the terminals obtained by adding ethylene oxide to polyoxyalkylene polyols having substantially only oxypropylene groups or oxypropylene groups and oxybutylene groups as oxyalkylene groups. It is a polyoxyalkylene polyol having a proportion of primary hydroxyl groups. Therefore, in order to solve the problem of water absorption, it was considered necessary to use a polyoxyalkylene polyol with a reduced content of oxyethylene groups while maintaining a high proportion of primary hydroxyl groups.

The average hydroxyl value of the high molecular weight polyoxyalkylene polyols used in reaction injection molding is in the range of about 15-60. Conventionally, it was thought that the proportion of primary hydroxyl groups, ie, the number of primary hydroxyl groups to the total number of hydroxyl groups, was required to be at least 80%. For example, the primary hydroxyl group ratio is 8
For example, a polyoxyalkylene polyol with a hydroxyl value of 35 requires an oxyethylene group content of at least about 25% by weight, and a polyoxyalkylene polyol with a hydroxyl value of 25 requires an oxyethylene group content of at least about 20% by weight. weight%
oxyethylene group is required. That is, as the hydroxyl value of the polyoxyalkylene polyol decreases (ie, as the molecular weight increases), the relatively necessary content of oxyethylene groups decreases. However, if this is calculated as the number of oxyethylene groups per hydroxyl group (hereinafter referred to as units) of the polyoxyalkylene polyol, it is necessary to calculate the number of oxyethylene groups per hydroxyl group to obtain a primary hydroxyl group ratio of 85 units regardless of the hydroxyl value. This means that at least about 5.5 to 6.0 units of υoxyethylene groups are required. Theoretically, if there are 91 units of oxyethylene group per hydroxyl group, the proportion of primary hydroxyl groups should be 100 units. The reason why this does not happen is that when ethylene oxide is added to a polyoxyalkylene polyol having secondary hydroxyl groups, the addition of ethylene oxide to the hydroxyl groups is non-uniform;
This is because the primary hydroxyl group converted by the addition of ethylene oxide to the molecule is more likely to react with ethylene oxide than the secondary hydroxyl group, and even if the number of ethylene oxides added increases, the ratio of addition to secondary hydroxyl groups decreases. Conceivable.

Therefore, for these reasons, reducing the proportion of oxyethylene groups in p-polyoxyalkylene polyol inevitably leads to a decrease in the proportion of primary hydroxyl groups, and the proportion of primary hydroxyl groups is high enough to be used in reaction injection molding. Polyoxyalkylene with +ie! I-all is not obtained. fact,
As shown in the comparative example below, the conventional production of polyurethane elastomer using a polyoxyalkylene triol with a hydroxyl group restriction of 26 and an oxyethylene group content of about 8% fjk requires a molding time (expressed as demolding time) of It is extremely long and the physical properties of the resulting polyurethane elastomer are poor, making it completely impractical.

The inventors of the present invention have taken up the challenge of the above-mentioned problem, which was previously thought to be theoretically impossible, and have conducted various research studies. As a result, even if the proportion of primary hydroxyl groups in polyether polyol is low, as long as certain conditions are met, We have discovered that it is possible to produce a polyurethane-based elastomer with the same molding time as conventional methods.

A certain condition means that the amount of the unsaturated group-containing monol component contained in the high molecular weight polyoxyalkylene polyol is G,
The condition is that it is less than or equal to I G meq/f. The amount of unsaturated group-containing monool component in polyoxyalkylene polyols having a high proportion of primary hydroxyl groups used in conventional reaction injection molding is about 0.12 meq/f when the oxypropylene group content is high. It was above average.

The present inventor has conducted various studies on the reason why a good polyurethane elastomer can be obtained even with a low proportion of primary hydroxyl groups by setting this to 0.10 meq/P or less, but the clear reason is It is unknown (the reasoning will be explained later).

However, the effect of using the polyoxyalkylene polyol is significant. Therefore, since it is not necessary to maintain a high proportion of primary hydroxyl groups, the content of oxyethylene groups in the polyoxyalkylene polyol can be reduced, and even if the content of oxyethylene groups is high to some extent, It is also possible to obtain a polyurethane elastomer that is better than conventional polyoxyalkylene polyols having the same amount of oxyethylene groups.

The present invention relates to a method for producing a polyurethane elastomer by a reaction injection molding method characterized by using the above-mentioned specific polyol. Manufacture of polyurethane elastomer by reaction injection molding to manufacture a non-foamed or microcellular polyurethane elastomer molded article by reaction injection molding using at least two isocyanate components having an isocyanate compound as an essential component. In the method, substantially all or at least 80% by weight of the high molecular weight polyol consists of a polyoxyalkylene polyol having an oxyethylene group at the end, and the polyoxyalkylene polyol has an average number of hydroxyl groups of 2 or more and an average oxyethylene group content of 15 Less than % by weight, average unsaturated group-containing monool component content 0.10 meq/g! The following is a method for producing a polyurethane elastomer by a reaction injection molding method, characterized in that the polyoxyalkylene polyol is a single or mixed polyoxyalkylene polyol having an average hydroxyl group restriction of 15 to 60.

The reason why unsaturated group-containing monool components exist in polyoxyalkylene polyols is thought to be due to side reactions in the production of oxypropylene groups by addition of propylene oxide, and the side reactions are thought to be as follows. .

Accordingly, in the polyoxyalkylene polyol, CH,
=CH-CH,OH or an unsaturated group-containing monool component (hereinafter simply referred to as monool) produced by adding an alkylene oxide to the hydroxyl group thereof. This monool has a relatively low molecular weight, and although its amount is small in terms of equivalent weight in the polyoxyalkylene polyol, it is present in a relatively large amount in terms of molar amount. It is believed that ethylene oxide has a high tendency to react selectively to monool during addition. Therefore, it seems that oxyethylene groups, which were conventionally necessary to increase the proportion of primary hydroxyl groups, were often allocated to monools and were not sufficiently allocated to polyoxyalkylene polyols.

Therefore, in conventional polyoxyalkylene polyols, the high proportion of primary hydroxyl groups takes into account the primary hydroxyl groups of this monool, and the proportion of primary hydroxyl groups in polyoxyalkylene polyols excluding monools is actually It is estimated that the ratio was lower than its apparent value.

Therefore, it is considered that if the amount of monol is small, the reaction activity equivalent to that of conventional polyoxyalkylene polyols can be maintained even if the proportion of primary hydroxyl groups in polyoxyalkylene polyols is lower than that of conventional polyoxyalkylene polyols.

In addition, when considering the molding time, that is, the time until demolding becomes possible, the molding time is theoretically considered to be in a parallel relationship with the time until the crosslinking of polyurethane has progressed to a certain level. . However, as mentioned above, the hydroxyl groups of monools have a high proportion of primary hydroxyl groups, and because the proportion of primary hydroxyl groups of polyoxyalkylene polyols is relatively low in practice, monools react with low molecular weight. Due to its high activity, it is presumed that the reaction between the hydroxyl group and isocyanate group of the monool precedes the reaction between the hydroxyl group and isocyanate group of conventional polyoxyalkylene polyols. On the other hand, crosslinking does not proceed in the reaction between monools and polyisocyanate compounds, so in the case of conventional polyoxyalkylene polyols that contain a large amount of monools, their apparent reactivity must be sufficiently high in order to increase the crosslinking rate. It seems that a higher proportion of primary hydroxyl groups was required than expected. Therefore, if the content of monol is reduced, the reaction between the polyoxyalkylene polyol and the polyisocyanate compound will proceed faster and crosslinking will proceed, and even if the proportion of primary hydroxyl groups is low, a molding time equivalent to or longer than the conventional one can be achieved. It is thought that it is possible to do so.

In addition, the small amount of monol allows for more complete crosslinking within the molding time of the polyurethane elastomer, and if after-curing is required, it can be completed in a shorter time. Moreover, the physical properties of the resulting polyurethane elastomer are better than those obtained using a polyoxyalkylene polyol containing a large amount of monool. In particular, the water absorption dimensional change rate of polyurethane elastomers obtained using polyoxyalkylene polyols with low oxyethylene group content is
What used to be about 1.1 inches can now be reduced to 0.8% or less.

In the present invention, the high molecular weight polyol consists essentially of the entire amount or at least 80% by weight of a polyoxyalkylene polyol having an oxyethylene group at the terminal, and the polyoxyalkylene polyol has an average number of hydroxyl groups of 2 or more, an average of oxyethylene Group content [less than 15% by weight,
Average unsaturated group-containing monool component content 0.10 meq
/f or less and an average hydroxyl value of about 15l60 polyol. The average number of hydroxyl groups in the polyoxyalkylene polyol is more preferably 2 to 4, and even more preferably 2.1.
~55. A more preferable range of the average hydroxyl value is about 20-40. A more preferable range of the average unsaturated group-containing monool component content is 0. 0 8 5 me
q/f or less. The average oxyethylene group content can be changed depending on the purpose. That is, when the primary objective is to reduce the water absorption dimensional change rate of the polyurethane elastomer, the average oxyethylene group content is preferably less than 14% by weight, particularly less than 13% by weight. but,
1 if the purpose is to improve other physical properties or reactivity, etc.
The average oxyethylene group content can be increased to nearly 5% by weight. The lower limit of the average oxyethylene group content is 5
It is about % by weight. If it is lower than this, the reactivity is usually insufficient as a polyoxyalkylene polyol for reaction injection molding.

Substantially all or most of the oxyethylene groups are present at the ends of the polyether chains of the polyoxyalkylene polyol. Although it is preferable that no oxyethylene group be present at the non-terminal sites of the polyether chain, a small amount of oxyethylene group may be present in some cases. In particular, polyoxyarekylene polyols obtained using ethylene glycol, diethylene glycol, or ethylene glycol as an initiator are useful.

The polyoxyalkylene polyol is preferably a mixed polyoxyalkylene polyol containing polyoxypropylene/oxyethylene triol or polyoxypropylene/oxyethylene diol as a main component. Furthermore, as will be described later, a portion of the oxypropylene groups of this polyoxypropylene/oxyethylene tri(or di)ol may be substituted with oxybutylene groups. The most preferred mixed polyoxyalkylene polyol is one in which at least 70% by weight of the mixed polyoxyalkylene polyol has an oxyethylene group content of less than 10% by weight and an unsaturated group-containing monool component content of 1 8 5 me
It is a mixed polyoxyalkylene polyol which is a polyoxypropylene/oxyethylene triol (hereinafter referred to as a) having a hydroxyl value of q/f or less and a hydroxyl value of 20 to 40. This polyoxypropylene oxyethylene triol (a
) is preferably used alone, but other polyoxyalkylenes may be used within a range that does not deviate from the above average number of hydroxyl groups, average oxyethylene group content, average unsaturated group-containing monool component content, and average hydroxyl value. It is more preferable to use it in combination with a polyol (hereinafter referred to as C). The next preferred mixed polyoxyalkylene polyol has an oxyethylene group content of 5 to 12% by weight, an unsaturated group-containing monool component content of less than a 8 5 meq/f, particularly 0.75 meq/f or less, and an average of Hydroxyl value 20
It is a mixed polyoxyalkylene polyol whose main component is polyoxypropyleneoxyethylene diol (hereinafter referred to as "1") of 40. Although this polyoxypropylene/oxyethylene diol (b) (c) can be used alone, it is more preferably used in combination with a trivalent or higher polyoxyalkylene polyol (hereinafter referred to as "d"). In this case as well, polyoxypropylene/oxyethylene diol (b) and polyoxyalkylene polyol (d
) must be within the ranges of the average number of hydroxyl groups, average oxyethylene group content, average unsaturated group-containing monool component content, and average hydroxyl value. Further, the proportion of polyoxypropylene/oxyethylene triol (a) and trioxyalkylene polyol (C) may be 70 to 100% by weight of the former and 0 to 60% by weight of the latter in the mixed polyoxyalkylene polyol. preferable. Similarly, the proportion of the combination of polyoxypropylene/oxyethylene diol (C) and polyoxyalkylene polyol (d) is 60 to 90% by weight of the former.
and the latter preferably in an amount of 10 to 40% by weight.

The polyoxyalkylene polyol (C) in the above mixed polyoxyalkylene polyol has its own number of hydroxyl groups, oxyethylene group content, unsaturated olomonol component content, and The hydroxyl value is not limited. For example, the oxyethylene group content may be as high as about 50% by weight. Of course, polyoxypropyleneoxyethylenediol (b) may also be used.

A more preferable polyoxyalkylene polyol (C) has an oxyethylene group content of 35% by weight or less and a hydroxyl value of 15.
~60 polyoxypropylene oxyethylene diol. As with the polyoxyalkylene polyol (C), the conditions for the polyoxyalkylene polyol (d) are not particularly limited. However, preferred is polyoxypropylene/oxyethylene polyol, particularly polyoxypropylene/oxyethylene triol, which has an oxyethylene group content of 60% by weight or less and a hydroxyl value of 15 to 60, and has a valence of 3 or more, particularly a valence of 3 to 4. It should be noted that the mixed polyoxyalkylene polyol is not limited to the combination of the above two components, and it goes without saying that a mixed polyoxyalkylene polyol of a multi-g content type may also be used as long as the above conditions are satisfied. .

Polyoxyalkylene polyol is produced by adding alkylene oxide to a divalent or higher initiator. The initiator may be a mixture of two or more types of initiators.

Initiators include polyhydric alcohols, alkanolamines, mono- or polyamines, polyhydric phenols,
There are other things. Especially di- to octahydric polyhydric alcohol,
Particularly preferred are di- to tetrahydric polyhydric alcohols. Examples of initiators include the following compounds.

Ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane,
Hexanetriol, pentaerythritol, diglycerin, dextrose, sorbitol, sucrose, triethanolamine, jetanolamine, ethylenediamine, bisphenol A1 bisphenol F As the alkylene oxide, an alkylene oxide having 2 to 4 carbon atoms is preferable. Further, other epoxides such as halogen-containing alkylene oxides, styrene oxides, glycidyl ethers, glycidyl esters, etc. may be used in combination with the alkylene oxide. As the alkylene oxide, it is essential to use ethylene oxide as described above. The production of the monool is due to the use of propylene oxide, and it is thought that the above problem will not occur unless propylene oxide is used, so the use of propylene oxide is also essential. Therefore,
As the alkylene oxide, a combination of substantially only two types of propylene oxide and ethylene oxide, or a combination of substantially only three types of propylene oxide, butylene oxide, and ethylene oxide is preferred. Particularly suitable are polyoxyalkylene polyols in which at least 60% by weight, preferably at least 80% by weight, are oxypropylene groups, and from an economic point of view,
Preferred is a polyoxyalkylene polyol whose oxyalkylene groups consist essentially of oxypropylene groups and oxyethylene groups.

The production of a polyoxyalkylene polyol with a small amount of unsaturation-containing monool components in the present invention involves the selection of catalyst components in the production of ordinary polyoxyalkylene polyols,
It can be carried out by changing reaction conditions, purifying by removing the monol component, or by other methods. For example, JP-A-54-30110, JP-A-54-44720, JP-A-56-58522, JP-A-56-4
No. 3322, U.S. Patent No. 3,427,256,
U.S. Patent No. 5427'554, U.S. Patent No. 34
No. 27335, US Pat. No. 3,395,245 and the like describe methods for producing polyoxyalkylene polyols containing a small amount of unsaturated group-containing monool components.

In particular, it is useful to select catalyst components and to produce polyoxyalkylene polyols under milder reaction conditions (compared to conventional methods). Measurement of unsaturated group-containing monool components is based on JIS K
1557 (1970) by measuring the "total unsaturation degree" as described in "Polyether Test Methods for Polyurethanes". In the present invention, the unsaturated group-containing monool component content is used in the same meaning as the total unsaturation.

In the present invention, the high molecular weight polyol may consist essentially only of the above polyoxyalkylene polyol, but may also contain up to 20% by weight of other high molecular weight polyols. Examples of other high molecular weight polyols include high molecular weight polyols other than the above-mentioned polyoxyalkylene polyols, such as polyester l diols, polyester ether polyols, polyether polyols such as polyoxytetramethylene polyols produced by methods other than the addition reaction of alkylene oxides, Examples include hydroxyl group-containing hydrocarbon polymers such as hydroxyl group-containing polybutadiene. In particular, it is effective to use a hydrocarbon-based polymer containing a hydroxyl group, which is a hydrophobic polyol, in order to reduce the dimensional change rate of a polyurethane-based elastomer upon water absorption. Suitable examples of the hydroxyl group-containing hydrocarbon polymer include a butadiene homopolymer having hydroxyl groups at both ends, and a butadiene copolymer consisting of a copolymer of butadiene and other vinyl monomers such as acrylonitrile, styrene, and so on.

Further, a high molecular weight polyol obtained by adding a small amount of alkylene oxide to this hydroxyl group-containing hydrocarbon polymer may also be used.

The chain extender consists of a low molecular weight polyol and/or a polyamine compound having a molecular weight of 400 or less. Special 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 are aromatic diamines having alkyl substituents and/or halogens. Preferred specific chain extenders are ethylene glycol, 1,4-/tanediol, propylene glycol, diethylene glycol, dipropylene glycol, chrycerin, trimethylolpropane, jetanolamine, triethanolamine, especially ethylene glycol. Preferred is 1,4-butanediol. The amount used is 5 to 4% based on the total amount of high molecular weight polyol.
0% by weight, especially 10-30% by weight is suitable.

It has been found that the use of a chain extender having an oxyethylene group such as ethylene glycol does not have any adverse effect on the water absorption dimensional change of the polyurethane elastomer. The reason is that the chain extender reacts with the polyisocyanate compound to form a hard block of the polyurethane elastomer, and this hard block has low water absorption even if oxyethylene groups are present therein, and even if it does not absorb water, However, since it is hard, it is not considered to be a cause of deformation.

On the other hand, the oxyethylene group at the terminal KW of the molecular chain of high molecular weight polyol is thought to exist adjacent to this hard block, but unlike the case where it is located within the hard block, the oxyethylene group in this part belonging to the soft block is considered to exist adjacent to this hard block. It is thought that the presence of ethylene groups has a large influence on the change in water absorption dimensions.

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-t! J diisocyanate, 2.6-t
-lylene diisocyanate, 4,4'-diphenylmethane diisocyanate, polymethylene polyphenylisocyanate, xylylene diisocyanate, isophorone diisocyanate, methylene-bis(cyclohexyl isocyanate), hexamethylene diisocyanate, and the like. Examples of modified products include dimers, trimers, prepolymer modified products, carbodiimide modified products, urea modified products, and others. Two or more of these polyisocyanate 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 amount of polyisocyanate compound used is 90 to 12 expressed in isocyanate index.
0, especially 95 to 110 is suitable.

In the production of polyurethane elastomers using the reaction injection molding method, it is usually essential to use a catalyst in addition to the above-mentioned main raw materials, and it is also preferable to use a blowing agent. The catalyst may be various tertiary amine catalysts or organometallic compounds such as organotin compounds, and both may be used alone or in combination. In the present invention, the blowing agent is not necessarily essential.
Even without using a foaming agent, a slightly foamed elastomer can be obtained due to the presence of air and water dissolved in the raw materials, and by sufficiently removing these, a non-foamed elastomer can be obtained.

However, it is preferable to use a small amount of blowing agent for reasons such as improving moldability. Air, water, etc. can be used as the blowing agent, but halogenated hydrocarbons with a low boiling point are preferably used.

Specifically, trichlorofluoromethane, dichlorodifluoromethane, and methylene chloride are suitable. The amount thereof 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 polyol and chain extender.

Furthermore, various additives may be added as optional additive components. Examples include reinforcing fibers, fillers, colorants, ultraviolet absorbers, antioxidants, flame retardants, and internal mold release agents. In particular, blending reinforcing fibers has the effect of lowering the water absorption dimensional change rate.

This seems to be to improve the rigidity and strength of the polyurethane elastomer. Suitable reinforcing fibers include milled glass fibers, cut fibers, and wollastonite. The amount thereof is approximately 20% by weight or less based on the entire polyurethane elastomer to have a sufficient effect. These additives, including the catalysts and blowing agents mentioned above, are usually added to the polyol component containing the high molecular weight polyol and chain extender. However, additives which are inert towards isocyanate groups can also be added to the isocyanate component.

The reaction injection molding method is usually carried out by rapidly mixing the polyol component and the isocyanate component, immediately injecting the mixture into a mold, reacting the mixture in the mold, and taking out the molded product after curing. In some cases, three or more components may be used by dividing the polyol component or isocyanate component into two or more components, or by using a third component. Rapid mixing is usually achieved by impingement 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.

However, the present invention is not limited to this use, and can also be applied to molded products and other uses that require water resistance.

EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples.

Examples and Comparative Examples A mixture of high molecular weight polyols, chain extenders, etc. listed in Table 1 below was charged into a tank on the polyol component side of a high-pressure foaming machine.
On the other hand, a polyisocyanate compound was charged into the isocyanate component side tank.

Reaction injection molding was carried out by adjusting the discharge pressure of the high-pressure foaming machine to 150K17cm'', the discharge rate from 60 to 120 9/min, and the liquid temperature of each component to 30 to 40℃.The size of the mold was 140cm×
A mold for molding an outer shell of an automobile bumper having a size of 120 pieces x 1400 pieces and three inner thicknesses was used, and the mold temperature was adjusted to 60 to 70°C. A sample for measuring physical properties was cut out from the obtained molded product, and the physical properties listed in Table 1, including the water absorption dimensional change rate, were measured. The demolding time and physical properties described in Table 1 were measured by the following methods.

Demolding time: The time from the completion of injection until the mold can be demolded (the molded product can be demolded without cracking, etc.).

Density: method by water or alcohol displacement.

(AS'I'M-D792) Water absorption dimensional change rate: Molded product sample (IDOX200
3m) at 100°C for 3 hours.The length in the long side direction is t.

If this is immersed in warm water at 40° C. for 240 hr and the length is t, then the water absorption dimensional change rate ΔL is given by the following equation.

Δl=’-Kan×100 t.

Flexural modulus: Based on A8TM-D790 method.

Tensile strength: Based on JI8-650 dumbbell No. 2.

Elongation; 6501 Dumbbell No. 2 for y-works-.

The raw materials used were as follows.

■, polyoxyalkylene polyol The following polyols A to G are polyoxypropylene/oxyethylene polyols having an oxyethylene group at the end, and their number of hydroxyl groups, oxyethylene group content, unsaturated monool content, and hydroxyl value is as follows.

Poly+1 A5 B Heavy-Jit%
0.08 meq/f 26
11B5 8# 0.14# 26〃
c3 15 s O, 121/26
1D320s O,07it 28
〃E2 1Or 0.0+S
tt 28tt F 2 20
# [1, [18g 28//G2
50 1 0.07 #38 The mixed polyoxyalkylene polyol used in the examples and comparative examples is a mixture of the above polyols, and the composition ratio (
Weight) and the average number of hydroxyl groups, etc. are shown below in the same way as above.

■, Other high molecular weight polyol PBd: Polybutadiene glycol with an average molecular weight of about 6000■, Polyisocyanate compound [The amount used is the lid whose isocyanate index is 105] Polyisocyanate A: Carbodiimide-modified diphenylmethane diisocyanate (Neo-containing 1i 28.5%) Polyisocyanate B: Prepolymer type modified diphenylmethane diisocyanate (NCO content 26%) IV, other raw materials EG: Ethylene glycol catalyst A + triethylenediamine solution (trade name: DABCO 33LV) Catalyst B Nidibutyltin dilaurate R-11 = trichlorofluoromethane MFB : Milled glass fiber procedural amendment with average length of approximately Q and 15 strips February 72, 1980 Commissioner of the Patent Office Mr. Kazuo Wakasugi 3 Relationship to the case of the person making the amendment Patent applicant address 2 Marunouchi, Chiyoda-ku, Tokyo Chome 1-2 name
(004) Asahi Glass Co., Ltd. 4, Agent 6 No number of υ increased due to amendment 7, Specification subject to amendment 4F [Claims] and "Detailed Description of the Invention" Wings 2-8, Amendment The content of (1 claim on pages 1 to 3 of the specification) will be amended in Attachment 2.

(2) From page 10, line 4 of the specification [High molecular weight polyols and...] to page 11, line 2 of the specification, ``...
The manufacturing method of...'' shall be corrected as follows.

[Non-foamed or microcellular foam is produced by reaction injection molding using at least two isocyanate components, each of which has a polyisocyanate compound as an essential component, in addition to a polyol component that has a high molecular weight polyol and a chain extender as an essential component.] In a method for producing a polyurethane elastomer by reaction injection molding for producing a molded article of a polyurethane elastomer, substantially all of the high molecular weight polyol or at least 80 weight by weight is not a polyoxyalkylene polyol, and the average amount of the polyoxyalkylene polyol is Number of hydroxyl groups: 2 or more, average oxyethylene group content [15% by weight]
less than 10 meq/g, and at least 5N dioxylic acid is present at the end of the oxyalkylene chain, and the average unsaturated group-containing monool component content Q is 10 meq/g or less, and the average hydroxyl value is 15 to 60, alone or in combination. ``A method for producing a poly-3-urethane disstomer by a reaction injection molding method, characterized in that it is a polyoxyalkylene polyol.'' (3) The last line of page 14 of the specification reads ``At the end...''. On page 15, line 7, up to ``It is a polyol.'' are corrected as follows.

[consisting of a polyoxyalkylene polyol, the polyoxyalkylene polyol has an average number of hydroxyl groups of 2 or more, an average oxyethylene group content of less than 15% by weight, and at least 5 weight percent of the polyoxyalkylene polyol is present at the terminal portion of the oxyalkylene chain; Go containing an average unsaturated group-containing monol component,
1 o meq/g or less, and average hydroxyl value 15-60
Single or mixed polyoxyalkylene polyols. (4) Specification, page 16, line 1, ``Average oxyethylene group...'', page 13, line 13 [... useful. ] are corrected as follows.

"The lower limit for the average oxyethylene group content is 5% by weight, which is present in the terminal portions of the oxyalkylene groups. Lower amounts of oxyethylene groups in the terminal portions are typically used for reaction injection molding polyoxy The reactivity as an alkylene polyol becomes insufficient.Substantially all or most of the oxyethylene groups in the polyoxyalkylene polyol are preferably present at the terminal portion of the oxyalkylene chain.The non-terminal portion of the oxyalkylene acid Although it is preferable that no oxyethylene group be present in
'fi moiety or a non-terminal oxyalkylene fiK oxyethylene group may be present. In particular, polyoxyalkylene polyols obtained by using polyethylene glycols such as ethylene glycol and diethylene glycol as initiators are useful. However, the amount of oxy-r-ti v:y group f) in this non-terminal portion is 15 times 1t
It is preferably 5% by weight or less, particularly 5% by weight or less, of the total oxyalkylene groups in the undropped ts, and it is especially preferable that it is substantially absent as described above. The polyoxyalkylene polyols described below do not contain oxyethylene groups in the non-terminal portions of the oxyalkylene chains unless otherwise specified. (5) The text from page 19, line 9, ``tato'' to page 11, line 11, ``...the rule may be higher,'' are amended as follows.

“For example, the content of oxyethylene groups at the end portion is 30
The polyoxyalkylene polyol may be as high as thi1', some or all of the oxyethylene groups may be present in non-terminal portions, and furthermore, it may be a polyoxyalkylene polyol containing no oxyethylene groups. □” 5- (6) “35 weight or less” on page 19, line 14 of the specification
is corrected to "35% by weight or less, most of which is present at the end of the oxyalkylene chain."

(7) “130% by weight or less” on the last line of page 19 of the specification” should be changed to “3
0% by weight or less, most of which is present at the end of the oxyalkylene chain.

(8) Insert the following sentence between page 22, line 10 and line 11 of the specification.

"The oxyethylene group at the terminal portion of a polyoxyalkylene polyol is obtained by adding ethylene oxide as a final step to a polyoxyalkylene polyol whose terminal portion is not an oxyethylene group. The use of an initiator and the addition of alkylene oxide to ethylene oxide and alkylene oxide sequentially (however, the addition immediately before the addition of ethylene oxide in the final step mentioned above is an alkylene oxide other than ethylene oxide), or the addition of ethylene oxide and other By adding a mixture of alkylene oxides (ethylene oxide has high reactivity, it reacts relatively quickly and rarely ends up with oxyethylene groups), and by a combination of these steps, polyoxyalkylene polyols can be produced. In addition, the polyoxyalkylene polyol (Q) or (d
), ethylene oxide is added to the polyoxyalkylene polyol, and then a small amount of alkylene oxide other than ethylene oxide is added to convert some or all of the primary hydroxyl groups resulting from the terminal oxyethylene groups into secondary hydroxyl groups.
It is also possible to use polyoxyalkylene polyols in which the hydroxyl groups have been changed. Of course, if the polyoxyalkylene polyol <C> or (1) does not have an oxyethylene group, the addition of ethylene oxide is not necessary. For example, if only propylene oxide is added to the initiator. can be manufactured. ” (9) E! In the 3rd line of page 2 of the A booklet, ``at the end'' is corrected to ``only at the end.''

(10) Amend the entire 35 pages of v4 details as shown in Attachment 1.

Attachment 2, Claim 1, Reaction injection molding is carried out using at least two incyanate components having a polyisocyanate compound as an essential component in a polyol component pot having a high molecular weight polyol and a chain extender as essential components. In a method for producing a polyurethane disstomer by reaction injection molding to produce a non-foamed or microcellular polyurethane disstomer molded article, substantially all of the high molecular weight polyol or at least 80% of the high molecular weight polyol is derived from a polyoxyalkylene polyol. The polyoxyalkylene polyol has an average number of hydroxyl groups of 2 or more, an average of 5% by weight of oxyethylene is present at the terminal portion of the oxyalkylene chain, and an average unsaturated group-containing monool component content i 0.10 meq/g
A method for producing a polyurethane didistomer by a reaction injection molding method, characterized in that the following polyoxyalkylene polyols are used alone or as a mixture and have an average hydroxyl value of 15 to 60.

2 Polyoxyalkylene polyol has an average number of hydroxyl groups of 2
1 to 3.5, the average oxyethylene group content is 5 to 14 diagonals, most of which is present at the end of the oxyalkylene chain, and contains an average unsaturated group-containing monool component!
0.85mθq1g or less, and average hydroxyl value 20-4
2. The method according to claim 1, wherein the polyoxyalkylene polyol is 0 or a mixture of polyoxyalkylene polyols.

1 The polyoxyalkylene polyol has substantially all the oxyethylene groups present at the terminal portion of the oxyalkylene chain, the oxyethylene group content is less than 10% by weight, and the unsaturated group-containing monool component content is 0.85 meq
, /g or less and a hydroxyl value of 20 to 40 polyoxypropylene/oxyethylene triolua 0 to 100*Amount s
and 0 to 30% by weight of another polyoxypropylene/oxyethylene polyol.

4. The polyoxyalkylene polyol has a substantial monool component content o of 85 meq/g or less and 60 to 90% by weight of polyoxypropylene/oxyethylene diol having a hydroxyl value of 20 to 40 and polyoxypropylene having a valence of 3 or more. - The method according to claim 2, characterized in that it consists of 10 to 40 polyoxyethylene polyols. ” Procedural amendment dated January 1, 1980, Mr. Kazuo Wakasugi, Commissioner of the Patent Office, 1, Indication of the case, Patent Application No. 225784, filed in 1982, 2, Name of the invention, Process for manufacturing polyurethane elastomer, 3, Person making the amendment Case Relationship with Patent applicant address: 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Name (
004) Asahi Glass Co., Ltd. 4, Spontaneous amendment by agent 6, Number of inventions increased by amendment None 7, Specification subject to amendment “Claims” and “Detailed description of the invention”
Column 2-8, Contents of amendment (1) The "Claims" on pages 1 to 3 of the specification are amended as shown in the attached sheet.

(2) rO, 85meq/gJ on page 17, line 6 of the specification and line 20 on the same page as ro, 085meq/gJ
Correct to.

(3) "ro, 75" on page 17, page 20 of the specification, ro,
Corrected to 075J.

(4) "Total unsaturation" on page 23, line 12 of the specification is corrected to "total degree of unsaturation."

Attachment ``Claim 1, Non-foaming by reaction injection molding using at least two components: a polyol component containing a high molecular weight polyol and a chain extender as essential components, and an isocyanate component containing a polyisocyanate compound as an essential component. In a method for producing a polyurethane elastomer by reaction injection molding to produce a shaped or microcellular polyurethane elastomer molded article, substantially the entire amount or at least 80% of the high molecular weight polyol is composed of a polyoxyalkylene polyol, and The polyoxyalkylene polyol has an average number of hydroxyl groups of 2 or more, an average oxyethylene group content of less than 15% by weight, and at least 5% by weight of the polyoxyalkylene polyol is present at the end of the oxyalkylene chain, and contains an average unsaturated group-containing monool component. A method for producing a polyurethane didistomer by a reaction injection molding method, characterized in that the amount is 0.10 meq/g or less and an average hydroxyl value of 15 to 60, singly or mixed polyoxyalkylene polyols.

2. Polyoxyalkylene polyol has an average number of hydroxyl groups of 2
．． 1 to 3.5, average oxyethylene group content.

5 to 14% by weight, most of which is present at the end of the oxyalkylene chain, an average unsaturated group-containing monool component content of 0, 0.115 meq/g or less, and an average hydroxyl value of 20 to 40. 2. The method of claim 1, wherein the polyoxyalkylene polyol is a mixed polyoxyalkylene polyol.

3. The polyoxyalkylene polyol is such that substantially all of the oxyethylene groups are present at the end portions of the oxyalkylene chain, the oxyethylene group content is less than 10% by weight, and the content of the unsaturated group-containing monool component is low. meq7g
0 to 100% by weight of polyoxypropylene/oxyethylene triole having a hydroxyl value of 20 to 40 and 0 to 100% by weight of other polyoxypropylene/oxyethylene polyols:
30% by weight.

4. The polyoxyalkylene polyol has substantially all the oxyethylene groups present at the terminal portions of the oxyalkylene chains, and the oxyethylene group content is 5 to 12% by weight.
, unsaturated group-containing monool component content: 85 meq/
A patent characterized in that it consists of 60 to 90% by weight of polyoxypropylene/oxyethylene diol having a hydroxyl value of 20 to 40 and 10 to 40% by weight of a trivalent or higher polyoxypropylene/oxyethylene polyol The method according to claim 2. J or more

Claims (1)

[Scope of Claims] At least two isocyanate components containing a polyisocyanate compound as an essential component are placed in a polyol component pot containing a high molecular weight polyol and a chain extender as essential components, and are processed into a non-foamed or micro-polymer by reaction injection molding. In a method for producing a polyurethane elastomer by a reaction injection molding method for producing a cellular polyurethane elastomer molded article, substantially all or at least 80% by weight of the high molecular weight polyol is a polyoxyalkylene polyol having an oxyethylene group at its terminal. Karanasi, the polyoxyalkylene polyol has an average number of hydroxyl groups of 2 or more, an average oxyethylene group content of less than 15% by weight, an average unsaturated group-containing monool component content of 0.10 meq/S' or less, and an average hydroxyl value 1. A method for producing a polyurethane elastomer by a reaction injection molding method, characterized in that polyoxyalkylene polyols having 15 to 60 polyoxyalkylene polyols are used alone or as a mixture. 2 Polyoxyalkylene polyol has an average number of hydroxyl groups of 2
1~! 1.5, average oxyethylene group content 5-12 weight, average unsaturated group-containing monool component content i 0.
85 meq/f or less and a single or mixed polyoxyalkylene polyol having an average hydroxyl value of 20 to 40. 5. The polyoxyalkylene polyol is a polyoxypropylene/oxyethylene trio-containing oxyethylene group-containing monool component containing 0.85 meq/f or less, and a hydroxyl value of 20 to 40. 3. A method according to claim 2, characterized in that the method comprises 0 to 100 mfi-chi of Lua and 0 to 30% by weight of another polyoxypropylene/oxyethylene polyol. 4. Polyoxyalkylene polyol-1, polyoxypropylene with an oxyethylene group content of 5 to 12% by weight, an unsaturated group-containing monool component content of 0.85 meq/f or less, and a hydroxyl value of 20 to 40. Special f! characterized by consisting of 60-90% by weight of oxyethylene diol and 10-40% by weight of polyoxypropylene/oxyethylene polyol of hexavalent or higher valence! f. The method according to claim 2.