JPS60197718A - Production of polyurethane - Google Patents

Abstract

PURPOSE:To obtain a polyurethane having high reactivity and self-releasability and suited as an automobile trimming material, by reacting a polyol component containing a specified polymer polyol with an organic polyisocyanate. CONSTITUTION:A polymer polyol is produced by reacting an ethylenically unsaturated monomer (e.g., acrylic acid) with a polyoxyethylene chain-terminated block polyoxyalkylene polyol having a functionality >=5 and an equivalent weight >=1,450. Next, a polyol component containing at least 20wt% above polymer polyol is reacted with an organic polyisocyanate (e.g., hexamethylene diisocyanate) in the presence of, if necessary, a blowing agent to obtain the purpose polyurethane. The obtained polyurethane is suitably used in molding, especially, by a reaction injection molding process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing polyurethane, specifically a method for producing polyurethane having high reactivity and self-releasing properties, particularly RIM method (
This invention relates to a method for producing polyurethane that provides excellent reactivity and self-releasing properties when molded using a reaction injection molding method.

BACKGROUND ART Conventionally, the RIM method has been put to practical use as a means of producing urethane molded products for applications such as automobile exterior and interior materials such as bumpers, instrument panels, and steering nozzles.・As a urethane raw material for RIM, it is required to have high reactivity and be able to be cured and demolded in a short period of time, as well as to have self-releasing properties so that there is no need to apply a mold release agent to the mold each time. It is desired that the mold can be released.

The present inventors conducted studies to find raw material polyols and polyurethane manufacturing methods that satisfy these requirements. By using a specific polymer polyol, polyurethane molded products with high reactivity and self-releasing properties were produced. The present invention was achieved by discovering that the present invention can be obtained.

That is, the present invention relates to a method for producing polyurethane by reacting an organic polyisocyanate and a polymer polyol in the presence of a blowing agent if necessary.

As at least a part of the polyol, a polymer polyol (
2) A method for producing polyurethane having self-releasing properties (first invention); invention).

The block polyoxyalkylene polyol (b), which is a raw material for the polymer polyol (4) used in the present invention, contains at least 5 (preferably 6 to 1
Compounds having a structure in which ethylene oxide and other alkylene oxides are block-added to a compound having 2) active hydrogen atoms (for example, polyhydric alcohol, polyhydric phenol, amines) so as to form the terminal oxyethylene chain, and Mixtures thereof may be mentioned.

Examples of the polyhydric alcohol include sugar alcohols such as pentitol such as adonitol, arabitol, and xylitol; hexitol such as sorbitol, mannitol, iditol, talitol, and dulcitol; and sugars such as monosaccharides such as glucose, mannose, fructose, and sorbose.

Oligosaccharides such as sucrose, ) levalose, lactose, and raffinose; Examples include polyglycerols such as triglycerin and tetraglycerin, polypentaerythritols such as dipentaerythritol and tripentaerythritol; and cycloalkane polyols such as tetrakis(hydroxymethyl)cyclohexanol. Examples of the polyhydric phenol include novolak, such as the polyphenol described in US Pat. No. 8,265,641;
Examples of amines include polyalkylene polyamines such as diethylenetriamine and triethylenetetramine. Two or more of these active hydrogen atom-containing compounds may be used in combination. In addition, in a mixture of one or more of these compounds and a compound having 2 to 4 active hydrogen atoms (for example, those listed as raw materials for polyether polyol in (8) below), the average number of functional groups (active hydrogen atoms Those having a number) of 5 or more (preferably 6 to 12) can also be used. Preferred among these are polyhydric alcohols, especially sorbitol and sucrose.

Propylene oxide (hereinafter abbreviated as PO) is usually used as another alkylene oxide (hereinafter abbreviated as AO) to be added to the above active hydrogen atom-containing compound together with ethylene oxide (hereinafter abbreviated as EO). (butylene oxide, styrene oxide, etc.) may also be used in small amounts (for example, 5% or less).

The block polyoxyalkylene polyol (b) includes EO and AO in the active hydrogen atom-containing compound.
(1) Added in the order of AO-EO (chipped), (It) added in the order of AO-EO-AO-EO (balanced), (HD EO-AO
Examples include those added in the order -EO. Among these, preferred are &i(+) and (II).

The equivalent weight (molecular weight per OH) of the above polyol (b) is 1
450 or more, preferably 1,500 to 8,200, particularly preferably 1,600 to 8,000. If the equivalent weight is lower than 1450, the physical properties such as temperature characteristics and elongation of the resulting polyurethane will deteriorate. If the equivalent weight exceeds 8200, the viscosity will increase, flowability will deteriorate, and reactivity will decrease.
Undesirable.

(b) Terminal polyoxyethylene chain content (hereinafter referred to as terminal EO
Quantity (abbreviation) is usually 10% (weight%, the same applies hereinafter) or more,
Preferably 12-80%, more preferably 15-28%
%. If the amount of terminal EO is less than 10%, polyurethane having low reactivity, low curing properties and low initial physical properties, and self-releasing properties cannot be formed, and a satisfactory effect cannot be obtained especially when molded by the RIM method. do not have. Also, terminal E
If the amount of O exceeds 30%, the curing properties will improve, but the viscosity will increase and it will become cloudy at a temperature slightly lower than room temperature, resulting in poor workability, and physical properties such as temperature characteristics and water absorption will deteriorate, so this is not preferable. . Even if the terminal EO amount is less than 10%, it can be combined with a terminal EO amount of 10% or more, or if the terminal EO amount exceeds 80%, it can be combined with a terminal EO amount of 80 or less (average terminal EO amount). They can be used by blending so that the amount of EO falls within the above range.

In addition, the total polyoxyethylene chain content (hereinafter referred to as total E
(abbreviated as O amount) is usually 10% or more, preferably 12 to 80%
It is.

The ethylenically unsaturated monomer (b) used in the production of the polymer polyol used in the present invention includes the following: (+) Acrylic acid, methacrylic acid and derivatives thereof: acrylic nitrile, Metaacrylonitrile.

Acrylic acid, methacrylic acid and their salts.

Methyl acrylate, methyl methacrylate, dimethylaminoethyl methacrylate, acrylamide, methacrylic acid amide, etc.

(ii) Aromatic vinyl monomers: styrene, α-methylstyrene, etc.

(iiD, olefinic hydrocarbon monomer: ethylene,
propylene, butadiene, isobutylene, isoprene,
l,4-pentagenato.

(iv) Vinyl ester monomer: vinyl acetate, etc.

■Vinyl halide monomers: vinyl chloride, vinylitine chloride, etc.

(V) Vinyl ether monomer: vinyl methyl ether, etc.

Among these, preferred is acrylonitrile.

These are methyl methacrylate, styrene, and butadiene. Particularly preferred is acrylonitrile, or a combination of acrylonitrile and styrene (styrene:acrylonitrile weight ratio of 10:90 to 60:40).

The above-mentioned polyol (b) may be used in combination with other polyols (for example, high-molecular polyols and/or low-molecular polyols mentioned as examples of (6) and (C) below) to produce a polymer polyol, if necessary. In this case, the amount of (b) in the total amount of polyols is usually 20% or more, preferably 50% or more, and the amount of low molecular weight polyol is usually 20% or less.

The ratio of polyol [(b) and other polyols as necessary] and monomers in polymer polyol (2) can be varied over a wide range, but usually podiol 10
The amount of the ethylenically unsaturated monomer (or polymer) is 2 to 70 parts by weight, preferably 5 to 40 parts by weight.

The production of polymer polyols from polyols and ethylenically unsaturated monomers can be carried out by conventional methods. For example, in a polyol, an ethylenically unsaturated monomer is polymerized with a catalyst (
A method of polymerizing in the presence of a radical generator, etc.) (U.S. Patent No. 8888851, Japanese Patent Publication No. 89-24787, etc.)
Japanese Patent Publication No. 47-47999, Japanese Patent Publication No. 50-15894) and a method in which a polymer obtained by pre-polymerizing the above monomers and a polyol are graft-polymerized in the presence of a radical generator (Japanese Patent Publication No. 47-47597). ) can be given. The former method is preferred. As the polymerization catalyst (radical generator) used in the polymerization reaction, azo compounds, peroxides, persulfates, perborates, etc. can be used, but azo compounds are preferred in practical terms. The amount used is not particularly limited,
For example, ethylenically unsaturated monomers (or polymers)
0.1 to 20 parts by weight, preferably 0.1 to 20 parts by weight per 100 parts by weight.
It is 1 to 15 parts by weight. The above polymerization can also be carried out in the presence of a solvent such as toluene, xylene and the like. The reaction temperature is usually 60-170°C, preferably 90-150°C.
It is ℃.

When carrying out the method for producing polyurethane of the present invention, the polymer polyol (2) may be used alone or in combination with other polymer polyols (2) or/and low molecular active hydrogen-containing compounds (C
) in combination with an organic polyisocyanate.

Other polymer polyols (2) that may be used in combination include polyether polyols, polyester polyols, and other polymer polyols. As the polyether polyol, the above (b); and (b)
Polyether polyols other than polyols such as compounds having 2 to 4 active hydrogen atoms (low-functional polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol) etc. 2
alcohol, glycerin, trimethylolpropane,
Alkylene oxides (EO and/or AO) adducts such as PO, low-functionality polyether polyols such as polytetramethylene ether glycol; polyether polyols with a functional group number of 5 or more, terminal polyoxyethylene chains and internal random poly(oxymethylene/oxypropylene) those that have polyoxyethylene chains, those that do not have terminal polyoxyethylene chains (less than 10%) (PO adducts, PO/EO random adducts, PO/EO block adducts that have only internal polyoxyethylene chains, etc.), or equivalent is 1
Examples include those less than 450.

As the polyester polyol, the above-mentioned low-functionality polyhydric alcohol (a dihydric alcohol such as ethylene glycol and diethylene glycol, or a mixture of this and an octahydric alcohol such as glycerin and trimethylolpropane) and/or the above-mentioned low-functionality polyether polyol is used. ,
Reaction (condensation) of polycarboxylic acids (e.g. adipic acid, maleic acid, phthalic acid, etc.) or their anhydrides and alkylene oxides (EO, PO, etc.), ring opening of certain ihalactones (e.g. ε-caprolactone)
□ Examples include those obtained by polymerization.

Other polymer polyols include polyols (e.g. JP-A No. 54-101899 and JP-A No. 54-122896) are preferred.Among (g), preferred are low-functional polyether polyols [especially those having terminal polyoxyethylene chains]. (diol and/or triol, terminal E
(O amount 1O~80%)] and its polymer polyol.

The amount of (2) in the total amount of the polymeric polyol (and optionally (6)) is usually 20% or more, preferably 80% or more, and more preferably 40% or more.

If (2) is less than 20%, a polyurethane with good curing properties, initial physical properties and self-releasing properties cannot be obtained. In addition, (b) in the polymer polyol portion (excluding the polymer portion) in the polymer polyol [(2) and optionally (2)] [(b) in (2) and optionally added ( b)] is usually 20% or more, preferably 80%
% or more, more preferably 40% or more. The amount of terminal EO in the entire polymer polyol is usually 10% or more, preferably 12 to 80%, and more preferably 16 to 28%.

The equivalent weight (average) of the entire polymer polyol is usually 1450~
8,000, preferably 1,600 to 2,800.

As the optionally used low-molecular active hydrogen-containing compound (Q, a chain extender such as a low-molecular diol, diamine, amino alcohol, etc. can be used).

Low molecular weight diols include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butanediol, neopentyl glycol,
Hexanediol, polyethylene glycol and polypropylene glycol with a molecular weight of 200 to 40G, low molecular weight diols having a cyclic group (e.g. Japanese Patent Publication No. 45-14
No. 74; propylene oxide adduct of bisphenol A, etc.), 8th or quaternary nitrogen atom-containing low-molecular diols (for example, those described in JP-A-54-180699; alkyl dialkanolamines, etc.) and quaternized products thereof), thiodiethylene glycol, and the like. Examples of diamines include aromatic diamines such as toluene diamine, xylylene diamine, diethyldiaminotoluene, diaminodiphenylmethane, methylene bis-〇-di1, luaniline, diaminophenyl sulfone, dichlorobenzidine, dianisidine, and o-nitro-p-phenylene diamine; isophorone; Alicyclic diamines such as ethylene diamine, propylene diamine, hexane diamine, 2.2.4-)limethyl bexane diamine; heterocyclic diamines such as piperazine; Can be mentioned.

Ethanolamine is an amino alcohol.

Propertoolamine, ethylethanolamine.

Phenylethanolamine, 8-amino-2-methyl-
1-Proper Tools and the like. Among these, preferred are low molecular diols (especially ethylene glycol and 1,4-butanediol).

neopentyl glycol) and diamines (especially toluenediamine, diethyldiaminotoluene). By using a chain extender in combination, the amount of heat generated during the reaction with the isocyanate becomes larger, thereby improving the curing property.

In addition to the flexibility possessed by polymeric polyols, the hardness increases due to the increased concentration of urethane bonds (or urea bonds) in the molded product, resulting in a molded product with high physical properties that has a good balance of rigidity and flexibility. can get.

(The amount of 0 used (if a low molecular weight polyol is contained in the polymer polyol, that amount is also included. The same applies hereinafter) can be varied depending on the required performance (rigidity, etc.).Low molecular weight In the case of diol, it is usually 80% of the total polyol.
It is preferably used in an amount of 4 to 25%. When a diamine is used, it is used in a smaller amount than the above, for example, 10% or less, preferably 1 to 8%, based on the total amount of polyol and amine. If the amount of the chain extender is greater than the above, the urethane becomes too rigid, resulting in a decrease in initial strength, elongation, and impact properties. The molar ratio of polymer polyol and chain extender is usually 1:
20-16G, preferably 1:25-140.

Chain extenders are preferred as zero, but alternatively or in addition to crosslinking agents such as glycerin.

Trimethylolpropane, triethanolamine.

It is also possible to use low molecular weight polyols having a valence of 8 or higher, such as tris or tetrakis(hydroxypropyl)ethylenediaminediethyldiaminotoluene. The use of crosslinking agents increases the viscosity of the reaction system, reduces the flowability during injection into the mold, reduces the elongation of the physical properties of the molded product, and increases the hardness, so it is preferable not to use them.If used, use a small amount and adjust the amount of chain extender. It is preferable that the amount is 20% or less.

The average equivalent weight of all active hydrogen components [(2) and optionally (g) and/or (0) is usually 120-1000, preferably 140-900.

As the organic polyisocyanate used in the present invention, those conventionally used in the production of polyurethane can be used. For example, aliphatic polyisocyanates (hexamethylene diisocyanate).

lysine diisocyanate, etc.), alicyclic polyisocyanates (hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, hydrogenated)'J diisocyanate, etc.), aromatic polyisocyanates (toluene diisocyanate) (TDI), diphenylmethane diisocyanate ) (MDI), naphthylene diisocyanate, xylylene diisocyanate, etc.] and mixtures thereof. Among these, aromatic diisocyanates are preferred, and T
DI, MDI. These polyisocyanates are crude polyisocyanates, such as crude TD1. Rough $
1! MDI [crude diaminophenylmethane (condensation product of formaldehyde and aromatic amines or mixtures thereof;
0% by weight) of octafunctional or higher functional polyamine) phosgenated product: polyallyl polyisocyanate (PAPI
) ), or modified polyisocyanates such as liquid MDI (carposiimide modified, trihydrocarbyl phosphate modified, etc.) or excess polyisocyanate (
It can also be used as a free incyanate-containing prepolymer obtained by reacting TDI, MDI, etc.) with a polyol, or they can be used in combination (for example, a modified polyisocyanate and a prepolymer are used together). The polyols used in the production of the prepolymer include polyols having an equivalent weight of 80 to 200, such as glycols such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; triols such as trimethylolpropane and glycerin;
Highly functional polyols such as pentaerythritol and sorbitol; and alkylene oxide (ethylene oxide and/or propylene oxide) adducts thereof.

Among these, those having 2 to 8 functional groups are preferred. The content of free isocyanate groups in the above-mentioned modified polyisocyanates and prepolymers is generally 10-88%, preferably 15-80%, particularly preferably 20-29%.

When producing polyurethane using the polymer polyol according to the present invention, it may be foamed once to produce a polyurethane foam, or it may be foamed twice to produce a polyurethane resin (elastomer, sheet). In the former case, the total density of the resulting polyurethane (foam) is usually 0.
It is preferable to carry out foaming so that the density is 8 g/cm' or more, preferably 0.5 g/cm', particularly preferably 0.8 g/cm3 or more. If the total density is less than 0.8 g/cm3, self-releasing occurs. Polyurethane resin with excellent properties cannot be manufactured.

Foaming is usually carried out using a foaming agent, but foaming can also be carried out by introducing a gas such as air during molding (air loading).

As the blowing agent, water and/or a halogen-substituted aliphatic hydrocarbon blowing agent (fluorocarbons such as trichloromonofluoromethane) can be used. The amount of water used is usually 0.4% or less, preferably 0.2% or less, based on the polymer polyol (polyether polyol). If the amount of water used exceeds 0.4%, carbon dioxide gas generated by the reaction will be exposed to the surface as bubbles, impairing the appearance of the molded product. In addition, in terms of rigidity, the increase in urea bonds increases hardness and increases brittleness, especially at low temperatures, which is undesirable. The amount of halogen-substituted hydrocarbon foaming agent to be used is the amount of resin raw materials (organic polyisocyanate, polymer polyol, chain extender) when water is not used.

It is usually 80% or less (preferably 2 to 20%) based on the weight (total of crosslinking agents), and 0.0% based on the weight of the polymer polyol.
When 4% of water is used in combination, it is usually preferably 20% or less (especially 0 to 15%) based on the weight of the resin raw material.

The ratio of polyisocyanate and active hydrogen atom-containing compound (polymer polyol, chain extender, crosslinking agent, water) may be the same as that of normal polyurethane (resin, foam).
For example, the O index is 95 to 120, especially 100 to 11.
0). It is also possible to form a polyisocyanurate (molecular weight, )ohm) using an excess of isocyanate (for example, as an index of 120 to 1000, especially 150 to 500).

In addition, if necessary, the reaction may be carried out in the presence of solvents (eighth class amines, organic tin compounds, organic lead compounds, etc.), surfactants (silicone surfactants, etc.), and other auxiliary agents. can. If necessary, pigments, fillers, flame retardants, solvents, internal mold release agents, thixotropic agents, etc. may be added.

The polyurethane manufacturing method may be the same as conventional methods, and either one-shot method or prepolymer method (quasi-prepolymer method) can be applied.

The polyurethane manufacturing method of the present invention is particularly useful for molding by the RIM method, but it can also be applied to other methods such as injection molding using a low-pressure foaming machine, spraying method, etc.

In the present invention (second invention), a method for producing a polyurethane molded article by molding by the RIM method can be carried out by a conventional method. For example, polyol with chain extender5. crosslinking agent,
Catalyst, blowing agent (water and/or fluorocarbons) if necessary
, pigment, and foam stabilizer are added and mixed uniformly as liquid A.
Prepare organic isocyanate in advance as liquid B,
Fill tanks A and B of the high-pressure foaming machine. The injection nozzle of the high-pressure foaming machine is connected in advance to the injection port of the seven molds, and liquids A and B are mixed using a mixing head, injected into a closed mold, and removed from the mold using a curing machine.

According to the present invention, at least a part of the polyol contains an ethylenically unsaturated monomer (a) and the number of functional groups is 5 or more and the equivalent is 1.
By reacting the polymer polyol (3) made from the block polyoxyalkylene polyol (b) containing 450 or more terminal polyoxyethylene chains with the organic polyisocyanate, the curing property is fast and the self-releasing property is strong. The strength of the resin is greatly improved, and a polyurethane with excellent initial strength can be obtained. In addition, the polymer polyol has excellent curing properties and requires only a small amount of catalyst, which avoids deterioration in the physical properties and heat resistance of polyurethane caused by the use of a large amount of catalyst.Furthermore, since the polymer polyol tends to exhibit rigidity, polyether polyol is The amount of chain extender used can be reduced compared to the case where the chain extender is used, a decrease in the elongation of the molded product can be avoided, and the amount of expensive isocyanate used can be reduced. In addition, since the amount of chain extender can be reduced,
It has the advantage that the concentration of urethane groups, which have adhesive strength with metals, etc., is relatively reduced, and the effect of self-releasing property is further enhanced. Furthermore, when painting polyurethane molded products, molded products that use a large amount of catalyst to speed up curing have the disadvantage that the paint color changes over time.
According to the present invention, such a problem does not occur. In addition, in the present invention, by using a chain extender in combination with the polyol (6), the verarethane bond concentration becomes higher than when it is not used in combination, and the calorific value further increases.
The initial strength increases and the curing properties can be further improved.

Further, it has excellent effects in that it improves the curing property while maintaining the viscosity of the urethane reactant low, and has a good balance between elongation and hardness in the physical properties of the molded product.

The present invention, in which the polymer polyol (4) and organic polyisocyanate are reacted and molded by the RIM method, is superior to conventional methods in the following points: 1) Excellent curing properties. Therefore, it is extremely effective in shortening the cycle time from injection to demolding, which is the original purpose of the RIM method.

11) Since the curing property is excellent even with a small amount of catalyst, the increase in viscosity when reacted with polyisocyanate is moderate, and it is possible to avoid insufficient filling and the formation of voids caused by poor flowability in the molded product.

11. Conventional methods for increasing curing properties require a large amount of catalyst, resulting in a significant deterioration in the physical properties of molded products, whereas the RIM method of the present invention requires only a small amount of catalyst, so molded products using catalysts Problems such as deterioration of physical properties and discoloration of painted molded products do not occur.

+V+ Excellent curing properties even with a small amount of catalyst, so the viscosity increase is mild when reacted with polyisocyanate, but it quickly reaches the cream state, which is the state before reaction curing, so it flows in the mold. When molding, the urethane flows and hardens without penetrating the uneven surfaces of the mold surface, so the adhesion between the mold surface and the urethane is weak, and the resistance during demolding is extremely small, making it difficult to use an external mold release agent. When sprayed one layer, it has a self-releasing property that allows it to be released continuously 5 times or more, especially 10 to 20 times.

Furthermore, the method of the present invention can be applied to various polyurethane manufacturing methods (foam, elastomer, sheet, etc.) other than the RIM method, particularly polyurethane manufacturing methods that conventionally required a relatively large amount of catalyst, and polyurethane manufacturing methods that use chain extenders. Demonstrates excellent effects.

The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. (The parts shown in the Examples are parts by weight.) The components used in the Examples and Comparative Examples are as follows.

Polyol I: 100 parts of a polyether polyol with a valency of 06 and 28 obtained by adding 182 parts of sorbitol to 9418 parts of propylene oxide and then 2400 parts of ethylene oxide, and 10 parts of acrylonitrile and 10 parts of styrene as ethylenically unsaturated monomers. Premixed monomers were reacted at a temperature of 125-186°C using 10 parts of azobisisobuty9nitrile as an initiator.

Polyol placement: 100 parts of polyether polyol with an OH value of 84 obtained by adding 6115 parts of propylene oxide and 1815 parts of ethylene oxide to a mixture of 92 parts of glycerin and 228 parts of sucrose to give an average functional group number of 5. A premixed monomer of 8 parts of acrylonitodyl and 2 parts of styrene as ethylenically unsaturated monomers was reacted at a temperature of 125 to 185°C with 0.5 part of azoisobutyronitrile as an initiator.

Polyol base: 100 parts of a polyether polyol with an OH value of 25 obtained by adding 2154 parts of ethylene oxide to 842 parts of sucrose with propylene oxide and 25 parts of acrylnitodyl as an ethylenically unsaturated monomer at 125 to 185°C. Reacted at temperature with 1.0 part of azobisisobuty9nitrile as an initiator.

Polyol ■: 622 parts of novolac with an average functional group number of 6, 7800 parts of nipropylene oxide, and 100 parts of OHHBO2 polyether polyol obtained by adding 2800 parts of ethylene oxide, and 125 to 180 parts of acrylonitrile as an ethylenically unsaturated monomer. Polyol V 146 parts of nitriethylenetetramine was reacted with 1.0 part of azoisobutyronitrile as an initiator at a temperature of ) 2888 parts of the mixture, 10 G parts of OHHE11 polyether polyol obtained by adding 1680 parts of ethylene oxide, and 10 parts of acrylonitrile and 10 parts of styrene as ethylenically unsaturated monomers were mixed in advance at 125 to 185°C. Reacted at temperature with 1.0 part of azobisisobuty9nitrile as an initiator.

Polyol ■: 21,000 parts of a polyether polyol obtained by adding 18,726 parts of propylene oxide to 182 parts of sorbitol and 2,100 parts of ethylene oxide were reacted with 774 parts of trimellitic anhydride, and then 2,400 parts of ethylene oxide were reacted. 100 parts of the 12-functional polyol with a valence of 28 and 18 parts of acrylonitrile as an ethylenically unsaturated monomer were reacted at a temperature of 125 to 185°C with 0.5 part of azobisisobutylnitrile as an initiator. Something.

Polyol A: 100 parts of OHHE11 polyether polyol obtained by adding 4908 parts of propylene oxide to 92 parts of glycerin and 2000 parts of ethylene oxide and 25 parts of acrylonitrile as an ethylenically unsaturated monomer at a temperature of 125 to 185°C. Reacted with 1.0 part of azobisisobutyronitrile as an initiator.

Polyol B: OHHBO2 polyether polyol obtained by adding 186 parts of pentaerythritol, 4660 parts of propylene oxide, 1200 parts of a mixture of propylene oxide and ethylene oxide at a ratio of 1:1 (weight ratio), and then 1500 parts of ethylene oxide. 100 parts of acrylonitrile and 12.5 parts of styrene as ethylenically unsaturated monomers were mixed at a temperature of 125 to 185°C with 1.0 part of azobisisobutyfurnitrile as an initiator. Something that reacted.

Polyol C: 100 parts of OHHE11 polyether polyol obtained by adding 8124 parts of propylene oxide to 76 parts of propylene glycol and then 800 parts of ethylene oxide, and 20 parts of acrylonitrile and 5 parts of styrene as ethylenically unsaturated monomers are mixed in advance. The obtained monomer was reacted at a temperature of 125 to 185°C with 1.0 part of azobisisobutyσ nitrile as an initiator.

Polyol D: OHHE11 polyether polyol obtained by adding 4908 parts of propylene oxide and 2000 parts of ethylene oxide to 92 parts of glycerin.

Polyol E: OHHE11 polyether polyol obtained by adding 8124 parts of propylene oxide and 800 parts of ethylene oxide to 76 parts of brobylene glycol.

Polyol C: A polyether polyol with an OH value of 47 obtained by adding 1,600 parts of propylene oxide to 76 parts of propylene glycol and then 700 parts of ethylene oxide.

Daiflon-11u: Daikin Industries, Ltd. Freon-11
Black toner: Carbon black, anti-aging agent (mixture of ultraviolet absorber, antioxidant, heat resistance improver, etc.) dispersed in polyether polyol.

DABCO88LV: Amine catalyst manufactured by Sankyo Air Products.

DABCODC-2: Catalyst manufactured by Sankyo Air Products.

DBTDL dibutyltin dilaurate foam U
L-28: Tin catalyst handled by Kasei Upjohn Co., Ltd.

Sumidur PC: Manufactured by Sumitomo Bayer Urethane Co., Ltd., modified D
I Rikei agent B-511: External mold release agent manufactured by Chukyo Yushi Co., Ltd. (Table 2
Table 1 shows the appearance and analytical values of the above polyol (used for molding of ゜-4, 6).

Table 1: Analytical Values of Each Polyol Example and Comparative Examples Using polyols I to ① and polyols A to F, high-density polyurethane was formed under the following conditions.

That is, the main components are polyol, chain extender, and catalyst.

Polyol component (A liquid), isocyanate component (B liquid)
into the raw material tanks of the high-pressure foaming machine, and separate A and B.
After mixing the liquid with a high-pressure foaming machine, the molded products in Table 1-2 to 5 have a thickness of 2.
．． 5mm r Width 400mm L Length 1000mm It is a flat plate type sealed mold (hereinafter abbreviated as flat type) that can control the temperature, and Tables 6 and 7 show the thickness of the molded product of the mold.
Polyurethane molded products with high density and medium density were created by injecting the mixture into flat plate molds with a diameter changed to 2 mm.

〔Molding condition〕

Discharge amount: Approx. 20-40 kg/min Discharge pressure (A liquid/B liquid) (kg/cm"G): 16
0/150 Injection time: Approximately 1.5 to 2.2 seconds Raw material temperature (both A and B liquids): Approximately 40°C Mold temperature: Approximately 70°C Isocyanate index: 105 Molding recipe and physical properties of the obtained high-density polyurethane Is Table-2~? It is as follows.

The molded polyurethane was left to stand under the following conditions and then measured. The molded products in Tables 8 and 5 were annealed at 120°C for 80 minutes after release from the mold, and then at 25°C x 60% RH. Measurement was carried out after being left for 8 days or more. The molded products in Table 7 were left for one week or more at 25° C. and 60% RH after being released from the mold, and then measured.

Note) The mold release time and physical properties are as follows.

Mold release time: The time from the start of injection of the reaction liquid into the mold until it is taken out Initial strength - ■: The time from the start of injection until no cracks appear when the end of the molded product is bent 180 degrees immediately after the molded product is removed from the mold ( seconds) 0 Initial strength-I: Immediately after taking out the molded product from the mold, punch it out with a No. 1 dumbbell to create a sample for tensile strength measurement.

Then, this sample was released from the mold for 60 seconds. Measure the tensile strength at the point of initial strength. It was a degree.

Self-release number: After applying one layer of external mold release agent to the mold,
The number of times that the same mold releasability as during coating can be obtained by performing continuous molding. The mold used was a flat plate mold and a real mold (Table 29, Table 4 shows the mold for producing passenger car bumpers, Table 5 shows the mold for producing passenger car handles). 0 Tear strength: Dumbbell B shape, cross head speed 50 mm Bending modulus: Sample 25X125X2.5mm
Span 40mm Loading nose 5R Crosshead speed 10mm/min Chart speed 100mm/min Heat sag: Sample 25 x 125 x 2.5 mm After leaving the above sample at 120°C for 1 hr with a 100 mm overhang.

Cool at room temperature for 80 minutes and measure the sagging distance. Fixed.

Brittle temperature: According to JIS K-6801.

Table-2 Molding recipe, mold release time and initial strength Table-8 Physical properties of molded products

Claims (1)

[Claims] 1. A method for producing polyurethane by reacting an organic polyisocyanate and a polymeric polyol in the presence of a blowing agent if necessary, in which an ethylenically unsaturated monomer ( Self-releasing property characterized by using a polymer polyol (2) made from a) and a block polyoxyalkylene polyol (b) containing a terminal polyoxyethylene chain having a functional group number of 5 or more and an equivalent weight of 1450 or more. A method for producing polyurethane having 2. (A) at 20% based on the weight of the polymeric polyol
Use the above amount. A manufacturing method according to claim 1. 8. The terminal polyoxyethylene chain content of (b) is 10% by weight or more. A manufacturing method according to claim 1 or 2. 4. The polyoxyethylene chain content of (b) is 10 to 80% by weight. The manufacturing method according to claim 1.2 or 8. 5, (2) and another high molecular polyol (5) or/and a low molecular active hydrogen-containing compound 0. 6. The manufacturing method according to claim 5, wherein @ is a terminal polyoxyethylene chain-containing diol and/or triol. ? , (Q is a low molecular diol. Claim 5
Or the manufacturing method described in Section 6. 8, (A), (2), (4-2 based on the total weight of Q)
Use 5% 0. The manufacturing method according to any one of claims 5 to 7. 9. Add the foaming agent to polyurethane with a total density of 0.5 g/cm.
The manufacturing method according to any one of claims 1 to 8, wherein an amount of 3 or more is used. 10. In a method for producing polyurethane by reacting an organic polyisocyanate and a polymeric polyol, if necessary in the presence of a blowing agent, as at least a part of the polyol, an ethylenically unsaturated monomer (a) and a functional group having a number of 5 or more and a terminal polyoxyethylene chain-containing block polyoxyalkylene polyol (b) having an equivalent weight of 1460 or more and a polymer polyol (g) formed by the RIM method. Manufacturing method. 11. The manufacturing method according to claim 10, wherein the organic polyisocyanate and polyol are introduced without applying a mold release agent to the mold each time.