JPS6360772B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for producing polyisocyanurate resin,
For details, please refer to the high density (0.5g/
This invention relates to a method for producing a polyisocyanurate resin (having a density higher than cm ³ ), which has excellent curing properties and high rigidity. It is known that polyisocyanurate foam has excellent heat resistance and flame resistance, and when producing such polyisocyanurate foam, polyether (polymer polyol) grafted with acrylonitrile is used. , is also known to be produced by cyclization of a grafted side chain acrylonitrile group to form a heterocyclic structure having high temperature stability (Japanese Patent Publication No. 34437/1983). However, these materials are highly foamed and brittle, and not only have poor impact resistance but also insufficient heat resistance. The present inventors have arrived at the present invention as a result of repeated studies to find a method for producing a resin with high rigidity. That is, the present invention provides a method for producing a polyisocyanurate resin by reacting an organic polyisocyanate and a polymeric polyhydroxy compound in the presence of a blowing agent in the presence of a trimerization catalyst. A polymer polyol manufactured from at least a part of a polymer polyol having an OH equivalent of 500 to 3000 and an ethylenically unsaturated monomer is used, (2) the isocyanate index is 200 to 500, and (3) (crosslinked) agent + organic polyisocyanate): the equivalent ratio of the polymeric polyhydroxy compound at least
(4) Density of polyisocyanurate resin is 0.5 g/
This is a method for producing a high-density polyisocyanurate resin having excellent rigidity characterized by a rigidity larger than mm ³ . The polyol used in the production of the polymer polyol used in the present invention has an OH equivalent of
500-3000 (preferably 1500-3000) high molecular weight polyether polyols, polyester polyols and mixtures thereof. Examples of polyether polyols include compounds having a structure in which an alkylene oxide is added to a polyfunctional compound containing an active hydrogen atom, such as a polyhydric alcohol, a polyhydric phenol, or a polycarboxylic acid. The above polyhydric alcohols include ethylene glycol,
Dihydric alcohols such as propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and neopentyl glycol, and trivalent or higher polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, and sucrose. Alcohol, etc. Polyhydric phenols include polyhydric phenols such as pyrogallol and hydroquinone, as well as bisphenol A.
bisphenols such as; polycarboxylic acids include aliphatic polycarboxylic acids such as succinic acid and adipic acid, and aromatic polycarboxylic acids such as phthalic acid, terephthalic acid and trimellitic acid.
Two or more kinds of the above-mentioned active hydrogen atom-containing compounds can also be used. Examples of the alkylene oxide to be added to the active hydrogen atom-containing compound include ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, and epichlorohydrin. The alkylene oxides may be used alone or in combination of two or more, and in the latter case, block addition, random addition, or a mixture of both may be used. Among these alkylene oxides, propylene oxide and/or ethylene oxide are preferred, but depending on the required performance, it is also preferable to use a small amount of other alkylene oxides (butylene oxide, tetrahydrofuran, styrene oxide, etc.) in combination with these alkylene oxides. . From the reaction point of view, particularly preferred is a combined system of propylene oxide and ethylene oxide (normally
30:70 to 95:5, especially 70:30 to 90:10).
The addition of alkylene oxide can be carried out in the usual manner, either without catalyst or in the presence of a catalyst (alkaline catalyst, amine catalyst, acidic catalyst) (particularly in the latter stages of alkylene oxide addition) at normal pressure or under pressure. It is done under pressure. Examples of the polyester polyol used in the polyester-based polymer polyol include condensed polyester polyols obtained by reacting low-molecular-weight polyols with dicarboxylic acids, and polyester polyols obtained by ring-opening polymerization of lactones. The above-mentioned low molecular polyols include ethylene glycol, propylene glycol,
Diols such as 1,6-hexanediol, diethylene glycol, neopentyl glycol, bis(hydroxymethyl)cyclohexane, bis(hydroxyethyl)benzene; trimethylolpropane, glycerin, etc., and mixtures thereof. Examples of dicarboxylic acids include succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, phthalic acid, terephthalic acid, dimer acid, and mixtures thereof. Examples of lactones include ε-caprolactone. Preferred among these polymer polyols are polyether polyols. Among the polyether polyols, preferred are those having 1 at the end.
It has grade OH. The terminal primary OH content is usually 10 to 80%, preferably 30 to 50%. As a polyether polyol with terminal primary OH,
Examples include those in which ethylene oxide is added at the end, usually 5 to 50% (by weight), preferably 5 to 30% (tipped type, balanced type). Terminal primary OH
By using a polymer polyol produced from a polyol, a high-density polyisocyanurate resin molded product with excellent moldability, high rigidity, impact resistance, and heat resistance can be obtained. In the present invention, the ethylenically unsaturated monomers used in the production of the polymer polyol used include the following. (a) Acrylic acid, methacrylic acid, and their derivatives: acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid and their salts, methyl acrylate, methyl methacrylate, dimethylaminoethyl methacrylate, acrylic acid amide, methacrylic acid amide, etc. . (b) Aromatic vinyl monomers: styrene, α-methylstyrene, etc. (c) Olefinic hydrocarbon monomers: ethylene, propylene, butadiene, isobutylene, isoprene, 1,4-pentadiene, etc. (d) Vinyl ester monomer: vinyl acetate, etc. (e) Vinyl halide monomers: vinyl chloride, vinylidene chloride, etc. (f) Vinyl ether monomers: vinyl methyl ether, etc. Among these, preferred are acrylonitrile, methyl methacrylate, styrene, and butadiene. Particularly preferred is acrylonitrile, a combination of acrylonitrile and styrene (styrene:acrylonitrile weight ratio 0:100 to 60:40)
It is. Although the proportions of polyol and monomer used in polymer polyols can vary over a wide range,
Usually, the amount of the ethylenically unsaturated monomer (or polymer) is 2 to 70 parts by weight, preferably 5 to 40 parts by weight, per 100 parts by weight of the polyol. The production of polymer polyols from polyols and ethylenically unsaturated monomers can be carried out by conventional methods. For example, a method in which an ethylenically unsaturated monomer is polymerized in a polyol in the presence of a polymerization catalyst (such as a radical generator) (U.S. Pat. No. 3,383,351,
Special Publication No. 39-24737, Special Publication No. 47-47999, Publication No.
50-15894) or a method in which a polymer obtained by prepolymerizing the above monomers and a polyol are graft-polymerized in the presence of a radical generator (Japanese Patent Publication No. 1973-
47597). The former method is preferred. Polymerization catalysts (radical generators) used in polymerization reactions include azo compounds, peroxides,
Persulfates, perborates, etc. can be used, but azo compounds are practically preferred. The amount used is not particularly limited, and is, for example, 0.1 to 20 parts by weight, preferably 0.1 to 15 parts by weight, per 100 parts by weight of the ethylenically unsaturated monomer (or polymer). The above polymerization can also be carried out in the presence of a solvent such as toluene, xylene and the like. Reaction temperature is usually 50-170℃
Preferably it is 90-150°C. Examples of the crosslinking agent used in the present invention include active hydrogen-containing low-molecular polyfunctional compounds such as polyols, polyamines, and amino alcohols. Examples of low-molecular polyols include polyhydric alcohols (mentioned as raw materials for polyether polyols); and low-mole alkylene oxide adducts of active hydrogen atom-containing polyfunctional compounds such as polyhydric alcohols, polyhydric phenols, and polycarboxylic acids; Amines (for example, ammonia, monoamines such as butylamine, aliphatic polyamines such as ethylenediamine, trimethylenediamine, diethylenetriamine, cyclohexylenediamine,
Alicyclic polyamines such as dicyclohexylmethanediamine, isophoronediamine, phenylenediamine, tolylenediamine, xylylenediamine,
Low molar alkylene oxide adducts of aromatic polyamines such as diphenylmethanediamine and polyphenylmethanepolyamine, heterocyclic polyamines such as piperazine and aminoethylpiperazine, and alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine. can give. Preferred low molecular weight polyols are ethylene glycol, 1,4-butanediol, trimethylolpropane, glycerin and alkylene oxide adducts thereof. The polyamines include the above aliphatic, alicyclic,
Examples include aromatic and heterocyclic polyamines. Examples of amino alcohols include ethanolamine and propanolamine. Among the crosslinking agents, preferred are low molecular weight polyols. The equivalent weight of the crosslinking agent used in the present invention is usually 30 to 140, preferably 30 to 100. The number of functional groups is usually 2 to 8, preferably 2 to 4. In the case of polyol, 3 to 4 are preferable. In the present invention, in addition to the crosslinking agent and the polymer polyol, other polymer polyols can be used in combination, if necessary. Examples of other polymer polyols include the polyether polyols and polyester polyols mentioned in the section of raw materials for polymer polyols. In the present invention, the amount of crosslinking agent used can be varied depending on the purpose and required performance, but generally (crosslinking agent + organic polyisocyanate) and a polymer polyhydroxy compound (polymer polyol and other polymers as necessary) are used. The equivalent ratio of polyol) is at least 20:1, and when trying to obtain a product with good rigidity and heat resistance, it is particularly 30:1 to 150:1.
40:1 to 80:1 is preferable, and when trying to obtain a product with good impact resistance, it is less than 30:1, especially 20:1 to
25:1 is preferred. The equivalent ratio of the organic polyisocyanate crosslinking agent is 84 or more: 16 or less, especially 84.5:15.5 or more
87:13 is preferred. The equivalent ratio of crosslinking agent to polymeric polyhydroxy compound is usually 2.5:1 to 30:1. The amount of polymer polyol is usually 70 to 90% (based on the total weight of the polyhydroxy compound and crosslinking agent, the same applies hereinafter), preferably 85 to 95%. If the amount of polymer polyol is less than the above range, heat resistance and rigidity will be insufficient. As the organic polyisocyanate used in the present invention, those conventionally used in polyurethane production can be used. For example, aliphatic polyisocyanates (hexamethylene diisocyanate, lysine diisocyanate, etc.), alicyclic polyisocyanates (hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, etc.), aromatic polyisocyanates [tolylene diisocyanate (TDI)] ,
diphenylmethane diisocyanate (MDI), naphthylene diisocyanate, xylylene diisocyanate, etc.] and mixtures thereof. Preferred among these are aromatic diisocyanates, particularly preferred are TDI,
It is MDI. These polyisocyanates are crude polyisocyanates, such as crude TDI, crude
MDI [crude diaminodiphenylmethane {condensation product of formaldehyde and aromatic amine or mixture thereof: mixture of diaminodiphenylmethane and a small amount (e.g. 5 to 20% by weight) of trifunctional or higher functional polyamine}]: polyallylpolyisocyanate (PAPI)] or modified polyisocyanates, such as liquefied MDI (carbodiimide modification, trihydrocarbyl phosphate modification, etc.) or excess polyisocyanate (TDI, MDI
It can also be used as a free isocyanate-containing prepolymer obtained by reacting a polyisocyanate with a polyol, or they can be used in combination (for example, a modified polyisocyanate and a prepolymer can be used in combination). The polyols used in the production of the above prepolymer include polyols with an equivalent weight of 30 to 200;
For example, glycols such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; triols such as trimethylolpropane and glycerin; high functional polyols such as pentaerythritol and sorbitol; and alkylene oxides thereof (ethylene oxide and/or propylene oxide). Additives can be mentioned. Among these, those having 2 to 3 functional groups are preferred. The free isocyanate group content of the modified polyisocyanate and prepolymer is usually 10 to 30%, preferably 15 to 30%, particularly preferably
It is around 25%. As the trimerization catalyst used in the present invention, known ones can be used. Such catalysts include tertiary amines or salts thereof, metal salts of carboxylic acids or phenols, phosphines, strong bases, etc.
For example, JP-A-52-47898, JP-A-46-42386,
One example is the one described in Special Publication No. 46-25107. Specific examples include 2,4,6-tri(dimethylaminomethyl)phenol, N-methylmorpholine, and sodium or potassium benzoate. Preferred are tertiary amines, especially 2,4,
This is a combination system of 6-tris(dimethylaminomethyl)phenol, N,N',N''-tris(dimethylaminopropyl)hexahydro-S-triazine, and an alkali metal carboxylic acid salt.
The amount of catalyst used is usually 0.1 to 20 parts, preferably 0.5 to 5 parts, per 100 parts of the organic polyisocyanate. Examples of the blowing agent used in the present invention include water and/or halogen-substituted aliphatic hydrocarbon blowing agents (such as Freon-11). The amount of blowing agent used is such that the total density of the polyisocyanurate resin is usually 0.5 g/cm ³ or more, preferably 0.8
Use an amount that is at least g/cm ³ . The amount of blowing agent is 5×x% of the halogen-substituted aliphatic hydrocarbon blowing agent based on the weight of the resin raw material (total of polyisocyanate, polyhydroxy compound, and crosslinking agent).
(preferably 2×x% or less) and water 1×
y% or less (preferably 0.5×y% or less).
(However, x and y are numbers from 0 to 1 that satisfy x + y = 1.) If the amount of blowing agent is larger than the above, the mold equipment will be huge in order to obtain a high-density molded product. In order to obtain a large molded product, which is one of the features of , a large amount of cost is required, which is not desirable. In addition, the rigidity of the polyisocyanurate resin becomes low (flexural modulus is lower than 8000 kg/cm ² ), and impact resistance and heat resistance are reduced. In the present invention, when producing polyisocyanurate resin, the isocyanate index is usually
200-500 preferably 300-500. Increasing the isocyanate index increases heat resistance and rigidity, but decreases impact resistance. Further, if necessary, the reaction can be carried out in the presence of other catalysts (tertiary amines, organic tin compounds, organic lead compounds, etc.), surfactants (silicone surfactants, etc.), and other auxiliaries. Pigments, fillers, etc. can also be added if necessary. The method for producing the polyisocyanurate resin may be the same as conventional methods, and any of the one-shot method, prepolymer method, and (semi-prepolymer method) can be applied. For example, the foam manufacturing method described in Japanese Patent Publication No. 41-13037 and Japanese Patent Publication No. 46-42386 can be used. The polyisocyanurate resin production method of the present invention is particularly useful for molding by the reaction in-die extraction molding method (RIM method), but other methods such as molding by open molding, PVC integral molding method, etc. ), slab method,
It can also be applied to various methods such as on-site construction, spraying, injection, coating, and impregnation. A polyisocyanurate resin molded article can be produced by a conventional method using the RIM method. For example, a catalyst, a blowing agent (water or Freon 11), and if necessary, a pigment and a foam stabilizer are added to the polyol and mixed uniformly to form the A liquid, and an organic isocyanate is prepared in advance as the B liquid. Fill the A and B liquid tanks. Connect the injection nozzle of the high-pressure foaming machine and the injection port of the mold in advance, mix liquids A and B with the mixing head, and inject into the closed mold.
Demold after curing. The high-density polyisocyanurate resin obtained by the present invention has higher rigidity than conventional polyisocyanurate resins (flexural modulus of 8000 kg/cm ² or more), and is quick to demold and has low flyability, resulting in excellent moldability and impact resistance. is also good. sealant,
It also has excellent effects when used in paints, adhesives, etc. Since the resin obtained by the present invention has high rigidity, it can be used in various fields of application, such as electrical products such as sketch covers, power distribution boxes, lamp and light accessories, and battery boxes; acoustic products such as speaker boxes; frying pan handles, For household items such as iron handles and bathroom cabinets, and as parts for automobiles and aircraft, such as air filter boxes, ignition distributors, heaters and their boxes, internal accessories, and luggage. It is particularly useful in applications where rigidity is required, such as in shells, lattice components, and dart board substrates. 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 represent parts by weight.) The components used in the following examples and comparative examples are as follows; Polyol 1: 92 parts of glycerin, 4408 parts of propylene oxide, and 500 parts of ethylene oxide. 25 parts of acrylonitrile were reacted with 100 parts of a polyether having an equivalent weight of 1666 and a terminal oxyethylene chain content of 10% by weight at a temperature of 100 to 120°C using 1.0 part of azobisisobutyronitrile as an initiator. A polyol with a hydroxyl value of 28. Crosslinking agent 1: A low-molecular polyol with an equivalent weight of 94 and a hydroxyl value of 600 obtained by adding 120 parts of propylene oxide and 120 parts of ethylene oxide to 136 parts of pentaerythritol. Isocyanate 1: Isocyanate with a free isocyanate content of 26%, which is a mixture of a prepolymer synthesized from 745 parts of MDI and 100 parts of triethylene glycol, and an isocyanate obtained by converting a part of MDI into carbodiimide. Example 1 A foam according to the present invention (No. 1
-3) and a comparative example foam (No. 4) were manufactured, and the physical properties of the obtained foams were measured. The results are shown in Table 1. Molding conditions: Mixing time 10 seconds, raw material temperature 25°C, mold release time 3 minutes, mold temperature 50°C In Table 1, the physical property values are as follows. (1) Density (g/cm ³ ): Indicates the density of each measurement sample. (2) Bending strength (Kg/cm ² ) and bending modulus (Kg/cm ² ): A molded product measuring 1.27 cm x 1.27 cm x 12.7 cm was measured with a span of 10 cm. (3) Impact strength (Kg·cm/cm ² ): Measured using the Izot impact strength measurement method without notches. (4) Heat distortion temperature (°C): According to ASTM D-648. The load used is 18.6Kg/cm ² . 【table】

Claims (1)

[Claims] 1. An organic polyisocyanate and a polymeric polyhydroxy compound in the presence of a trimerization catalyst and a blowing agent. In a method for producing a polyisocyanurate resin by reacting the resin, (1) as at least a part of the polymeric polyhydroxy compound, a polymeric polyol having an OH equivalent of 500 to 3000 and an ethylenically unsaturated monomer are used. (2) the isocyanate index is set to 200 to 500, and (3) the equivalent ratio of (crosslinking agent + organic polyisocyanate):polymer polyhydroxy compound is at least
20:1, and (4) a method for producing a high-density polyisocyanurate resin having excellent rigidity, characterized by making the density of the polyisocyanurate resin greater than 0.5 g/cm ³ . 2 The blowing agent is water and/or halogen-substituted aliphatic hydrocarbon blowing agent Claim 1
A method for producing a polyisocyanurate resin as described in Section 1. 3 Based on the total weight of the organic polyisocyanate and the polymeric polyhydroxy compound, a halogen-substituted aliphatic hydrocarbon blowing agent in an amount of 5 x x% or less and water in an amount of 1 x y% or less (where x, y are x + y = 1
A method for producing a polyisocyanurate resin according to any one of claims 1 to 2, wherein the reaction is carried out in the presence of a number satisfying 0 to 1. 4 Terminal primary containing 10 to 80% of the polymer polyol
4. The method for producing a polyisocyanurate resin according to any one of claims 1 to 3, which is a polyether polyol having an OH content and terminally added with 5 to 50% by weight of ethylene oxide. 5 Equivalent ratio of organic polyisocyanate:crosslinking agent
The method for producing a polyisocyanurate resin according to any one of claims 1 to 4, wherein the polyisocyanurate resin is 84/16 or more.