JP2594117B2 - Method for producing polyurethane polymer gel - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a polyurethane polymer gel by a non-aqueous dispersion polymerization method.

[Prior Art] A method for producing a thermoplastic polyurethane powder by a non-aqueous dispersion polymerization method is known in Japanese Patent Publication No. 57-29485. The most important technique of this polymerization method is the selection of a dispersant. In particular, in the production of a polyurethane-based polymer gel, the performance of the dispersant greatly affects the success or failure of the formation of the polymer gel. When a conventionally known dispersant, for example, a copolymer of lauryl methacrylate and methyl methacrylate is used, the dispersing ability is low, the dispersion is insufficient depending on the polyurethane composition, and a particulate polymer gel is formed. There was a disadvantage that it was not generated.

The present inventor has conducted intensive studies on the dispersant composition and the dispersing method in order to improve the disadvantage of the poor dispersing performance of the conventional dispersing agent. By using a dispersant obtained by graft-polymerizing an ethylenically unsaturated monomer having a hydrocarbon side chain, and using a high shear stirrer to finely disperse the polyurethane raw material and the organic medium, a polyurethane with excellent dispersibility can be obtained. The inventors have found that a system-based polymer gel can be produced, and have completed the present invention.

That is, the present invention provides a method for producing a polyurethane polymer gel in which a polyisocyanate, a compound having two or more active hydrogen groups in a molecule, and a dispersion stabilizer are dispersed and reacted in an organic medium. As an ethylenically unsaturated monomer 20 to 400 having a side chain consisting of a hydrocarbon group having 6 or more carbon atoms per 100 parts by weight of a polyol having an unsaturated bond in the molecule.
A method for producing a polyurethane polymer gel, comprising using a compound obtained by reacting parts by weight.

The production of the polymer gel in the present invention can be performed by a method in which a polyisocyanate, an active hydrogen compound and a dispersion stabilizer are polymerized in an organic medium, and a polymer is formed in a discontinuous particle form using the organic medium as a continuous phase. it can.

The polyisocyanate that can be used in the present invention is a compound having at least two isocyanate groups. Examples of these include aromatic diisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate and isomers thereof, aliphatic diisocyanates such as 1,6-hexamethylene diisocyanate and 1,12-dodecane diisocyanate, cyclohexane 1 And alicyclic diisocyanates such as 1,4-diisocyanate and isophorone diisocyanate. In addition, isocyanate group-terminated compounds by the reaction of these compounds with an active hydrogen group-containing compound, isocyanate modified by carbodiimidization reaction, isocyanuration reaction, etc., polyisocyanate obtained by condensing aniline and formaldehyde as phosgenation, etc. can give. Also, methanol, n-butanol, benzyl alcohol, ε-caprolactam, methyl ethyl ketone oxime, phenol,
Polyisocyanates and the like can also be used by stabilizing some or all of them with a blocking agent having one active hydrogen in the molecule such as cresol.

Examples of the compound having two or more active hydrogen groups in the molecule that can be used in the present invention include (a) high molecular weight compounds having a molecular weight in the range of 400 to 5,000, such as polyester polyols, polyalkylene ether polyols, and polyalkylene ether polyols. Acrylic polyols, polyamines, polycarbonate polyols and the like can be mentioned.

(B) As a low molecular weight compound having a molecular weight of 400 or less, ethylene glycol, 1,4-butanediol, propylene glycol, diethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, diethanolamine, triethanolamine, etc. and as a normal chain extender The active hydrogen group-containing compound used is mentioned.

When a high molecular weight compound (A) having three or more active hydrogen groups in the molecule is used, these may be a compound (A) having two active hydrogen groups in the molecule or (B) Low molecular weight compounds having two or more active hydrogen groups in the molecule can be used in combination.

Further, when a high molecular weight compound having two active hydrogen groups in the molecule of (a) is used, three (3)
It is necessary to use a compound having two or more active hydrogen groups in combination.

The number of functional groups of the polyisocyanate and the compound having two or more active hydrogen groups in the molecule (hereinafter referred to as active hydrogen compound for short) can be freely selected according to the performance of the resulting polymer gel. Usually, when the number of functional groups of both the polyisocyanate and the active hydrogen compound is 2.0, the resulting polymer is linear and does not become a gel. Therefore, an active hydrogen compound having three or more active hydrogen groups is required, and a polyisocyanate having three or more functional groups can be used as necessary.

As the polyol having an unsaturated bond in the molecule used in the dispersion stabilizer of the present invention, for example, in the case of a polyester polyol, the raw material glycols, glycols containing unsaturated groups or unsaturated groups in some of the dibasic acids, etc. It can be produced using a contained dicarboxylic acid.

In the case of a polyether polyol, there may be mentioned those produced using an unsaturated group-containing glycol as a starting material.

Further, polyols obtained by esterification of a hydroxyl group-terminated polyester, polyether, polycarbonate or the like having a molecular weight of 2,000 or less with an unsaturated group-containing dicarboxylic acid are also included. Examples of the unsaturated group-containing glycol described herein include 2-butene-1,4-diol, glycerin monoallyl ether and the like. Examples of the unsaturated group-containing dicarboxylic acid include maleic acid and itaconic acid. The molecular weight and unsaturated bond concentration of the polyol having an unsaturated bond in the molecule that can be used in the present invention are not particularly limited, but the molecular weight is 3000 or less, and the unsaturated bond concentration is an unsaturated group per polyol molecule.
Up to 10 can be used, preferably in the range of 1 to 3 per molecule.

The production of the polyol having an unsaturated bond in the molecule of the present invention can be carried out by a usual method such as polyester and polyether.

Examples of the ethylenically unsaturated monomer having a side chain comprising a hydrocarbon group having 6 or more carbon atoms used in the dispersion stabilizer of the present invention include, for example, 1-octene, 1- or 2-nonene, 1- or 2 -Decene, 1- or 2-heptadecene, 2-methyl-1-nonene, 2-methyl-1-decene, 2-methyl-1-dodecene, 2-methyl-1-hexadecene, 2-methyl-1-heptadecene and the like A vinyl, propenyl or isopropenyl group-containing aliphatic linear unsaturated hydrocarbon, acrylic acid or methacrylic acid
-Esters with aliphatic alcohols having 6 or more carbon atoms such as ethylhexyl alcohol and hexyl alcohol, and alicyclic alcohols having 6 or more carbon atoms such as cyclohexanol, norbornanol and adamantanol. These can be used alone or in combination of two or more.

The dispersion stabilizer used in the present invention is obtained by reacting a polyol having an unsaturated bond with an ethylenically unsaturated monomer. These reactions are not particularly limited, and a usual polymerization method of an ethylenic monomer using a radical initiator or the like as a reaction initiator can be used. In this reaction, a solvent can be used if necessary. As the solvent, for example, all solvents used for polymerization of ordinary ethylenic monomers such as butyl acetate, cyclohexane, and n-heptane can be used. Further, the quantitative ratio of the polyol having an unsaturated bond to the ethylenically unsaturated monomer of the present invention is 100/20 to 10
0/400 (weight) is desirable. When the amount of the ethylenically unsaturated monomer is less than 20 parts by weight with respect to 100 parts by weight of the polyol, the performance as a dispersant is deteriorated, and it is necessary to increase the amount of the dispersant charged when producing a polymer gel. At an economic disadvantage. When the amount of the ethylenically unsaturated monomer exceeds 400 parts by weight with respect to 100 parts by weight of the polyol, the balance between polarity and non-polarity is lost, and the performance as a dispersant tends to decrease.

As the organic medium in the present invention, an organic medium which is insoluble in the produced polymer gel and has an inert property which does not inhibit the polymerization reaction can be used. These are, for example, n-
Examples thereof include aliphatic hydrocarbons such as hexane, octane, dodecane, and liquid paraffin, and alicyclic hydrocarbons such as cyclohexane. These solvents preferably have a boiling point of 60 ° C. or higher in consideration of the reaction temperature. These can be used alone or in a mixture of two or more. Also, a somewhat polar solvent such as ethyl acetate can be used if desired.

The content of the polyisocyanate, active hydrogen compound, and dispersion stabilizer for producing the polymer gel cannot be limited because it differs depending on the purpose of use of the polymer gel. Preferably the ratio is usually in the range 1.5 to 0.8. The content of the dispersion stabilizer is preferably 1 to 30% by weight based on the total of the polyisocyanate and the polyol. In the production of the polymer gel of the present invention, the amount ratio of the organic medium serving as the continuous phase to the polymer gel serving as the dispersed phase is preferably in the range of 10 to 80% by weight based on the total amount. From the viewpoint of production efficiency and cost, 40% by weight or more is particularly preferable.

The polymer gel in the present invention is a polyisocyanate,
Any known type of emulsifier may be used to disperse the reactant comprising the active hydrogen compound and the dispersion stabilizer in the organic medium. However, it is preferable that the stirrer part of the emulsifier has a structure with a high shear, and the rotation speed is high (1500
rpm or more). As a dispersion method, it is preferable to disperse as finely as possible in the initial stage of dispersion.

In this case, it is preferable to charge the active hydrogen compound and the dispersion stabilizer uniformly, then add the polyisocyanate, uniformly mix the mixture, add an organic medium, finely disperse the mixture, and perform a polyurethane conversion reaction. .

In the production of the polymer gel, a catalyst can be used to increase the reaction rate and complete the reaction.
Examples of this catalyst are dibutyltin dilaurate, stannous octoate, tertiary amines such as N-methylmorpholine and triethylamine, lead naphthenate, lead octoate, and the like. These catalysts are used in an amount necessary for providing a catalytic action, and the amount is usually preferably about 0.01 to 1% by weight based on the reactants. The catalyst may be charged at any time, but is preferably charged after the entire amount has been charged.

The particulate polymer gel obtained in this manner may be, before or after the reaction, if necessary, with an appropriate blocking agent having one active hydrogen in the molecule such as methanol, ε-caprolactam, methyl ethyl ketone oxime, or phenol. An addition reaction can be performed.

The particulate polymer gel dispersion thus obtained is
The polymer gel powder can be recovered by filtration or decantation and then drying under normal pressure or reduced pressure. The average particle size of the obtained polymer gel powder is 0.
Particles in the range of 1 to 2000 μm and more.

〔Example〕

Next, the present invention will be described in detail with reference to examples and comparative examples.

Example 1. (1) Synthesis of Polyol Having Unsaturated Bond in Molecule Stirrer, thermometer, distillation tower,
A N ₂ gas inlet tube was attached, 1000 g of polybutylene adipate having a molecular weight of 1,000 (trade name: Nipporan 4009, manufactured by Nippon Polyurethane Industry, hydroxyl value 100 mgKOH / g) and maleic anhydride 4
9 g is weighed and heated and mixed while flowing N ₂ gas. 140
After the condensed water was taken out of the system at ℃ 160 ° C., the reaction was continued while gradually reducing the pressure in the system. Finally, the reaction was completed at 190 ° C. and 30 mmHg for 4 hours, and the reaction was completed. The polyester had a hydroxyl value of 53 mgKOH / g and an acid value of 4.1 mgKOH / g. This polyester has a molecular weight of 2,100 and has an average of one double bond in one molecule.

(2) Synthesis of dispersion stabilizer A 500 ml four-necked flask was equipped with a stirrer, thermometer, dropping funnel and cooler, and 44 g of the polyol synthesized in (1) was added.
And weigh 99 g of butyl acetate. Heat and mix while flowing N ₂ gas into the system from the top of the dropping funnel. When the temperature reaches 110 ° C., a dissolution mixture of 51 g of 2-ethylhexyl methacrylate, 51 g of lauryl methacrylate and 2 g of benzoyl peroxide is started dropwise from the dropping funnel. 1
The dropping was completed in half an hour, and then the reaction was completed at 130 ° C. for 2 hours to complete the reaction. The hydroxyl value of this dispersion stabilizer is 11 mgKOH / g
Met.

(3) Synthesis of Polymer Gel A thermometer and a cooler were attached to the upper lid of an HV-M type homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), and a flask with a body length of 1 was set. In the flask, 17.8 of the dispersion stabilizer obtained in (2) was added.
g, 62 g of a multifunctional polyester polyol heated to 60 ° C. (trade name: Nipporan 800, manufactured by Nippon Polyurethane Industry Co., Ltd., hydroxyl value 290 mgKOH / g, average number of functional groups is 3 or more), and 27.4 g of hexamethylene diisocyanate are charged and uniformly mixed.
92.9 g of Shellsol 71 (manufactured by Shell Chemical Co., paraffin having a boiling point of 170 to 200 ° C., the same applies hereinafter) is added, and the mixture is stirred and dispersed at high speed (about 1500 rpm). Then dibutyltin dilaurate
Add 0.05g and reduce the stirring speed (about 1000rpm) 60 ℃
Incubate for 1 hour. The temperature was raised to 90 ° C. and the reaction was carried out for 5 hours to obtain a particulate polymer gel dispersed in Shellsol 71.
The dispersion was allowed to stand, the supernatant was removed by decantation, and dried under reduced pressure to obtain a polymer gel powder. This powder was a gel that did not dissolve in tetrahydrofuran and did not dissolve at 200 ° C., and had a main particle diameter of about 100 to 300 μm.

Example 2. (1) Synthesis of polymer gel The flasks used in Examples 1. and (3)
9.8 g of the dispersion stabilizer obtained in (2), ADEKA polyether
85.2 g of GR-2505 (manufactured by Asahi Denka, triol having a hydroxyl value of 69.0 mg KOH / g) and 9.1 g of Coronate T-80 (manufactured by Nippon Polyurethane Industry, Tillylenediisocyanate) are charged and uniformly mixed. Add 96.2 g of Shersol 71 and add high speed (about 1500
(rpm) to disperse. Next, 0.05 g of dibutyltin dilaurate was added, and the stirring speed was reduced (about 1000 r).
pm) at room temperature for 1 hour. The temperature was raised to 60 ° C. and the reaction was carried out for 4 hours to obtain a particulate polymer gel dispersed in Shellsol 71. The dispersion was allowed to stand, the supernatant was removed by decantation, and dried under reduced pressure to obtain a polymer gel powder. This powder is a highly water-absorbing gel with a main particle size of about 50
200200 μm.

Example 3 (1) Synthesis of Dispersion Stabilizer Example of frosco of the apparatus used in Examples 1. and (2)
1. Weigh 74.6 g of the polyol synthesized in (1) and 99.4 g of butyl acetate. Heat and mix while flowing N ₂ gas into the system from the top of the dropping funnel. When the temperature reaches 110 ° C, a dissolution mixture of 74.6 g of 2-ethylhexyl methacrylate and 1.5 g of benzoyl peroxide is started to be dropped from the dropping funnel. Dropping is completed in one and a half hours,
The reaction was completed at 130 ° C. for 2 hours to complete the reaction. The hydroxyl value of this dispersion stabilizer was 15 mgKOH / g.

(2) Synthesis of polymer gel In the flask of the apparatus used in Examples 1. and (3), (1)
13.0 g of the dispersion stabilizer obtained in the above, trimethylolpropane
Heated mixture of 50.0 g of 6.7 g of polyethylene adipate diol with molecular weight of 1000 (trade name: Nipporan 4002, manufactured by Nippon Polyurethane Industry, hydroxyl value 56 mgKOH / g), and liquid MDI
(Millionate MTL, manufactured by Nippon Polyurethane Industry, N
Charge 30.5 g with CO content 29.0%) and mix uniformly. Add 100 g of Schelsol 71 and stir and disperse at high speed (about 1500 rpm). Next, 0.02 g of dibutyltin dilaurate was added, and the mixture was allowed to react at 60 ° C. for 1 hour at a low stirring speed (about 1000 rpm). The temperature was raised to 80 ° C., and the mixture was reacted for 2 hours to obtain a particulate polymer gel dispersed in Shellsol 71. The dispersion was allowed to stand, the supernatant was removed by decantation, and dried under reduced pressure to obtain a polymer gel powder. This powder was a gel that did not dissolve in tetrahydrofuran and did not melt at 200 ° C., and had a main particle diameter of 50 to 250 μm.

Comparative Example 1. (1) Dispersion stabilizer In a flask similar to that used in Examples 1. and (2), 97.7 g of Shellsol 71 was charged, and N ₂ gas was flown into the system from the top of the dropping funnel. Heated. A mixture of 119 g (0.47 mol) of lauryl methacrylate prepared in advance, 27.5 g (0.28 mol) of methyl methacrylate and 2.5 g of benzoyl peroxide was added dropwise with stirring at the same temperature over 2 hours. The temperature was raised to 140 ° C., and the mixture was reacted for 4 hours to obtain a dispersion stabilizer.

(2) Synthesis of polymer gel The polymer gel was dispersed in the same manner as in Examples 1 and (3) except that 17.8 g of the dispersant of (1) was used as a dispersion stabilizer. As a result, the reactants were poorly dispersed in Shelsol 71 and formed into a lump.

Comparative Example 2 (1) Synthesis of Polyol Having Unsaturated Bond in Molecule Stirrer, thermometer, distillation tower,
Attach an N ₂ gas inlet tube and add methyl hexahydrophthalic anhydride
150 g, adipic acid 156 g, fumaric acid 27 g, lauryl alcohol 194 g, trimethylolpropane 78 g, Kajura E (manufactured by Shell Chemical, glycidyl ester of saturated fatty acid) 395 g were charged and reacted at 230 ° C. for 15 hours, and the acid value was 5.2 mg KOH / g. An ester having a hydroxyl value of 108 mgKOH / g was obtained. This was diluted to 70% solids with mineral spirits.

(2) Synthesis of polyester-modified vinyl resin dispersion stabilizer In the same 500 ml four-necked flask as in (1), 100 g of mineral spirit was heated to 90 ° C., and the polyol 8 of (1) was added.
5.7 g, isobutyl methacrylate 45 g, styrene 2
0 g, 35 g of 2-ethylhexyl acrylate and 0.8 g of benzoyl peroxide were added dropwise over 3 hours, 1.2 g of bezoyl peroxide was added, and the mixture was further reacted at the same temperature for 4 hours to obtain a dispersion having a solid content of 56.3% and a hydroxyl value of 23.7. A stabilizer was obtained.

(3) Synthesis of polymer gel The same raw materials as in Examples 1 and (3) were used and dispersed by the same method except that 17.8 g of the dispersant of (2) was used as a dispersion stabilizer. As a result, the reaction product was poorly dispersed in Shellsol 71 and became a lump.

〔The invention's effect〕

The polymer gel obtained by the present invention can be used as various modifiers such as an organic filler, a matting agent and an antiglare agent by adding the polymer gel dispersion as it is to paints, adhesives and the like. .

The polymer gel powder obtained by the present invention has a wide range of applications such as organic fillers, various modifiers, and functional polymers such as water absorption and hygroscopicity.

Claims (1)

(57) [Claims] 1. A method for producing a polyurethane polymer gel in which a polyisocyanate, a compound having two or more active hydrogen groups in a molecule and a dispersion stabilizer are dispersed and reacted in an organic medium, wherein: What was obtained by reacting 20 to 400 parts by weight of an ethylenically unsaturated monomer having a side chain composed of a hydrocarbon group having 6 or more carbon atoms with respect to 100 parts by weight of a polyol having an unsaturated bond in the molecule. A method for producing a polyurethane polymer gel, which is used.