JP7069541B2 - Allophanate group-containing polyisocyanate composition - Google Patents

Description

The present invention relates to an allophanate group-containing polyisocyanate composition containing an allophanate group-containing polyisocyanate prepolymer derived from a diphenylmethane diisocyanate and a monool component, and at least one siloxane compound.

Modules using hollow fibers or flat membranes as separation membranes are widely used in industrial fields such as water treatment and medical fields such as blood treatment. In particular, the demand for water purifiers, artificial kidneys, artificial lungs, and the like is extremely increasing.

Generally, a polyurethane resin having excellent flexibility, adhesiveness, and chemical resistance at room temperature is widely used as a film sealing material for adhesively fixing a converged end of a module using a hollow or flat membrane fiber separation film. Has been done.

Therefore, in order to improve the productivity of the membrane module for the polyurethane resin used for such applications, there is an increasing demand for lowering the viscosity of the isocyanate group-terminated prepolymer and the polyol.

As such a polyurethane resin, for example, as an isocyanate component, a polyurethane resin obtained by curing a polyisocyanate prepolymer obtained from liquefied diphenylmethane diisocyanate and a castor oil or a castor oil derivative polyol with a polyol has been proposed (). For example, see Patent Document 1).

Further, the allophanate group-containing polyisocyanate prepolymer derived from diphenylmethane diisocyanate (hereinafter, also referred to as MDI) and monool has a low viscosity, less precipitation of MDI at low temperature, and is easy to handle. It is useful in the field of sealing materials and is widely applied.

Alofanate group-containing polyisocyanate prepolymers derived from MDI and aliphatic monoalcohols and polyoxypropylene glycol monoalkyl ethers are known (see, for example, Patent Document 2), but MDI and urethanes using these allophanates are used. In the resin composition, there is a problem that a large amount of extract is eluted from the urethane resin, and a solution is desired.

Japanese Unexamined Patent Publication No. 53-98398 Japanese Unexamined Patent Publication No. 2009-030059

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a urethane resin having a small amount of extract that elutes when the urethane resin is extracted with a solvent.

As a result of diligent studies, the present inventors have found that the MDI-based allophanate group-containing polyisocyanate composition can solve the above-mentioned problems by containing a predetermined amount of a siloxane compound, and have completed the present invention. ..

That is, the present invention includes the following embodiments.

(1) An allophanate group-containing polyisocyanate composition containing an allophanate group-containing polyisocyanate prepolymer (C), which is a reaction product of a diphenylmethane diisocyanate (A) and a monool compound (B), and a siloxane compound (D). A polyisocyanate composition containing an allophanate group, which comprises 1 to 100 ppm of the siloxane compound (D) in the allophanate group-containing polyisocyanate prepolymer (C).

(2) The allophanate group-containing polyisocyanate according to (1) above, wherein the monool compound (B) contains at least one selected from the group consisting of an aliphatic monoalcohol and a polyoxypropylene glycol monoalkyl ether. Composition.

(3) A polyurethane resin-forming composition containing the allophanate group-containing polyisocyanate composition according to (1) or (2) above and a polyol component.

(4) A sealing material made of a cured product of the polyurethane resin-forming composition according to (3) above.

(5) A membrane module characterized by being sealed with the sealing material according to (4) above.

By using the allophanate group-containing polyisocyanate composition obtained by the present invention, it is possible to obtain a urethane resin having a small amount of extract eluted from the urethane resin.

The allophanate group-containing polyisocyanate composition of the present invention comprises an allophanate group-containing polyisocyanate prepolymer (C) which is a reaction product of diphenylmethane diisocyanate (A) and a monool compound (B), and at least one siloxane compound (D). ).

As the MDI (A) used in the present invention, any commonly available MDI monomer can be used, and the isomer of the MDI monomer is usually 0 to 5% by weight of 2,2'-MDI and 2,4'-MDI. 0 to 95% by weight and 4,4'-MDI are 5 to 100% by weight.

As the MDI (A) used in the present invention, it is preferable to use the above-mentioned MDI in order to obtain a polyisocyanate prepolymer containing a lower viscosity allophanate group, but if a certain degree of high viscosity is allowed, a polypeptide MDI is used. Polymethylenepolyphenylene polyisocyanate, which is In that case, the content of polymethylene polyphenylene polyisocyanate is preferably 0 to 50% by weight in the isocyanate component used. If it exceeds 50% by weight, the viscosity becomes too high and insoluble matter may be formed.

Examples of the monool compound (B) used in the present invention include aliphatic monoalcohols, aromatic monoalcohols, alicyclic monoalcohols, aromatic aliphatic monoalcohols, polyoxypropylene glycol monoalkyl ethers and the like.

Examples of the aliphatic monoalcohol include methanol, ethanol, 1- and 2-propanol, 1- and 2-butanol, 1-pentanol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2. -Pentanol, 2-ethyl-1-butanol, 1-heptanol, 1-octanol, 2-octanol, 2-ethylhexanol, 3,5-dimethyl-1-hexanol, 2,2,4-trimethyl-1-pen Tanol, 1-nonanol, 2,6-dimethyl-4-heptanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentanol, 1-hexadecanol, Fatal monoalcohols such as 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatricontanol, 1-oleyl alcohol, 2-octyldodecanol, and Examples thereof include a mixture thereof.

The molecular weight of the aliphatic monoalcohol is preferably 32 to 1500, and more preferably 100 to 1000 from the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin.

Examples of the aromatic monoalcohol include phenol, cresol and the like.

Examples of the alicyclic monoalcohol include cyclohexanol and methylcyclohexanol.

Examples of the aromatic aliphatic monoalcohol include benzyl alcohol and the like.

Examples of the polyoxypropylene glycol monoalkyl ether include the above-mentioned reaction products of the aliphatic monoalcohol and polyoxypropylene glycol, which include polyoxypropylene methyl ether, polyoxypropylene ethyl ether, polyoxypropylene butyl ether, and polyoxypropylene. Examples thereof include -2-ethylhexyl ether, polyoxypropylene oleyl ether, polyoxypropylene-2-octyldodeca ether and mixtures thereof.

The molecular weight of the polyoxypropylene glycol monoalkyl ether is preferably 90 to 1500. The molecular weight is more preferably 150 to 1000 from the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin.

In the present invention, the monool compound (B) preferably contains at least one selected from the group consisting of aliphatic monoalcohols and polyoxypropylene glycol monoalkyl ethers.

The siloxane compound (D) used in the present invention is not particularly limited as long as it is a compound having a siloxane bond. Examples thereof include polydimethylsiloxane, phenyl-modified polysiloxane, hydrogen-modified polysiloxane, amine-modified polysiloxane, silanol-modified polysiloxane, carbinol-modified polysiloxane, mercapto-modified polysiloxane, and mixtures thereof.

Of these, polydimethylsiloxane, amine-modified polysiloxane, silanol-modified polysiloxane, carbinol-modified polysiloxane, and mercapto-modified polysiloxane are preferable, and polydimethylsiloxane is particularly preferable from the viewpoint of ease of handling and availability.

The amount of the siloxane compound (D) added is in the range of 1 to 100 ppm in the allophanate group-containing polyisocyanate composition, preferably in the range of 3 to 50 ppm. If it is less than 1 ppm, the amount of eluate does not decrease, and if it exceeds 100 ppm, the separation of the siloxane compound causes the appearance of the allophanate group-containing polyisocyanate composition and the polyurethane resin composition to deteriorate.

Examples of the catalyst (E) used in the present invention include zinc acetone, metal carboxylates such as zinc, lead, tin, copper and cobalt, mixtures thereof, tertiary amines and tertiary amino alcohols, and 4 Examples thereof include grade ammonium salts and mixtures thereof.

The amount of the catalyst (E) added is preferably in the range of 1 to 1000 ppm, more preferably in the range of 10 to 500 ppm. If it is 1 ppm or less, the reaction is slow, and if it is 1000 ppm or more, the prepolymer is heavily colored, which is not preferable.

As the catalytic poison (F) used in the present invention, an acidic substance is suitable, for example, anhydrous hydrogen chloride, sulfuric acid, phosphoric acid, monoalkyl sulfate ester, alkyl sulfonic acid, alkylbenzene sulfonic acid, mono or dialkyl phosphoric acid ester, benzoyl chloride. And Lewis acid are also included. The addition amount is preferably equal to or more than the molar number of the catalyst (E), and is preferably 1.0 to 1.5 times the molar equivalent.

The isocyanate group content of the allophanate group-containing polyisocyanate composition in the present invention is preferably 3 to 30% by weight, more preferably 5 to 28% by weight, and 10 from the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin. Most preferably, it is ~ 26% by weight.

The viscosity of the allophanate group-containing polyisocyanate composition at 25 ° C. in the present invention is preferably 50 to 10000 mPa · s, more preferably 100 to 5000 mPa · s, and 200 to 3000 mPa · s from the viewpoint of excellent molding processability of the polyurethane resin. Most preferably, it is s.

In the allophanate group-containing polyisocyanate composition of the present invention, MDI (A) and the monool compound (B) are subjected to a urethanization reaction, and then a predetermined amount of a catalyst (E) is added to form an allophanate to form a catalyst poison (F). It can be obtained by stopping the reaction with the above method and adding the siloxane compound (D). The siloxane compound (D) may be added before the urethanization reaction or before the allophanate reaction.

The urethanization reaction is preferably carried out in the temperature range of 40 to 80 ° C. until the target NCO content is reached. Below 45 ° C, there is a risk of crystal precipitation of the monomer MDI, and above 80 ° C, there is a risk of producing side reactants.

The allophanate reaction is preferably carried out in the temperature range of 90 to 130 ° C. until the target NCO content is reached. If the temperature is lower than 90 ° C, the progress of the reaction may be slowed down, and if the temperature exceeds 130 ° C, a side reaction product may be produced.

During the allophanate formation reaction, if the catalytic poison (F) is added before the target NCO content is reached, the urethane product obtained by the reaction between MDI (A) and the monool compound (B) remains, resulting in a large amount of eluate. There is a fear. Further, if the reaction proceeds too much and becomes lower than the target NCO content, the viscosity may become high and the moldability may deteriorate.

In the present invention, the polyol component (G) that reacts with the allophanate group-containing polyisocyanate composition to form the urethane resin-forming composition is not particularly limited as long as it is a compound containing an active hydrogen group. Can also be used. Examples thereof include low molecular weight polyols, polyether polyols, polyester-based polyols, polylactone-based polyols, castor oil-based polyols, polyolefin-based polyols, hydroxyl group-containing amine-based compounds, and the like. These can be used alone or in combination of two or more. Among these, castor oil-based polyol is preferable because it has excellent chemical resistance and elution resistance.

Low molecular weight polyols include divalents such as ethylene glycol, diethylene glycol, propylene glycol, 1,2-, 1,3- or 1,4-butanediol, 1,5-pentanediol, 3-methyl-1, 5-Pentanediol, 1,6-hexaneglycol, 1,8-octanediol, 1,10-decandiol, neopentyl glycol, hydrogenated bisphenol A, etc., and trivalent or higher, such as glycerin, trimethylol Examples thereof include propane, hexanetriol, pentaerythritol, sorbitol and the like. The molecular weight of the small molecule polyol is preferably 50 to 200.

Examples of the polyether polyol include an alkylene oxide (alkylene oxide having 2 to 4 carbon atoms, for example, ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the low molecular weight polyol, a ring-opening polymer of the alkylene oxide, and the like. Specific examples thereof include polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, and chipped ether which is a copolymer of ethylene oxide and propylene oxide. The number average molecular weight of the polyether polyol is preferably 200 to 7,000, and more preferably 500 to 5,000 from the viewpoint of excellent molding processability at the time of producing the membrane sealing material.

Examples of the polyester-based polyol include polycarboxylic acids (aliphatic saturated or unsaturated polycarboxylic acids such as azelaic acid, dodecanoic acid, maleic acid, phthalic acid, itaconic acid, lysinoleic acid, dimerized linoleic acid, and aromatic polycarboxylic acids. Examples thereof include a polyol obtained by condensation polymerization of an acid (for example, phthalic acid, isophthalic acid, terephthalic acid) and a polyol (at least one selected from the group consisting of the above low molecular weight polyol and a polyether polyol). The number average molecular weight of the polyester-based polyol is preferably 200 to 5000, and the number average molecular weight is more preferably 500 to 3000 from the viewpoint of excellent molding processability at the time of producing the membrane sealing material.

Polylactone-based polyols include polymerization initiators such as glycols and triols, ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone and the like, and β-methyl-σ-valerolactone and the like. Examples thereof include a polyol obtained by addition-polymerizing at least one selected from the above group in the presence of a catalyst such as an organic metal compound, a metal chelate compound, and a fatty acid metal acyl compound. The number average molecular weight of the polylactone-based polyol is preferably 200 to 5000, and the number average molecular weight is more preferably 500 to 3000 from the viewpoint of excellent molding processability at the time of producing the membrane sealing material.

The castor oil-based polyol is a linear or branched polyester obtained by reacting a castor oil fatty acid with a polyol (at least one selected from the group consisting of the above low molecular weight polyol and a polyether polyol), for example, diglyceride of a castor oil fatty acid. , Monoglyceride, mono of castor oil fatty acid and trimethylalkane, di or triester, mono of castor oil fatty acid and polypropylene glycol, di, or trimester and the like. The number average molecular weight of the castor oil-based polyol is preferably 300 to 4000, and the number average molecular weight is more preferably 500 to 3000 from the viewpoint of excellent molding processability at the time of producing the membrane sealing material.

Examples of the polyolefin-based polyol include polybutadiene-based polyols in which a hydroxyl group is introduced at the end of a copolymer of polybutadiene or butadiene and styrene or acrylonitrile.

In addition, a polyether ester-based polyol obtained by addition-reacting an alkylene oxide such as ethylene oxide or propylene oxide to a polyester having at least one selected from the group consisting of a carboxyl group and a hydroxyl group at the terminal can be mentioned.

Examples of the hydroxyl group-containing amine compound include amino alcohols and the like as oxyalkylated derivatives of amino compounds.

Examples of the amino alcohol include N, N, N', N'-tetrakis [2-hydroxypropyl] ethylenediamine, N, N, N', N, which are propylene oxide or ethylene oxide adducts of amino compounds such as ethylenediamine. '-Tetrakiss [2-hydroxyethyl] ethylenediamine and the like, mono, di and triethanolamine, N-methyl-N, N'-diethanolamine and the like can be mentioned. Among these, propylene oxide or an ethylene oxide adduct of an amino compound such as ethylenediamine is preferable, and N, N, N', N'-tetrakis [2-hydroxypropyl] ethylenediamine is more preferable. By using N, N, N', N'-tetrakis [2-hydroxypropyl] ethylenediamine, excellent effects are exhibited by improving processability during molding and reducing eluate.

When the hydroxyl group-containing amine compound is used, the blending amount of the polyol component (G) is preferably in the range of 1 to 30% by mass, and particularly preferably in the range of 5 to 25% by mass. If the proportion in the polyol component (G) is less than 1% by mass, the effect of the hydroxyl group-containing amine compound cannot be obtained, and if it exceeds 30% by mass, the reactivity becomes too high, the workability is deteriorated, and the filling property is impaired. In addition, there may be a problem that the hardness of the obtained sealing material becomes too high.

The allophanate group-containing polyisocyanate composition of the present invention can be reacted with the polyol component (G) to obtain a polyurethane resin-forming composition, which can be used as various sealing materials. In particular, since the amount of extract eluted from the obtained polyurethane resin is small, it is useful as a sealing material for membrane modules constituting medical and industrial separation devices.

As the polyurethane resin-forming composition for a film sealing material in the present invention, the molar ratio (isocyanate group / active hydrogen group) of the isocyanate group of the allophanate group-containing polyisocyanate composition to the active hydrogen group of the polyol component (G) is 0. It is preferably in the range of .8 to 1.6, more preferably in the range of 0.9 to 1.2, and particularly preferably in the range of 1.0 to 1.1. According to the composition obtained in such a mixing ratio, a composition having excellent durability and an extremely small amount of eluate from the urethane resin in water can be obtained.

In the present invention, if necessary, a metal compound catalyst such as an organic tin compound or triethylenediamine (triethylenediamine) that promotes the reaction between the isocyanate group of the allophanate group-containing polyisocyanate composition and the active hydrogen group of the polyol component (G). Use known urethanization catalysts such as tertiary amine catalysts such as TEDA), tetramethylhexamethylenediamine (TMHMDA), pentamethylethylenetriamine (PMDETA), dimethylcyclohexylamine (DMCHA), bisdimethylaminoethyl ether (BDMAEA). can do.

When the polyurethane resin-forming composition for a film-sealing material in the present invention is used to obtain a film-sealing material for a module using a hollow or flat membrane-like fiber separation film, the composition is reacted at room temperature or gelled. In order to shorten the time and reduce the mixed viscosity, the allophanate group-containing polyisocyanate composition and the polyol component (G) may be heated to 30 to 60 ° C. for each reaction. In order to shorten the gelation time, the molding temperature may be set to a temperature condition of 0 to 100 ° C., preferably 20 to 80 ° C., more preferably 30 to 60 ° C., if necessary.

As an index of the extract, 10 times the weight of methanol is added to the cured product of a 1 cm square polyurethane resin-forming composition, shaken in an atmosphere of 25 ° C. for 24 hours, filtered and dried, and the resin weight before and after extraction. The extraction rate calculated from can be used. Usually, it is preferably 2.0% by weight or less, but particularly preferably 1.5% by weight or less from the viewpoint of safety.

Further, in order to apply the polyurethane resin-forming composition of the present invention to a sealing material, it is necessary to be transparent. In particular, in the sealing material for a membrane module constituting a medical or industrial separation device, it is required that there is no turbidity visually in order to confirm the inclusion of foreign matter.

Hereinafter, the present invention will be described, but the present invention is not construed as being limited to these examples. In the following, "%" means "% by weight" unless otherwise specified.

The following components were used in Examples and Comparative Examples.

[Diphenylmethane diisocyanate (A) (component A)]
a1; 4,4'-MDI (Tosoh Milionate MT, isocyanate group content = 33.6%)
a2; Mixture of 2,4'-MDI and 4,4'-MDI (Tosoh Milionate NM, isocyanate group content = 33.6%)
[Monool compound (B) (B component)]
b1; Polyoxypropylene glycol mono2-ethylhexyl ether (Lion's Leocon 1015H, OHV = 70 mgKOH / g)
b2; 2-Octyldodecanol (Kao Corporation Calcol 200GD)
[catalyst]
Catalyst E; Acetylacetone Zinc (manufactured by Tokyo Kasei)
[Catalyst poison]
Catalyst poison F; Benzoyl chloride (manufactured by Tokyo Kasei)
[Siloxane compound]
Siloxane Compound D; Polydimethylsiloxane (ACP-1500 manufactured by Toray Dow Corning)
[Polyol component (G)]
g1; Castor oil (Castor oil LAV manufactured by Itoh Oil Chemicals, OHV = 160mgKOH / g)
g2; N, N, N', N'-tetrakis [2-hydroxypropyl] ethylenediamine (EDP-300 manufactured by ADEKA, hydroxyl value = 760 mgKOH / g)
In addition, in Examples and Comparative Examples, the predetermined amount means each composition amount shown in Table 1 and Table 2.

[Example 1]
A predetermined amount of a1 was added to a 1-liter four-necked flask, and the temperature was adjusted to 50 ° C. while stirring under a nitrogen stream. Then, a predetermined amount of b1 was added while stirring, and the temperature was raised to 90 ° C. after the heat generation of the urethanization reaction subsided. When the internal temperature became stable at 90 ° C., a predetermined amount of catalyst E was added and reacted at 90 ° C. for 4 hours, and a predetermined amount of catalyst venom F and siloxane compound D were added to stop the reaction to obtain prepolymer C-1. Prepolymer C-1 was a pale yellow transparent liquid. The properties are shown in Table 1.

[Examples 2 to 9, Comparative Examples 1 to 3]
The components A and B were changed to the compositions shown in Table 1, and the prepolymer was synthesized by the same operation as in Example 1. The properties are shown in Table 1.

[Polyol G preparation example]
70 parts by weight of the polyol (g1) and 30 parts by weight of the polyol (g2) were mixed to prepare a polyol component G-1.

[Examples 10 to 18, Comparative Examples 4 to 6]
The urethane resin composition was molded with the composition shown in Table 2.

[Extraction test procedure]
The amount of extract shown in Table 2 was calculated from the following test results.

1) Each of the polyurethane resin-forming compositions according to Examples 10 to 18 and Comparative Examples 4 to 6 was defoamed under reduced pressure (1 minute at 10 to 20 kPa), and then on a release paper to a thickness of about 1 to 2 mm. The sheet was molded so as to be.

2) This was cut into 1 cm squares, 10 times the weight of methanol was added to the weight of the resin, and the mixture was shaken in an atmosphere of 25 ° C. for 24 hours.

3) After filtration and drying, the extraction rate was calculated from the weight of the resin before and after extraction.

[Appearance evaluation procedure]
The appearances of the prepolymers C-1 to C-12 and the resin composition were visually evaluated, and those in which turbidity could not be confirmed were regarded as good, and those in which turbidity was observed even slightly were regarded as turbidity.

As shown in Table 2 above, the polyurethane resin compositions according to Examples 10 to 18, Comparative Example 4 and Comparative Example 5 were all pale yellow and transparent, but Comparative Example 6 showed turbidity in appearance. .. In addition, all of the polyurethane resin compositions according to the comparative examples had a high extraction rate.

According to the present invention, it is possible to provide a polyurethane resin-forming composition having a small amount of extract. The membrane sealing material using the polyurethane resin-forming composition of the present invention has many excellent performances, especially excellent low extraction rate. Therefore, the sealing material of the present invention can be suitably used as a sealing material for a membrane module constituting a medical or industrial separation device. Specific examples of the medical and industrial separation devices include a plasma separator, an artificial lung, an artificial kidney, an artificial liver, and a household / industrial water treatment device.

Claims (5)

An allophanate group-containing polyisocyanate composition containing an allophanate group-containing polyisocyanate prepolymer (C) which is a reaction product of diphenylmethane diisocyanate (A) and a monool compound (B), and a siloxane compound (D). ,
The siloxane compound (D) is contained in the allophanate group-containing polyisocyanate prepolymer (C) at 1 to 100 ppm.
An allophanate group-containing polyisocyanate composition, wherein the siloxane compound (D) is polydimethylsiloxane . The allophanate group-containing polyisocyanate composition according to claim 1, wherein the monool compound (B) contains at least one selected from the group consisting of an aliphatic monoalcohol and a polyoxypropylene glycol monoalkyl ether. A polyurethane resin-forming composition containing the allophanate group-containing polyisocyanate composition according to claim 1 or 2 and a polyol component. A sealing material made of a cured product of the polyurethane resin-forming composition according to claim 3 . A membrane module characterized by being sealed by the sealing material according to claim 4 .