JPH0749519B2 - Polyurethane composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyurethane composition used for forming a breathable porous polyurethane resin layer and the like.

[Conventional technology]

Organic solvent composition of polyurethane resin, that is, 20% by weight or less of polyvinyl acetate, polyvinyl chloride, polyacrylic acid ester based on the organic solvent solution of polyurethane resin or polyurethane resin which does not impair the physical properties of polyurethane resin and polyurethane resin, Water in organic solvent solutions of polymers such as polyamides and polyesters, and compositions in which additives such as colorants, antistatic agents and stabilizers against light and heat are added to these solutions, with the aid of a surfactant. A water-in-oil type water-containing polyurethane dispersion that has been mixed and dispersed by applying and impregnating it, then evaporating the organic solvent first, and then evaporating the water to give a breathable porous polyurethane resin. It is used to form layers and the like. In general, such a water-in-oil type polyurethane dispersion has a tendency that when the standing time from the time of preparation to the time of use is a little long, dispersed particles of water associate with each other to become coarse and unevenly distributed, or a film is formed on the surface. There is a problem that it is easily formed. However, when the surfactant previously invented by the present inventors, which is known from JP-B-57-27232, is used as the surfactant, the surfactant has the flexibility, antistatic property and stain of the artificial leather. A water-in-oil type polyurethane dispersion having relatively good stability can be obtained for the purpose of improving the preventive property.

[Problems to be Solved by the Invention]

A water-in-oil polyurethane dispersion using a surfactant described in JP-B-57-27232 is also formed so that a film can be formed on the surface when left in a closed or open atmosphere at a relatively high temperature for a long time. There is a problem that the dispersed particles of water become coarse and unevenly distributed. Further, when trying to solve this problem by increasing the amount of the surfactant used, the mechanical properties of the polyurethane resin to be formed are significantly deteriorated, or the surfactant easily exudes to the surface of the polyurethane resin layer or the like. It becomes a problem to become.

The present invention has been made in order to solve the above-mentioned problems, and reduces the mechanical properties of a polyurethane resin to be formed, or facilitates the leaching of a surfactant onto the surface of a polyurethane resin layer or the like. It is possible to disperse a relatively large amount of water with fine particles by using a surfactant in the range where there is no such phenomenon, and a film is formed on the surface or the dispersed particles of water become coarse even if left for a long time under rough conditions. An object of the present invention is to provide a polyurethane composition capable of forming a water-in-oil type polyurethane dispersion liquid that is easy to store and is not unevenly distributed.

[Means for Solving the Problems]

As a result of repeated research on a surfactant capable of stably dispersing a large amount of water in the form of fine particles, the present inventors have found that an interface composed of a polyalkylene oxide-modified polysiloxane obtained by adding a polyalkylene oxide component to a polysiloxane component. The weight ratio of the polyethylene oxide chain in the polyalkylene oxide component to the surfactant is 20.
Using ~ 80% surfactant in the polyurethane composition,
It has been found that the target polyurethane composition can be obtained.

The present invention has been made based on this finding, an organic solvent composition of an organic solvent and a polyurethane resin having a water solubility of 1 to 50 g / 100 g of an organic solvent, and water is added to mix the water. A polyurethane composition capable of forming a dispersed water-containing polyurethane dispersion, comprising a polyalkylene oxide-modified polysiloxane obtained by adding a polyalkyl oxide component to a polysiloxane component, comprising a polyethylene oxide chain in the polyalkylene oxide component. The weight ratio of the surfactant to the surfactant is 20 to 80%, and the surfactant is contained in the ratio of 0.1 to 15% of the weight of the polyurethane resin. A polyurethane composition is characterized in that 90% or less of water can be added to form a stable hydrous polyurethane dispersion.

[Work]

The polyurethane composition of the present invention can disperse water in a relatively large amount in the form of fine particles due to the above-mentioned constitution, and the formed water-containing polyurethane dispersion is stable. A polyurethane resin layer or the like having a porous structure with excellent mechanical properties can be stably formed, and an effect that a surfactant does not exude to the surface of the formed polyurethane resin layer or the like is provided. .

〔Example〕

The polyurethane resin in the present invention has, for example, a molecular weight
Polyalkylene ether diols such as 1000 to 4000 polyethylene ether glycol, polypropylene ether glycol, polytetramethylene ether glycol, etc. and polyester diols such as polyethylene adipate, polybutylene adipate and polyhexamethylene adipate having a molecular weight of 1000 to 4000 are long chain diols, Diphenylmethane-4,4'-diisocyanate, Tolylene-2.4
-Diisocyanate, phenylene diisocyanate, xylene diisocyanate, dicyclohexylmethane-4
.4'-diisocyanate, hexamethylene diisocyanate, etc. as diisocyanates, ethylene glycol, 1,4-butanediol, cyclohexane-1,4-
Diol, α ・ α'-p-xylene diol, 1.4-bis (β-hydroxyethoxy) benzene, 2.2-bis [4- (β-hydroxyethoxy) phenyl] propane, propylenediamine, hexamethylenediamine, etc. As the low molecular weight chain extender, a known polyurethane resin obtained by melt polymerization, solution polymerization or slurry polymerization can be used. As the organic solvent for the solution or slurry polymerization, those having a water solubility of 1 to 50 g / 20 ° C. per 100 g of the organic solvent are preferably used, and specifically, methyl ethyl ketone, diethyl ketone, methyl propyl ketone, methyl isobutyl. Ketone, ethyl formate,
Propyl formate, butyl formate, methyl acetate, ethyl acetate, etc., or by mixing them with a water-miscible organic solvent such as tetrahydrofuran, acetone, dioxane, etc. and a water-immiscible organic solvent such as benzene, toluene, xylene, etc. For example, those having water solubility adjusted to the above range are used.

The organic solvent composition of the polyurethane resin, in addition to the polyurethane resin, within the range that does not impair the physical properties of the polyurethane resin,
20% or less of the weight of polyurethane resin, polyvinyl acetate,
It may contain polymers such as polyvinyl chloride, polyacrylic acid ester, polyamide and polyester. Further, additives such as colorants, antistatic agents, flame retardants, stabilizers against heat and light may be added. As the organic solvent for this composition, the boiling point of the organic solvent for slurry polymerization is 12
A substance having a temperature of 0 ° C. or lower, particularly 100 ° C. or lower is preferably used, and when the composition contains a polymer other than the polyurethane resin, a polymer in which the polymer is also dissolved is used. Therefore,
In the case of slurry-polymerized polyurethane resin, the composition may be prepared using the polymerized slurry without separating the polyurethane resin. The composition has a concentration of polyurethane resin or, if it also contains other polymers, a concentration of 5 to 5, including
The content of 30% by weight is preferable for obtaining a water-in-oil type polyurethane dispersion liquid that is widely used for coating, impregnation and the like.

As the surfactant, an alkylene oxide is added to a polysiloxane by a known method, or a polysiloxane component having an active group such as a hydroxyl group or an amino group at a terminal or a side chain is added with polyoxyarylene glycol and a polyisocyanate. And a hydrophilic component consisting of polyethylene oxide in polyoxyalkylene oxide and a hydrophobic component consisting of a polysiloxane component and a component excluding polyethylene oxide in polyoxyalkylene oxide. If the weight ratio of the polyethylene oxide chain in the polyalkylene oxide component to the surfactant in this surfactant is less than 20%, it may be due to the lack of hydrophilic groups. When the storage temperature of the water-containing polyurethane dispersion becomes high due to deterioration of dispersion stability, association and uneven distribution of water-dispersed particles are likely to occur, and when it exceeds 80%, water tends to remain due to formation of a polyurethane resin layer or the like. Then, if the temperature is raised so as to evaporate the water sufficiently, the porous material is likely to collapse. Further, the molecular weight of the polysiloxane component and the polyoxyalkylene oxide component, which are the hydrophobic components of the surfactant, is preferably 740 or more, and when it is less than 740, the surfactant easily exudes from the surface of the polyurethane resin layer or the like after it is formed. Become. Then, the molecular weight of the surfactant is 1200 or more, particularly 2000 or more and 12000 or less, or a method using a diisocyanate as described in JP-B-57-27232 for the polysiloxane component and the polyalkylene oxide component. It is preferable that the polysiloxane component and the polyalkylene oxide component obtained by bonding with each other or the polyalkylene oxide component are bonded with urethane or urea. That is, the molecular weight of the surfactant has the same effect as the molecular weight of the polysiloxane component, and when the bond is made of a urethane bond or a urea bond, the affinity with the polyurethane resin becomes high, and it is formed. This is because the risk of the surfactant leaching from the polyurethane resin layer or the like is reduced.

The amount of surfactant added is 0.1% by weight of polyurethane resin.
If it is less than, it becomes impossible to finely disperse water, or the dispersion becomes unstable, and it becomes impossible to obtain a hydrous polyurethane dispersion liquid which stably forms a polyurethane resin layer or the like having a fine porous structure, If it exceeds 15% by weight, water cannot be easily evaporated from the formed polyurethane resin layer or the like, or mechanical properties of the polyurethane resin layer or the like are deteriorated.

The optimum amount of water to be dispersed in the organic solvent composition of the polyurethane resin containing a surfactant varies depending on the concentration of the polyurethane resin and the amount of the surfactant added, but the maximum criticality for gelation due to the addition of water. 90% or less of the amount of water added, preferably 50 to 90%. If the amount of water added exceeds 90% of the maximum critical water addition amount, coarse water-dispersed particles will be mixed and the polyurethane resin will gel, resulting in a dense porous breathable polyurethane resin. It becomes impossible to form a layer or the like, or the mechanical properties of the polyurethane resin layer or the like are deteriorated.

Hereinafter, specific examples and comparative examples of the present invention will be shown.

Examples 1 (1) to (4) 1) Polymerization of polyurethane slurry 300 parts of polytetramethylene glycol (molecular weight 2190),
296 parts of polycaprolactone diol (molecular weight 1810), 30 parts of diethylene glycol, 315 parts of diphenyl 4.4'-diisocyanate are dissolved in 235 parts of methyl ethyl ketone,
After adding 0.2 parts of triethylenediamine and reacting at 60 ° C for 90 minutes, 710 parts of a mixed solvent having a methylethylketone / toluene mixing ratio of 9/1 was added, and then 60 parts of tetramethylene glycol was added to bring the temperature to 65 to 70 ° C. Stirring under controlled conditions, as the viscosity rises, a mixed solvent of methyl ethyl ketone / toluene mixing ratio 9/1 is poured and reacted for about 4 hours to produce a polyurethane slurry (A) with a viscosity of 1800 cps / 70 ° C / 20% polyurethane. Got

2) Synthesis of polyalkylene oxide-modified polysiloxane Polyethylene oxide (PEO) is further added after addition reaction of polypropylene oxide (PPO) with a caustic catalyst to dimethyl polysiloxane having two hydroxyl groups at the end and an average molecular weight of 3400. The reaction was performed to synthesize the surfactants shown in Table 1, respectively.

3) Preparation and Storage of Hydrous Polyurethane Dispersion After adding surfactants to 100 parts of the above-mentioned polyurethane slurry (A) in the ratios shown in Table 1, water was slurried with stirring with a homomixer (A). 28 out of 100
A W / O type aqueous dispersion was prepared by adding little by little so as to become a part. Put the resulting dispersion in a closed Erlenmeyer flask and
Immerse and store in a constant temperature bath adjusted to ℃, and after 3 hours W /
The size of the water-dispersed particles in the O-type water dispersion was examined with a light transmission optical microscope, and the results are shown in Table 1.

4) The structure of the porous sheet was adjusted and the W / O type aqueous dispersion stored at 40 ° C for 3 hours was coated on a nylon film with a layer of about 30 g / m ² and then the temperature was adjusted to 60
5 minutes at 100 ° C after drying for 5 minutes at 40 ° C and 40% relative humidity
Min dried.

The characteristics of the obtained polyurethane resin sheet, moisture permeability, water pressure resistance, and porous structure are shown in Table-1.

Example 2 1) Synthesis of polyalkylene oxide-modified polysiloxane 180 parts of dimethylpolysiloxane diol having two hydroxyl groups at the end and having an average molecular weight of 900 and diphenylmethane 4 ·
After reacting with 76 parts of 4'diisocyanate at 90 ° C for 60 minutes, a Pluronic type polypropylene / ethylene oxide diol 400 having a molecular weight of 500 for polypropylene oxide and 1500 for polyethylene oxide
A urethane group-containing polyalkylene oxide-modified polysiloxane was synthesized by adding another part and reacting for another 60 minutes.

2) Preparation of Polyurethane Dispersion After adding 100 parts of the polyurethane slurry (A) prepared in Example 1 to 7.5 parts of the urethane group-containing polyalkylene oxide-modified polysiloxane obtained in 1) above,
While stirring with a homomixer, up to 30 parts of water was added and mixed.

When the obtained dispersion was stored at 40 ° C, the water-dispersed particles were 3
It was stable at 1 μm or less even after the lapse of time, and was stable even after 1 day when stored at 25 ° C. When a porous sheet was prepared in the same manner as in Example 1 using the dispersion liquid after the storage, the porous structure was fine, the water vapor transmission rate was 6.5 mg / cm ² hr, and the water pressure resistance was 1500 mm.
Met.

Comparative Example 1 Table 2 shows the results of the production of a porous sheet in the same manner as in Example 1 except that the addition amount of PEO in the synthesis of polyalkylene oxide-modified polysiloxane was 15%.
When the W / O type dispersion obtained in this example was allowed to stand at 40 ° C,
The water-dispersed particles tended to associate with each other and become coarse, and the dispersion stability of water was insufficient, and the porous sheet prepared from this dispersion had pinholes and coarse pores, which was not preferable.

Comparative Example 2 The results of carrying out the production of a porous sheet in the same manner as in Example 1 except that the addition amount of PEO in the synthesis of the polyalkylene oxide-modified polysiloxane was 90% are shown in Table-2.
When the W / O type dispersion obtained in this example was allowed to stand at 40 ° C,
The dispersion stability of water was good, but the porous sheet obtained using this dispersion had a solid feel and low water vapor transmission rate.

Comparative Examples 3 and 4 Example 1 (2) in Preparation of Hydrous Polyurethane Dispersion
Preparation of a porous sheet was carried out in the same manner as in Example 1 except that the addition amount of the surface active agent was changed to 0.05 part and 20 parts. If the added amount of surfactant is 0.05 parts, the W / O type dispersion liquid should be 40 ℃.
When left to stand, the water-dispersed particles tended to agglomerate and the porous structure became coarse, which was not preferable. Further, when the addition amount of the surfactant is 20 parts, the dispersion stability of water is improved, but the evaporation of the solvent during formation of the porous sheet is suppressed,
The amount of residual solvent increased in the same drying time as in Example 1, and the obtained porous sheet became full. Therefore, when the solvent was slowly removed over a period of time, fine porosity could be formed, but the strength of the porous sheet was poor and it was not sufficient.

Comparative Example 5 The maximum critical water addition amount of the polyurethane dispersion prepared in Example 1- (2) was 45 parts with respect to 100 parts of the polyurethane dispersion. On the other hand, when 50 parts of water was added to 100 parts of the same polyurethane dispersion and mixed, gelation of the polyurethane resin occurred and a stable W / O type dispersion could not be formed.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY The polyurethane composition of the present invention is a hydrous polyurethane that is stable because it can disperse water in a relatively large amount in the form of fine particles and forms a polyurethane resin layer having a dense breathable porous structure with excellent mechanical properties. The dispersion liquid can be obtained, and the surfactant is prevented from leaching out from the formed polyurethane resin layer or the like.

Claims (1)

[Claims] 1. An organic solvent composition of an organic solvent and a polyurethane resin having a water solubility of 1 to 50 g / 100 g of an organic solvent, wherein water can be added to form a hydrous polyurethane dispersion liquid in which water is mixed and dispersed. In a polyurethane composition, a surfactant comprising a polyalkylene oxide-modified polysiloxane obtained by adding a polyalkylene oxide component to a polysiloxane component, wherein the weight ratio of polyethylene oxide chains in the polyalkylene oxide component to the surfactant is
20-80% of the surfactant is the weight of polyurethane resin
It is contained in a ratio of 0.1 to 15%, and characterized by being able to form a stable hydrous polyurethane dispersion by adding 90% or less of the maximum critical water addition amount in which gelation occurs when water is added. A polyurethane composition.