JPH0621144B2 - Method for producing polyamino acid urethane resin molding - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a polyamino acid urethane resin molded product by curing reaction of a polyamino acid urethane resin.

Conventionally, polyamino acid urethane resin (hereinafter abbreviated as PAU) has been used in the field of textile processing, especially in the field of artificial leather and waterproof cloth.

[Conventional technology]

A fiber-processed product coated with PAU with excellent moisture permeability and texture is obtained. However, these resins are so-called solution type dissolved in a solvent, and gelation or coagulation after coating is usually performed only by removing the solvent. That is, it does not involve cross-linking due to a chemical reaction during gelation or solidification. Therefore, there is a drawback in that the adhesive strength to the adherend, solvent resistance, and heat resistance are poor.

[Object of the Invention]

As a result of repeated studies for the purpose of improving the above-mentioned drawbacks, the inventors of the present invention have found that if a specific method is adopted, the adhesion force to an adherend, solvent resistance, and heat resistance are improved when forming a coating film of PAU. That is, the present invention has been reached. That is, in the present invention, (A) α-amino acid-N-
A carboxylic acid anhydride, (B) a urethane prepolymer having an isocyanate group at the terminal and (C) water, hydrazine, or an amino acid urethane resin liquid having an amino group at the terminal obtained by reacting with an organic amine having active hydrogen , A curing agent composed of a polyisocyanate compound having an isocyanate equivalent of 80 or more, and an equivalent ratio of NCO / NH
_2. A polyamino acid urethane resin molded product characterized by being mixed in a ratio of ₂ > 1 to obtain a mixed liquid, and then applying or impregnating the mixed liquid on an adherend, followed by desolvation and curing by a dry method. Exists in the manufacturing method.

[Structure of Invention]

 The present invention will be described in detail below.

First, in the present invention, α-amino acid-in an organic solvent
A polyamino acid urethane having an amino group at the terminal by mixing N-carboxylic acid anhydride and a urethane prepolymer having an isocyanate group at the terminal and then adding water, hydrazine or an organic amine having an active hydrogen to react with each other. Obtain a resin liquid. The organic solvent referred to here is chlorinated aliphatic hydrocarbons such as dichloromethane, 1,2-dichloroethane, 1,1,2-trichloroethane, chloroform, 1,1,2,2-tetrachloroethane, benzene, and toluene. , Aromatic hydrocarbons such as xylene, chlorinated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene, acetic acid esters such as ethyl acetate and butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone , Dimethylformamide, diethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylene carbonate, dimethylsulfoxide, dioxane, tetrahydrofuran, hexamethylphosphoramide, etc. And the like.

The α-amino acid-N-carboxylic acid anhydride (hereinafter abbreviated as α-amino acid NCA) used in the present invention has 2 to 2 carbon atoms such as glycine, alanine, leucine, isoleucine, valine, and α-aminopeptanoic acid. 12 neutral amino acids, β-benzylaspartic acid, γ-methyl-L-glutamate, γ-methyl-D-glutamate, γ-benzyl-L-glutamate, and other monoesterified acidic amino acids, ε-acrylidine, δ-acyl An anhydride such as an α-ω-diaminocarboxylic acid derivative in which the ω-amino group such as ortinin is protected by an appropriate masking group, or an α-amino acid derivative such as o-acetylthreonine is used.

Urethane prepolymers with isocyanate groups at the ends are polyisocyanate compounds and polyols in the equivalent ratio NC
Obtained by reacting under the condition of O / OH> 1. As the polyisocyanate component, aromatic diisocyanates, aliphatic diisocyanates and alicyclic diisocyanates are usually used alone or in a mixture thereof. For example, toluene-2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, metaphenylene diisocyanate, 3,
3'-dimethyl-4,4'-biphenyl diisocyanate,
Meta-xylene diisocyanate, para-xylene diisocyanate, 1,6-hexane diisocyanate, 1,10-decamethylene diisocyanate, 1,4-cyclohexane diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 3-isocyanate methyl-3,5,5 −
Trimethylcyclohexyl isocyanate (isophorone diisocyanate) and the like can be mentioned.

Examples of the polyol component include polyether polyol and polyester polyol, or a mixture thereof. Examples of the polyether polyol include polypropylene ether glycol, polyethylene polypropylene ether glycol, polytetramethylene ether glycol, polypentamethylene ether glycol, glycol having an aromatic ring obtained by adding propylene oxide or ethylene oxide to bisphenol A, and the like. can give.

Typical examples of polyester polyols include polycaprolactone polyols, or those obtained by reacting diols such as ethylene glycol and 1,4-butanediol with dibasic acids such as adipic acid and sebacic acid.

Further, a special polyol such as a polyol obtained by adding caprolactone to polytetramethylene ether polyol or polypropylene ether polyol, or a polysiloxane polyol can also be used.

The number average molecular weight of these polyethers, polyesters and special polyols is preferably 200 to 300 or more.

The water used in the present invention means ordinary water and may be tap water, non-demineralized water, or demineralized water.

Hydrazine may be either anhydrous hydrazine or hydrous hydrazine, and hydrous hydrazine is industrially advantageous in terms of safety.

Organic amines having active hydrogen include aliphatic primary diamines such as ethylenediamine and propanediamine, alicyclic secondary diamines such as piperazine, aromatic diamines such as phenylenediamine and diphenylmethanediamine, and dihydrazide having a hydantoin ring. For example, 1,3-bis (hydrazidecarboethyl) -5-isopropylhydantoin is suitable.

The weight ratio of the α-amino acid NCA and the urethane prepolymer in obtaining the polyamino acid urethane resin solution having an amino group at the terminal is 90:10 to 10:90, and more preferably 80:20 to 20:80. It is a range. This weight ratio is determined according to the physical properties of the intended product. For example, when giving an artificial leather silver surface having excellent texture and moisture permeability, it is preferable that the α-amino acid NCA is large. When importance is attached to adhesiveness and texture, it is preferable that the content of urethane prepolymer is large.

The amount of hydrazine and the organic amine having active hydrogen used is preferably 1/2 equivalent or more, more preferably 2/3 equivalent or more, based on the isocyanate group of the urethane prepolymer as an amino group.

Water reacts with an isocyanate group to generate an amino group and can be used as a substitute for an amine.

The amount of the organic solvent used is such that the resin concentration in the PAU liquid of the final product is usually in the range of 3 to 50% by weight in terms of the produced resin solution, but preferably in the range of 10 to 30% by weight. Good. If the concentration is too high, the viscosity will be extremely high and a gel will be formed. When coating and impregnating an adherend, it may be diluted with a solvent before use, but it is difficult to handle. If the concentration is too low, it is difficult to obtain a high viscosity (10,000 cps or more) and the versatility is poor.

In the present invention, the reaction temperature for producing the polyamino acid urethane resin solution is preferably a temperature at which a high molecular weight polyamino acid single polymer can be synthesized from α-amino acid NCA, and a range of 10 to 60 ° C is preferable. When the temperature is higher than 60 ° C., the amino acid chain is less likely to have an α-helix structure during copolymerization, so that the degree of polymerization of the amino acid chain cannot be increased and a high molecular weight product may not be obtained in some cases. In addition, when the reaction is carried out at a high temperature, the isocyanate group may undergo a biuret reaction with the urea bond generated by the reaction between the isocyanate group and the amino group, and gelation may occur.

The PAU liquid obtained as described above contains α-amino acid N
When the amount of CA is small, for example, when the weight ratio of α-amino acid NCA and urethane prepolymer is within the range of 5:95 to 15:85, the solution becomes relatively cloudy, but α-amino acid NCA
As the ratio of CA increases, turbidity increases and the viscosity becomes 10
An arbitrary viscosity can be obtained within the range of cps to 1,000,000 cps / 25 ° C.

As a preferred method for producing a polyamino acid urethane resin solution having an amino group at the terminal, (a) in the organic solvent, a urethane prepolymer,
A method of reacting with water, hydrazine or an organic amine having active hydrogen, and then adding α-amino acid NCA to react.

(B) A method in which the α-amino acid NCA and the urethane prepolymer are mixed in the organic solvent, and then water, hydrazine or an organic amine having active hydrogen is added and reacted.

(C) A method in which the α-amino acid NCA and the urethane prepolymer are mixed in the organic solvent, water, hydrazine or an organic amine having active hydrogen is added and reacted, and then the urethane prepolymer is added.

(D) After reacting the urethane prepolymer with water, hydrazine, or an amine having active hydrogen in the organic solvent, the α-amino acid-N-carboxylic acid anhydride is added and mixed, and then water is further added. , A method of adding and reacting hydrazine or amines having active hydrogen.

Etc.

According to the method of the present invention, a polyamino acid urethane resin liquid having an amino group at the terminal obtained as described above is added with a polyisocyanate compound having an isocyanate equivalent of 80 or more as a curing agent and, optionally, a curing accelerator to effect a curing reaction. Let

As the polyisocyanate compound having an isocyanate equivalent weight of 80 or more used as a curing agent, most of the polyisocyanate component used in the above-mentioned urethane prepolymer synthesis can be used, and typically, toluene-2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-biphenyl diisocyanate, xylene diisocyanate, 1,6-hexane diisocyanate, 3-isocyanate methyl-3,5,5
-Trimethylcyclohexyl isocyanate, dicyclohexylmethyl-4,4'-diisocyanate and the like can be mentioned.

Further, as a polyisocyanate compound having an isocyanate equivalent of 80 or more, such a polyisocyanate component and the above-mentioned bifunctional polyol or trimethylolpropane,
Urethane prepolymer with isocyanate equivalent of 80 or more obtained by reacting with trifunctional or higher polyfunctional polyol such as pentaerythritol under the condition of equivalent ratio NCO / OH> 1, and isocyanurate ring containing obtained by trimerization reaction of diisocyanate Polyisocyanate, other urea bond-containing polyisocyanates, acid bond-containing polyisocyanates, imide bond-containing polyisocyanates, and the like can be similarly used.

Here, the isocyanate equivalent refers to a value obtained by dividing the molecular weight of the polyisocyanate compound by the number of isocyanate groups in the molecule, that is, the formula weight per one isocyanate group.

The addition ratio of the polyisocyanate compound having an isocyanate equivalent weight of 80 or more to the polyamino acid urethane resin liquid (PAU liquid) is equivalent to the amount of terminal amino groups in PAU.
NCO / NH ₂ > 1, and 1 to the resin content in the PAU liquid
The amount is 100% by weight, preferably 1 to 30% by weight, more preferably 1 to 20% by weight.

The method of adding polyisocyanate to a PAU liquid having an amino group at the end and curing it is as follows. In the case of film production, after mixing the polyisocyanate compound with the PAU liquid, coating on a release paper or other flat plate having good peelability is carried out. It may be cast and desolvated. Also in the case of applying or impregnating the adherend, it is sufficient to mix the polyisocyanate compound with the PAU liquid and then apply or impregnate it to remove the solvent.

In order to further accelerate the curing reaction, a curing accelerator may be optionally added together with the curing agent. As typical examples, tertiary amines such as triethylamine and trimethylamine, and organic tin compounds such as dibutyltin dilaurate and dibutyltin dioctoate are preferable.

In order to further accelerate the curing reaction, it is preferable to heat the desolvated molded product in the temperature range of 30 to 60 ° C. for 20 to 100 hours.

In the case of a solvent mainly composed of dimethylformamide, the viscosity of the PAU liquid changes with time. Storage temperature 10-1
When the temperature is 5 ° C or lower, the viscosity increases with time, and the lower the storage temperature, the greater the viscosity increase.

When the storage temperature is 10 to 15 ° C. or higher, the viscosity increases once and then decreases.

When the storage temperature is around 10 ° C, the viscosity rises once and then maintains a substantially constant viscosity.

Regarding the intrinsic viscosity, when stored at 10 ° C. or lower, there is almost no change in viscosity with time, but when stored at 10 ° C. or higher, the viscosity decreases with time, and the degree increases with increasing storage temperature.

From the above, the storage temperature of PAU is preferably around 10 ° C. When stored at a temperature considerably lower than around 10 ° C, the longer the storage period is, the higher the viscosity becomes, and when the storage period is different, the reproducibility is poor in processing the resin. When stored at a temperature considerably higher than around 10 ° C, the longer the storage period, the lower the apparent viscosity and the larger the intrinsic viscosity due to molecular scission. Therefore, the reproducibility in terms of physical properties of processed products and processed products is poor.

A film obtained by desolventizing a mixed solution obtained by adding the curing agent and optionally the curing accelerator to the PAU liquid of the present invention has the same moisture permeability and aeration as the film obtained by desolvating the PAU liquid alone. It has excellent properties, and has greatly improved adhesive strength and solvent resistance, and is useful as a resin for artificial leather itself, but is particularly useful as a coating material.

Examples of the adherend (base material molding) when the coated liquid is applied or impregnated to produce a coated molding include sheet materials such as woven fabrics, non-woven fabrics, and porous films.

More specifically, as the substrate, cotton, hemp, pulp, wood, bamboo, viscose silk, Bemberg silk, cellulose acetate and other fibrin and derivatives thereof, silk, wool,
Hair, natural leather, regenerated leather, synthetic leather, artificial leather, polyamino acids, polyamides, polyurethanes, polyesters, polyesteramides, acrylonitrile polymers, vinyl chloride polymers, polystyrene and copolymers thereof, polyvinyl Alcohol and its derivatives, polyvinyl acetate and its copolymers, polyacrylamide,
Or polymethacrylamide and derivatives thereof, natural rubber and synthetic rubber such as polyisoprene or polybutadiene, or a mixture thereof, polyethylene and copolymers thereof, polypropylene and copolymers thereof,
Examples thereof include various plastics such as phenol resin, melamine resin, and urea resins, quartz, glass, cements, various metals, and the like, or a mixture of two or more thereof.

In addition, the shape of the molded product is powder, powder, block, film, sheet, plate, fibrous, porous, etc. By selecting the type and shape of the base material, it is possible to make one suitable for the purpose. I can.

A dry method is employed as a method for removing the solvent after coating or impregnating the mixed liquid on the adherend.

In the case of the dry method, after applying or impregnating the adherend with the mixed liquid,
The solvent can be removed by heating or air drying. In the present invention, if necessary, a surfactant, a water repellent, a colorant, and other additives may be previously added to the PA.
It is also possible to use in addition to the U solution.

Further, the amount of the mixed liquid applied to or impregnated on the adherend is determined depending on the use and type of the product (sheet-like substance) and the required performance.

〔Example〕

 Next, the present invention will be described more specifically by way of examples.

Example 1 Polytetramethylene ether glycol (OH value 56.
7) 989.5 g and tolylene diisocyanate (2,4-
A mixture of tolylene diisocyanate and 2,6 tolylene diisocyanate. 174 g of 2,4-tolylene diisocyanate having a content of 80% by weight was reacted at 70 ° C. for 5 hours to obtain a urethane prepolymer having an isocyanate group at a terminal.

200 g of the urethane prepolymer and 95 g of γ-methyl-L-glutamate NCA were added to dimethylformamide 927.
hydrazine hydrate 4.5
g was dissolved in 120.5 g of dimethylformamide and the reaction was carried out dropwise, and then 15.4 g of the urethane prepolymer was dissolved in 62 g of dimethylformamide and added. Emulsion (a) with a viscosity of 25,000 cps / 25 ° C when reacted for 2 hours
was gotten.

The terminal amino group equivalent was 14,000.

On the other hand, 1 mol of trimethylolpropane and 3 mol of 2,4-tolylene diisocyanate were reacted in ethyl acetate at a concentration of 70% by weight to give 3.1 × 10 ⁻³ isocyanate group equivalent /
g · solution of urethane prepolymer (b) was obtained.

Urethane prepolymer (b) per 100 parts of emulsion (a)
5 parts were mixed (equivalent ratio NCO / NH ₂ = 16/7), and nylon taffeta was glued with this mixture (c) and emulsion (a) as adhesives and dried in a hot air dryer at 60 ° C for 30 minutes. After 40
The peel strength was measured after standing in a thermostat at 4 ° C for 4 days. The peel strength of the mixture (c) used as an adhesive was 7 kg / cm, and the peel strength of the emulsion (a) used was 0.2 kg.
The mixture (c) and emulsion (a) were each coated on nylon taffeta, dried in a hot air dryer at 60 ° C for 30 minutes, and then left in a thermostat at 40 ° C for 4 days. An amount of 20 g / m ² ) of coating cloth (d) (resin weight of 20 g / m ² ) and (e) (resin weight of 19 g / m ² ) were obtained.

The water resistance of the coating liquid (d) of the mixed liquid (c) is 5000 mmH.
₂ O or more, water vapor transmission rate is 3500 g H ₂ O / m ² 24 h (40
C., 90% RH). The water pressure resistance of the coating statement (e) coated with the emulsion (a) alone is 5000 mm.
H ₂ O or more, water vapor transmission rate is 3400 g · H ₂ O / m ² · 24 h (40
C. 90% RH).

From the above, it is clear that by mixing the urethane prepolymer (b) with the PAU emulsion (a), the adhesive strength to the adherend is remarkably improved, and there is no negative effect on the moisture permeability, which is the characteristic of PAU. is there.

〔The invention's effect〕

A molded product obtained by coating or impregnating a liquid in which a polyisocyanate compound is mixed with a PAU solution has a significantly increased adhesive force to the adherend as compared with a molded product obtained by coating or impregnating the PAU liquid alone. However, excellent mechanical properties are obtained, and moisture permeability, waterproofness, gas permeability and separability are almost the same as when using the PAU liquid alone by adjusting the type and addition amount of the polyisocyanate compound. You can get

The coated molded article obtained by such a method is obtained by appropriately selecting the type of the adherend and the coating method,
It can be applied to various purposes. Typical examples of its use include artificial leather such as synthetic leather and artificial leather, and waterproof cloth.

In particular, as a waterproof cloth, one having high moisture permeability and high waterproof performance can be obtained, and specific applications thereof include tents, waterproof clothing, packaging materials, diapers and diaper covers.

Further, it can be applied to a composite film having a high moisture permeability such as water vapor, oxygen, carbon dioxide, etc., a separating material for liquid or gas mixture, a filter and the like.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 61-40315 (JP, A) JP 59-179512 (JP, A) JP 59-140217 (JP, A) JP 58- 57420 (JP, A) Japanese Patent Sho 49-48477 (JP, B1) Japanese Patent Sho 49-27114 (JP, B1) Japanese Patent Sho 46-20157 (JP, B1) Japanese Patent Sho 52-10917 (JP, B1)

Claims (1)

[Claims] 1. An organic solvent having (A) an α-amino acid-N-carboxylic acid anhydride, (B) a urethane prepolymer having an isocyanate group at the terminal and (C) water, hydrazine, or active hydrogen in an organic solvent. To the amino acid urethane resin liquid having an amino group at the terminal obtained by reacting an amine, a curing agent composed of a polyisocyanate compound having an isocyanate equivalent of 80 or more is added in an equivalent ratio NCO /
A polyamino acid urethane resin molded article, characterized in that NH ₂ > 1 is mixed to obtain a mixed solution, and then the mixed solution is applied or impregnated on an adherend, followed by desolvation and curing by a dry method. Manufacturing method.