JP2003192758A - Moisture absorbing and desorbing resin and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a moisture absorbing and desorbing resin which has excellent moisture absorbency and desorbing and excellent heat stability upon molding, and to provide a manufacturing method of the resin. <P>SOLUTION: The moisture absorbing and desorbing resin comprises a polyether component (A) as a constituent component, the resin having a glass transition temperature of ≤-20°C being used, the carbon/oxygen atomic ratio of a polyoxyalkylene (-C<SB>n</SB>H<SB>2n</SB>O-) constituting the polyether component (A), and a content of the component (A) being set in a specific scope. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a moisture absorptive and desorptive resin containing a polyether component as a constituent unit and a method for producing the same.

[0002]

2. Description of the Related Art Synthetic fibers made of polyester or polyamide are widely used as clothing or industrial materials. However, since these fibers are hydrophobic, they have a low hygroscopic property, and there is a problem that they tend to get stuffy due to perspiration.

In order to solve this problem, it has been proposed that the hygroscopic resin composition be made into a fiber alone, or that it be mixed or compounded with a polyester fiber or a polyamide fiber. As a resin composition having such hygroscopicity, JP-A-62-267352 discloses a polyester composition containing a specific alkylene glycol. However, although this polyester composition is certainly improved in hygroscopicity, its level is not yet satisfactory, and since the improvement is limited to imparting hydrophilicity, the hygroscopicity is insufficient. Met.
Furthermore, the polyalkylene glycol, which is a contained component,
It was not possible to put it into practical use because it was markedly colored by heat deterioration during polymerization.

In addition to the above, a technique for copolymerizing a polyalkylene glycol with a polyester by polycondensation has been disclosed. Generally, however, when the amount of polyalkylene glycol is increased, polycondensation produces a carboxylic acid at the terminal. Since the amount of the product is large, there is a problem that the thermal stability at the time of molding the copolymer is lowered and the spinnability is lowered.

[0005]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a moisture absorptive and desorptive resin having excellent moisture absorptive and desorptive properties and thermal stability during molding, and a method for producing the same. Especially.

[0006]

The moisture absorptive and desorptive resin of the present invention contains a polyether component (A) as a constituent component,
Glass transition temperature is a moisture sorption resin is -20 ° C. or less, a carbon / oxygen atomic ratio of polyoxyalkylene (-C _n H _2n O-) constituting the polyether component (A) 2
Is about 2.5, and the content of the polyether component (A) is 4
It is characterized by being 5 to 95% by weight.

The present invention will be described in detail below. The moisture absorptive and desorptive resin of the present invention is a moisture absorptive and desorptive resin containing a polyether component (A) as a constituent and having a glass transition temperature of -20 ° C or lower, and constitutes the polyether component (A). polyoxyalkylene carbon / oxygen atomic ratio of (-C _n H _2n O-) is 2 to 2.5, the polyether component (a)
Is 45 to 95% by weight.

As the polyether component (A) which is a constituent component of the moisture absorptive and desorptive resin of the present invention, a polyoxyalkylene having a carbon / oxygen atom ratio of 2 to 2.5 is used. Among the polyether components (A), polyethylene glycol in which the carbon / oxygen atomic ratio of polyoxyalkylene is 2 is preferable. Further, the polyether component (A) is
By mixing polyethylene glycol and polyoxyalkylene having a carbon / oxygen atomic ratio of 3 or more, carbon /
You may use what was adjusted so that an oxygen atom ratio might be 2.5 or less.

As the polyether component (A) in which the carbon / oxygen atomic ratio of the polyoxyalkylene is 3 or more,
Examples thereof include polypropylene glycol, polyhexamethylene glycol, poly (ethylene glycol-tetramethylene glycol) copolymer, and poly (ethylene glycol-propylene glycol) copolymer.

The number average molecular weight of the polyether component (A) is preferably 500 to 3000, more preferably 1000 to 2000. Number average molecular weight is 500
If it is smaller, the flexibility and the moisture absorptivity of the resulting moisture absorptive and desorptive resin may decrease. The number average molecular weight is 3
If it is more than 000, the compatibility with the polyester component (B) described later is lowered, the degree of polymerization of the resulting moisture absorptive and desorptive resin is not increased, and sufficient mechanical strength and moldability may not be imparted. The number average molecular weight of the polyether component (A) is a numerical value corresponding to the average molecular weight of the polyether (a) described later.

The content of the polyether component (A) in the moisture absorptive and desorptive resin is 45 to 95% by weight, preferably 60 to 90% by weight. When the content of the polyether component (A) is less than 45% by weight, flexibility of the moisture absorptive and desorptive resin is reduced and components having high molecular mobility are reduced, so that the moisture absorptive and desorptive properties are reduced. When the content of the polyether component (A) is more than 95% by weight, it becomes impossible to impart sufficient mechanical strength and moldability to the moisture absorptive and desorptive resin.

The glass transition temperature of the moisture absorptive and desorptive resin is -2.
The temperature is limited to 0 ° C or lower, preferably -30 ° C or lower.
When the glass transition temperature is higher than −20 ° C., the molecular motion is reduced and the moisture absorption / desorption property is reduced.

The glass transition temperature is the temperature at which the maximum due to the micro Brownian motion of the polyether component (A) contained in the moisture absorptive and desorptive resin appears among the maximums of the loss tangent (tan δ) obtained by viscoelasticity measurement. means.

The melting point of the moisture absorptive and desorptive resin due to the polyether component (A) is preferably 0 to 30 ° C., more preferably 0 to 20 ° C. It is an important characteristic that the moisture absorbing / releasing resin has a large difference between the moisture absorption amount at high temperature and the moisture absorption amount at normal temperature. When crystals are present in the polyether component (A), the amount of moisture absorption is suppressed as compared with the case where no crystals are present. Therefore, when the melting point due to the polyether component (A) exists at 0 to 30 ° C., the amount of moisture absorption at room temperature is suppressed, and the difference between the amount of moisture absorption at high temperature and the amount of moisture absorption at room temperature becomes large. When the melting point is lower than 0 ° C. or higher than 30 ° C., such a difference in moisture absorption amount does not appear.

The melting point is a numerical value measured by differential scanning calorimetry, and the endotherm caused by crystal melting was evaluated by its peak temperature. The measurement condition is that the temperature rising rate is 5 ° C./min, and as the measuring device, for example, “DSC2920” manufactured by TA Instruments is used.

The polyether component (A) and the polyester component (B) may be used as the constituent components of the moisture absorptive and desorptive resin. As the polyester component (B), a short-chain polyester component represented by the following general formula (1) 50-
It is preferably composed of 100% by weight and 50 to 0% by weight of a long-chain polyester component represented by the following general formula (2). ^{-CO-R 1 -CO-O-} R 2 -O- ····· (1) -CO-R 3 -CO-O-R 4 - ····· (2) wherein, R ¹ and R ³ represents a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, R ² represents an alkylene group having 2 to 8 carbon atoms, and R ⁴ represents —R—O— (wherein R represents 2 carbon atoms. ??? 8 represents an alkylene group).

The short-chain polyester component is obtained, for example, by reacting an aromatic dicarboxylic acid or its ester with a low molecular weight diol. The long-chain polyester component is obtained, for example, by reacting an aromatic dicarboxylic acid or its ester with a high molecular weight diol.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, naphthalene dicarboxylic acid, paraphenylenedicarboxylic acid,
Dimethyl terephthalate, dimethyl isophthalate, dimethyl orthophthalate, dimethyl naphthalene dicarboxylate,
Examples include dimethyl paraphenylene dicarboxylate and the like, and these may be used alone or in combination of two or more kinds.

Examples of the low molecular weight diols include:
Ethylene glycol, 1,2-propanediol, 1,
3-propanediol, 1,3-butanediol, 1,
4-butanediol, neopentyl glycol, 1,5
-Pentanediol, 1,6-hexanediol, cyclohexyldimethanol, diethylene glycol, triethylene glycol and the like can be mentioned, and these may be used alone or in combination of two or more kinds.

Examples of the above-mentioned high molecular weight diol include:
Polyethylene glycol, polypropylene glycol,
Examples thereof include polytetramethylene glycol and polyhexamethylene glycol.

The proportion of the short-chain polyester component in the polyester component (B) is 50 to 100.
Weight percent is preferred. 50% by weight of short-chain polyester component
When it is less than the above, the melting point of the polyester component (B) becomes low, which adversely affects the mechanical strength of the moisture absorptive and desorptive resin at high temperatures.

The number average molecular weight of the polyester component (B) is preferably 500 to 5000, more preferably 5
It is 00 to 2000. When the number average molecular weight is less than 500, the blocking property of the polyester component (B) is deteriorated, which may adversely affect the handling of the resulting moisture absorptive and desorptive resin. The number average molecular weight is 5000
When it exceeds, the compatibility with the above-mentioned polyether component (A) becomes low, and therefore the degree of polymerization of the resulting moisture absorptive and desorptive resin does not increase, and sufficient mechanical strength and moldability may not be imparted. The number average molecular weight of the polyester component (B) is usually a numerical value corresponding to the average molecular weight of the polyester (b).

The above moisture absorbing / releasing resin can be obtained by a known method. For example, an aromatic dicarboxylic acid or its ester together with an excess of a low molecular weight diol and optionally a high molecular weight diol, such as tetrabutyl titanate. The transesterification reaction is carried out by heating to 160 to 200 ° C. in the presence of a catalyst, and subsequently to 240 to 2 under reduced pressure.
By performing a polycondensation reaction at 50 ° C., a moisture absorbing / releasing resin can be obtained.

The moisture absorbing / releasing resin is obtained by binding the polyether component (A) with the polyisocyanate component (C), or the polyether component (A) and the polyester component (B). It is preferably formed from the original linked by C).

The polyisocyanate component (C) is preferably a diisocyanate component represented by the following general formula (3). —O—CO—NH—R ⁵ —NH—CO—O— (3) In the formula, R ⁵ is an alkylene group having 2 to 15 carbon atoms, a phenylene group, or a phenylene group and a methylene group. Represents a group bonded with.

As the polyisocyanate component (C), the average number of isocyanate groups per molecule is 2 to 2.
Those in the range of 2 are preferable. Examples of the polyisocyanate compound (c) having an average number of isocyanate groups per molecule of 2 include, for example, aromatic diisocyanates such as 4,4′-diphenylmethane diisocyanate, tolylene diisocyanate, phenylene diisocyanate and naphthalene diisocyanate; 1,2-ethylene. Diisocyanate, 1,3-propylene diisocyanate, 1,4
-Butane diisocyanate, 1,6-hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated aliphatic diisocyanates such as 4,4'-diphenylmethane diisocyanate, and the like.

The polyisocyanate compound (c) having an average number of isocyanate groups per molecule of more than 2.2
Alternatively, the polyisocyanate compound (c) having an average number of isocyanate groups of 2 may be mixed to adjust the average number of isocyanate groups per molecule to a range of 2 to 2.2.

Polymeric MDI is a typical polyisocyanate compound (c) having an average number of isocyanate groups per molecule of more than 2.2, and commercially available products include, for example, "Millionate MR" manufactured by Nippon Polyurethane Company.
200 "(average isocyanate group number 2.8), triphenylmethane triisocyanate (average isocyanate group number 3.0), tris (isocyanatophenyl) thiophosphate (average isocyanate group number 3.0), hexamethylene triisocyanate (average isocyanate group number 3) .0)) and the like.

The molar amount of the isocyanate group contained in the polyisocyanate compound (c) is the group containing active hydrogen contained in the polyether (a) and polyester (b) used in the present invention (which can react with the isocyanate group. The molar amount of (group) is preferably 0.8 to 1.05 times, and more preferably 0.9 to 1.01 times. The above-mentioned polyether (a), polyester (b) and polyisocyanate compound (c) are mentioned above in the explanation of the polyether component (A), polyester component (B) and polyisocyanate component (C), respectively. Compounds similar to those used are used.

The molar ratio of the above isocyanate groups is 0.
When it is smaller than 8, the molecular weight of the resulting moisture absorptive and desorptive resin becomes low, and sufficient mechanical strength and moldability cannot be obtained. The molar ratio of the number of isocyanate groups is 1.05.
If it is larger than the above, the amount of side reaction products containing unstable allophanate groups or burette groups in the moisture-absorbing and desorbing resin obtained increases, and the moldability and physical properties of the resulting moisture-absorbing and desorbing resin decrease over time. May be noticeable.

The moisture absorptive and desorptive resin formed by combining the polyether component (A) and the polyester component (B) with the polyisocyanate component (C) is the polyether (a) and the polyisocyanate compound (c). Is a two-step process comprising a first step of obtaining a prepolymer in which both ends are isocyanated, and a second step of reacting the prepolymer with a polyester (b) having hydroxyl groups at both ends. It is preferable to manufacture it via.

In the first step, the molar amount of the isocyanate group contained in the polyisocyanate compound (c) is 1. The molar amount of the group containing active hydrogen capable of reacting with the isocyanate group contained in the polyether (a) is 1. It is preferably 1 to 2.2 times, and more preferably 1.2 to 2 times.

If the molar ratio is less than 1.1, both ends of the prepolymer to be produced may be completely isocyanated, which may hinder the reaction in the second step. On the other hand, when the molar ratio exceeds 2.2, the unreacted polyisocyanate compound (c) remains, so that it causes a side reaction during the reaction in the second step and contains an allophanate group or a buret group. The amount of side reaction products increases, which may cause deterioration of the moldability of the resulting moisture absorptive and desorptive resin and deterioration of its physical properties over time.

The reaction temperature in the first step is 100 to 24.
0 degreeC is preferable, More preferably, it is 160-220 degreeC. If the reaction temperature is lower than 100 ° C., the reaction may not proceed sufficiently, and if it exceeds 240 ° C., the polyether (a) may be decomposed, resulting in remarkable coloring of the moisture absorptive and desorptive resin.

In the second step, the prepolymer produced in the first step is reacted with the polyester (b). Here, the molar amount of the isocyanate group contained in the polyisocyanate compound (c) is the same as that of the group containing active hydrogen contained in the polyether (a) and the group containing active hydrogen contained in the polyester (b). It is preferably 0.8 to 1.05 times, and more preferably 0.9 to 1.01 times the total molar amount with the molar amount. By selecting such a molar amount range, it becomes difficult for a side reaction to occur, the obtained moisture absorbing / releasing resin has a large molecular weight, and the physical properties are excellent.

The reaction temperature in the second step is 100 to 24.
0 degreeC is preferable, More preferably, it is 160-220 degreeC. If the reaction temperature is lower than 100 ° C., the reaction may not proceed sufficiently, and if it exceeds 240 ° C., the prepolymer may be decomposed, and coloring of the resulting moisture absorptive and desorptive resin becomes remarkable. Here, the polyester (b) may be separately melted by heating and added to the prepolymer by using a pump, or the prepolymer may be added after the polyester (b) is heated and melted by an extruder. .

The reaction during the production of the moisture absorptive and desorptive resin is preferably a bulk reaction because the reactivity in the second step is improved. The reaction equipment is not particularly limited, but it is preferable to use a single-screw or twin-screw extruder. In particular, considering the good efficiency of stirring and mixing, among the extruders, a co-rotating twin screw extruder or a different rotating twin screw extruder is more preferable, and a co-rotating meshing twin screw extruder is more preferable. is there. By using such a reaction equipment, the reactivity is improved particularly in the second step. Also,
It is preferable to use a tandem type extruder because the reaction of the first step and the second step is continuously performed.

A catalyst can be used when stirring and mixing the above-mentioned polyether (a), polyester (b) and polyisocyanate compound (c). Examples of the catalyst include diacyl stannous tin, tetraacyl stannic tin,
Dibutyltin oxide, dibutyltin dilaurate, dimethyltin malate, tin dioctanoate, tin tetraacetate, triethyleneamine, diethyleneamine, triethylamine, naphthenic acid metal salt, octylic acid metal salt, triisobutylaluminum, tetrabutyl titanate,
Examples thereof include calcium acetate, germanium dioxide, antimony trioxide and the like, and these may be used alone or in combination of two or more kinds.

As mentioned above, the prepolymer obtained by reacting the polyether (a) with the polyisocyanate compound (c) and having both ends isocyanated is reacted with the polyester (b) having hydroxyl groups at both ends. By so doing, the polyether component (A) and the polyester component (b) are not chain-extended by the polyisocyanate compound (c) alone, and the polyether component (A) and the polyester component (B) are surely separated from each other. A moisture-absorbing / releasing resin composed of the block copolymer bound by (1) is obtained. Further, the prepolymer and the polyester (b) are partially reacted to serve as a compatibilizing agent for the polyether (a) and the polyester (b), and the compatibility between the polyether (a) and the polyester (b). Polymerization is possible even when the ratio is poor.

Further, as compared with the case of polycondensation, the thermal history given to the polyether (a) at the time of polymerization is reduced, so that the decomposition and deterioration of the polyether (a) can be suppressed. Further, the above polyisocyanate compound (c)
By using, it becomes possible to reduce the acid generated in the polymerization system.

Furthermore, by controlling the equivalence of the polyether (a), the polyester (b) and the polyisocyanate compound (c), for example, in the second step, excess polyester (b) relative to the prepolymer (b) can be obtained. It is possible to use the polyester component (B) at the molecular end of the resulting moisture absorptive and desorptive resin. This makes it possible to stabilize the molecular ends of the moisture absorptive and desorptive resin and improve the moldability and the thermal stability during molding.

A stabilizer may be used in the moisture absorbing / releasing resin during or after its production. Examples of the stabilizer include pentaerythritol tetrakis [3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate, octadecyl-3- (3,5-di-t-butyl-
4-hydroxyphenyl) propionate, N, N'-hexane-1,6-diylbis [3- (3,5-di-t-
Butyl-4-hydroxyphenylpropionamide, diethyl {[3,5-bis (1,1-dimethylethyl) -4
-Hydroxyphenyl] methyl} phosphonate and other hindered phenolic antioxidants; Tris (2,4-
Di-t-butylphenyl) phosphite, bis [2,2
4-bis (1,1-dimethylethyl) -6-methylphenyl] ethyl ester phosphorous acid, tetrakis (2,4-
Di-t-butylphenyl) [1,1-biphenyl]-
4,4'-diylbisphosphonite, bis (2,4-
Di-t-butylphenyl) pentaerythritol diphosphite, 4,4′-butylidene-bis (3-methyl-)
Phosphorus stabilizers such as 6-t-butylphenyl-di-tridecyl) phosphite and bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite; 3-hydroxy-5 , 7-di-t-butyl-furan-2-one and a reaction product of o-xylene (for example, "HP-1 manufactured by Ciba Specialty Chemicals").
36 ") and other lactone-based heat stabilizers.

Additives such as an inorganic filler, a flame retardant, an ultraviolet absorber, an antistatic agent, an inorganic substance and a higher fatty acid salt may be added to the ester elastomer of the present invention within a range not impairing the practicality. .

Examples of the inorganic fillers include calcium carbonate, titanium oxide, mica, talc and the like. Examples of the flame retardant include hexabromocyclododecane, tris- (2,3-dichloropropyl) phosphate, pentabromophenyl allyl ether, and the like.

Examples of the ultraviolet absorber include p-
t-butylphenyl salicylate, 2-hydroxy-4
-Methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,4,5-trihydroxybutyrophenone and the like can be mentioned.

Examples of the antistatic agent include N, N
Examples thereof include bis (hydroxyethyl) alkylamine, alkylallyl sulfonate, and alkyl sulfanate. Examples of the inorganic material include barium sulfate,
Examples thereof include alumina and silicon oxide. Examples of the higher fatty acid salt include sodium stearate, barium stearate, sodium palmitate and the like.

The ester-based elastomer obtained in the present invention may be mixed with other thermoplastic resins and rubber components to improve its properties before use. As the thermoplastic resin, for example, polyolefin, modified polyolefin,
Examples thereof include polystyrene, polyvinyl chloride, polyamide, polycarbonate, polysulfone and polyester.

Examples of the rubber component include natural rubber, styrene-butadiene copolymer, polybutadiene,
Polyisoprene, acrylonitrile-butadiene copolymer, ethylene-propylene copolymer (EPM, EPD
M), polychloroprene, butyl rubber, acrylic rubber,
Examples thereof include silicone rubber, urethane rubber, olefin-based thermoplastic elastomer, styrene-based thermoplastic elastomer, vinyl chloride-based thermoplastic elastomer, ester-based thermoplastic elastomer, and amide-based thermoplastic elastomer.

The moisture absorptive and desorptive resin of the present invention may be molded alone, or may be mixed with another thermoplastic resin and molded. Moreover, you may shape | mold so that it may become a multilayer structure. in this case,
The moisture absorbing / releasing resin may be either the surface layer or the inner layer.
Examples of the other thermoplastic resins include polyesters such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate; polyamides such as nylon 6 and nylon 66; polystyrene, AB.
S etc. are mentioned.

The form in which the moisture absorptive and desorptive resin of the present invention is used is not particularly limited, and examples thereof include a plate form, a sheet form, a film form, a fiber form, and a fabric form. Among them, the fibrous use is most effective, and examples of the fibrous use include sports clothing, vehicle seats, carpets, curtains and the like.

(Function) The moisture absorptive and desorptive resin of the present invention has a soft segment composed of a specific polyether component (A) in the molecule, so that the affinity with water is increased and the adsorption of water molecules is promoted. To be done. Furthermore, by having a specific glass transition temperature and a soft segment, the molecular mobility of the resin is enhanced and the diffusion of water molecules is promoted. By these molecular designs, it is possible to provide a moisture absorbing / releasing material having both extremely high moisture absorbing and moisture releasing properties that have never been obtained.

The moisture absorptive and desorptive resin of the present invention has a melting point due to the polyether component (A) within a specific range, so that the moisture absorption amount at room temperature is reduced and the moisture absorption amount at a high temperature required for practical use is reduced. It is possible to increase the difference from the moisture absorption amount at room temperature. Further, by using a specific polymerization method, generation of acid terminals at the time of polymerization is suppressed, and excellent thermal stability at the time of molding is exhibited.

[0053]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Synthesis of polyester (b) 100 parts by weight of dimethyl terephthalate, 102 parts by weight of 1,4-butanediol, 0.3 parts by weight of tetrabutyl titanate as a catalyst, and 1,3,5-trimethyl- as a stabilizer. 0.3 parts by weight of 2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene and 0.3 parts by weight of tris (2,4-di-t-butylphenyl) phosphite And the reaction system under nitrogen at 200 ° C.
The temperature was maintained for 3 hours to carry out a transesterification reaction. The progress of the transesterification reaction was confirmed by measuring the amount of distilled methanol. After the transesterification reaction proceeded, the temperature was raised to 240 ° C. in 20 minutes, and depressurization operation was performed. The polymerization system reached a degree of reduced pressure of 266 Pa or less in 20 minutes. As a result of polycondensation reaction for 10 minutes in this state, 112 parts by weight of white polyester (b) was obtained. This polyester (b) has a number average molecular weight of 2,000, an acid value and a hydroxyl value of 5.0 (μeq / g) and 1000 (μeq / g), respectively.
g).

The number average molecular weight of the polyester (b),
The acid value and the hydroxyl value were measured by the following methods. (A) Number average molecular weight gel permeation chromatography (“HLC 8 manufactured by Tosoh Corporation”
020 series ”). Two “HFIP 806M” manufactured by Shodex are used as columns, and hexafluoroisopropanol (0.005) is used as a solvent.
N sodium trifluoroacetate was added), and polymethyl methacrylate was used as a standard.

(B) Acid value A sample was dissolved in a benzyl alcohol / chloroform mixed solvent, and then neutralized titration was carried out using a phenol red indicator to determine the acid value. (C) A hydroxyl value sample and succinic anhydride are dissolved in a nitrobenzene / pyridine mixed solvent and reacted for 10 hours, the reaction solution is reprecipitated with methanol, and the acid value of the obtained reaction product is measured. The hydroxyl value was used.

Example 1 As the polyether (a), a number average molecular weight of 1000 and a hydroxyl value of 2000 (μeq / g)
And polyethylene glycol 2 having an acid value of 0 (μeq / g)
00 parts by weight and 62.5 parts by weight of 4,4′-diphenylmethane diisocyanate having an NCO value of 8000 (μeq / g) as a polyisocyanate compound (c) were mixed with a twin-screw extruder (L / D = 58 manufactured by Toshiba Machine Co., Ltd.). From the first barrel of the extruder, and from the fifth barrel of the extruder, 100 parts by weight of the polyester (b) and tris (2,4-
After feeding 5 parts by weight of di-t-butylphenyl) phosphite using a forced feeder, melt kneading was performed to obtain pellets of the moisture absorptive and desorptive resin of the present invention. The melt-kneading temperature was 200 ° C. The pellets obtained were press-molded (press temperature 220 ° C.) to a thickness of 2 mm and 100 μm.
A sheet of m was prepared and used as a sample for measuring physical properties.

Example 2 As the polyether (a), the number average molecular weight is 2000 and the hydroxyl value is 1000 (μeq / g).
And polyethylene glycol 2 having an acid value of 0 (μeq / g)
00 parts by weight and 37.5 parts by weight of 4,4′-diphenylmethane diisocyanate having an NCO value of 8000 (μeq / g) as a polyisocyanate compound (c) were mixed with a twin-screw extruder (L / D = 58 manufactured by Toshiba Machine Co., Ltd.). Pellets of the moisture absorptive and desorptive resin were obtained in the same manner as in Example 1, except that the pellets were supplied from the first barrel. The pellets obtained were press-molded (press temperature 230 ° C.) to a thickness of 2 mm and 100 μm.
A sheet of m was prepared and used as a sample for measuring physical properties.

Example 3 Polyether (a) having a number average molecular weight of 2000 and a hydroxyl value of 1000 (μeq / g)
And polyethylene glycol 4 having an acid value of 0 (μeq / g)
00 parts by weight and 62.5 parts by weight of 4,4′-diphenylmethane diisocyanate having an NCO value of 8000 (μeq / g) as a polyisocyanate compound (c) were mixed with a twin-screw extruder (L / D = 58 manufactured by Toshiba Machine Co., Ltd.). Pellets of the moisture absorptive and desorptive resin were obtained in the same manner as in Example 1, except that the pellets were supplied from the first barrel. The pellets obtained were press-molded (press temperature 220 ° C.) to a thickness of 2 mm and 100 μm.
A sheet of m was prepared and used as a sample for measuring physical properties.

(Example 4) Dimethyl terephthalate 100
Parts by weight, 102 parts by weight of 1,4-butanediol, 170 parts by weight of polyethylene glycol having a number average molecular weight of 1000, 0.3 parts by weight of tetrabutyl titanate as a catalyst,
And 1,3,5-trimethyl-2, as a stabilizer,
0.3 parts by weight of 4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene and tris (2,2)
0.3 parts by weight of 4-di-t-butylphenyl) phosphite was added, and the reaction system was kept under nitrogen at 200 ° C. for 3 hours.
A transesterification reaction was performed. The progress of the transesterification reaction was confirmed by measuring the amount of distilled methanol. After the transesterification reaction proceeded, the temperature was raised to 240 ° C. in 20 minutes, and depressurization operation was performed. 266 in 20 minutes
A pressure reduction degree of Pa or less was reached. As a result of polycondensation reaction for 6 hours in this state, 283 parts by weight of a white moisture absorbing / releasing resin was obtained. The obtained pellets were press-molded (pressing temperature: 220 ° C.) to prepare a sheet having a thickness of 2 mm and a thickness of 100 μm, which was used as a sample for measuring physical properties.

Comparative Example 1 Polyether (a) having a number average molecular weight of 2000 and a hydroxyl value of 1000 (μeq / g)
And polyethylene glycol 8 having an acid value of 0 (μeq / g)
0 parts by weight and N as the polyisocyanate compound (c)
Except that 22.5 parts by weight of 4,4′-diphenylmethane diisocyanate having a CO value of 8000 (μeq / g) was supplied from the first barrel of a twin-screw extruder (L / D = 58 manufactured by Toshiba Machine Co., Ltd.). By the same method as in Example 1, pellets of a moisture absorbing / releasing resin were obtained. The pellets obtained were press-molded (press temperature 220 ° C.) to a thickness of 2 mm and 100 μm.
A sheet of m was prepared and used as a sample for measuring physical properties.

Comparative Example 2 Polyethylene glycol 30 having a number average molecular weight of 400, a hydroxyl value of 5000 (μeq / g) and an acid value of 0 (μeq / g) as the polyether (a).
0 parts by weight and N as the polyisocyanate compound (c)
Example 1 except that 200 parts by weight of 4,4′-diphenylmethane diisocyanate having a CO value of 8000 (μeq / g) was supplied from the first barrel of a twin-screw extruder (L / D = 58 manufactured by Toshiba Machine Co., Ltd.). Pellets of the moisture absorptive and desorptive resin were obtained in the same manner as in. The obtained pellets were press-molded (pressing temperature: 220 ° C.) to prepare a sheet having a thickness of 2 mm and a thickness of 100 μm, which was used as a sample for measuring physical properties.

Comparative Example 3 Pellets of a moisture absorbing / releasing resin were prepared in the same manner as in Example 4 except that 170 parts by weight of polyethylene glycol having a number average molecular weight of 2000 was used in place of polyethylene glycol having a number average molecular weight of 1000. Got The obtained pellets were press-molded (pressing temperature: 220 ° C.) to prepare a sheet having a thickness of 2 mm and a thickness of 100 μm, which was used as a sample for measuring physical properties.

The manufacturer's guaranteed values were used for the acid value and hydroxyl value of the polyether (a) and the isocyanate value (NCO value) of the isocyanate compound (c).

The polyether (a) used in the above Examples and Comparative Examples and the moisture absorptive and desorptive resins obtained in Examples and Comparative Examples were evaluated for the following items, and the results are shown in Tables 1 and 2. (1) Glass transition temperature (Tg) of polyether (a) Using a viscoelasticity spectrometer ("RSA-II" manufactured by Rheometric Scientific Effie Co., Ltd.), heating rate 3 ° C / min, frequency 1.61Hz , Distortion 0.05%
It was measured at. (2) The melting point of the polyether (a) was measured using a differential scanning calorimeter (DSC) at a heating rate of 5 ° C / min. (3) An acid value sample of the polyether (a) was dissolved in a benzyl alcohol / chloroform mixed solvent, and neutralization titration was performed using a phenol red indicator to determine the acid value. (4) Moisture Absorption / Desorption The moisture absorption / desorption of the resin was evaluated by the following procedure. (I) Test piece (sheet: 50 mm x 50 mm x 2 mm)
After being placed in a desiccator containing a desiccant (silica gel) and sufficiently dried, the weight (W ₀ ) of the test piece is measured. (Ii) After leaving the test piece for 24 hours in a thermo-hygrostat at 20 ° C. and 65% RH, the weight (W ₁ ) of the test piece is measured, and the moisture absorption rate (WA ₁ ) is calculated from the following formula. Moisture absorption rate (WA ₁ ) [wt%] = [(W ₁ −W ₀ ) / W ₀ ] ×
100 (iii) Then, 2 in a thermo-hygrostat at 40 ° C and 90% RH.
After leaving the test piece for 4 hours, the weight (W ₂ ) of the test piece is measured, and the moisture absorption rate (WA ₂ ) is calculated from the following formula. Moisture absorption (WA ₂₎ [wt%] = _{[(W 2 -W 0) / W} 0 ] ×
100 (iv) Subsequently, after leaving the test piece for 120 minutes in a thermo-hygrostat at 20 ° C. and 65% RH, the weight of the test piece (W
₃ ) Measure. (V) Calculate the hygroscopicity and the hygroscopicity from the following formulas. Hygroscopicity (wt%) = WA ₂ -WA ₁ Moisture release (wt% / min) = {[(W ₂ -W ₃ ) / W ₀ ] / 1
20} x 100

(5) A heat-stable moisture absorbing / releasing resin was press-molded at 220 ° C. and 260 ° C. to prepare a sheet having a thickness of 2 mm, and the yellow index (YI) of each sheet was manufactured by Tokyo Denshoku Co., Ltd. It was measured using a color analyzer "TC-1800MK-II". Then, the thermal stability was evaluated by the difference (ΔYI) between YI at 260 ° C. and YI at 220 ° C. Furthermore, the presence or absence of decomposition and foaming in the sheet was visually observed and evaluated according to the following criteria. ○: No decomposition foaming in the sheet,
B: Very little decomposition and foaming in the sheet, X: Significant decomposition and foaming in the sheet.

[0067]

[Table 1]

[0068]

[Table 2]

[0069]

EFFECT OF THE INVENTION The moisture absorptive and desorptive resin of the present invention and the method for producing the same have the above-mentioned constitutions, and the moisture absorptive and desorptive resin obtained is excellent in moisture absorptive and desorptive property as well as thermal stability during molding. Also,
The moisture absorbing / releasing resin can be easily molded using an extruder or the like.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4J005 AA04                 4J034 BA07 DA01 DA05 DB03 DB04                       DB07 DC02 DF16 DF21 DF22                       DG03 DH02 DH06 DH10 HA01                       HA06 HA07 HA13 HC03 HC12                       HC13 HC22 HC46 HC52 HC61                       HC64 HC67 HC71 HC73 JA32                       JA42 KB02 KC07 KC17 KC18                       KC23 KD02 KD05 KD12 KE02                       QB04 QC08 QD04 RA03 RA09

Claims (7)

[Claims] 1. A hygroscopic resin containing a polyether component (A) as a constituent and having a glass transition temperature of −20 ° C. or lower, which is a polyoxyalkylene (which constitutes the polyether component (A). Moisture-absorbing and desorbing resin, wherein the carbon / oxygen atomic ratio of —C _n H _2n O-) is 2 to 2.5 and the content of the polyether component (A) is 45 to 95% by weight. 2. The moisture absorptive and desorptive resin according to claim 1, wherein the polyether component (A) comprises polyethylene glycol. 3. The moisture absorptive and desorptive resin according to claim 1 or 2, which contains a polyether component (A) and a polyester component (B) as constituent components. 4. The polyester component (B) comprises 50 to 100% by weight of a short chain polyester component represented by the following general formula (1) and 50 to 0 long chain polyester component represented by the following general formula (2). The moisture absorptive and desorptive resin according to claim 3, wherein the moisture absorptive and desorptive resin comprises —CO—R ¹ —CO—O—R ² —O— (1) —CO—R ³ —CO—O—R ⁴ — (2) [wherein R ¹ And R ³ each represent a divalent aromatic hydrocarbon group having 6 to 12 carbon atoms, R ² represents an alkylene group having 2 to 8 carbon atoms, and R ⁴ represents —R—O— (wherein R represents the number of carbon atoms. 2-8
Represents an alkylene group of)) 5. A polyether component (A) bound by a polyisocyanate component (C), or a polyether component (A) and a polyester component (B) bound by a polyisocyanate component (C). The moisture absorptive and desorptive resin according to any one of claims 1 to 4, which is formed of a resin. 6. The moisture absorptive and desorptive resin according to claim 5, wherein the polyisocyanate component (C) comprises a diisocyanate component represented by the following general formula (3). —O—CO—NH—R ⁵ —NH—CO—O— (3) (In the formula, R ⁵ is an alkylene group having 2 to 15 carbon atoms, a phenylene group, or a phenylene group and a methylene group. Represents a group bonded with and) 7. A first polymer obtained by reacting a polyether (a) with a polyisocyanate compound (c).
And the prepolymer and polyester (b)
The method for producing a moisture absorptive and desorptive resin according to claim 5 or 6, comprising a second step of reacting with.