JPH0539322A - Hydrophilic resin - Google Patents

Abstract

PURPOSE:To obtain a hydrophilic resin excellent in hydrophilicity, transparency, heat resistance and elasticity by polymerizing a monomer mixture containing a specified itaconic diester. CONSTITUTION:A monomer mixture containing an itaconic diester of formula I (wherein R1 and R2 are each a polyethylene glycol residue of formula II (wherein (n) is 1-10), 1-8C alkyl, 2-6C alkenyl or 5-12C cycloalkyl, and at least one of them is a polyethylene glycol residue) is polymerized for producing the objective hydrophilic resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrophilic resin having excellent hydrophilicity, transparency and heat resistance.

[0002]

2. Description of the Related Art A hydrophilic resin is a resin which has a hydrophilic group such as a hydroxyl group, a carboxylic acid group, a carboxylate salt or an amide group in its molecule and exhibits a water-soluble or water-swelling state. It is used in various fields such as cosmetics, adhesives, sanitary materials, and medical products. As the hydrophilic resin,
For example, polyvinylpyrrolidone, methyl vinyl ether-maleic anhydride copolymer (US Pat. No. 27,939).
66), polyacrylamide, polyvinyl alcohol (“Poly Vinyl Alcohol Basic Properties and Uses”)
JG Pritchard (1969)), polyethylene glycol, poly (2-hydroxyethyl methacrylate) are known.

[0003]

However, the above-mentioned polyvinylpyrrolidone, methyl vinyl ether-maleic anhydride copolymer and polyacrylamide have a remarkably high polymerization rate, so that it is difficult to control the polymerization reaction and the molecular weight cannot be adjusted. There's a problem. Further, the produced polymer has problems that it is unstable and markedly colored, and further, it is fragile when used as a film or a molding material.

Although the above-mentioned polyvinyl alcohol, poly (2-hydroxyethyl methacrylate) and polyethylene glycol can be used as a film or a molding material, they are difficult to use at high temperature because of their low heat resistance, and they also contain water. Under the conditions, there is a problem that tensile strength, tear strength, etc. are low, and further, polyvinyl alcohol and polyethylene glycol have a problem that transparency cannot be obtained in a non-hydrated state.

Therefore, an object of the present invention is to provide a hydrophilic resin which is hydrophilic and is excellent in transparency, heat resistance and elasticity.

[0006]

According to the present invention, a hydrophilic resin obtained by polymerizing a raw material monomer containing an itaconic acid diester represented by the following general formula (2) (hereinafter referred to as itaconic acid diester 1) is provided. Provided.

[0007]

[Chemical 2]

The present invention will be described in more detail below.

In the hydrophilic resin of the present invention, the itaconic diester used as an essential constituent is the itaconic acid diester 1 represented by the general formula 2. In the itaconic acid diester 1, when R ₁ or R ₂ is an alkyl group having 9 or more carbon atoms, an alkenyl group having 7 or more carbon atoms, or a cycloalkyl group having 13 or more carbon atoms, the polymerizability of itaconic acid diester 1 And the heat resistance and mechanical strength of the resulting resin are significantly reduced. Further, if at least one of R ₁ and R ₂ is not the polyethylene glycol, the hydrophilicity is remarkably reduced, and therefore it cannot be used. Further, when n exceeds 10, the polymerizability of the itaconic acid diester 1 is lowered, and the transparency of the resin produced is
Mechanical strength is reduced.

Specific examples of the itaconic acid diester 1 represented by the general formula 2 include 2-hydroxyethyl-methyl itaconate, 2-hydroxyethyl-ethyl itaconate and 2-hydroxyethyl-isopropyl. Itaconate, 2-hydroxyethyl-n-butyl itaconate, 2-hydroxyethyl-sec-butyl itaconate, 2-hydroxyethyl-iso-butyl itaconate, 2-hydroxyethyl-t-butyl itacone 2-hydroxyethyl-neopentylitacone, 2-hydroxy-n-hexylitacone
2-hydroxyethyl- (2-ethylhexyl) itacone, 2-hydroxyethyl-vinylitacone
2-hydroxyethyl allyl itaconate, 2-
Hydroxyethyl-cyclopentyl itaconate, 2-
Hydroxyethyl-cyclohexyl itaconate, diethylene glycol-ethyl itaconate, diethylene glycol-isopropyl itaconate, diethylene glycol-sec-butyl itaconate, diethylene glycol-n-butyl itaconate, diethylene glyco-
L-t-butyl itaconate, diethylene glycol
Vinyl itaconate, diethylene glycol-allyl itaconate, diethylene glycol-cyclopentyl itaconate, diethylene glycol-cyclohexyl itaconate, triethylene glycol-ethyl itaconate, triethylene glycol-isopropyl itaconate -To, triethylene glycol-n-butyl itacone
G, triethylene glycol-t-butyl itacone
, Triethylene glycol-allyl itaconate, triethylene glycol-cyclohexyl itaconate,
Tetraethylene glycol-ethyl itaconate, tetraethylene glycol-isopropyl itaconate, tetraethylene glycol-n-butyl itaconate, tetraethylene glycol-t-butyl itaconate, tetraethylene Glycol-allyl itaconate, tetraethylene glycol-cyclohexyl itaconate, nonaethylene glycol-ethyl itaconate, nonaethylene glycol-isopropyl itaconate, nonaethylene glycol-n-butyl Itaconate, nonaethyleneglycol-t-butylitaconate, nonaethyleneglycol-cyclohexylitaconate, di (2-hydroxyethyl) itaconate, di (diethyleneglycol) itacone, di (Triethylene glycol) itaconate, di ( Tiger ethylene glycol - Ruitakone -
And di (nonaethylene glycol) itaconate can be preferably mentioned.

The itaconic acid diester 1 can be prepared easily by, for example, a method of reacting a monoalkyl itaconic acid chloride, an itaconic acid dichloride or itaconic acid with a corresponding glycol in the presence of an amine or an acid catalyst. Obtainable. Further, the obtained product can be purified by a known method such as distillation or recrystallization.

In the present invention, if necessary, a copolymerizable monomer may be used as a raw material monomer in addition to the itaconic acid diester 1. Specific examples of the copolymerizable monomer include styrene and
Methyl styrene, α-methyl styrene, chlorostyrene, vinyl acetate, vinyl propionate, vinyl pivalate, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, (meth)
Monofunctional monomers such as acrylic acid, (meth) acrylic acid amide, 2-hydroxyethyl (meth) acrylate, ethyl vinyl ether, n-butyl vinyl ether, N-vinylpyrrolidone, vinyl chloride, vinylidene chloride, ethylene, propylene, isobutylene, and acrylonitrile. -; Polyfunctional monomers such as allyl (meth) acrylate, di (meth) acrylate, diallyl phthalate, divinylbenzene and methylenebisacrylamide can be preferably mentioned, and they can be used alone or as a mixture when used. The copolymerizable monomer
In the case of using the above, for example, in the case of the above-mentioned monofunctional monomer, it is preferable to use it in the range of 1000 to 5 parts by weight based on 100 parts by weight of the itaconic acid diester 1. When it exceeds 1000 parts by weight, the properties such as hydrophilicity and heat resistance of the diester monomer-1 are deteriorated, and when it is less than 5 parts by weight, the effect of copolymerization cannot be exhibited, which is not preferable. Further, in the case of the above polyfunctional monomer, it is preferable that the amount is 20 parts by weight or less relative to 100 parts by weight of the itaconic acid diester 1, and the resin obtained at this time may be a resin composed of a cross-linking polymer.

To prepare the hydrophilic resin of the present invention, radical polymerization or copolymerization is carried out in the presence of a radical polymerization initiator by a known polymerization method such as bulk polymerization, suspension polymerization, emulsion polymerization or solution polymerization. Can be easily obtained. Examples of the radical polymerization initiator include benzoyl peroxide, lauroyl peroxide, diisopropyl peroxydicarbonate, t
-Butylperoxy-2-ethylhexanoate, t-
Butyl peroxypivalate, t-butyl peroxydiisobutyrate, azobisisobutyronitrile, azobisdimethylvaleronitrile, persulfate or persulfate-hydrogen sulfite system can be preferably used. The amount of the polymerization initiator used is preferably 0.01 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the raw material monomer.

To carry out the above-mentioned polymerization or copolymerization, nitrogen,
The polymerization system is replaced with an inert gas such as carbon dioxide or helium or under an atmosphere, the polymerization temperature is preferably in the range of 30 to 100 ° C., and the polymerization time is preferably 5 to 72 hours. The number average molecular weight of the hydrophilic resin obtained at this time is not particularly limited, but is preferably in the range of 5,000 to 300,000, and a high molecular weight resin may be obtained by further performing an operation such as fractionation. it can.

[0015]

Since the hydrophilic resin of the present invention is obtained by polymerizing a raw material monomer containing an itaconic acid diester having a specific structure, it can be obtained by a simple method such as a radical polymerization method. Excellent heat resistance, 100 ° C
High elasticity can be maintained even under the above high temperature. Also, by changing the type of ester group,
The hydrophilicity can also be adjusted. Therefore, as hydrophilic resin, coating materials, contact lens materials, cosmetics,
It can be used in many fields such as biocompatible materials, hygiene materials, and medical fields. Further, in addition to the above applications, it can be used as a material for improving the adhesiveness, dyeability, and antifogging property of the polymer, and further mixed with another isocyanate group, carboxylic acid group, monomer or polymer having a glycidyl group, etc. It can also be used as a cross-linking polymer.

[0016]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

[0017]

[Synthesis Example 1] A reaction vessel was charged with 1 mol of the itaconic acid compound shown in Table 1, 3 mol of the ethylene glycol compound shown in Table 1, 2 g of paratoluenesulfonic acid as a catalyst, and 200 ml of toluene as a solvent, and charged under a nitrogen stream of 110 ~ 12
The esterification reaction was carried out at 0 ° C. for 8 hours. After the reaction,
After adding 500 ml of ethyl acetate, the mixture was neutralized and washed with a separating funnel, and toluene and ethyl acetate were distilled off from the obtained oil layer, followed by distillation purification to obtain the desired itaconic acid diester. The resulting itaconic acid diester is shown in Table 1.

[0018]

[Table 1]

[0019]

Example 1 10 g of 2-hydroxyethyl-isopropyl itaconate was mixed with 10 cc of tetrahydrofuran containing 20 mmol / l of azobisisobutyronitrile as a radical polymerization initiator, and the mixture was sealed at 60 ° C.
Then, solution polymerization was carried out for 20 hours. After completion of the polymerization, the obtained polymer solution was put into hexane, and the precipitated polymer was filtered, washed and dried to obtain the polymerization rate. As a result of ¹ H-NMR analysis of the obtained polymer, CH ₂ = C <(5.70 ppm, 6.
It was confirmed that the double bond was cleaved. The analysis results are shown in Table 2. Also,
The molecular weight was measured by GPC, and other physical properties were measured using a polymer transparent cast film. The measuring method is shown below. (A) Heat resistance Dynamic viscoelasticity-The dynamic elastic modulus E ″ (GPa) at 120 ° C. was measured by temperature measurement. (B) Water content (W1-W2) / W1 × 100 W1: Weight when saturated water content W2: Initial weight of film (C) Deformation amount The elongation percentage when a load of 150 g / mm ² was added to the film when saturated with water was measured and defined as the amount of deformation, and the results are shown in Table 2.

[0020]

Examples 2 to 12 Polymerization was carried out in the same manner as in Example 1 except that the raw material monomers shown in Table 2 were used, and the physical properties of the obtained resin were measured. Also, the obtained polymer is ¹ H
-When NMR measurement was performed, the absorption of the aromatic ring in the styrene copolymer was 6.75 to 7.22 ppm, and the absorption in the copolymer with methyl methacrylate was 3.60 ppm of methyl. The absorption of the group (methyl ester) is 2 pp for the copolymer with vinyl acetate.
Absorption of m-OCOC H ₃ was observed. The results are shown in Table 2.

[0021]

Comparative Examples 1 to 3 Polymerization was carried out in the same manner as in Example 1 except that the raw material monomers shown in Table 2 were used, and the physical properties of the obtained resin were measured. The results are shown in Table 2.

[0022]

[Table 2]

Claims (1)

[Claims] 1. A hydrophilic resin obtained by polymerizing a raw material monomer containing an itaconic acid diester represented by the following general formula 1. [Chemical 1]