JPH10176021A - Hydrophilic resin and medical material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hydrophilic resin and a medical material having hydrophilicity, stain-proofness and biocompatibility and further having heat- resistance, mechanical strength, durability, etc. SOLUTION: This hydrophilic resin is produced by polymerizing a raw material containing (A) 0.1-99wt.% of a monomer containing a (meth)acrylate having phosphorylcholine group and expressed by the formula (R<1> and R<2> are each H or CH3 ; (n) is 1-10) and (B) 1-99.9wt.% of a polymer having a solubility parameter of >=9.0(cal/cm<3> )<1/2> . The medical material-is produced by using the hydrophilic resin as a component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a hydrophilic resin and a medical material using the resin. More specifically, the present invention relates to a hydrophilic resin and a medical material excellent in hydrophilicity, antifouling property, biocompatibility, mechanical strength and the like.

[0002]

2. Description of the Related Art Conventionally, polymer materials have been hydrophilized for the purpose of imparting properties such as antifogging property, antistatic property, printability, coloring property and adhesiveness to the polymer material, or improving the performance. The technology to make it happen has been developed. For example, a method of adding a hydrophilic material such as a surfactant to a material, a method of copolymerizing a monomer having a functional group such as a carboxylic acid group, a hydroxyl group, or an amino group in a polymer, and the like are known. . However, the method of adding a hydrophilic material such as a surfactant to a polymer material has a problem of durability such as migration of the hydrophilic material from the polymer material. In the method of copolymerizing a monomer having a functional group, the durability has been improved, but the performance other than hydrophilicity, for example, the physiological performance such as antifouling property and biocompatibility has been satisfied. Not in.

On the other hand, as a method of modifying only the surface of a polymer material to impart properties such as hydrophilicity, the surface of the polymer material is treated with plasma, corona, ultraviolet (UV), electron beam, radiation, or the like. Techniques and techniques for grafting a polymer surface to make the surface hydrophilic are known. In particular, in the case of treatment with plasma, many examples are used for improving biocompatibility, and "surface" (Vol. 18, No. 4, p. 195 (198)
0)) and “industrial materials” (Vol. 25, p. 68 (197)
7)). However, these techniques have problems such as the need for expensive processing equipment and the limitation on the modification depth of the surface layer.

[0004] In order to improve these problems, a method of coating a base polymer with a hydrophilic polymer or a biocompatible polymer has been proposed. For example, JP-A-49-4
No. 4590 discloses a method of coating a base polymer with a resin grafted with a hydrophilic monomer, and Japanese Patent Publication No. Hei 7-502053 discloses a method in which a specific zwitterionic group and a bonding group to the material surface are used. A method for coating a polymer on a surface of a base polymer is disclosed. However, the coating method is suitable for improving the surface layer, but the coating material is peeled off from the base polymer,
A problem remains in the durability of the coating. As another method, Japanese Patent Application Laid-Open No. 7-504449 discloses an example of a blend of a polymer having a zwitterionic group and another polymer material. The dispersibility between the polymers worsens due to the difference and the blending amount, hydrophilicity,
Biocompatibility, mechanical strength, heat resistance, etc. are not always satisfactory.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hydrophilic resin and a medical material having hydrophilicity, antifouling property, biocompatibility, heat resistance, mechanical strength and durability. Is to do.

[0006]

According to the present invention, the following general formula (1) (wherein R ¹ and R ² represent a hydrogen atom or a methyl group, and n represents a number of 1 to 10) (A) containing a phosphorylcholine group-containing (meth) acrylate monomer (1) (hereinafter abbreviated as monomer (1)) represented by And a mixture of the ethylenic monomer (2) (hereinafter abbreviated as monomer (2)), and the blending amount of the monomer (2) is the monomer (A)
0.1 to 99% by weight of a monomer (A) having 95% by weight or less,

[0007]

Embedded image

When the solubility parameter is 9.0 (cal / cm)
³ ) A hydrophilic resin obtained by polymerizing a raw material containing 1 to 99.9% by weight of a polymer (B) which is ^1/2 or more.
Further, according to the present invention, there is provided a medical material containing the hydrophilic resin.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The hydrophilic resin of the present invention comprises a monomer (1) represented by the above formula (1) and, if necessary, a monomer (2) containing a specific amount of the monomer (2). It is a raw material polymer containing A) and a polymer (B) having a specific solubility parameter (δ). The molecular weight of the hydrophilic resin is preferably 30,000 or more as a number average molecular weight. In the above formula (1),
When n exceeds 10, the strength and processability of the obtained hydrophilic resin decrease.

The monomer (1) which is the specific phosphorylcholine group-containing (meth) acrylate monomer used in the present invention includes, for example, 2- (meth) acryloyloxyethyl-2 ′-(trimethylammonium). E) Ethyl phosphate, 2- (meth) acryloyloxypropyl-2 ′-(trimethylammonio) ethyl phosphate, 2- (meth) acryloyloxyethoxyethyl-
2 ′-(trimethylammonio) ethyl phosphate,
2- (meth) acryloyloxydiethoxyethyl-
2 ′-(trimethylammonio) ethyl phosphate,
2- (meth) acryloyloxytriethoxyethyl-
2 ′-(trimethylammonio) ethyl phosphate and the like can be mentioned. 2- from the point of economy and availability
(Meth) acryloyloxyethyl-2 ′-(trimethylammonio) ethyl phosphate can be preferably exemplified. When used, they can be used alone or as a mixture. The mixing ratio of the monomer (1) is preferably 5 to 100% by weight in the monomer (A).

The monomer (2) which can be used as required in the present invention may be any other copolymerizable ethylenic monomer other than the monomer (1), which will be described later. In order to facilitate mixing with the polymer (B), the system is preferably in a liquid state, and particularly preferably a monomer which is liquid at room temperature. The mixing ratio of the monomer (2) is 95% in the monomer (A).
% By weight or less is preferred. Examples of the monomer (2) include styrene-based monomers such as styrene and nuclear-substituted styrene;
(Meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate; (meth) acrylate-2- Hydroxyethyl,
Hydroxyalkyl (meth) acrylates such as 2-hydroxypropyl (meth) acrylate; diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, and polyethylene glycol mono (meth) acrylate Polyoxyalkylene mono (meth) acrylates; fluoroalkyl (meth) acrylate, (meth)
Silylalkyl acrylate, (meth) acrylic acid-N,
Monofunctional monomers such as N-dimethyl (meth) acrylamide, N-vinylpyrrolidone, N-vinylpyridine; ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acryl Acid esters, polyoxyalkylene di (meth) acrylates such as polyethylene glycol di (meth) acrylate;
Neopentyl glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, allyl (meth) acrylate, divinylbenzene,
Examples thereof include crosslinkable polyfunctional monomers such as bisacrylamide, diallyl phthalate, and divinyl adipate. When used, they can be used alone or as a mixture.

The polymer (B) used in the present invention is a polymer having a solubility parameter (δ) of 9.0 (cal / cm ³ ) ^1/2 or more. Reference: PASmall, J. Appl. Chem., Vol. 3 , p 71 (1953). When the dissolution parameter is less than 9.0 (cal / cm ³ ) ^1/2 , the hydrophobicity of the polymer (B) increases, and the compatibility with the monomer (A) deteriorates. Examples of the polymer (B) include polymethyl methacrylate (hereinafter abbreviated as “PMMA”, δ = 9.3),
Polystyrene (hereinafter abbreviated as “PS”, δ = 9.1), polyvinyl chloride (hereinafter abbreviated as “PVC”, δ = 9.5)
5), polyvinylidene chloride (δ = 12.2), chloroprene (δ = 9.4), celluloses (δ = 10-12)
(Cellulose nitrate (hereinafter abbreviated as “NC”, δ = 12),
Cellulose acetate (hereinafter abbreviated as “AC”, δ = 11),
Polyethylene terephthalate (δ = 10.7), polybutylene terephthalate (δ = 9.2), nylon 6 (hereinafter abbreviated as “N6”, δ = 12.7), nylon 66 (δ
= 13.6), polyurethane (hereinafter abbreviated as “PU”, δ
= 10.0), epoxy resin (δ = 9.7), unsaturated polyester resin (δ = 9.0-13.0), styrene-
Acrylonitrile copolymer (δ = 9.5 to 11.9),
Styrene-butadiene-acrylonitrile copolymer (δ
= 9.0-10.0), polycarbonate (hereinafter “P
C ”, δ = 10.3), polyacrylonitrile (hereinafter abbreviated as“ PAN ”, δ = 12.8), poly (2-
Hydroxyethyl methacrylate) (δ = 10.4),
Polyvinyl alcohol (PVA, δ = 12.6) and the like.

In the hydrophilic resin of the present invention, the mixing ratio when the raw material containing the monomer (A) and the polymer (B) is polymerized is 0.1 to 99% by weight of the monomer (A). , Preferably 10 to 60% by weight, polymer (B) 99.9 to 1% by weight, preferably 90 to 40% by weight. Monomer (A)
If the mixing ratio is less than 0.1% by weight, the performance such as hydrophilicity and biocompatibility is not sufficiently improved, and if it exceeds 99% by weight, the physical and chemical properties of the polymer (B) are obtained. Cannot be applied to hydrophilic resins.

In the present invention, in order to polymerize the monomer (A) and the polymer (B), the monomer (A) and the polymer (B) are mixed together by a known method. It can be polymerized. The mixing of the monomer (A) and the polymer (B), etc.
For example, a mixed state in which the polymer (B) is dissolved in the monomer (A), a state in which the monomer (A) is impregnated in the polymer (B), a state in which the monomer (A) is mixed with the polymer (B) )), And the monomer (A) and the polymer (B) may be mixed with a latex or the like in a solvent. Solvents used as necessary in such a state include water, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, ethyl acetate, butyl acetate, methylene chloride, chloroform, acetonitrile, tetrahydrofuran (hereinafter referred to as “THF”). Abbreviated), 1,4-
Dioxane, acetone (hereinafter abbreviated as “ACT”), methyl ethyl ketone (hereinafter abbreviated as “MEK”), benzene,
Toluene, dimethylsulfoxide, dimethylformamide (hereinafter abbreviated as "DMF") and the like can be used, and when used, they can be used alone or as a mixture. These solvents are preferably used, for example, in the range of 0 to 90 parts by weight based on 100 parts by weight of the monomer (A).

The polymerization can be carried out by a usual radical polymerization method. That is, the monomer (A) and the polymer (B)
In the presence of a radical polymerization initiator, nitrogen,
The polymerization can be carried out with an inert gas such as helium, argon or the like under a substitution or atmosphere. Specifically, a radical polymerization initiator is added in the above-mentioned state, etc.,
Polymerization in a general polymerization reaction vessel or a desired mold made of metal, glass, plastic, or the like, or polymerization by heating or light irradiation in a state where the monomer (A) is applied to the polymer (B) It can be performed by a method or the like. At the time of this polymerization, a colorant such as a coloring agent, an inorganic filler, an ultraviolet absorber, an oxidation stabilizer, and further, such a function as necessary so as not to affect the performance of the hydrophilic resin of the present invention. And the like can be added.

The obtained polymer can be used as it is as a solution in a solvent, or may be formed by precipitation or washing with an appropriate solvent to isolate a hydrophilic resin. Furthermore, the obtained hydrophilic resin can be subjected to melt molding, cutting, polishing, and the like, if necessary, and the obtained hydrophilic resin is blended or coated with another resin to obtain a desired product form. You can also.

The radical polymerization initiator used in the polymerization is not particularly limited, and examples thereof include benzoyl peroxide, diisopropyl peroxycarbonate,
t-butylperoxy-2-ethylhexanoate, t
-Butylperoxypivalate, t-butylperoxydiisobutyrate, lauroyl peroxide, azobisisobutyronitrile (hereinafter abbreviated as "AIBN"), azobis-2,4-dimethylvaleronitrile, benzoin methyl ether (hereinafter "benzoin methyl ether") BME ”), organic peroxides such as benzoin ethyl ether and azo compounds; and inorganic peroxides such as sodium persulfate and ammonium persulfate. The amount of the polymerization initiator charged is 0.001 to 10% by weight, particularly 0.01 to 5% by weight, based on 100 parts by weight of the total amount of the monomer (A) and the polymer (B).
Is desirable. The polymerization temperature of the polymerization varies depending on the type of radical polymerization initiator, but is preferably from 20 to 140 ° C,
The polymerization time is preferably from 6 to 120 hours.

The hydrophilic resin of the present invention can be applied to medical materials; cosmetic materials such as foundations and manicures; printing films; organic glasses; medical chemical fibers; marine paints; It is. For such a purpose, the hydrophilic resin of the present invention can be used as it is in the form of a melt-molded polymer, a solution of the polymer, a powder, an aqueous emulsion or the like, with the molded polymer as it is.

The medical material of the present invention is not particularly limited as long as it is a medical material using the hydrophilic resin, and examples thereof include catheters, dialysis membranes, artificial organs, blood circuits, spectacle lenses, contact lenses, and the like. . Such a medical material can be obtained by forming the hydrophilic resin into a predetermined shape and a predetermined form by a known method according to a desired material.

[0020]

The hydrophilic resin of the present invention is a resin obtained by polymerizing the raw material containing the monomer (A) and the polymer (B), so that the hydrophilic resin has hydrophilicity, antifouling property and biocompatibility. It has excellent heat resistance, mechanical strength and durability. Since the medical material of the present invention contains the hydrophilic resin, it is excellent in antifouling property, hydrophilicity, antifogging property, antistatic property and the like.

[0021]

The present invention will be described below in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Example 1 5 g of 2-methacryloyloxyethyl-2 ′-(trimethylammonio) ethyl phosphate (hereinafter abbreviated as “MPC”) as a monomer (1) and methyl methacrylate (hereinafter abbreviated as “MPC”) (Abbreviated as "MMA")
5 g of the mixed monomer (A) (mixing ratio of the monomer (A) 50% by weight), AIBN 0.1 g, and ethanol 5
0 g, and 10% by weight PMMA (δ =
9.3, polymerization degree n = 7000 to 7,500, 100 g of a THF solution of polymer (B) (50% by weight of polymer (B)) and a stirrer, a thermometer, a reflux condenser, and a nitrogen inlet tube. Into a 300 ml four-necked flask equipped with
Polymerization was carried out by heating at 60 ° C. for 20 hours in a thermostat. After polymerization,
The polymerization solution was poured into a large amount of diisopropyl ether to precipitate a polymer, which was separated by filtration and dried under vacuum. The obtained polymer was further dissolved in a solvent, and a cast sheet was prepared on a hot plate at 50 to 100 ° C., and the following evaluation test was performed. The composition is shown in Table 1, and the evaluation test results are shown in Table 5.

Evaluation Test Method Preparation of Test Pieces : A test piece having a size of 10 mm × 10 mm and a thickness of 0.5 mm, and this test piece was rubbed 10 times with a wrapping paper particle size of 3 μm to examine the durability of the surface. Each was made. Measurement of contact angle: The contact angle was measured by a water droplet method using a contact angle measuring device manufactured by Kyowa Science Co., Ltd. Antifouling test: In albumin 6 mg / ml phosphate buffer,
The prepared test piece or resin powder was put therein, immersed at 37 ° C. for 3 hours, and then the test piece or resin powder was taken out and lightly rinsed with physiological saline. Then, the protein was separated from the test piece or the resin powder with a 0.5% by weight solution of sodium dodecylbenzenesulfonate. The separated protein was quantified by injecting a reagent for protein quantification and UV measurement. Heat resistance test: The test piece was left in an oven at 80 ° C. for 2 hours, and the presence or absence of deformation and alteration was measured. “Present” in the table indicates that there is a change in the shape of the test piece surface and that there is a remarkable dimensional change. On the other hand, "none" indicates that there is no change in the shape of the surface of the test piece and that there is almost no dimensional change. Antithrombotic test (platelet adhesion state): Place the test piece in the bottom of the glass tube, pour platelet-rich plasma from rabbit,
C. and left for 1 hour. Thereafter, the test piece was removed, washed with a phosphate buffer, and the mucous platelets on the test piece were examined by an electron microscope. The evaluation is represented by an evaluation symbol shown in the table. In the table, x indicates that there are many platelets, Δ indicates that some platelets are observed, and ○ indicates that there are few platelets. In addition, only the antifouling test was performed for the resins prepared in Examples 17 to 21.

Examples 2 to 8 Polymers and cast sheets were prepared in the same manner as in Example 1 except that the monomers (A), polymers (B) and solvents having the compositions shown in Table 1 were used. An evaluation test was performed. Table 5 shows the evaluation results.

Example 9 A polymer and a cast sheet were prepared in the same manner as in Example 1 except that 2-methacryloyloxyethoxyethyl-2 '-(trimethylammonio) ethyl phosphate (MEPC) was used instead of MPC. Each evaluation test was performed. Table 5 shows the evaluation results.

[0025]

[Table 1]

Example 10 0.045 g of MPC as monomer (1), 0.105 g of 2-hydroxyethyl methacrylate (hereinafter abbreviated as "HEMA") as monomer (2), ethylene glycol dimethacrylate (Hereinafter abbreviated as "EGMA")
1 g of BME was added and dissolved in a mixed solution of 0.3 mg of the mixed monomer (A) (9.2% by weight as the mixing ratio of the monomer (A)) and 10 g of THF. Then
PMMA (δ = 9.3, polymerization degree n = 7000-750)
0, polymer (B)) 50 mm x 5 made with 1.48 g
A 0 mm × 0.5 mm film was immersed in the mixed solution and kept at 50 ° C. for 3 hours. Thereafter, the film was taken out and subjected to UV irradiation for 10 minutes at room temperature under a nitrogen stream. Next, the obtained film was washed in isopropyl alcohol and dried to prepare 1.63 g of a hydrophilic resin sheet. An evaluation test was performed on the obtained sheet in the same manner as in Example 1. Table 2 shows the composition, and Table 5 shows the results of the evaluation test.

Examples 11 to 15 Sheets were prepared in the same manner as in Example 10 except that the monomer (A), polymer (B) and solvent shown in Table 2 were used, and each evaluation test was performed. Table 5 shows the evaluation results. The weight of the obtained sheet was 1.50 g in Example 11, 1.45 g in Example 12, 1.51 g in Example 13, and 1.50 g in Example 14.
50 g and Example 15 weighed 1.54 g.

Example 16 A sheet was prepared in the same manner as in Example 10 except that the raw material as the monomer (2) was not used and the composition was as shown in Table 2, and each evaluation test was performed. Table 5 shows the evaluation results.

Example 17 5 g of MPC as a monomer (1), 25 ion-exchanged water
g, an aqueous solution consisting of 5 g of MEK as a solvent and 0.005 g of sodium persulfate as a polymerization initiator,
MA (δ = 9.3, degree of polymerization n = 7000 to 7,500, polymer (B)) 50 g of fine powder and normal hexane (hereinafter abbreviated as “n-HX”) were mixed with a stirrer, a thermometer, and a reflux condenser. And a 1-liter four-necked flask equipped with a nitrogen inlet tube, and polymerized by heating at 70 ° C. for 5 hours in a thermostat in a non-aqueous suspension system. After the polymerization, the resultant was separated by filtration and dried in a vacuum, and an evaluation test was performed in the same manner as in Example 1. Table 2 shows the composition, and Table 5 shows the results of the evaluation test.

Examples 18 to 21 Polymers were prepared in the same manner as in Example 17 except that the monomer (A), polymer (B) and solvent having the compositions shown in Table 2 were used.
Each evaluation test was performed. Table 5 shows the evaluation results.

[0031]

[Table 2]

Comparative Examples 1 and 2 Raw materials shown in Table 3 (MA in Table 3 indicates methacrylic acid)
Then, 0.1 g of AIBN and 100 ml of benzene were added thereto, and the mixture was polymerized under the same polymerization conditions as in Example 1, followed by reprecipitation in ether to prepare each polymer. The same evaluation test as in Example 1 was performed on the obtained polymer. Table 5 shows the results.

Comparative Examples 3 to 6 The polymer materials shown in Table 3 were placed in a discharge apparatus (6 cm between electrodes, voltage between electrodes 270 V, frequency 60 Hz).
Glow discharge was performed for 5 seconds in an argon atmosphere of 04 Torr. After exposing the polymer obtained by the glow discharge to the air, the polymer was put into a test tube, 100 g of a 10% by weight aqueous solution of acrylamide (hereinafter abbreviated as “ADD”) as monomer (2) was added, and the atmosphere was replaced with argon gas. Thereafter, the tube was sealed under reduced pressure. Next, the test tube was allowed to stand in a constant temperature bath at 80 ° C. for 1 hour, and then the polymer surface was washed with methanol and dried under vacuum to obtain a grafted polymer. An evaluation test was performed on the obtained polymer in the same manner as in Example 1. Table 3 shows the composition and processing conditions, and Table 5 shows the test results.

Comparative Examples 7 to 12 Polymerization was carried out in the same manner as in Example 1 using the monomer raw materials shown in Table 3, and the resulting copolymer was purified by repeated precipitation in ether. . A film made of the polymer material shown in Table 3 was immersed in an ethanol solution of the obtained polymer, and a sheet was prepared in the same manner as in Example 10.
An evaluation test was performed on the obtained sheet in the same manner as in Example 1. Table 3 shows the composition and processing conditions, and Table 5 shows the test results.

[0035]

[Table 3]

Comparative Examples 13 to 16 Monomer raw materials shown in Table 4 were polymerized in the same manner as in Comparative Examples 7 to 12 to obtain polymers, and 100 g of a 10% by weight solution of the obtained polymer in ethanol was added to Table 4 The polymer material was mixed at room temperature to prepare a polymer blend. A cast sheet was prepared from the obtained polymer blend on a hot plate at 50 to 100 ° C. The same evaluation test as in Example 1 was performed on the obtained cast sheet. Table 5 shows the results.

Comparative Examples 17 to 24 As shown in Table 4, 100 g of a 10% by weight solution of the polymer material alone as the polymer (B) used in Examples 1 to 8
A cast sheet was formed on a plate at 100 ° C., and the obtained cast sheet was subjected to the same evaluation test as in Example 1. Table 5 shows the results.

[0038]

[Table 4]

[0039]

[Table 5]

From the results shown in Table 5, it can be seen that in Examples of the present invention, the contact angle was small and the contact angle was small even after the surface was polished. You can see that. Furthermore, from the protein adsorption test, it can be seen that the amount of adsorption is small in Examples and the amount of adsorption is small even after surface polishing. On the other hand, Comparative Examples 13 to 16 in which sheets were prepared by polymer blending had a low protein adsorption amount,
It can be seen that the heat resistance test of the sheet changes. On the other hand, in Examples 1 to 16, the amount of protein adsorbed was small and the heat resistance was unchanged. Furthermore, Comparative Examples 16 to 18, 21 and 2
It can be seen that Examples 1-3, 5 and 6 have less platelet adhesion in the antithrombotic test than that of Example 2.

Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI C08L 43/02 C08L 43/02 (72) Inventor Yasumi Koinuma 32-16 Higashiarai, Tsukuba City, Ibaraki Prefecture (72) Inventor Kiyoshi Inomata Kasuga, Tsukuba City, Ibaraki Prefecture 2-17-1 (72) Inventor Norio Nakabayashi 5-6-20 Koganehara, Matsudo City, Chiba Prefecture (72) Inventor Kazuhiko Ishihara 3-16-37, Josuihoncho, Kodaira City, Tokyo

Claims (3)

[Claims] 1. The following general formula (1) wherein R ¹ and R ² are
Represents a hydrogen atom or a methyl group, and n represents a number of 1 to 10.) The monomer (A) containing the phosphorylcholine group-containing (meth) acrylic acid ester monomer (1) represented by the formula (1) 0.1 to 0.1:
99% by weight A hydrophilic resin obtained by polymerizing a raw material containing 1 to 99.9% by weight of a polymer (B) having a solubility parameter of 9.0 (cal / cm ³ ) ^1/2 or more. 2. The monomer (A) is a mixture of the phosphorylcholine group-containing (meth) acrylate monomer (1) and another ethylenic monomer (2),
2. The hydrophilic resin according to claim 1, wherein the amount of the other ethylenic monomer (2) is not more than 95% by weight in the monomer (A). 3. A medical material comprising the hydrophilic resin according to claim 1.