JPH01182303A - Acrylic acid copolymer and production thereof - Google Patents

Abstract

PURPOSE:To obtain a copolymer useful as adhesives, coating compounds, etc., showing high bond strength on metals, etc., having excellent hydrolytic resistance, by polymerizing a (meth)acrylic acid with an acrylic acid ester derivative and reducing. CONSTITUTION:A (meth)acrylic acid shown by formula I (R<1> is R or CH3) is polymerized with an acrylic acid ester derivative (e.g., 3-acryloyloxy-1- adamantanecarboxylic acid benzyl ester) shown by formula II (R<2> is H or CH3; R<3> is protecting group; Ad is adamantyl which may contain one or two 1-3C alkyl substituent groups; n is 0-4) by a polymerization initiator (e.g., potassium persulfate) to give a polymer shown by formula III, which is reduced with a reducing agent (e.g., palladium black-hydrogen base) to give an acrylic acid copolymer having repeating units shown by formulas IV and V. The copolymer having >=93mol% repeating unit shown by formula IV is water-soluble and that having <93mol% repeating unit shown by formula IV is hydrophobic.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an acrylic acid copolymer and a method for producing the same, and more particularly to adhesives and paints.

This invention relates to an acrylic acid copolymer useful as a coating agent, etc., and a method for producing the same.

[Conventional technology and its problems] Traditionally, the technology has been characterized by a high glass transition point, low shrinkage, low elongation, high transparency, high thermal stability, and low water absorption.
A copolymer of l-7 damantyl 7 acrylate and an acrylic acid ester and a method for producing the same are known (see Japanese Patent Publication No. 4B-28419). It is used for various purposes depending on its properties.

However, because of the above-mentioned characteristics, the above copolymers cannot be used for applications that require appropriate hydrophobicity or water solubility, so their applications are naturally limited. . Furthermore, since the above copolymer is made by copolymerizing two types of 7-acrylates in terms of 1,8' wood, even if the copolymer composition ratio is changed, hydrophobicity will be lowered and water solubility will be increased. There are also problems such as not being able to harden due to metal oxides, decreasing Al mechanical strength, and having low adhesion to metal surfaces. Furthermore, the copolymer has adamantyl groups bonded through ester bonds.

Money! ! When cured with an oxide, there was also the problem that the matrix phase was brittle.

The purpose of the present invention is to provide an acrylic acid-based copolymer and a method for producing the same which improve the drawbacks of the above-mentioned prior art. Can be controlled arbitrarily by changing the ratio,
It exhibits strong adhesion to metals, etc., and has hydrolysis resistance while being wood-loving.

[Means for Solving the Problems] As a result of intensive studies to achieve the above object, the present inventors have completed the present invention.

In other words, the first configuration of the present invention is the formula (1): % formula %) (In the formula, R1 represents a hydrogen atom or a methyl group.) The compensation unit is expressed as .

Formula (2): %Formula% (In the formula, 1i2 represents a hydrogen atom or a methyl group, and A
d represents an adamantyl group which may be substituted with a maximum of two alkyl groups having 1 to 3 carbon atoms, and n is an integer of θ to 4. ) is an acrylic acid-based copolymer having a repeating unit represented by:

The second configuration of the present invention is acrylic acid and/or methacrylic acid represented by formula (3): % formula % (3) (in the formula, ill represents a hydrogen atom or a methyl group), and formula (0: %Formula %(4) (In the formula, R2 represents a hydrogen atom or a methyl group, and R3
represents a protecting group, and Ad has 1 to 3 carbon atoms, maximum 2
represents an adamantyl group which may be substituted with alkyl groups, and n is an integer of θ to 4. ) is polymerized with a polymerization initiator to obtain a polymer represented by formula (5): (wherein R1, R2, R3, Ad and n have the same meanings as above) After that, the method for producing an acrylic acid copolymer is characterized in that the polymer is reduced with a reducing agent.

The acrylic acid copolymer of the present invention is a novel copolymer having repeating units represented by formulas (1) and (2) above.

In addition, this acrylic acid copolymer has a molecular weight of 1 usually 3.000 to
100,000, preferably 5,000-30,00
Preferably, it has a molecular weight of 0.

The acrylic acid copolymer of the present invention is not particularly limited as long as it has the above-mentioned repeating unit, and may be a random copolymer, a block copolymer, or an alternating copolymer.

The acrylic acid copolymer of the present invention preferably contains repeating units represented by formula (2) in an amount of 0.2 to 83 mol%.

The acrylic acid copolymer of the present invention has a noteworthy feature that it is water-soluble when the repeating unit represented by formula (1) is 93 mol% or more, and hydrophobic when it is less than 93 mol%. These properties of wood can be varied by appropriately changing the manufacturing conditions.

If this acrylic acid-based copolymer is a water-soluble polymer, it can be used, for example, in dental polycarboxylic acid cement or glass ionomer cement, and its good hydrolysis resistance significantly improves the lifespan of dental cement. can be done. Also, when used in dental cement,
The molecular weight of the acrylic acid copolymer is not particularly limited, but
Preferably, the number average molecular weight is 1.000 or more.
In addition, in the case of hydrophobic polymers, for example, adhesives,
Can be used for paints and coating materials, etc.

Note that the acrylic acid copolymer of the present invention may have repeating units other than the repeating units shown in formulas (1) and (2) above, as long as the object of the present invention is not impaired.
As such other engaeshi units, for example.

(However, in the formula, R1 represents the same meaning as above, and R
4 represents a lower alkyl group such as a methyl group, an ethyl group, a butyl group, etc.) 1←CH2-CR2→- GO? -(C:Hz)n-Ad (2)
(However, in the formula, R2 represents the same meaning as above.).

The acrylic acid copolymer of the present invention can be produced as follows.

First, acrylic acid or methacrylic acid represented by formula (3) (in the formula, R1 represents a hydrogen atom or a methyl group) and formula (4) (in the formula , R2 represents a hydrogen atom or a methyl group, R3
represents a protecting group, and Ad has 1 to 3 carbon atoms, maximum 2
represents an adamantyl group which may be substituted with alkyl groups, and n is an integer of θ to 4. ) is polymerized with an acrylic acid ester derivative represented by After obtaining the polymer, it can be obtained by reducing it with the base agent (ii).

In the method of the present invention, the acrylic ester derivative represented by formula (4) has a protecting group at its terminal.

Specific examples of the protecting group include benzyl group, methylbenzyl group, etc. Specific examples of the acrylic acid ester derivative having the protecting group include 3-7 chloroyloxy-1-7 damantane carboxylic acid benzyl ester , 3-methacryloyloxy-1-7 damantanecarboxylic acid benzyl ester.

Examples include 3-acryloyloxy-1-7 damantanecarboxylic acid p-methylbenzyl ester.

The copolymerization of the above formulas (3) and (0) may be carried out by ionic polymerization or living polymerization, but usually radical polymerization is used.

In the case of radical polymerization, the polymerization initiator used is
For example, potassium persulfate, ammonium persulfate, t-butyl peroxide, cumene hydroperoxide, acetyl peroxide, benzoyl peroxide, lauroyl peroxide,
Examples thereof include azobisinbutyronitrile, azobiscyclohexanecarbonitrile, methyl azobisisobutyramidine, azobisisobutyramidine hydrochloride, azobisschiff)valeric acid, and the like.

The copolymerization reaction can be carried out in the form of solution polymerization, bulk polymerization, emulsion polymerization, etc., but usually solution polymerization is used.

In the case of solution polymerization, the solvents used include methyl alcohol, ethyl alcohol, isopropyl alcohol,
Examples include alcohols such as n-propyl alcohol and n-butyl alcohol, ethers such as ether, tetrahydrofuran and dioxane, and ketones such as acetone and methyl ethyl ketone. If absolute alcohol is used as a solvent, esterification may proceed, so hydrous alcohol is preferable to absolute alcohol, and its water content is usually 0.2 to 5! i amount %, but it may exceed 531 amount % depending on the case.

Further, the single polymerization solvent may be a mixed solvent of alcohols and other solvents, and the solvents that can be used may be those inert to the reaction, such as aliphatic hydrocarbons,
Examples include aromatic hydrocarbons, and among these, aromatic hydrocarbons are preferred.

Specific examples include benzene, toluene, xylene and the like.

The polymerization temperature is usually 50-100°C.

For copolymers with a high composition ratio of acrylic acid, after the first stage of polymerization reaction is completed, an aromatic hydrocarbon such as benzene, toluene, or xylene is added to the polymer solution to precipitate the polymer. After the polymer is once filtered, it is dissolved in alcohol and purified by reprecipitation with aromatic hydrocarbons such as benzene, toluene, and xylene.

On the other hand, in the case of a copolymer with a low composition ratio of acrylic acid, one reaction mixture is poured into a mixed solvent of water and methyl alcohol to precipitate the polymer. The polymer is once filtered, then dissolved in toluene, and poured into a mixed solvent of water and methyl alcohol again to reprecipitate the polymer for purification.

The transition agent used in the second step of the method of the present invention, which is the primary component of the acrylic acid copolymer, is a metal catalyst-hydrogen system,
Examples of the metal catalyst include palladium, platinum, rhodium, and osmium, with palladium being particularly preferred. Among palladium, palladium black is preferred; catalysts containing activated carbon and palladium are difficult to remove from the copolymer. The amount of catalyst added is 1 to 30% by weight, preferably 10 to 20!1% by weight, based on the acrylic acid copolymer. Further, hydrogen is used at a flow rate of 10 to 200 ml/min at normal pressure.

Solvents that can be used during hydrogen reduction include:
Alcohols, especially hydrous ethyl alcohol, are preferred;
The water content is 10-50% by weight, preferably 10-30% by weight. Water content is 50! If it exceeds 1% by weight, the catalyst will be severely dispersed and it will be difficult to remove it by filtration, and if it is less than 10% by weight, the carboxylic acid produced by hydrogen reduction will be esterified by the alcohol of the reaction solvent. This may cause some inconvenience.

The reaction temperature during hydrogen reduction is usually 5 to 50°C.

Thus, the acrylic acid copolymer according to the present invention can be obtained by hydrogen reduction.

[Example] Next, examples of this invention will be shown.

(Adjustment example) Literature (Ches+, Ber, 95,667 (1911i
7)) The 3-hydroxy-adamantanecarboxylic acid synthesized by the method described in 7)) was neutralized with an aqueous potassium hydroxide solution to obtain an aqueous solution of 3-hydroxy-liumantanecarboxylic acid potassium salt. This salt was dried overnight in a vacuum dryer at 150°C to remove water. 1 dry potassium salt
Dissolve 0.2g (0,05:) so of) in 100 mal of dimethylformamide (DMF), and dissolve benzyl bromide 8
．． 4 g (0,050 layers o1) were added and stirred at 110° C. for 8 hours under an argon gas atmosphere, and most of the DMF was distilled off from the reaction solution using a rotary evaporator. Thereafter, the reaction product was dissolved in 300 ml of ether, transferred to a separating funnel, washed 3 times with 100 ml of saturated saline, then washed 5 times with 100 ml of pure water, and then anhydrous magnesium sulfate was added. After filtering the magnesium sulfate that had been dried overnight, recrystallization was performed using a mixed solvent of acetone/cyclohexane (volume ratio 15/85) from which the ether had been distilled off using a rotary evaporator. (0,0405 oil) of purified 3-hydroxy-1-7 tamantanecarboxylic acid benzyl ester was obtained. 3-Hydroxy-1-adamantanecarboxylic acid benzyl ester thus obtained 10
．． 0 g (0,035 sof ) was dissolved in 150 layers of toluene dehydrated with calcium hydride, and further 8.2 g (0,0
Next, while flowing dry argon gas into the reaction vessel, the reaction vessel was cooled in an ice-water bath, and while stirring, 6.5 g (0,
070 moi) of acrylic chloride was added dropwise over 30 minutes. After the completion of the 0 drop addition, the ice water bath was removed and the temperature was returned to room temperature.
Stirred for 6 hours. After that, the amine hydrochloride in the reaction mixture was removed by filtration, and the filtrate was transferred to a separating funnel and washed three times with 100 ml of IN aqueous solution of hydrochloric acid.Then, the filtrate was washed three times with 100 ml of 3N aqueous sodium hydroxide solution. Finally, the solution was washed with pure water until it became neutral. Add anhydrous magnesium sulfate to the washing solution, add 11 g of magnesium sulfate, which had been dried overnight, and distill off toluene using a rotary evaporator. 1-adamantanecarboxylic acid benzyl ester was obtained. IH-NM of the obtained comonomer
The R spectrum is shown in FIG.

In addition, the attribution of the spectrum is as follows.

■ 5.85pps ■ 6.25PP■■
6.05PP Otori ■ 2.2Op
p layer■ 2.05pp@■ 1.80pp■
■ 160pp layer ■ 5.1O
PP layer■? , 35pp■ Note that the peak at 2.50pp is due to impurities in DMSO-d6.

(Example 1) 3.8 g (0,011 layers ou) of 3-7 chloroyloxy-1-7 damantancarboxylic acid benzyl ester obtained in the above preparation example and acrylic acid 3 (distilled immediately before use)
8g of L (0.43g) was dissolved in 130mM of 2% aqueous ethyl alcohol, and 0.19g of penzoyl oxide was added and stirred to homogeneously dissolve 0.
Next, argon gas was blown into the reaction solution for 1 hour to replace the air in the system with argon gas. Thereafter, the reaction solution was brought to a reflux state by heating and stirring while blowing argon gas, and this state was continued for 5 hours. After cooling the reaction solution to room temperature, the reaction solution was poured into 600 mJl of toluene, and the acrylic acid The copolymer was precipitated. After removing the supernatant liquid by decantation, the precipitated acrylic acid copolymer was dissolved in 150 mJL of ethyl alcohol and poured into another 600 mJL of toluene to precipitate the acrylic acid copolymer. This operation was repeated 5 times to remove unreacted additives from the acrylic acid copolymer.
ml of distilled water was added, and the mixture was concentrated under reduced pressure using a rotary evaporator in a hot water bath at 40 to 60°C. 50m of aqueous solution containing copolymer! When the mixture was concentrated to about 1.0 L, 100 mJl of distilled water was added again and concentration under reduced pressure was carried out. After repeating this operation four times to completely remove ethyl alcohol, the temperature of the hot water bath was raised to 80° C. to dryness. The yield of the obtained acrylic acid copolymer was 26.4. FIG. 2 shows IH-NMR of the obtained copolymer.

After dissolving the obtained ILOg acrylic acid copolymer in 150 mJL of 10% ethanol, 3.0 g of palladium black powder, which is a hydrogen reduction catalyst, was added. Then, hydrogen was blown into the reaction solution at normal pressure. The benzyl group was removed by vigorous stirring. Note that the flow rate of hydrogen was 100 m/min, and the stirring time was 10 hours. Thereafter, palladium black was removed by filtration, 100 mJl of distilled water was added to the filtrate, and the mixture was concentrated using a 40-50°C hot water bath and a rotary evaporator. Liquid volume is 5
When it was concentrated to about 0 ml, 100 mjL of distilled water was added again and concentrated under reduced pressure. After repeating the above procedure 4 times to completely remove the ethyl alcohol, the temperature of the hot water bath was raised to 80°C. The acrylic acid copolymer was dried. The yield of the obtained acrylic acid copolymer was 14.5 g.
Met. Figure 3 shows tH-NMR after hydrogen reduction.

In addition, the attribution of the spectrum is as follows.

■ 1,70pp■, j, 90pp■@2.
40pp layer @ 5.45pp layer■ 2.25PP layer■ 2.1OPP layer■ T-aspp layer■ T,5opp■ @5.10pp layer■? , 35pp Proverb: Absorption due to impurities in the solvent CD5OD
．． Absorption by ethyl ester in the 3PP intestine is 1.25 pp.
layer, appearing at 4.1 pp■.

Note that 18-NMR shows that the acrylic acid copolymer contains units containing adamantane groups, but the quantitative determination is based on the acrylic acid copolymer before hydrogen reduction in which benzyl groups exist. Acid-based copolymers are easier, so that's it! According to H-NMR, it was found to be 2.4 intestine on%.

In addition, the attribution of the spectrum is as follows.

■ 1=70ppm, 1.9011P layer @ 2.4O
PP layer ■ 5.45PP■ @ 2.25pp set■ 2.109P meeting■ 1.85PP■ ■ 1.55ppm Note that the absorption due to impurities in the solvent CD30D is 3
．． Absorption by ethyl ester is 1.25pp in 3pp
m, 4.1PP appears in the intestine.

In addition, regarding the molecular weight of the obtained acrylic acid copolymer, since the molecular weight of the hydrogen-reduced acrylic acid copolymer cannot be measured by normal methods, the acrylic acid copolymer was measured using an ether solution of diazomethane. After converting all the carboxyl groups therein into methyl esters, the measurement was performed by gel permeation chromatography. In addition, as a 1 separation column.

Manufactured by Toyo Soda, TSK GH8P, GMH6 and G
200H8 was used in conjunction. Moreover, tetrahydrofuran was used as a developing solvent, and polystyrene was used as a standard substance. The molecular weight distribution curve obtained in this way is shown in Figure 4, and the values of number average molecular weight and weight average molecular weight are 1.4 x 104 and 3.7 x 104, respectively.
Met.

A peel strength test was conducted on the acrylic acid copolymer obtained in the example as follows.

The peel strength of an acrylic acid copolymer synthesized using a steel plate with dimensions of 25 sm x 1 G0 x 1 mm (thickness) and an aluminum foil with dimensions of 25 layers x 100 layers x 60 mm (thickness) was measured. An aqueous solution of the above acrylic acid copolymer containing 20% methyl alcohol was applied to a steel plate that had been washed and degreased with trichlene to a height of 25 cm from one side of the steel plate, and dried for 20 minutes in a vacuum dryer at 70°C. Next, the aluminum foil degreased with Triclean was placed on the steel plate, held down with a steel plate from above to prevent it from shifting, and heated to 18
Bonding was carried out for 5 minutes at 0°C and 60 kg/cm2. Thereafter, a 180 degree peel test was conducted at a tensile strength of 200 mm/min to obtain a strength of 2.0 kg/250 m layer.

[Effects of the Invention] The acrylic acid copolymer of the present invention can be made wood-philic or hydrophobic by changing the composition of the acrylic ester derivative and/or the acrylic ester derivative. The applications of copolymers are dramatically expanded. In addition, this acrylic acid-based copolymer has free carboxylic acid, so it has the ability to form a chelate structure. Acid-based copolymers have an adamantane structure in their molecules, so they have a high glass transition point and a small coefficient of thermal expansion.
#I It has advantages such as high stability and good water resistance.

Therefore, it is useful as adhesives, coating materials, paints, organic glasses, and biological materials. Furthermore, there is an advantage that the strength of the resin itself can be increased by the fluoromer crosslinked structure.

[Brief explanation of the drawing]

Figure 1 is an IH-NMR spectrum of 3-7 chloroyloxy-1-adamantanecarboxylic acid benzyl ester monomer, and Figure 2 is an IH-NMR spectrum of an acrylic acid copolymer, which is an intermediate of the present invention. , 3rd
The figure shows the acrylic acid copolymer obtained by the present invention.
This is an IH-NMR spectrum, and FIG. 4 is a molecular weight distribution curve of the acrylic acid copolymer obtained according to the present invention. Figure 4 Molecular weight distribution curve “Continued to the amendment document - February 7, 1989

Claims (6)

[Claims] (1) Formula (1): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (1) (In the formula, R^1 represents a hydrogen atom or a methyl group.) A repeating unit represented by and Formula (2): ▲There are mathematical formulas, chemical formulas, tables, etc.▼(2) (In the formula, R^2 represents a hydrogen atom or a methyl group, and A
d represents an adamantyl group which may be substituted with a maximum of two alkyl groups having 1 to 3 carbon atoms, and n is an integer of 0 to 4. ) An acrylic acid-based copolymer having a repeating unit represented by: (2) Formula (3): CH_2=CR^1-CO_2H (3) (In the formula, R^1 represents a hydrogen atom or a methyl group.) Acrylic acid and/or methacrylic acid represented by the formula (4) ): CH_2=CR^2CO_2-(CH_2)_n-Ad
CO_2R^3(4) (in the formula, R^2 represents a hydrogen atom or a methyl group, R^3 represents a protecting group, and Ad substitutes up to two alkyl groups having 1 to 3 carbon atoms. represents an adamantyl group which may be an adamantyl group, and n is an integer from 0 to 4.) is polymerized using a polymerization initiator to form the compound represented by formula (5): ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (5) After obtaining the polymer represented by (wherein R^1, R^2, R^3, Ad and n have the same meanings as above), the polymer is reduced with a reducing agent. A method for producing an acrylic acid copolymer, characterized by: (3) The manufacturing method according to claim 2, wherein the polymerization is carried out in an alcoholic solvent or a solvent prepared by adding an aromatic hydrocarbon solvent to these solvents. (4) The manufacturing method according to claim 3, wherein the alcoholic solvent is a hydrous alcohol. (5) The manufacturing method according to claim 2, wherein the reducing agent is a palladium-hydrogen based reducing agent. (6) The manufacturing method according to claim 2, wherein the polymerization initiator is a radical initiator.