JPH0693162A - Cellulosic polymer alloy - Google Patents

Abstract

PURPOSE:To provide an alloy comprising a cellulosic derivative and a synthetic polymer compound. CONSTITUTION:The alloy comprises a mixture of a grafted cellulose, prepared by bonding a polyalkylene glycol to the glucose units of a cellulosic derivative through an ether bond, with an acrylic resin. A desirable example of the cellulosic derivative is hydroxypropylcellulose, and a desirable example of the polyalkylene glycol is monomethyl-polyethylene glycol. An example of the production process comprisers replacing the hydroxylic hydrogen atoms of a cellulose derivative with sodium atoms to obtain a sodium-substituted cellulose and reacting this compound with polyalkylene glycol monoethr tosylate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellulosic polymer alloy obtained by mixing a cellulosic substance and an acrylic resin.

[0002]

2. Description of the Related Art Cellulose, which is a natural polymer most widely distributed in nature, is a renewable resource and is expected to be effectively used as a naturally disintegrating polymer. Such cellulose itself is originally difficult to dissolve in water and general organic solvents, and has no thermoplasticity. Therefore, there are many technical difficulties involved in directly using it industrially. In order to overcome such a point, various cellulose derivatives have been developed in which cellulose is reacted with various etherifying agents and esterifying agents to impart solubility and thermoplasticity to a solvent. Nevertheless, such cellulose derivatives still have unsolved parts, and improvement of durability, decomposition resistance, processability, etc. is still insufficient. Therefore, it has not reached the stage of making full use of the excellent properties of cellulose and industrially using it widely.

Recently, a polymer alloying technique has been attracting attention, in which two or more kinds of polymer components are compatibilized with each other to produce a material having the advantages of each polymer. If a polymer alloy composed of a cellulose derivative and a synthetic polymer compound can be made, it is possible to obtain an excellent new material that has the advantages of the cellulose derivative and the durability and processability of the synthetic polymer compound. is there. However, except for nitrocellulose, the cellulose derivative has poor compatibility with the synthetic polymer compound, and thus far, there has been almost no polymer alloy in which the cellulose derivative and the synthetic polymer compound are combined, and it has not been possible to produce it.

[0004]

The present invention has been made to solve the above problems, and an object thereof is to provide a polymer alloy comprising a cellulose derivative and a synthetic polymer compound.

[0005]

The cellulosic polymer alloy of the present invention, which has been made to achieve the above object, comprises:
It is a mixture of a cellulose graft body in which polyalkylene glycol is ether-bonded to the unit glucose ring of the cellulose derivative, and an acrylic resin.

In the cellulose graft body mixed with the acrylic resin, polyalkylene glycol is ether-bonded to the cellulose derivative. Examples of the ether-bonded cellulose derivative include cellulose esters such as cellulose acetate and cellulose butyrate, and cellulose ethers such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, and cyanoethyl cellulose. . Hydroxypropyl cellulose and the like have hydroxypropyl groups ether-bonded to part or all of the hydroxypropyl groups as side chains that are directly ether-bonded to the unit glucose ring to form hydroxypropyl cellulose. May be. In addition to this, as the cellulose derivative in which the polyalkylene glycol is ether-bonded, many other known cellulose derivatives can be mentioned.

Examples of the polyalkylene glycol ether-bonded to the cellulose derivative include monomethyl polyethylene glycol, monoethyl polypropylene glycol, monononylphenyl polyethylene glycol, and monomethyl polyoxyethylene / polyoxypropylene block polymer. Among them, monomethyl polyethylene glycol is preferable from the viewpoint of easy availability of raw materials for producing a cellulose graft body. The average molecular weight of the polyalkylene glycol is preferably 300 or more.

The position of the ether bond may be any carbon atom in the 2, 3 and 6 positions of the unit glucose ring, or may be a derivatizing group directly bonded to those carbon atoms.

Such a cellulose graft is represented by the following formula 1, for example.

[0010]

[Chemical 1]

[0011] R ¹ in the above formula 1, formula - (C _x H _2x -
O) _m R ² , which is a polyoxyalkyl group formed from polyalkylene glycol. Besides, R ¹
May be a hydrogen atom, an acyl group, an alkyl group, a hydroxyalkyl group, a cyanoalkyl group, or the like. Examples of the acyl group in this case include an acetyl group and a butyryl group, examples of the alkyl group include a methyl group and an ethyl group, examples of the hydroxyalkyl group include a hydroxyethyl group and a hydroxypropyl group, and a cyanoalkyl group. Examples of the group include a cyanoethyl group. In addition, examples of R ¹ also include a case where the above polyoxyalkyl group is an ether bond to a hydroxyalkyl group. R in the polyoxyalkyl group
Examples of ² include a methyl group, an ethyl group, and a nonylphenyl group. In the formula, x is an integer and m is also an integer, but is the number of repeating alkylene glycols. Note that x may be the same or different between adjacent repeating units.

The average number of substitution moles (degree of substitution) of the polyalkylene glycol monoether is preferably 0.5 or more, more preferably 1.0 or more per unit glucose ring represented by the formula 1. If the degree of substitution is less than 0.5, the compatibility with the acrylic resin decreases, which is not preferable.

As a method for producing such a cellulose graft, the hydrogen of the hydroxyl group of the cellulose derivative is replaced with sodium to obtain a sodium-substituted cellulose.
Examples thereof include a method of reacting this with polyalkylene glycol monoether tosylate.

As the cellulose derivative forming the sodium-substituted compound, the cellulose derivative already mentioned above such as cellulose ester or cellulose ether can be mentioned in this case as well. However, these cellulose derivatives must have a sufficient proportion of hydroxyl groups that can be substituted by the polyalkylene glycol when it is substituted. In particular, from the viewpoint of grafting efficiency, it is preferable that the number of hydroxyl groups is as large as possible, and in that sense, hydroxypropyl cellulose having 3 hydroxyl groups per unit glucose ring is most preferable.

The synthetic reaction formula of the cellulose graft is shown below.

[0016]

[Chemical 2]

In the above formula, Celldev represents a cellulose derivative and -OH represents a hydroxyl group contained in the cellulose derivative. R ² is R in the above polyoxyalkyl group
Same as ² . Ts is a tosyl group represented by the following formula.

[0018]

[Chemical 3]

In the above equation, R ² — (OC _x H _2x ) _n −
The polyalkylene glycol monoether tosylate represented by OTs can be easily produced by using the corresponding polyalkylene glycol monoether as a raw material according to the following reaction formula.

[0020]

[Chemical 4]

The cellulose-based polymer alloy is a mixture of the above-mentioned cellulose graft body and an acrylic resin.

Examples of acrylic resins include polymethyl methacrylate, polymethyl acrylate, polypropyl methacrylate, and polyethyl acrylate.

In addition to the acrylic resin as described above, for example, a cellulose derivative or a synthetic polymer compound having a good compatibility with the acrylic resin may be mixed together. As such a cellulose derivative, the above-mentioned cellulose derivative such as a cellulose ester or a cellulose ether can also be mentioned in this case. Examples of the synthetic polymer compound having a good compatibility with the acrylic resin include polyvinyl chloride. When polyvinyl chloride or the like is mixed, a so-called multi-component polymer alloy is formed.

Regarding the mixing ratio of the respective components in the polymer alloy as described above, the ratio of the cellulose graft in the whole is 10 to 90% by weight, and the ratio of the acrylic resin is 90 to 10.
It is good that it is weight%. The ratio of cellulose graft is 1
If it is less than 0% by weight, it is generally not preferable because it is difficult to exhibit the excellent properties of cellulose. If it exceeds 90% by weight, it is difficult to exhibit the excellent properties of the synthetic resin, which is not preferable.

Such a cellulosic polymer alloy is manufactured by the following method. For example, a cellulose graft body in which a polyalkylene glycol is ether-bonded to a unit glucose ring of a cellulose derivative and an acrylic resin are mixed in the above-mentioned ratio. As a method for mixing the polyalkylene glycol monoether graft body of the cellulose derivative and the acrylic resin, for example, both powder and granules are stirred together, and then both are melted by heating at a temperature at which they are melted together and then cooled. There is a method. In addition, a method of dissolving the graft body and the acrylic resin in a common rich solvent and adding the solution to the common poor solvent of both to coprecipitate, or the graft body and the acrylic resin in the common rich solvent As long as the object of the present invention is not impaired, the method of dissolving, casting the solution, and then drying the solution can be mentioned without particular limitation.

A polymer alloy obtained by mixing a cellulose derivative, a graft body and an acrylic resin can also be obtained by the same method as described above.

As the acrylic resin to be mixed,
For example, polymethylmethacrylate is preferable because it is easily available.

The cellulosic polymer alloy thus produced can be used as, for example, a naturally disintegrating resin.

[0029]

[Function] The polyalkylene glycol monoether graft of the cellulose derivative and the acrylic resin are excellent in compatibility, and phase separation is difficult in the mixture.

[0030]

According to the cellulose-based polymer alloy of the present invention, the polyalkylene glycol monoether graft product of the cellulose derivative is compatible with the acrylic resin even if it is a cellulose-based substance. A polymer alloy comprising the compound is obtained. As a result, the excellent properties of cellulose can be effectively utilized industrially.

[0031]

EXAMPLES Examples of the present invention will be described below. Monomethyl polyethylene glycol tosylate was preliminarily synthesized according to Synthesis Example 1, and then monomethyl polyethylene glycol graft of hydroxypropyl cellulose was synthesized according to Synthesis Example 2.

Synthesis Example 1 Synthesis of Monomethyl Polyethylene Glycol Tosylate 10 parts by weight of monomethyl polyethylene glycol having an average molecular weight of 1900 was dissolved in 87.4 parts by weight of benzene, and the mixture was mixed at 5 ° C.
Below, 0.36 parts by weight of n-butyllithium was added thereto, and monomethyl polyethylene glycol was reacted with n-butyllithium to obtain a gel-like material. Benzene 8.7
1.62 parts by weight of p-toluenesulfinyl chloride
Part by weight was added to prepare a p-toluenesulfinic acid chloride mixed solution, and the p-toluenesulfinic acid chloride mixed solution was added to the above gel. 16 at room temperature
The above gel-like substance is reacted with p-toluenesulfinic acid chloride for a period of time, the resulting reaction mixture is filtered in a nitrogen stream to remove by-produced lithium chloride, and then benzene is evaporated to obtain a crude reaction product. Got The obtained crude reaction product was dissolved in 33 parts by weight of dry ethanol and left at -18 ° C for 1 hour to precipitate the desired product. The obtained precipitate was dried to obtain 7 parts by weight of purified monomethyl polyethylene glycol tosylate.

Synthesis Example 2 Synthesis of Monomethyl Polyethylene Glycol Graft of Hydroxypropyl Cellulose 10 parts by weight of monomethyl polyethylene glycol tosylate obtained in Synthesis Example 1 was added to 52.6 parts by weight of N, N'-dimethylformamide, and the mixture was stirred at room temperature. Solution A with stirring for 1 hour
Was prepared. 0.34 part by weight of hydroxypropylcellulose having an average substitution mole number of 3.2 per unit glucose ring is added to another 2.3 parts by weight of N, N′-dimethylformamide, and stirred at room temperature for 1 hour to prepare solution B. Was prepared. Then, the solution A and the solution B were mixed, stirred at room temperature for 2 hours, and cooled to 0 ° C. The hydroxyl group contained in the above-mentioned hydroxypropyl cellulose is 5 times the molar amount of 0.
69 parts by weight of sodium hydride (NaH) was added to N, N'-
It was dissolved in 1.94 parts by weight of dimethylformamide, added to the above mixture cooled to 0 ° C., and stirred at room temperature for 24 hours to react hydroxypropyl cellulose, sodium hydride, and monomethyl polyethylene glycol tosylate.

The reaction mixture thus obtained was neutralized with a 33% aqueous acetic acid solution, further subjected to dialysis and ultrafiltration, and then freeze-dried to give hydroxypropylcellulose monomethyl polyethyleneglycol having a substitution degree of 1.8. -1.86 parts by weight of a ru graft was obtained.

FIG. 1 shows hydroxypropyl cellulose (HPC (A)) used as a raw material and monomethyl polyethylene glycol graft (HPC-g-mPEG).
The infrared absorption spectrum (IR) of (B)) is shown. HPC
From -g-mPEG (B), it can be seen that the degree of absorption of hydroxyl groups present in HPC is reduced. 2 is HP
Proton nuclear magnetic resonance spectrum of C-g-mPEG (N
MR).

FIG. 3 shows HPC used as a raw material, monomethyl polyethylene glycol (mPEG), and monomethyl polyethylene glycol graft (HPC-gm).
It is the analytical data by a differential scanning calorimeter (DSC) with PEG). In HPC-g-mPEG, there is no endothermic peak at a temperature corresponding to the melting point of HPC, and an endothermic peak newly appears near 60 ° C. corresponding to the melting point Tm.

From the above, it was confirmed that a monomethyl polyethylene glycol graft was produced.

Example 1 The proportion of the monomethyl polyethylene glycol graft obtained in Synthesis Example 2 was 10% by weight and the proportion of polymethylmethacrylate was 90% by weight, and both were dissolved in tetrahydrofuran. Then, the solution was poured into petroleum ether to obtain a coprecipitate, and the coprecipitate was dried to obtain a binary cellulosic polymer alloy.

Differential scanning calorimetry (DSC) analysis was performed on the obtained binary cellulosic polymer alloy. The results are shown in Fig. 4. % In FIG. 4 is HPC-g-mP
The EG content weight ratio is shown.

Examples 2 and 3 The same as Example 1 except that the content of the monomethyl polyethylene glycol graft was 25% by weight or 50% by weight. Tg, Tc, and Tm in FIG. 4 indicate a glass transition temperature, a crystallization temperature, and a melting point, respectively.

Comparative Example 1 Polymethylmethacrylate was dissolved in tetrahydrofuran and then poured into petroleum ether to obtain a precipitate,
The obtained precipitate was dried. The analysis result of the differential scanning calorimeter (DSC) performed after the drying is shown in FIG.

From FIG. 4, it was found that when the weight composition ratio of the monomethyl polyethylene glycol graft product was increased, the glass transition temperature was moved correspondingly. From this, it was confirmed that the monomethyl polyethylene glycol graft body and methyl polymetalate were compatible with each other to form a polymer alloy.

Example 4 Hydroxypropyl cellulose, the monomethyl polyethylene glycol graft product obtained in Synthesis Example 2 and polymethylmethacrylate were simultaneously dissolved in tetrahydrofuran at a weight ratio of 4: 2: 4, and the solution was added to petroleum. The mixture was poured into ether to obtain a coprecipitate, and the coprecipitate was dried to obtain a ternary cellulosic polymer alloy.

Differential scanning calorimetry (DSC) analysis of the ternary cellulosic polymer alloy is shown by A in FIG. The temperature in the figure indicates the glass transition temperature.

Example 5 Example 4 except that the ratio of the components of hydroxypropyl cellulose, monomethyl polyethylene glycol graft and polymethyl methacrylate was 4.5: 1: 4.5.
Same as. The results are shown as B in FIG.

Comparative Example 2 The same procedure as in Example 4 was carried out except that the component ratio of hydroxypropyl cellulose, monomethyl polyethylene glycol graft product and polymethyl methacrylate was 5: 0: 5. The results are shown as C in FIG.

From FIG. 5, the glass transition temperature is shifted in accordance with the change in the composition ratio of the component polymers, and the monomethyl polyethylene glycol graft product (HPC-g-mPE) is obtained.
It was confirmed that a polymer alloy of G) and polymethylmethacrylate (PMMA) was formed.

[Brief description of drawings]

FIG. 1 shows infrared absorption spectra of HPC and HPC-g-mPEG.

FIG. 2 shows a proton nuclear magnetic resonance spectrum of HPC-g-mPEG.

FIG. 3 is analysis data of HPC, mPEG, and HPC-g-mPEG by a differential scanning calorimeter.

FIG. 4 is analysis data of a binary cellulosic polymer alloy by a differential scanning calorimeter.

FIG. 4 shows analysis data of a ternary cellulosic polymer alloy by a differential scanning calorimeter.

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[Procedure amendment]

[Submission date] March 15, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a diagram showing infrared absorption spectra of HPC and HPC-g-mPEG.

FIG. 2 is a diagram showing a proton nuclear magnetic resonance spectrum of HPC-g-mPEG.

FIG. 3 is a diagram showing analysis data of HPC, mPEG, and HPC-g-mPEG by a differential scanning calorimeter.

FIG. 4 is a diagram showing analysis data of a binary cellulose-based polymer alloy by a differential scanning calorimeter.

FIG. 5 is a diagram showing analysis data of a ternary cellulosic polymer alloy by a differential scanning calorimeter.

Claims (4)

[Claims] 1. A cellulosic polymer alloy comprising a mixture of a cellulosic graft body in which a polyalkylene glycol is ether-bonded to a unit glucose ring of a cellulosic derivative and an acrylic resin. 2. The cellulosic polymer alloy according to claim 1, wherein the cellulose derivative is hydroxypropyl cellulose. 3. The cellulosic polymer alloy according to claim 1, wherein the polyalkylene glycol is monomethyl polyethylene glycol. 4. The cellulose-based polymer alloy according to claim 1, wherein the cellulose derivative is mixed together.