ACRYLIC POLYMER COMPOSITION

Abstract

Provided is an acrylic polymer composition comprising an acrylic polymer and a polyfunctional organic compound represented by the following general formula (1):

##STR00001##

(in the general formula (1), R.sup.4 and R.sup.2 are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R.sup.3 and R.sup.4 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, and k is an integer of 1 or larger).

Claims

1. An acrylic polymer composition comprising an acrylic polymer and a polyfunctional organic compound represented by the following general formula (1): ##STR00019## (in the general formula (1), R.sup.1 and R.sup.2 are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R.sup.3 and R.sup.4 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, and k is an integer of 1 or larger).

2. The acrylic polymer composition according to claim 1, wherein the polyfunctional organic compound is a compound represented by the following general formula (2): ##STR00020## (in the general formula (2), R.sup.1, R.sup.2, and k are as defined in the general formula (1), and R.sup.5 to R.sup.14 are each independently a hydrogen atom, a halogen atom, an alkoxy group having 1 to 10 carbon atoms, a nitro group, a cyano group, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, or an alkyl group having 1 to 20 carbon atoms).

3. The acrylic polymer composition according to claim 1, wherein k is 6.

4. The acrylic polymer composition according to claim 1, wherein the polyfunctional organic compound has a half-life of 5 hours or longer at 190 C.

5. The acrylic polymer composition according to claim 1, wherein a content ratio of the polyfunctional organic compound is an amount of 0.002 or more in terms of the number of equivalents of the amide group contained in the polyfunctional organic compound with respect to an ester group contained in the acrylic polymer.

6. The acrylic polymer composition according to claim 1, wherein a content ratio of the polyfunctional organic compound is 0.4 parts by weight or more in terms of a weight ratio per 100 parts by weight of the acrylic polymer.

7. A cross-linked product prepared by cross-linking an acrylic polymer composition according to claim 1.

8. A cross-linkable acrylic polymer composition comprising an acrylic polymer, a polyfunctional organic compound represented by the following general formula (1), and a cross-linking agent: ##STR00021## (in the general formula (1), R.sup.1 and R.sup.2 are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R.sup.3 and R.sup.4 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, and k is an integer of 1 or larger).

Description

EXAMPLES

[0150] Hereinafter, one embodiment of the present invention will be more specifically described with reference to Examples and Comparative Examples. In each example, the team part is based on weight unless otherwise specified.

[0151] Various physical properties were evaluated according to the following methods:

[0152] [Measurement of Half-Life of Polyfunctional Organic Compound]

[0153] To measure the half-life of the polyfunctional organic compound, the temperature was raised according to the temperature increase program given below using a the gravimetry-differential thermal analysis apparatus (TG/DTA7200, manufactured by Seiko Instruments Inc. (SII)) so that the heating temperature by the apparatus was set to 180 C. Then, decrease in weight was measured when the sample temperature was stabilized at 190 C. The time at which the weight was halved was determined and regarded as the half-life of the polyfunctional organic compound.

[0154] Temperature increase program: 30 C. .fwdarw.increase at 50 C./min .fwdarw.keep at 170 C. for 3 minutes .fwdarw.increase at 10 C./min .fwdarw.keep at 180 C. for 300 minutes

[0155] [Measurement of Peak Top Molecular Weight (Mp) of Acrylic Polymer]

[0156] The peak top molecular weight (Mp) of the acrylic polymer was measured as a polystyrene-based molecular weight by dissolving a film of the acrylic polymer composition in DMF and performing measurement by gel permeation chromatography (GPC). Specific measurement conditions were as given below. In this measurement, a molecular weight of 1,000 or smaller was judged as being derived from the polyfunctional organic compound and was thus not taken into consideration for the determination of the peak top molecular weight (Mp) of the acrylic polymer.

[0157] Instrument: High-performance liquid chromatograph HPC-8220GPC manufactured by Tosoh Corp.

[0158] Column: SupeR AWM-H manufactured by Tosoh Corp. (two columns placed in series)

[0159] Temperature: 40 C.

[0160] Detector: RI-8220 manufactured by Tosoh Corp.

[0161] Eluent: DMF (containing 10 mmol/L lithium bromide)

[0162] [Percent Decrease in Molecular Weight Upon Heating at 190 C.]

[0163] A film of the acrylic polymer composition was heated at 190 C. for 144 hours in air to obtain a heated film of the acrylic polymer composition. Then, the peak top molecular weight (Mp) of the acrylic polymer contained in the acrylic polymer composition was determined in the same way as above as to the heated film of the acrylic polymer composition. The percent decrease in molecular weight upon heating at 190 C. (%) was calculated according to the following expression:

[0164] Percent decrease in molecular weight upon heating at 190 C. (%)=100 (Peak top molecular weight of the acrylic polymer after the heating/Peak top molecular weight of the acrylic polymer before the heating)100

Synthesis Example 1: Synthesis of Acrylic Polymer

[0165] A polymerization reactor equipped with a thermometer, a stirring apparatus, a nitrogen introduction tube and a pressure reducing apparatus was charged with 200 parts of water, 3 parts of sodium lauryl sulfate, and 100 parts of ethyl acrylate. Oxygen was thoroughly removed by repetitive deaeration under reduced pressure and nitrogen replacement. Then, 0.002 parts of sodium formaldehyde sulfoxylate and 0.005 parts of cumene hydroperoxide were added to the reactor. Emulsion polymerization reaction was started at room temperature under normal pressure. The reaction was continued until the rate of conversion in polymerization reached 95%. The polymerization was terminated by the addition of a polymerization terminator. Then, the obtained emulsion polymer solution was coagulated with an aqueous magnesium sulfate solution, washed with water, and dried to obtain a rubbery acrylic polymer (polyethyl acrylate).

Synthesis Example 2: Synthesis of Polyfunctional Organic Compound 1

[0166] A 500 cc four-neck flask equipped with a dropping funnel was charged with 11.53 g of hexamethylenediamine, 200 cc of methylene chloride, and 30.75 g of triethylamine and cooled in ice, and 35.14 g of benzoyl chloride was added dropwise thereto through the dropping funnel with stirring. After the completion of dropwise addition, the mixture was stirred at room temperature for 3.5 hours. The solvent was replaced with THF, and precipitates were collected by filtration. Then, the obtained precipitates were washed three times with water and then dried to obtain 30.28 g of polyfunctional organic compound 1 represented by the formula (8) given below (compound represented by the general formula (2) wherein R.sup.1 and R.sup.2=a hydrogen atom, R.sup.5 to R.sup.14=a hydrogen atom, and k=6, molecular weight: 324.42) at a yield of 94%. The half-life at 190 C. of the obtained polyfunctional organic compound 1 was measured according to the method mentioned above and was consequently 1351.4 hours.

##STR00010##

Synthesis Example 3: Synthesis of Polyfunctional Organic Compound 2

[0167] A 500 cc four-neck flask equipped with a dropping funnel was charged with 11.56 g of hexamethylenediamine, 400 cc of THF, and 30.28 g of triethylamine and cooled in ice, and 42.53 g of 4-methoxybenzoyl chloride was added dropwise thereto through the dropping funnel with stirring. After the completion of dropwise addition, the mixture was stirred at room temperature for 1 hour, and precipitates were collected by filtration. Then, the obtained precipitates were washed three times with water and then dried to obtain 36.88 g of polyfunctional organic compound 2 represented by the formula (9) given below (compound represented by the general formula (2) wherein R.sup.1 and R.sup.2=a hydrogen atom, R.sup.5, R.sup.6, R.sup.8 to R.sup.11, R.sup.13, and R.sup.14=a hydrogen atom, R.sup.7 and R.sup.12=a methoxy group, and k=6, molecular weight: 384.47) at a yield of 96%. The half-life at 190 C. of the obtained polyfunctional organic compound 2 was measured according to the method mentioned above and was consequently stable without decrease in weight at 190 C.

##STR00011##

Synthesis Example 4: Synthesis of Polyfunctional Organic Compound 3

[0168] A 500 cc four-neck flask equipped with a dropping funnel was charged with 4.58 g of hexamethylenediamine, 200 cc of THF, and 11.94 g of triethylamine and cooled in ice, and 14.29 g of 4-cyanobenzoyl chloride was added dropwise thereto through the dropping funnel with stirring. After the completion of dropwise addition, the mixture was stirred at room temperature for 2 hours, and precipitates were collected by filtration. Then, the obtained precipitates were washed three times with water and then dried to obtain 13.22 g of polyfunctional organic compound 2 represented by the formula (10) given below (compound represented by the general formula (2) wherein R.sup.1 and R.sup.2=a hydrogen atom, R.sup.5, R.sup.6, R.sup.8 to R.sup.11, R.sup.13, and R.sup.14=a hydrogen atom, R.sup.7 and R.sup.12=a cyano group, and k=6, molecular weight: 374.44) at a yield of 90%. The half-life at 190 C. of the obtained polyfunctional organic compound 3 was measured according to the method mentioned above and was consequently 1724.1 hours.

##STR00012##

Synthesis Example 5: Synthesis of Polyfunctional Organic Compound 4

[0169] A 500 cc four-neck flask equipped with a dropping funnel was charged with 9.33 g of hexamethylenediamine, 250 cc of THF, and 24.36 g of triethylamine and cooled in ice, and 23.61 g of hexanoyl chloride was added dropwise thereto through the dropping funnel with stirring. After the completion of dropwise addition, the mixture was stirred at room temperature for 1.6 hours, and precipitates were collected by filtration. Then, the obtained precipitates were washed three times with water and then dried to obtain 22.52 g of polyfunctional organic compound 2 represented by the formula (11) given below (compound represented by the general formula (1) wherein R.sup.1 and R.sup.2=a hydrogen atom, R.sup.3 and R.sup.4=a n-pentyl group, and k=6, molecular weight: 312.49) at a yield of 90%. The half-life at 190 C. of the obtained polyfunctional organic compound 3 was measured according to the method mentioned above and was consequently 78.4 hours.

##STR00013##

Synthesis Example 6: Synthesis of Antioxidant

[0170] An antioxidant represented by the following formula (12) was synthesized according to the method given below:

##STR00014##

[0171] Specifically, first, 50.0 g (250.92 mmol) of phenothiazine was added to a three-neck reactor equipped with a thermometer in the stream of nitrogen and dissolved in 200 ml of toluene. Subsequently, 59.31 g (501.83 mmol) of -methylstyrene and 1.19 g (6.27 mmol) of p-toluenesulfonic acid monohydrate were added to this solution and reacted at 80 C. for 1 hour. Then, the reaction solution was brought back to room temperature, and 48 ml of acetic acid and 85.34 g (752.7 mmol) of a 30% aqueous hydrogen peroxide solution were added thereto and further reacted at 80 C. for 2 hours. The reaction solution was brought back to room temperature and then added to 630 ml of methanol. Then, precipitated crystals were filtered and washed with 320 ml of methanol to obtain 85.7 g of an antioxidant represented by the formula (12) as white crystals at a yield of 73%.

Example 1

[0172] 1 g of the acrylic polymer (polyethyl acrylate) obtained in Synthesis Example 1 was dissolved in 9 g of THF. To this solution, 23.1 mg of the antioxidant obtained in Synthesis Example 6 and 40.6 mg (0.125 mmol, the number of functional group equivalents with respect to an ester group contained in the acrylic polymer: 0.025) of the polyfunctional organic compound 1 obtained in Synthesis Example 2 were added, and the mixture was stirred overnight. 1.2 g of the obtained mixture was collected into a 6 cc sample bottle and dried under reduced pressure overnight at 40 C. to obtain a film of an acrylic polymer composition. Then, the obtained film of the acrylic polymer composition was subjected to the measurement of the peak top molecular weight (Mp) of the acrylic polymer before heating and the measurement of the peak top molecular weight (Mp) of the acrylic polymer after heating at 190 C. for 144 hours according to the method described above. As a result, the peak top molecular weight of the acrylic polymer was 820,344 before the heating and 588,466 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 28.27%.

Example 2

[0173] A film of an acrylic polymer composition was obtained in the same way as in Example 1 except that the amount of the blended polyfunctional organic compound 1 obtained in Synthesis Example 2 was changed to 10.1 mg (0.0312 mmol, the number of functional group equivalents with respect to an ester group contained in the acrylic polymer: 0.0062). As a result of then conducting evaluation in the same way as in Example 1, the peak top molecular weight of the acrylic polymer was 810,814 before the heating and 456,222 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 43.73%.

Example 3

[0174] A film of an acrylic polymer composition was obtained in the same way as in Example 1 except that the polyfunctional organic compound 2 obtained in Synthesis Example 3 was blended in an amount of 48.1 mg (0.125 mmol) instead of the polyfunctional organic compound 1 obtained in Synthesis Example 2. As a result of then conducting evaluation in the same way as in Example 1, the peak top molecular weight of the acrylic polymer was 829,973 before the heating and 655,465 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 21.03%.

Example 4

[0175] A film of an acrylic polymer composition was obtained in the same way as in Example 3 except that the amount of the blended polyfunctional organic compound 2 obtained in Synthesis Example 3 was changed to 12.0 mg (0.0312 mmol). As a result of then conducting evaluation in the same way as in Example 3, the peak top molecular weight of the acrylic polymer was 764,633 before the heating and 540,820 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 29.27%.

Example 5

[0176] A film of an acrylic polymer composition was obtained in the same way as in Example 1 except that the polyfunctional organic compound 3 obtained in Synthesis Example 4 was blended in an amount of 46.8 mg (0.125 mmol) instead of the polyfunctional organic compound 1 obtained in Synthesis Example 2. As a result of then conducting evaluation in the same way as in Example 1, the peak top molecular weight of the acrylic polymer was 792,051 before the heating and 527,886 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 33.35%.

Example 6

[0177] A film of an acrylic polymer composition was obtained in the same way as in Example 5 except that the amount of the blended polyfunctional organic compound 3 obtained in Synthesis Example 4 was changed to 11.7 mg (0.0312 mmol). As a result of then conducting evaluation in the same way as in Example 5, the peak top molecular weight of the acrylic polymer was 792,051 before the heating and 484,880 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 38.78%.

Example 7

[0178] A film of an acrylic polymer composition was obtained in the same way as in Example 1 except that the polyfunctional organic compound 4 obtained in Synthesis Example 5 was blended in an amount of 39.1 mg (0.125 mmol) instead of the polyfunctional organic compound 1 obtained in Synthesis Example 2. As a result of then conducting evaluation in the same way as in Example 1, the peak top molecular weight of the acrylic polymer was 801,384 before the heating and 540,820 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 32.51%.

Comparative Example 1

[0179] A film of an acrylic polymer composition was obtained in the same way as in Example 1 except that the polyfunctional organic compound 1 obtained in Synthesis Example 2 was not blended. As a result of then conducting evaluation in the same way as in Example 1, the peak top molecular weight of the acrylic polymer was 792,051 before the heating and 86,008 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 89.14%.

Comparative Example 2

[0180] A film of an acrylic polymer composition was obtained in the same way as in Example 1 except that hexamethylenediamine carbamate (trade name Diak #1, manufactured by DuPont Elastomer Co., Ltd.) was blended in an amount of 20.0 mg (0.125 mmol) instead of the polyfunctional organic compound 1 obtained in Synthesis Example 2. As a result of then conducting evaluation in the same way as in Example 1, the peak top molecular weight of the acrylic polymer was 810,814 before the heating and 187,754 after the heating for 144 hours, and the percent decrease in molecular weight upon heating at 190 C. was 76.84%.

TABLE-US-00001 TABLE 1 Polyfunctional organic compound The number of functional Amound blended Percent decrease in group equivalent with per 1 g of acrylic molecular weight by respect to ester group polymer heating at 190 C. Type in acrylic polymer (mmol) (%) Example 1 Example 2 [00015] 0.025 0.0062 0.125 0.0312 28.27 43.73 Example 3 Example 4 [00016] 0.025 0.0062 0.125 0.0312 21.03 29.27 Example 5 Example 6 [00017] 0.025 0.0062 0.125 0.0312 33.35 38.78 Example 7 [00018] 0.025 0.125 32.51 Comparative None 89.14 Example 1 Comparative Hexamethylenediamine 0.025 0.125 76.84 Example 2 carbamate

[0181] As shown in Table 1, according to Examples 1 to 7, an acrylic polymer composition was able to be obtained which contained an acrylic polymer blended with a polyfunctional organic compound represented by the general formula (1), and was controlled to have less than 50% percent decrease in molecular weight upon heating at 190 C. Furthemore, such an acrylic polymer composition can effectively suppress decrease in molecular weight of the acrylic polymer caused by molecular chain scission even upon heating to 190 C. or higher and can therefore be appropriately prevented from being thermally degraded under heating. As for such an effect, a similar effect can be obtained even when the acrylic polymer composition is supplemented with a cross-linking agent and the like and prepared into a cross-linked product.

[0182] By contrast, both in Comparative Example 1 in which the polyfunctional organic compound represented by the general formula (1) was not blended, and in Comparative Example 2 in which hexamethylenediamine carbamate was blended instead of the polyfunctional organic compound represented by the general formula (1), the percent decrease in molecular weight upon heating at 190 C. exceeded 50%, resulting in marked decrease in molecular weight upon heating to 190 C. or higher.