KR100211533B1 - Process for preparing aliphatic polyester resin which has high crystallization rate - Google Patents

Abstract

첨가함으로써 결정화 온도와 결정화 속도의 상승에 따른 사출성형시 성형주기 감소 및 성형온도 저하에 의한 성형성 향상과 성형물의 역학적 성질이 우수한 지방족 폴리에스테르수지의 제조방법에 관한 것이다.The present invention relates to a method for producing an aliphatic polyester resin having a high crystallization rate, and a saccharin sodium salt (2) as a crystallization nucleating agent in a polybutylene succinate or an copolymer of an aliphatic polyester having a melt flow index of 5 to 50 (2). , 3-dihydro-3-oxobenzisosulfonazole sodium salt) 0.1-1.0 weight

The present invention relates to a method for producing an aliphatic polyester resin having excellent molding properties by reducing the molding cycle and lowering the molding temperature and increasing the mechanical properties of the molding by adding the crystallization temperature and the crystallization rate.

Description

Method for producing aliphatic polyester resin with high crystallization rate

The present invention relates to a method for preparing an aliphatic polyester resin having a high crystallization rate, and more specifically, to a polybutyl succinate (PBS) having a melt flow index of 5 to 50 or a copolymer of these, saccharin sodium salt (2). (3-dihydro-3-oxobenzisulfonazole sodium salt) as a crystallization nucleating agent to reduce the molding cycle during injection molding due to the increase in crystallization temperature and crystallization rate, and improve moldability by lowering the molding temperature and The present invention relates to a process for producing an aliphatic polyester resin having excellent mechanical properties.

In general, aliphatic polyesters are widely used in the natural environment because of their excellent biodegradability, and are difficult to recover after use.They are used in agriculture, fisheries, civil engineering films, food packaging containers, and garbage bags, which are effective for composting organic waste. It is a useful biodegradable polymer resin that can be naturally decomposed to prevent environmental pollution. However, since the crystallization rate is relatively slow at the time of molding as compared to other polymer resins, there is a disadvantage in that moldability and physical properties of the molded product are inferior.

As a method for solving this problem, a method of improving the crystallization rate of the melt is known by adding a small amount of nucleating agent in the case of the aromatic fortresses which are widely used as conventional fibers or films.

For example, in U.S. Pat. It improves moldability such as reduction of molding cycle and decrease of molding temperature, and improves physical properties of moldings such as flexural modulus, flexural strength, deformation temperature under load, tensile strength and solvent resistance.

In addition, US Pat. No. 4,440,92 describes that addition of a small amount of ionomer as a nucleating agent to a polyester blend containing PET and PET improves not only the crystallization rate but also the final crystallization during molding. See also Plastic Engineering, 1987, Vol. According to 43, difficulties in the molding process due to the slow crystallization rate of PET can be overcome by adding a small amount of polyolefin, and in particular, conventional polyolefin resins such as polyethylene and polypropylene not only increase the crystallization rate of PET but also release property. It is described to improve the viscosity and lower the melt viscosity.

As described above, in the case of aromatic polyester such as PET, a method of improving the crystallization rate by adding a small amount of nucleating agent is known, but in the case of aliphatic polyester which has recently been studied as a biodegradable polymer, the crystallization rate is known. There is no known method for improvement.

The object of the present invention is to focus on the fact that organic compounds such as acidamides, sulfonamides, lactams and polyamides contribute to an increase in the crystallization rate of the polymers. And a method of preparing an injection molded product of an aliphatic polyester resin having a relatively high crystallization temperature, a reduction in crystallization rate during molding and a lower molecular weight, compared to when not added, by adding a crystallization nucleating agent to the copolymer.

The present invention will be described in more detail as follows.

첨가하여 사출 성형함으로써 성형성과 성형물의 역학적 성질이 향상된 지방족 폴리에스테르수지를 제조할 수 있었다.Saccharin sodium salt (2,3-dihydro-3-oxo benzisosulfonazole sodium salt) is used as a crystallization nucleating agent when extruding polybutylene succinate, an aliphatic polyester having a melt flow index of 5-50, or a copolymer thereof. 0.1 to 1.0 weight

By addition and injection molding, an aliphatic polyester resin with improved moldability and mechanical properties of the molded product could be prepared.

첨가하는 것이 바람직하며, 더욱 좋게는 0.2∼0.5중량

가 바람직하다. 만일 첨가량이 0.1중량

미만일 경우에는 핵제로서의 작용이 미미하여 결정화 온도의 상승이나 결정화 속도의 향상을 기대하지 못하며, 첨가량의 1.0중량

를 초과할 경우에는 핵제에 의한 분자량 저하가 심하여 성형물의 역학적 성질이 저하되는 문제점이 발생하였다.Saccharin sodium salt used as a crystallization nucleating agent in the present invention is 0.1 to 1.0 weight

It is preferable to add, More preferably, it is 0.2-0.5 weight

Is preferred. If the added amount of 0.1 weight

If it is less than that, it acts as a nucleating agent, so it is not expected to increase the crystallization temperature or to improve the crystallization rate.

When exceeded, the molecular weight fall by the nucleating agent was severe, and the problem that the mechanical properties of the molding fall.

Characterization of aliphatic polyethers according to Examples and Comparative Examples of the present invention was carried out in the following manner.

1. Melt Flow Index (MFR)

에서 2.16㎏ 하중하에서 10분간 압출되는 수지의 양으로부터 용융유동지수를 측정하였다.Using a Melt Flow Index Meter

The melt flow index was measured from the amount of resin extruded for 10 minutes under a 2.16 kg load at.

2. DSC heating start temperature and DSC heating peak temperature

/분의 속도로 150

까지 승온한 후 10

/분의 속도로 강온하는 과정에서 나타나는 발열피크의 발열개시온도와 발열피크온도를 측정하였다. 여기서 발열개시온도와 발열피크온도는 고분자 용융물을 냉각시킬 때 발생하는 결정화 온도 및 속도와 관련된 것으로 발열개시온도와 발연피크온도가 높을수록 높은 온도에서 빠른 속도로 결정화가 진행된다.Using a differential scanning calorimeter (DSC)

150 at / min

After heating up to 10

The exothermic starting temperature and exothermic peak temperature of the exothermic peak during the temperature reduction at the rate of / min were measured. Here, the exothermic onset temperature and exothermic peak temperature are related to the crystallization temperature and speed that occur when cooling the polymer melt. The higher the exothermic onset temperature and the smoke peak temperature, the faster the crystallization proceeds at a higher temperature.

3. DSC melting temperature

/분의 속도로 승온할 때 나타나는 흡열피크로 용융온도를 측정하였다.Using DSC in accordance with KSM 3050

Melting temperature was measured by the endothermic peak appearing when heating up at a rate of / min.

4. Tensile Strength and Elongation at Break

The method of ASTM D638 was used.

5. Nazid Izod Shock

Nazid specimens 1/8 inch thick were measured with an Izod impact tester according to ASTM D256.

6. Biodegradability

인 경우는 0으로, 10

미만인 경우는 1로, 10∼30

인 경우를 2로, 30∼60

인 경우는 3으로하고, 60∼100

인 경우 4로 구분하여 측정하였다.The degree of mold cover on the film after incubating for at least 21 days according to ASTM G21-70 method

Is 0, 10

Less than 1, 10 to 30

Is 2, 30 to 60

Is 3, and 60 to 100

In the case of measured by dividing by 4.

As described above, the aliphatic polyester prepared by adding saccharin sodium salt as a crystallization nucleating agent and its copolymer resin have increased crystallization rate and temperature, which reduces the molding cycle during injection molding, and improves moldability and mechanical properties as the molding temperature decreases. This excellent biodegradable resin molded article can be produced.

는 특별한 언급이 없는 한 중량

를 의미한다.The following examples and comparative examples illustrate the invention in more detail, but do not limit the scope of the invention,

Weight unless otherwise noted

Means.

Example 1

첨가하고 다이나믹 믹서가 부착되어 있는 압출기에서 150

의 온도에서 충분히 혼합하여 마스터 뱃치를 제조하였다. 제조된 마스터 뱃치칩을 70

의 진공건조기에서 4시간이상 건조시킨 후 사출성형기에서 아래와 같은 조건으로 1/2×51/2캐버티(ASTM 표준플렉스바)로 사출성형하였다.0.4 weight of saccharin sodium salt in polybutylene succinate (PBS) with melt flow index (MFR) of 10.0

150 in an extruder with the addition and dynamic mixer

The master batch was prepared by mixing sufficiently at the temperature of. Manufactured master batch chip 70

After drying for 4 hours or more in a vacuum dryer of the injection molding machine was injection molded in 1/2 × 51/2 cavity (ASTM standard flex bar) under the following conditions.

, 2구역 : 125

, 3구역 : 120

4구역 : 115

, 성형부 : 40

Temperature condition-Zone 1: 120

Zone 2: 125

, Zone 3: 120

Zone 4: 115

, Forming part: 40

Injection pressure-150 psi

Holding pressure-50 psi

Molding cycle (automatic cycle: second)-delayed injection: 3.2, injection: 40, maintenance: 20, cooling: 20.0, die opening: 2.0

The crystallization characteristics of the master batch and the mechanical properties of the injection molding according to the above example were evaluated and the results are shown in Table 1.

Example 2

첨가하고 상기 실시예 1과 동일한 조건으로 사출성형하였다. 마스터 뱃치의 결정화 특성 및 사출성형물의 역학적 성질을 평가하여 그 결과를 표 2에 나타내었다.0.3 weight of saccharin sodium salt in polybutylene succinate adipate copolymer (PBS-co-BA) with a melt flow index (MFR) of 20.0

It was added and injection molded under the same conditions as in Example 1. The crystallization properties of the master batch and the mechanical properties of the injection molding were evaluated and the results are shown in Table 2.

[Comparative Examples 1 to 3]

Except having changed the addition amount of the saccharin sodium salt as shown in Table 1, it carried out similarly to Example 1, and the result is shown in Table 1.

Comparative Examples 4 to 6

Except having changed the addition amount of the saccharin sodium salt as shown in Table 2, it carried out similarly to Example 2, and the result is shown in Table 2.

As shown in Table 1 and Table 2, when an appropriate amount of sodium saccharin salt acting as a crystallization nucleating agent is added, the DSC heating start temperature and the exothermic peak temperature are increased as in Examples 1 and 2, and the polymer melt cools to a higher temperature. It crystallizes at a faster rate at, and the mechanical properties of the injection molding thus formed are excellent.

Therefore, by adding an appropriate amount of sodium saccharin salt to aliphatic polyester or a copolymer thereof, it is possible to prepare a biodegradable resin having a high crystallization rate and excellent physical properties of an injection molded article.

As can be seen from the detailed description and the examples of the present invention, the present invention is molded during injection molding by adding sodium saccharin salt as a crystallization nucleating agent to a polybutylene succinate, which is an aliphatic polyester, which is a biopolymer, and a copolymer thereof. It has the effect of improving the mechanical properties of the molding.

Claims (2)

Saccharin sodium salt (2,3-dihydro-3-oxobenzisulfonazole sodium) as a crystallization nucleating agent in a polybutylene succinate (PBS), an aliphatic polyester having a melt flow index of 5 to 50, or a copolymer thereof. Salt) 0.1-1.0 weight

A method for producing an aliphatic polyester resin having a high crystallization rate, which is added. The method of producing an aliphatic polyester resin having a high crystallization rate according to claim 1, wherein a polybutylene succinate adipate copolymer (PBS-co-BA) is used as the aliphatic polyester copolymer.