CN101003650A - Method for preparing moisture retentive plastic - Google Patents

Abstract

This invention discloses a method for preparing a moisture-absorption plastic. The method comprises: utilizing polyethylene or polypropylene as the matrix, adding molecular sieve powder as the moisture-absorption agent and poly (ethylene glycol) as the auxiliary moisture-absorption agent, mixing uniformly in a high-speed stirrer, extruding by a twin-screw extruder, and granulating. The moisture-absorption plastic can absorb moisture up to 3-30% of its weight.

Description

A kind of preparation method of hygroscopic plastic

Technical field

The invention belongs to organic high molecular compound, be specifically related to a kind of preparation method of hygroscopic plastic.

Technical background

The container of many commodity all is plastic containers, when its storage and transportation, be controlled under the environment of certain humidity, to guarantee the quality of commodity.If itself has hygroscopic property plastics, will absorb the moisture in the container, the quality that ensures commodity in the container is had vital role.Common plastics such as polyethylene, polypropylene etc. do not have hygroscopic property, and molecular sieve, silica gel etc. are good hygroscopic materials, if combine them, just can prepare the functional plastic with hygroscopic effect.

Among the Chinese patent CN1051742A, be in plastics, to add fiber-like as weighting agent, and then add one of linear alkylbenzene sulphonic acid, alkyl sodium sulfonate, sodium alkyl sulfate, Teepol, Soxylat A 25-7 and prepare hygroscopic plastic, its moisture uptake can reach the 5-10% of the weight of plastics own; Among the Chinese patent CN1350072A, be to add smooth property, flexibility, the water absorbability that pearl powder, tourmalinite and zeolite solve fiber in polyolein fiber, when relative humidity 65%, moisture regain is 7-8%.In addition, among Japanese patent laid-open 4-272212 and the Chinese patent CN1308149A, also all mention with the micropowder of trevira and tourmalinite or natural crystal and make raw material, come smooth property, flexibility, the water absorbability of fiber are improved; Among the Chinese patent CN1135494A, relate to the copolyester of copolymerization hydrophilic compounds, used its fiber to have suction, the moisture releasing characteristic that to control, can be used for suitable materials such as underwear, sweat shirt.But yet there are no report at home with general-purpose plastics and the compound hygroscopic plastic for preparing of molecular sieve.

Summary of the invention

The invention provides a kind of preparation method of hygroscopic plastic.Its step and condition are:

With polyethylene or polypropylene is matrix, and its melting index is 10-50; With the molecular sieve powder is moisture adsorbent, and the molecular sieve powder is pulverized by 4-15  molecular sieve and made, and particle directly is the 80-150 order; With polyoxyethylene glycol is auxiliary moisture adsorbent, and molecular weight is 30-600; Wherein, polyethylene or polypropylene: moisture adsorbent: auxiliary moisture adsorbent (weight ratio) is 30-80%: 15-60%: 5-25%;

With polyethylene or polypropylene particles and the oven dry of molecular sieve powder, by proportioning, the polyethylene or the polypropylene particles of oven dry are put into homogenizer, add the molecular sieve powder again, stir under the room temperature, add polyoxyethylene glycol again, high-speed stirring is even, extrudes on twin screw extruder then, and extrusion temperature is 140 ℃-230 ℃, air-cooled back granulation promptly gets a kind of hygroscopic plastic.

Prepared in this way hygroscopic plastic can absorb the moisture of own wt 3～30%.

Embodiment

Embodiment 1:

Polyethylene (melting index 10) 1Kg, 4  molecular sieve powder (100 order) 0.4Kg, stir putting into the 10L homogenizer after the two oven dry, add molecular weight again and be 200 polyoxyethylene glycol 0.15Kg, mix, extrude on Φ 45 twin screw extruders then, temperature is 150-175 ℃, and cooling, granulation promptly gets has hygroscopic plastic pellet.30 ℃ of temperature, during relative humidity 65%, this plastic pellet can absorb the moisture of own wt 6%.

Embodiment 2:

Polypropylene (melting index 20) 1Kg, 15  molecular sieve powder (100 order) 0.6Kg, stir putting into the 10L homogenizer after the two oven dry, add molecular weight again and be 300 polyoxyethylene glycol 0.3Kg, mix, extrude on Φ 45 twin screw extruders then, temperature is 150-175 ℃, and cooling, granulation promptly gets has hygroscopic plastic pellet.30 ℃ of temperature, during relative humidity 90%, this plastic pellet can absorb the moisture of own wt 9%.

Embodiment 3:

Polyethylene (melting index 20) 1Kg, 4  molecular sieve powder (100 order) 0.24Kg, stir putting into the 10L homogenizer after the two oven dry, add molecular weight again and be 200 polyoxyethylene glycol 0.2Kg, mix, extrude on Φ 45 twin screw extruders then, temperature is 150-175 ℃, and cooling, granulation promptly gets has hygroscopic plastic pellet.40 ℃ of temperature, during relative humidity 70%, this plastic pellet can absorb the moisture of own wt 4%.

Embodiment 4:

Polypropylene (melting index 50) 1Kg, 10  molecular sieve powder (120 order) 2.1Kg, stir putting into the 10L homogenizer after the two oven dry, add molecular weight again and be 500 polyoxyethylene glycol 0.4Kg, mix, extrude on Φ 45 twin screw extruders then, temperature is 150-175 ℃, and cooling, granulation promptly gets has hygroscopic plastic pellet.30 ℃ of temperature, during relative humidity 80%, this plastic pellet can absorb the moisture of own wt 30%.

Embodiment 5:

Polyethylene (melting index 15) 1Kg, 10  molecular sieve powder (80 order) 0.52Kg, stir putting into the 10L homogenizer after the two oven dry, add molecular weight again and be 200 polyoxyethylene glycol 0.08Kg, mix, extrude on Φ 45 twin screw extruders then, temperature is 140-165 ℃, and cooling, granulation promptly gets has hygroscopic plastic pellet.30 ℃ of temperature, during relative humidity 65%, this plastic pellet can absorb the moisture of own wt 9%

Embodiment 6:

Polypropylene (melting index 300) 1Kg, 10  molecular sieve powder (150 order) 1Kg, stir putting into the 10L homogenizer after the two oven dry, add molecular weight again and be 200 polyoxyethylene glycol 0.5Kg, mix, extrude on Φ 45 twin screw extruders then, temperature is 150-175 ℃, and cooling, granulation promptly gets has hygroscopic plastic pellet.25 ℃ of temperature, during relative humidity 65%, this plastic pellet can absorb the moisture of own wt 10%.

Claims (1)

1, a kind of preparation method of hygroscopic plastic is characterized in that: with polyethylene or polypropylene is matrix, and its melting index is 10-50; With the molecular sieve powder is moisture adsorbent, and the molecular sieve powder is pulverized by 4-15  molecular sieve and made, and particle directly is the 80-150 order; With polyoxyethylene glycol is auxiliary moisture adsorbent, and molecular weight is 30-600; Wherein, polyethylene or polypropylene: moisture adsorbent: auxiliary moisture adsorbent (weight ratio) is 30-80%: 15-60%: 5-25%;

With polyethylene or polypropylene particles and the oven dry of molecular sieve powder, by proportioning, the polyethylene or the polypropylene particles of oven dry are put into homogenizer, add the molecular sieve powder again, stir under the room temperature, add polyoxyethylene glycol again, high-speed stirring is even, extrudes on twin screw extruder then, and extrusion temperature is 140 ℃-230 ℃, air-cooled back granulation promptly gets a kind of hygroscopic plastic.