CN1330088A - Process for preparing high-crystallinity polypropylene in reactor - Google Patents

Abstract

A process for preparing high-crystallinity polypropylene (HCPP) includes such steps as using high-purity nitrogen gas to displace out the water and air in reactor, cooling to ordinary temp, adding hydrogen gas and propylene, stirring at 100-300 rpm, adding composite nucleator to assistant feeder on the reactor, adding catalyst to the catalyst feeder on the reactor, using propylene to flush said nucleator and catalyst into reactor, heating to 65-75 deg.C and react for 1.5-3 hr.

Description

The method of preparing high-crystallinity polypropylene in reactor

One, technical field

The present invention relates to a kind of method of preparing high-crystallinity polypropylene in reactor.

Two, background technology

Polypropylene is typical partially crystalline thermoplastic resin, and its good ratio of performance to price has determined it to have very wide range of application.In recent years, along with developing rapidly of automotive industry, bullet train, construction industry, electronics communications industry, and the high performance of polypropylene product, polyacrylic output and demand significantly improve, become fastest-rising general-purpose plastics over nearly 10 years, year demand growth is up to 8%.One of important channel that polyacrylic high crystallization is PP new product development and high performance.High-crystallinity polypropylene (HCPP) has higher degree of crystallinity, crystallization velocity, Tc, heat-drawn wire, rigidity, hardness, surperficial anti-ruled area and glossiness, has expanded the product application scope greatly, and PP is developed towards the engineering plastics direction.At present HCPP in Europe, the annual requirement of the U.S. and Japan surpasses 1,000,000 tons, also reached about 100,000 tons in the demand of China, has boundless market outlook.As the needs owing to environment protection, save energy, the automobile lightweight has been trend of the times.With the U.S. is example, and by 2005, self weight in average of its each heavy car will drop to 885 kilograms by present 1453 kilograms, decrease by 40%.Because characteristics such as the peculiar density of HCPP is low, high comprehensive performance, good processabilities, the demand to HCPP in the light-weighted process of automobile increases substantially in recent years.After using HCPP replacement conventional P P, can make the addition of mineral filler among the PP reduce by 60%.HCPP mainly has benefited from the high transparent trade mark in the rapid popularization of packaging market and promotes the PP resin and substitute PET, PS and PVC in transparent container market.Its development in consumer goods market then can make further thin-walled property of PP goods and lightweight because of it, thereby PP is improved in the competitive power in markets such as family expenses vessel, container and furniture.

Industrial production HCPP mainly contains two approach: (1) still adds the nucleator method outward.This method promptly was used from nineteen sixty, and external at present existing multiple inorganic and organic nucleating agent is used to still and prepares HCPP outward, and this method technology is simple, but shortcoming is that the nucleator addition is bigger, nucleator be difficult for disperseing and nucleation inhomogeneous etc.(2) synthesis method in the still.It comprises in the still on the spot adds the nucleator method in the nucleation process and still.In the still on the spot nucleation process be exactly adopt the pre-polymerization operation in still produce in situ high-melting-point prepolymer or with the PP of a large amount of 10 unit isotactic chain link spirane structures of polymerization technique production of connecting as nucleator.The key of this type of technology is to select pre-monomer to generate high-melting-point polymer as nucleator in the still, companies such as Mitsui oiling, Sumitomo, Chisso, Amoco, Montell just constantly had the patent of this respect to deliver after 1985, and its limitation is that it can only produce HCPP on slurry method technology at present.Still inner additive nucleator method is exactly by add organic or inorganic nucleator in polymerization process, or the organic or inorganic nucleator is directly generated the effective catalyst system as the 3rd component of catalyzer prepares HCPP in still, and its biggest advantage is not to be subjected to the restriction of polymerization technique.Wherein more patent is to adopt inert substance (as talcum powder, silica gel, polyolefine etc.) directly to prepare HCPP as nucleator in still, as CN1215061A.The shortcoming of this method is that amount of talc is bigger, causes the density of product to increase, and its nucleating effect is not fine, and the Tc of polymkeric substance is lower.

Three, summary of the invention:

Degree of crystallinity, modulus in flexure, flexural strength, heat-drawn wire that purpose of the present invention just provides a kind of propene polymer obviously improve, the method for the preparing high-crystallinity polypropylene in reactor that the shock resistance of while polymkeric substance significantly improves.

The method of preparing high-crystallinity polypropylene in reactor of the present invention, its concrete method is:

(1) displaces water and air in the reactor with high-purity nitrogen, be cooled to room temperature;

(2) add hydrogen and propylene, under 100-300rpm, stir;

(3) composite nucleating agent is added in the auxiliary agent feeder on reactor top;

(4) catalyzer is added in the catalyzer feeder on reactor top;

(5) respectively with propylene with above-mentioned nucleator, catalyzer pours in the reactor;

(6) reactor is warming up to 65-75 ℃, reacted 1.5～3 hours.

Have a kind of organic nucleating agent in the composite nucleating agent at least, this organic nucleating agent is a heterocycle series organo-metallic salt compounds, and fusing point is more than 300 ℃.Inorganic nucleator can be to contain more than one simultaneously in the composite nucleating agent, and this inorganic nucleator is the ultra-fine powder of solid, and particle diameter is between 0.001～10 μ m.Inorganic nucleator is wilkinite or talcum powder or lime carbonate or silicon-dioxide.Primary Catalysts in the catalyzer is a high efficiency load type titanium catalyst series, and the promotor in the catalyzer is an organo-aluminium compound, and external electron donor is an organosilicone compounds.

The invention has the advantages that:

The present invention then is directly used in polymerization system with organic nucleating agent, synthesizes HCPP by suitable catalyst preparation and adding technique.Its advantage is: under the situation that does not change polymerization technique, use very a spot of nucleator and other auxiliary agent can reach good nucleating effect, the over-all properties of PP is improved greatly, especially in the rigidity that improves polymkeric substance, degree of crystallinity, Tc, can increase substantially the impact property of polymkeric substance.

Four, concrete embodiment

Before polymerisation begins, with the high-purity pipeline nitrogen blowing reactor of heat 2 hours More than, to guarantee from reactor, to displace the water and air of all traces, then reactor is existed Be cooled to high temperature under the nitrogen protection. At room temperature add 36mmol hydrogen and 600 gram propylene, Stirred reactor under the 100rpm. Add 1.8 gram nucleators in the 100mL auxiliary agent batching bottle Rare hexane solution of " NA9981 ", 15mL triethyl aluminum (TEAL) and 2mL two cyclopenta diformazans Oxygen base silane (CPDS) stirs and joins in the additive feeding device on reactor top after 2 minutes. In 100mL catalyst batching bottle, add 60 milligrams of catalyst and 20mL hexane, mix After join in the catalyst feeder on reactor top. Help above-mentioned with 600 gram propylene respectively Auxiliary agent in agent feeder, the catalyst feeder and catalyst pour in 10 liters of reactors, propylene Total addition be 1800 the gram. Reactor is warmed up to 70 ℃ rapidly, under 200rpm, makes anti-Should carry out discharging the residue propylene after 2 hours, stop reaction. Gathering of other embodiment and Comparative Examples The condition of closing sees table 1 for details, and the physical property of product sees Table 2.

Table 1 preparing high-crystallinity polypropylene in reactor technological parameter list

	Propylene (g)	H 2   (mg)	Catalyst (mg)	External electron donor (ml)	Co-catalyst (ml)	Nucleator (mg)	Active (gPP/gAT)
								Embodiment 1	1800	72	60	4	15	1800	27308
Embodiment 2	2030	70	6	4	15	4160	27377
								Embodiment 3	2000	75	65	4	15	7040	28338
Embodiment 4	1830	68	59	4	20	1800	30666
								Embodiment 5	2050	64	60	4	17	2000	2838
Comparative Examples 1	1800	72	60	4	15	——	28500
								Comparative Examples 2	1950	70	63	4	15	——	27960

In this table embodiment and Comparative Examples, polymerization time is 2 hours, and polymerization temperature is 70 ℃, catalyst is the MC-105 of Montcl company, and external electron donor is two cyclopenta two Methoxy silane (CPDS), co-catalyst are triethyl aluminum (TEAl).

In embodiment 1-embodiment 3, used nucleator is NA9981, and is real at embodiment 4-Execute in the example 5, used nucleator is NA9930.

Table 2 preparing high-crystallinity polypropylene in reactor the physical property of product list

	Flexural modulus (MPa)	Impact strength (I/m)	Fusing point (℃)	Crystallization temperature (℃)	Degree of crystallinity (%)
						Method of testing	GB/T1042	GB/T1843	The DSC method	The DSC method	The DSC method
Embodiment 1	1227	51.3	167	125.7	50.3
						Embodiment 2	1563	62.5	167	127.5	53.5
Embodiment 3	1617	75.6	167	129.5	55.2
						Embodiment 4	1255	70.6	164	126.9	60.1
Embodiment 5	1320	64.4	164	127.1	51.4
						Comparative Examples 1	1080	34.5	164	112.4	45.0
Comparative Examples 2	1120	35.5	164	112.6	45.2

Claims (6)

1. the method for a preparing high-crystallinity polypropylene in reactor is characterized in that method is:

(1) displaces water and air in the reactor with high-purity nitrogen, be cooled to room temperature;

(2) add hydrogen and propylene, under 100-300rpm, stir;

(3) composite nucleating agent is added in the auxiliary agent candle adding device on reactor top;

(4) catalyzer is added in the catalyzer feeder on reactor top;

(5) respectively with propylene with above-mentioned nucleator, catalyzer pours in the reactor;

(6) reactor is warming up to 65-75 ℃, reacted 1.5～3 hours.

2. the method for preparing high-crystallinity polypropylene in reactor according to claim 1 is characterized in that having a kind of organic nucleating agent in the composite nucleating agent at least, and this organic nucleating agent is a heterocycle series organo-metallic salt compounds, and fusing point is more than 300 ℃.

3. the method for preparing high-crystallinity polypropylene in reactor according to claim 1 and 2 is characterized in that inorganic nucleator can be to contain more than one simultaneously in the composite nucleating agent, and this inorganic nucleator is the ultra-fine powder of solid, and particle diameter is between 0.001～10 μ m.

4. the method for preparing high-crystallinity polypropylene in reactor according to claim 3 is characterized in that inorganic nucleator is wilkinite or talcum powder or lime carbonate or silicon-dioxide.

5. the method for preparing high-crystallinity polypropylene in reactor according to claim 1 and 2, it is characterized in that the Primary Catalysts in the catalyzer is a high efficiency load type titanium catalyst series, promotor in the catalyzer is an organo-aluminium compound, and external electron donor is an organosilicone compounds.

6. the method for preparing high-crystallinity polypropylene in reactor according to claim 5 is characterized in that external electron donor is a diamyl dimethoxy silane.