WO2011079517A1

WO2011079517A1 - Co-extruded composite polypropylene hose and manufacturing method thereof

Info

Publication number: WO2011079517A1
Application number: PCT/CN2010/002176
Authority: WO
Inventors: 陈寿; 陈文涛; 林茂青
Original assignee: 上海通产丽星包装材料有限公司
Priority date: 2009-12-28
Filing date: 2010-12-28
Publication date: 2011-07-07
Also published as: CN101761707A

Abstract

A co-extruded composite polypropylene hose and a manufacturing method thereof are provided. The hose comprises a hose tip and a hose body. The hose body has a composite structure with 2-5 layers, wherein at least one layer is made of polypropylene or a mixture of polypropylene and polyethylene. The polypropylene adopted is randomly copolymerized polypropylene, which is catalyzed by metallocene catalyst and has a melt index of 0.5-2.0g/10min. The hose body is produced by co-extrusion process, in particular, material of each layer of the hose body is added into a respective single screw extruder from each hopper, and the materials are co-extruded through a moding/mixing die after being melted, subjecting to drawing, cooling, vacuum formation, heat treatment, pulling, and cutting to certain length, so as to obtain the hose body. The composite polypropylene hose final product is obtained by well-known processes such as, hose tip injection molding, printing, post processing, packaging and the like. The composite polypropylene hose manufactured according to the invention is high in transparency, and has higher rigidity and lower gross weight than the existing products.

Description

Co-extruded composite polypropylene hose and production method thereof

Technical field

The invention belongs to the field of composite packaging hoses, and in particular relates to a composite polypropylene hose and a production method thereof.

Background technique

At present, domestic co-extruded multilayer composite hoses for cosmetics and other products are generally made of polyethylene resin (also known as PE) by injection molding or extrusion molding. The polyethylene resin has excellent molding processability, good flexibility, excellent impact toughness and low temperature resistance, and excellent chemical stability, but is not high in heat resistance, and is resistant to environmental stress cracking, adhesion, adhesion, and printability. It has good permeability to 0 ₂ and C0 ₂ , but has poor permeability to water vapor and air. Polypropylene resin (also known as PP) is the lightest plastic in plastic except for 4-methyl-1-pentene and polyisocyanic crystal. It has excellent bending fatigue resistance and its products can be used at normal temperature. bent ¹⁰⁶ times without damage, good scratch resistance, water vapor barrier property good, good transparency packaging material. According to the search, in addition to the applicant, there is no domestic report on the use of polypropylene materials to prepare cosmetic packaging composite hoses.

Chinese patent CN 1675298A discloses a plasticized polyolefin composition which provides a propylene polymer having improved toughness without compromising its toughness and other properties, but the addition of a plasticizer undoubtedly increases the cost. Moreover, the general plasticizer is toxic, and the non-toxic plasticizer is expensive, so the plasticized polyolefin composition is used in the cosmetics packaging industry and its safety performance is worth worrying about.

Confirmation The high-tough polypropylene material involved in the Chinese patent CN1995124A is applicable to the manufacture of central air-conditioning exhaust hoses. The formulation contains many processing aids, one of the advantages of which is low cost, but if used in the manufacture of cosmetic composite hoses, the safety and contamination of the formulation is also worth considering.

SUMMARY OF THE INVENTION A first object of the present invention is to provide a safety, environmental protection, performance and polyethylene composite hose which is the same or better and can be softened in view of the above problems existing in the existing polyethylene co-extruded multilayer composite hose. Coextruded composite polypropylene hose with reduced overall weight of the tube.

A second object of the present invention is to provide a process for producing the coextruded composite polypropylene hose.

The coextruded composite polypropylene hose of the present invention comprises a pipe head and a pipe body, and the pipe body is

0 〜2. 0 g/10min, and is composed of a polymer having a melt index of 0. 5~2. 0 g/10min, and is composed of A random copolymerized polypropylene catalyzed by a metallocene catalyst. When the hose body is a two-layer composite structure, one of the materials is a blend of polypropylene or polypropylene and polyethylene, and the other layer is a blend of polypropylene or polypropylene and polyethylene. Or polyethylene, and the materials of the two layers are different.

When the hose body is a 3~5 layer composite structure, at least one of the materials is polypropylene or a blend of polypropylene and polyethylene; the remaining layers are made of polypropylene or polyethylene or a binder. Or a blend of polypropylene and polyethylene, or an intermediate barrier layer in the 3~5 layer composite structure, the barrier layer material is generally ethylene-vinyl alcohol copolymer (abbreviated as EV0H); the materials of the adjacent two layers are different, And the adhesive layer is not located at the outermost or innermost Floor.

The binder in the present invention is preferably an acid anhydride-modified linear low-density polyethylene polymer.

The polyethylene used in the present invention is preferably a low density polyethylene. Because low-density polyethylene raw materials are synthesized by high pressure method, high-pressure polyethylene has many branches, and the existence of branching will inevitably affect the repeated folding and close packing of molecular chains, eventually leading to a decrease in crystallinity. The crystallinity is reduced and the transparency of the product is better.

2毫米〜 1. 0毫米。 The thickness of the hose body of the present invention is generally 0. 2 legs ~ 1. 0mm.

The production method of the coextruded composite polypropylene hose of the present invention is:

The tube body of the polypropylene hose is produced by a co-extrusion process, and comprises the following steps: adding raw materials of each layer of the hose body body from each hopper to respective single-screw extruders, and melting and then mixing by the same molding The machine head is co-extruded, and then subjected to stretching, cooling, vacuum setting, and then heat-treated, drawn, and fixed-length cutting, thereby obtaining a pipe body; the polypropylene raw material of the polypropylene hose of the present invention adopts a melt index of 0. 5 g / 2 min, and is a random copolymerized polypropylene catalyzed by a metallocene catalyst.

The finished hose body is then finished with a mature injection head, printing, post-processing, packaging and other processes to obtain a finished polypropylene hose.

The polypropylene-containing layer of the hose body of the present invention (whose material is a blend of polypropylene or polypropylene and polyethylene) preferably has an extrusion temperature of from 190 ° C to 230 ° C. The vacuum pressure is between 0.003 and -0.10 MPa. The heat treatment uses hot water at 20 ° C to 40 ° C.

The invention has the following technical effects:

(1) The tube material of the hose of the present invention contains a new catalyst produced by metallocene catalyst A generation of random copolymer polypropylene. Compared with the conventional Ziegler-Natta catalytic technology, the random copolymer polypropylene has a uniform molecular chain length, a narrow molecular weight distribution and a low crystallinity, and a decrease in crystallinity leads to an increase in product transparency. . The 5% of the metallocene-catalyzed random copolymer polypropylene extrusion product has a haze of about 6.5%. The product prepared by homopolypropylene has a haze of 15%. Haze, also known as turbidity, reflects the extent to which a transparent or opaque material is unclear. Obviously, metallocene-catalyzed random copolymer polypropylene has better transparency. In the case of the same haze, for example, 6.5%, the metallocene-catalyzed random copolymer polypropylene has a flexural modulus of 2100 MPa, whereas the conventional Ziegler-Natta catalyzed polypropylene has a flexural modulus of elasticity only It is 1500 MPa. The flexural modulus of elasticity is a reflection of the material's rigidity, so the metallocene-catalyzed random copolymerized polypropylene produces a product that is stiffer than conventional Ziegler-Natta catalyzed polypropylene products. In addition, the random copolymer polypropylene has advantages such as lower heat sealing temperature and the like compared with the polypropylene obtained by the conventional Ziegler-Natta catalytic technique and the homopolypropylene.

(2) The method of the invention is based on the molding process of the existing polyethylene composite pipe, after the co-extrusion and cooling setting process of the machine head, before the traction drawing process, the hot water treatment is carried out at 20 ° C - 40 ° C It can eliminate the internal stress in the composite pipe, improve the toughness of the product, and also contribute to the improvement of printing performance.

(3) The hose of the present invention can reduce the weight of the hose and reduce the amount of the raw material, thereby saving cost, on the basis of satisfying the performance of the packaged composite hose such as cosmetics. According to the experimental comparison, the specification is D19*84 hose, the inner and outer parts are polyethylene layer, and the composite hose of the invention with polypropylene layer in the middle has a weight of about 1.96g, and the same specification polyethylene hose is used. The tube weight is 2.17g, and the tube weight is 2.17g.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing the structure of a composite polypropylene hose in an embodiment of the present invention.

Figure 2 is a longitudinal sectional structural view of a hose body of a section in the first embodiment.

Figure 3 is a longitudinal sectional structural view of a hose body of a section in the second embodiment.

Figure 4 is a longitudinal sectional structural view of a hose body of a section in the third embodiment.

Figure 5 is a longitudinal sectional structural view of a hose body of a section in the fourth embodiment.

Figure 6 is a longitudinal sectional structural view of a hose body of a section in the fifth embodiment.

Figure 7 is a schematic view showing the structure of an extrusion apparatus for producing a hose body in the fifth embodiment. detailed description

The structure of the coextruded multilayer polypropylene tube of the first embodiment to the fifth embodiment is shown in Fig. 1. It comprises a pipe body 14 and a pipe head 13 injection molded therewith, and the overall structure is the same as that of the existing packaging hose. The difference lies in the structure of the pipe body 14 and the materials used. The details are as follows:

Referring to Figures 1 to 5, the tube bodies 14 of the hoses of the first embodiment to the fourth embodiment are all three-layer composite structures. In the first embodiment, the inner layer 3 and the outer layer 2 of the hose body are metallocene-catalyzed random copolymer polypropylene layers, and the intermediate layer 1 is an adhesive layer. In the second embodiment, the inner layer 6 and the outer layer 5 of the hose body are metallocene-catalyzed random copolymer polypropylene layers, and the intermediate layer 4 is a polyethylene layer. In the third embodiment, the inner layer 9 of the hose body is a metallocene-catalyzed random copolymer polypropylene layer, the outer layer 8 is a polyethylene layer, and the intermediate layer 7 is an adhesive layer. In the fourth embodiment, the inner layer 12 of the hose body is a polyethylene layer, the outer layer 10 is a metallocene-catalyzed random copolymer polypropylene layer, and the intermediate layer 11 is an adhesive layer. The soft body of the multi-layer composite polypropylene hose of the above-mentioned Embodiments 1 to 4 is prepared by a co-extrusion process, and the specific steps are as follows: The raw materials used for each layer of the hose body are respectively added from the respective hoppers to the respective orders. In the screw extruder, after being softened and melted, it is co-extruded through the same molding mixer head, and then stretched, cooled, vacuum-shaped, and then heat-treated, stretched, and cut to obtain a hose body. The hose body obtained by the above method is obtained by the mature injection head, printing, post-processing, packaging and the like.

In the above embodiment, the extrusion temperature of the polypropylene layer of the hose body is 190 ° C to 230 ° C, the molding temperature of the polyethylene layer is 140 ° C to 190 ° C, and the molding temperature of the adhesive layer is 170. °C~210°C. The vacuum pressure of the vacuum is between 0. 003~ -O. OOlMPa. The heat treatment adopts 20 ° C -4 (TC hot water, the process is set after the cooling process, before the traction process. That is, the cooled plastic pipe advances toward the cutting table at a certain speed under the action of the traction force, when entering the heat treatment water tank When the hot water circulation system is turned on, the hot water is sprayed onto the circumferential surface of the plastic pipe. During the whole heat treatment process, the plastic pipe is in a uniform motion state, and the spray device is placed in the heat treatment water tank, thereby ensuring the heat treatment performance of the plastic pipe. Stability. The advantages of adding this process are: Compared with the unheated plastic tube, the residual internal stress is greatly reduced, which is manifested by the shortening of the pre-printing time and the tube body due to the presence of internal stress during the printing process. The phenomenon of deformation is reduced.

Referring to Fig. 6, in the fifth embodiment, the hose body is a five-layer composite structure, the innermost layer 19 and the outermost layer 15 are metallocene-catalyzed random copolymer polypropylene layers, and the intermediate layer 17 is a polyethylene layer, the innermost layer. Between 19 and the intermediate layer 17 is an inner adhesive layer 18, and between the outermost layer 15 and the intermediate layer 17 is an outer adhesive layer 16.

Referring to FIG. 7, the multi-layer composite hose forming apparatus used in the fifth embodiment includes four singles. The screw extruder is composed of an inner layer screw extruder 25, an outer layer screw extruder 21, an intermediate layer screw extruder 20, and an adhesive layer screw extruder 22. The material extruded by the bonding layer screw extruder 22 is split into two portions, an outer adhesive layer stream 23 and an inner binder layer stream 24.

In the fifth embodiment, the raw materials used in the five layers of the hose body are respectively added from the respective hoppers to the respective single-screw extruders, softened and melted, co-extruded through the same molding mixer head, and then stretched, cooled, and vacuum-shaped. Then, through heat treatment, traction, and fixed length cutting, the hose body is obtained. The detailed production process is as follows:

1. Start the power switch (main control box and cutter control box).

2. Determine if the direction of operation of each motor is correct.

3. Turn on the extruder heating plate (screw and die) and preheat for about 60 minutes.

4. Weigh the amount of raw materials required for each layer of hopper and mix well.

5. After the screw extruder reaches the set temperature (the forming temperature of the polyethylene layer is 140 ° C ~ 190 ° C, metallocene-catalyzed random copolymer polypropylene or metallocene-catalyzed random copolymer polypropylene and polyethylene The molding temperature of the blend is from 190 ° C to 230 ° C.), adding raw materials, sizing sleeves, fixing sleeves, wiper rings, cutter copper sleeves and cutter guide sleeves of the required size.

6. Open the cooling water pipes of each part.

7. Turn on the freezer and set the temperature at 5 °C ~ 10 °C.

8. Turn on the traction motor and set the required length of the pipe length and other parameters on the cutting table control box.

9. Start the screw motor. After the raw materials are softened and melted by heating, they are transported into the common extruder head by the respective screw extruders. Observe the material discharge, and start at a slow speed. It is advisable to accelerate slowly after the material is extruded.

10. The molten plastic is extruded into a tubular shape after being extruded by a co-extrusion die, and the plastic is stretched in the direction of the tractor, passed through a sizing sleeve fixing sleeve, a wiper ring for cooling setting and heat treatment, and then clamped by the tractor. Hold in the direction of the cutting table. The air pressure used for vacuum cooling is

-0. 003~0. OOlMPa, heat treatment uses circulating hot water of 20 °C ~ 40 °C.

11. Adjust the traction motor speed and the press-fitting clearance, so that the traction belt does not slip.

12. After starting the vacuum motor, use the hand wheel to move the entire tank toward the die to the proper position.

13. Close the water tank cover and open the cold water valve. The initial wide door is fully open. After the water is flooded through the plastic hose, adjust it to the half open position.

14. Lubricate the water before opening the water tank. It is the principle that water can wrap the circumference of the plastic tube.

15. Open the hot water wide door so that the hot water is evenly sprayed on the outer circumferential surface.

16. After molding, adjust the speed of the tractor and screw motor to shape it. The specific adjustment principle is: The screw speed increases, the wall thickness increases, and vice versa. The traction speed is increased, the wall thickness is reduced, the traction speed is slowed, and the wall thickness is increased.

17. Start the cutter motor switch, and then turn on the chasing button to cut the plastic tube. The plastic hose body is made.

After the obtained hose body is subjected to mature injection head, printing, post-processing, packaging and the like, a composite polypropylene hose product is obtained.

The raw material metallocene-catalyzed random copolymer polypropylene in the above examples was purchased from the manufacturer Hongkong King Pacific (International) Limited, model BSPP01, The melt index is 0. 5~2. 0 g/10min _o The polyethylene in the above embodiment is made of low density polyethylene and supplied by Maoming Branch of China Petroleum & Chemical Corporation. The binder in the above examples employs an acid anhydride-modified linear low density polyethylene polymer (abbreviated as ADMER).

For convenience of understanding, the present invention will be described only by the above embodiments. Equivalent transformations or modifications made on the basis of the invention are within the scope of the invention.

Claims

Claim

A coextruded composite polypropylene hose comprising a tube head and a tube body, wherein: the tube body is a 2 to 5 layer composite structure, wherein at least one layer of material is polypropylene or polypropylene and polyethylene And a polypropylene copolymer having a melt index of 0. 5 to 2. 0 g/10 min, and is a random copolymerized polypropylene catalyzed by a metallocene catalyst.

2. The coextruded composite polypropylene hose according to claim 1, wherein: the tube body is a two-layer composite structure, wherein one layer of material is polypropylene or a blend of polypropylene and polyethylene. The other layer of material is polypropylene or a blend of polypropylene and polyethylene or polyethylene, and the materials of the two layers are different.

3. The coextruded composite polypropylene hose according to claim 1, wherein: the tube body is a 3 to 5 layer composite structure, wherein at least one layer of material is polypropylene or polypropylene and polyethylene. Blend, the remaining layers of material are polypropylene or polyethylene or binder or a blend of polypropylene and polyethylene, or an intermediate barrier layer in the 3~5 layer composite structure; the material of the adjacent two layers is not The same, and the adhesive layer is not located in the outermost layer or the innermost layer.

The coextruded composite polypropylene hose according to claim 3, wherein the binder is an acid anhydride-modified linear low-density polyethylene polymer.

The coextruded composite polypropylene hose according to claim 1 or 2 or 3 or 4, wherein the polyethylene is a low density polyethylene.

6毫米〜1 0ram。 The thickness of the hose body is 0. 2 let ~ 1. 0ram.

7. A method of producing a coextruded composite polypropylene hose according to claim 1 or 2 or 3 or 4, wherein the hose body is produced by a co-extrusion process, including The following steps: the raw materials of each layer of the hose body are added from the respective hoppers to the respective single-screw extruders, melted, co-extruded through the same molding mixer head, and then stretched, cooled, vacuum-shaped, and then The propylene-catalyzed catalyst is catalyzed by a metallocene catalyst. The polypropylene material has a melt index of 0. 5~2. 0 g/10 min, and is catalyzed by a metallocene catalyst. Random copolymer polypropylene.

The method for producing a coextruded composite polypropylene hose according to claim 7, wherein: the polypropylene-containing layer of the hose body has an extrusion temperature of 190 ° C to 230 ° C .

The singularity of the singularity of the singularity of the singularity of the singularity of the singularity of the vacuum.

The method of producing a coextruded composite polypropylene hose according to claim 7 or 8, wherein the heat treatment is performed by using hot water at 20 ° C to 40 ° C.