METHOD FOR PREPARING A PULTRUDED POLYURETHANE COMPOSITE

Abstract

The present invention relates to a method for preparing a pultruded polyurethane composite by a polyurethane pultrusion process, a pultruded polyurethane composite prepared by said method, and uses thereof. The method for preparing a pultruded polyurethane composite of the present invention employs short molds, improves production efficiency and saves costs.

Claims

1. A method for preparing a pultruded polyurethane composite by a polyurethane pultrusion process, comprising: impregnating a fiber reinforcing material with a polyurethane composition comprising: a component A, including one or more organic polyisocyanates; a component B, including: b1) one or more organic polyols in an amount of 21 to 60 wt %, based on the total weight of the polyurethane composition as 100 wt %; b2) one or more compounds having a structure of formula (I) ##STR00006##  wherein R.sub.1 is selected from the group consisting of hydrogen, methyl or ethyl; R2 is selected from the group consisting of an alkylene group having 2 to 6 carbon atoms, 2,2-di(4-phenylene)-propane, 1,4-di(methylene)benzene, 1,3-di(methylene)benzene, 1,2-di(methylene)benzene; and n is an integer selected from 1 to 6; and a component C, free radical initiator; drawing the impregnated fiber reinforcing material at a speed of 0.2 to 2 m/min through a mold having a length of 21 to 55 cm and a controlled temperature of 110 to 230° C. to form the pultruded polyurethane composite.

2. The method as claimed in claim 1, wherein the component b2) is selected from the group consisting of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate ora combination thereof.

3. The method as claimed in claim 1, wherein b2) is present in an amount of 4.6 to 33 wt %, based on the total weight of the polyurethane composition as 100 wt %.

4. The method as claimed in claim 1, wherein the fiber reinforcing material is selected from the group consisting of glass fiber, carbon fiber, polyester fiber, natural fiber, aramid fiber, nylon fiber, basalt fiber, boron fiber, silicon carbide fiber, asbestos fiber, whisker, hard particle, metal fiber or a combination thereof.

5. The method as claimed in claim 1, wherein the polyurethane composition has a curing time of 10 to 120 seconds at 150 to 220° C.

6. The method as claimed in claim 1, wherein the polyurethane composition has a gel time of 15 to 90 minutes at room temperature.

7. The method as claimed in claim 1, wherein said impregnating is carried out in an impregnation device comprising an injection box and an open impregnation tank.

8. The method as claimed in claim 7, wherein the injection pressure in the injection box is 0.1 to 15 bar.

9. A pultruded polyurethane composite obtained by the method as claimed in claim 1.

10. (canceled)

11. The pultruded polyurethane composite as claimed in claim 9, wherein b2) is present in an amount of 4.6 to 33 wt %, based on the total weight of the polyurethane composition as 100 wt %.

12. The pultruded polyurethane composite as claimed in claim 9, wherein the polyurethane composition has a curing time of 10 to 120 seconds.

13. The pultruded polyurethane composite as claimed in claim 9, wherein the polyurethane composition has a gel time of 15 to 90 minutes.

14. A polyurethane product comprising the pultruded polyurethane composite as claimed in claim 9.

15. The polyurethane product as claimed in claim 14, wherein the polyurethane product is selected from the group consisting of a cable tray, a curtain wall frame, a ladder frame, a tent pole or tube, an anti-glare panel, a floor, a sucker rod, an electric pole, an electric crossarm, a guardrail, a grid, a profile for construction, a profile or plate for container, a bicycle frame, a fishing rod, a cable core, an insulator core rod, a radome, a single or sandwich continuous plate, or a spar cap for a wind turbine blade.

Description

DESCRIPTION OF DRAWINGS

[0110] The invention will be exemplarily described below with reference to the drawings:

[0111] FIG. 1 shows a mold and a process flow for the method for preparing a pultruded polyurethane composite by a pultrusion process according to an embodiment of the present invention, wherein: 1 and 2 represent fibers; 3 represents a yarn guiding device; 4 represents an impregnation device; 5 represents a mold; 6 represents a profile; 7 represents a drawing device; 8 and 9 represent a heating device.

EXAMPLES

[0112] Description of tested performance parameters in the examples of the present application:

[0113] Functionality refers to a value determined according to the formula in the industry: functionality=hydroxyl value*molecular weight/56100; wherein the molecular weight is determined by GPC high performance liquid chromatography;

[0114] Isocyanate index refers to a value determined by the following formula:

[00001]$\mathrm{Isocyanateindex}\left(\%\right)=\frac{\mathrm{Molesofisocyanategroups}\left(\mathrm{NCOgroups}\right)\mathrm{incomponentA}}{\mathrm{MolesofgroupsreactivetowardisocyanategroupsincomponentB}}\times d$

[0115] NCO content refers to the content of NCO groups in the system and is measured according to GB/T 12009.4-2016.

[0116] Pultrusion rate/speed, i.e. the speed at which the fiber reinforceing materials are drawn through the mold, refers to the length of the fiber reinforcing materials pultruded through the mold per minute, i.e. the length of the pultruded product produced per minute. In the test, a speed sensor or a stopwatch and a ruler are used. The pultrusion rate/speed, i.e. the length passing through the mold per unit time, is obtained as the measured length of the pultruded fiber reinforcing materials divided by the time used.

[0117] Curing time refers to a period of time that begins when the component A and the component B of the reaction system start to mix and ends when it is cured.

[0118] Gel time refers to a period of time that begins when the component A and the component B of the reaction system start to mix and ends when the viscosity reaches a certain value (for example, about 10000 mPa.Math.s). The gel time of the present invention is tested using a gel time tester. In the test, the component A and the component B are mixed uniformly and then placed in the gel time tester. The gel time is recorded as a period of time that begins when the power button is pressed and ends when the gel time tester stops working.

Source of Raw Materials and Description Thereof

[0119]

TABLE-US-00001 TABLE 1 List of raw materials Material/device Specification/type Supplier Isocyanate 1 Desmodur1511L Covestro Polymers (China) Co., Ltd. Isocyanate 2 Desmodur 0223 Covestro Polymers (with free radical (China) Co., Ltd. initiator) Polyol Baydur 18BD001 Covestro Polymers composition 1 (without component (China) Co., Ltd. b2)) Polyol Baydur 18BD207 Covestro Polymers composition 2 (with component (China) Co., Ltd. b2)) Internal mold Baydur 18BD101 Covestro Polymers releasing agent (China) Co., Ltd. Glass fiber PS 4100-2400Tex Owens Corning Composites (China) Co., Ltd. Pultrusion Crawler pultrusion Nanjing Nuoertai machine machine for Compound composites Materials Equipment Manufacturing Co., Ltd. Injection device Hydraulic Mini Magnum Venus Products Link System Gel time tester GT-STHP-220 Shanghai Senlan Scientific Instrument Co., Ltd.

Example 1

[0120] As shown in FIG. 1, 240 bundles of glass fibers were taken out from the creel and passed sequentially through the preformed plates into the injection box and the mold (length of the mold was 40 cm). Then, the glass fibers were drawn forward by the drawing device until they were straightened. The heating device of the mold was turned on. The mold temperature was set at the inlet and the outlet to 120° C./220° C. After the temperature was stable, the injection device was turned on. The component A (Desmodur 0223) and the component B (100 parts by weight of Baydur 18BD207 and 3 parts by weight of Baydur 18BD101) were continuously pumped by the injection device into the static mixing head of the injection box in a weight ratio of 92:100. The injection box was fully filled with the components after they were mixed by the static mixing head. The glass fibers were fully impregnated. The injection pressure in the injection box was set to 0.1 to 15 bar. The glass fibers impregnated by the injection box was continuously pulled by the drawing device through the mold at a speed of 0.4 m/min to obtain a pultruded polyurethane composite. When the pultruded polyurethane composite was knocked using a metal piece at 1 m from the outlet of the mold, the sound was clear, indicating that the curing was well.

[0121] The polyurethane composition of Example 1 had a cure time of about 40 seconds and a gel time of 40 minutes.

Comparative Example 1

[0122] As shown in FIG. 1, 240 bundles of glass fibers were taken out from the creel and passed sequentially through the preformed plates into the injection box and the mold (length of the mold was 40 cm). Then, the glass fibers were drawn forward by the drawing device until they were straightened. The heating device of the mold was turned on. The mold temperature was set at the inlet and the outlet to 120° C./190° C. After the temperature was stable, the injection device was turned on. The component A (Desmodur 1511L) and the component B (100 parts of Baydur 18BD001 and 5 parts of Baydurl8BD101) were continuously pumped by the injection device into the static mixing head in a weight ratio of 114:100. The injection box was fully filled with the components, after they were mixed by the static mixing head. The fiber yarns were fully impregnated. The injection pressure in the injection box was set to 0.1 to 15 bar. The fiber yarns impregnated by the injection box was continuously pulled by the drawing device through the mold at a speed of 0.4 m/min. When the profile was knocked using a metal piece at 1 m from the outlet of the mold, the sound was dull, indicating that the curing was poor.

[0123] The polyurethane composition of Comparative Example 1 had a cure time of about 70 seconds and a gel time of about 23 minutes.

[0124] It can be seen from the experimental results of Example 1 and Comparative Example 1 as above that the method for preparing a pultruded polyurethane composite using a suitable mold and a corresponding polyurethane composition of the present invention allows producing a well-cured pultruded polyurethane composite. The use of short molds improves the production efficiency, saves costs and energy and protects the environment. When the same mold was used, pultrusion of a polyurethane composition without the component b2) in the prior art could not provide a well-cured pultruded composite. In addition, the polyurethane composition of the present invention has a shorter curing time and a longer gel time, and can be better and more flexibly suitable for producing polyurethane composites, especially large polyurethane composites (for example, it can be impregnated and formed for longer time).

[0125] While the invention has been described in detail as above for the purposes of the present invention, it is understood that the detailed description is only exemplary. In addition to the contents defined by the claims, various changes can be made by those skilled in the art without departing from the spirit and scope of the invention.