A Styrene-free Modified BMC Molding Compound

Abstract

The present invention relates to the field of BMC molding compound preparation, and in particular to a styrene-free modified BMC molding compound. The modified BMC molding compound of the present invention can achieve the effect of not using styrene through the improvement of raw materials and processes, and is safer. In the existing process, materials other than resin are added one by one into a kneading machine, so a long time of kneading is required. The present invention directly designs a stirring mechanism above the kneading machine to stir the materials first and then directly input them into the kneading machine, which can greatly shorten the kneading time.

Description

Technical Field

[0001] The invention relates to the field of preparation of BMC molding compounds, and in particular to a styrene-free modified BMC molding compound. Background Art

[0002] BMC is a semi-dry molding intermediate material for glass fiber reinforced thermosetting products. It is pre-mixed into a paste with unsaturated polyester resin, low shrinkage / low profile additives, initiators, internal mold release agents, mineral fillers, etc., and then thickeners, colorants, etc. are added. It is stirred with glass fibers of different lengths in a special material kettle for thickening process, and finally forms a mass intermediate material that can be used for molding and injection molding.

[0003] Most existing BMC molding materials require the use of styrene, but styrene is toxic, so the present application hopes to provide a styrene-free BMC molding material. Summary of the invention

[0004] The present invention hopes to provide a styrene-free modified BMC molding compound, and the specific scheme is as follows:

[0005] A styrene-free modified BMC molding compound comprises the following components:

[0006]

[0007] The solid unsaturated polyester resin particles or powder are isophthalic polyester resin particles or powder prepared from isophthalic acid and neopentyl glycol.

[0008] A method for preparing a styrene-free modified BMC molding compound, the specific steps are as follows:

[0009] (1) solid unsaturated polyester resin particles or powders are placed in a constant temperature oven;

[0010] (2) The resin is introduced into an "S" type paddle kneader, and the mixture is kneaded and stirred in a sealed manner, and nitrogen is kept flowing during the stirring process for protection;

[0011] (3) Add PS powder / glass fiber / zinc stearate / curing agent / aluminum hydroxide / calcium carbonate in the ratio and continue kneading;

[0012] (4) After kneading, the material is taken out and pressed into a sheet with a thickness of 3-5 mm using a double-roller machine;

[0013] (5) crushing the particles to obtain particles of 40-80 mesh;

[0014] (6) Obtain modified BMC molding compound.

[0015] The temperature of the constant temperature oven in step (1) is 95°C.

[0016] The "S" type paddle kneader comprises a stirring mechanism and a kneading mechanism, wherein the stirring mechanism is located on the upper part of the kneading mechanism.

[0017] The stirring mechanism includes a shell, a plurality of material pipes are arranged on the top of the shell, an opening is arranged on the bottom of the shell, and the opening is communicated with the kneading mechanism. The shell is provided with a stirring motor, and a first stirring rod is arranged at one end of the stirring motor, and the first stirring rod is driven by the stirring motor. The kneading mechanism is provided with a sliding mechanism, and the sliding mechanism includes a driving cylinder and a movable plate. An opening is arranged on the shell, and the movable plate extends into the opening. A guide rail is arranged in the shell, and the movable plate is driven by the driving cylinder to move along the guide rail.

[0018] The first stirring rod is provided with a first gear, the first gear is matched with a second gear, the second gear is provided with a second stirring rod, and the first stirring rod and the second stirring rod are matched with each other.

[0019] A guide plate is arranged in the shell, and the guide plate is located at the lower side of the movable plate. The guide plate can better transfer the stirred materials to the lower side.

[0020] The kneading mechanism includes a shell, a kneading motor is provided on the outer side of the shell, the kneading motor drives the first S kneading rod to rotate, the first S kneading rod is provided with a third gear, the third gear is matched with a fourth gear, the fourth gear is provided with a second S kneading rod, and the first S kneading rod and the second S kneading rod are matched.

[0021] The shell includes a jacket, and a heating coil is arranged in the jacket. The kneading machine needs to heat the material, so the heating coil is arranged.

[0022] The shell is provided with a protrusion at the middle gap between the first S kneading rod and the second S kneading rod.

[0023] The modified BMC molding compound of the present invention can achieve the effect of not using styrene through the improvement of raw materials and processes, and is safer. In the existing process, materials other than resin are added one by one into the kneading machine, so a long time of kneading is required. The present invention directly designs a stirring mechanism above the kneading machine to stir the materials first and then directly input them into the kneading machine, which can greatly shorten the kneading time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The structure of the "S" type paddle kneader in the present invention is shown in FIG. Figure 1 ;

[0025] Figure 2 The structure of the "S" type paddle kneader in the present invention is shown in FIG. Figure 2 ;

[0026] Figure 3 The schematic diagram of the partial structure of the "S" type paddle kneader in the present invention Figure 1 (mainly the first S kneading rod and the second S kneading rod and the protrusion);

[0027] Figure 4 The schematic diagram of the partial structure of the "S" type paddle kneader in the present invention Figure 2 (Stirring mechanism);

[0028] Figure 5 The schematic diagram of the partial structure of the "S" type paddle kneader in the present invention Figure 3 (Stirring mechanism);

[0029] Figure 6 The modified BMC molding material of the present invention and the conventional BMC molding material are subjected to RPN odor measurement. The numbers are as follows: 1. stirring mechanism; 11. housing; 12. material pipeline; 13. opening; 14. stirring motor; 15. first stirring rod; 16. sliding mechanism; 161. driving cylinder; 162. movable plate; 17. opening; 18. guide rail; 19. first gear; 110. second gear; 111. second stirring rod; 112. guide plate; 2. kneading mechanism; 21. housing; 22. kneading motor; 23. first S kneading rod; 24. third gear; 25. fourth gear; 26. second S kneading rod; 27. heating coil; 28. protrusion. DETAILED DESCRIPTION

[0030] A method for preparing a styrene-free modified BMC molding compound is as follows:

[0031] 1. Heat the solid unsaturated polyester resin (isophthalic acid and neopentyl glycol made of isophthalic polyester resin) to 95 ° C in a constant temperature oven.

[0032] 2. Introduce the resin into an "S" type paddle kneader, seal and knead for 10 minutes, and keep nitrogen flowing during the stirring process for protection.

[0033] 3. Add PS powder / glass fiber / zinc stearate / curing agent, TBPB (tert-butyl perbenzoate) / aluminum hydroxide / calcium carbonate, etc. in the ratio and continue kneading for 20 minutes.

[0034] 4. After kneading, take out the material and use a double-roller machine to press it into a sheet with a thickness of 3-5mm.

[0035] 5. Use the particles to crush and obtain 40-80 mesh particles.

[0036] 6. Obtain modified BMC molding compound.

[0037] The formula of styrene-free modified BMC molding compound is as follows:

[0038]

[0039] Combine the following Figure 1-5 The "S" type paddle kneader of the present invention is further described:

[0040] The “S” type paddle kneader comprises a stirring mechanism 1 and a kneading mechanism 2 , wherein the stirring mechanism 1 is located on the upper part of the kneading mechanism 2 .

[0041] The stirring mechanism 1 includes a shell 11, a plurality of material pipes 12 are arranged on the top of the shell 11, an opening 13 is arranged at the bottom of the shell 11, and the opening 13 is communicated with the kneading mechanism 2. A stirring motor 14 is arranged on the shell 11, and a first stirring rod 15 is arranged at one end of the stirring motor 14, and the first stirring rod 15 is driven by the stirring motor 14. A sliding mechanism 16 is arranged on the kneading mechanism 2, and the sliding mechanism 16 includes a driving cylinder 161 and a movable plate 162. An opening 17 is arranged on the shell 11, and the movable plate 162 extends into the opening 17. A guide rail 18 is arranged in the shell 11, and the movable plate 162 is driven by the driving cylinder 161 to move along the guide rail 18. A first gear 19 is arranged on the first stirring rod 15, and a second gear 110 is arranged on the first gear 19, and a second stirring rod 111 is arranged on the second gear 110, and the first stirring rod 15 and the second stirring rod 111 are arranged in cooperation. A guide plate 112 is arranged in the shell 11, and the guide plate 112 is located at the lower side of the movable plate 162. The guide plate 112 can better transfer the stirred materials to the bottom.

[0042] The kneading mechanism 2 includes a housing 21, a kneading motor 22 is provided outside the housing 21, the kneading motor 22 drives the first S kneading rod 23 to rotate, the first S kneading rod 23 is provided with a third gear 24, the third gear 24 is provided with a fourth gear 25, the fourth gear 25 is provided with a second S kneading rod 26, the first S kneading rod 23 and the second S kneading rod 26 are provided in cooperation. The housing includes a jacket, and a heating coil is provided in the jacket. Since the kneading machine needs to heat the material, it is provided. A protrusion 28 is provided on the housing at the middle gap between the first S kneading rod and the second S kneading rod.

[0043] The iron shell was formed with the obtained material and the volatile gas test of the product was carried out under the following test conditions:

[0044]

[0045] The test results are as follows:

[0046]

[0047] The volatile gas of styrene-free modified materials is significantly improved, and there is almost no odor.

[0048] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A styrene-free modified BMC molding compound, characterized in that: The components include: Solid unsaturated polyester resin granules or powder 22-26% 100-200 mesh PS powder 3-5% Zinc stearate 1.8-2.3% Aluminum hydroxide 30-40% Calcium carbonate 25-28% Curing agent 0.5-0.8% Inhibitor 0.1-0.2% Glass fiber (fiber powder) 5-8% Pigment 0.1-0.5%; The solid unsaturated polyester resin particles or powder are isophthalic polyester resin particles or powder prepared from isophthalic acid and neopentyl glycol.

2. A method for preparing a styrene-free modified BMC molding compound as claimed in claim 1, characterized in that: The specific steps are as follows: (1) Use a constant temperature oven to heat solid unsaturated polyester resin particles or powder; (2) Introduce the resin into an "S" type paddle kneader, seal and knead, and stir. During the stirring process, keep nitrogen flowing for protection; (3) Add PS powder / glass fiber / zinc stearate / curing agent / aluminum hydroxide / calcium carbonate in the mixture and continue kneading; (4) After kneading, take out the material and use a double-roller machine to press it into a sheet with a thickness of 3-5 mm; (5) crushing the particles to obtain particles with a mesh size of 40-80; (6) Obtain modified BMC molding compound.

3. The method for preparing a styrene-free modified BMC molding compound according to claim 2, characterized in that: The temperature of the constant temperature oven in step (1) is 95°C.

4. The method for preparing a styrene-free modified BMC molding compound according to claim 1, characterized in that: The "S" type paddle kneader comprises a stirring mechanism and a kneading mechanism, wherein the stirring mechanism is located on the upper part of the kneading mechanism.

5. The method for preparing a styrene-free modified BMC molding compound according to claim 4, characterized in that: The stirring mechanism includes a shell, a plurality of material pipes are arranged on the top of the shell, an opening is arranged on the bottom of the shell, and the opening is communicated with the kneading mechanism. The shell is provided with a stirring motor, and a first stirring rod is arranged at one end of the stirring motor, and the first stirring rod is driven by the stirring motor. The kneading mechanism is provided with a sliding mechanism, and the sliding mechanism includes a driving cylinder and a movable plate. An opening is arranged on the shell, and the movable plate extends into the opening. A guide rail is arranged in the shell, and the movable plate is driven by the driving cylinder to move along the guide rail.

6. The method for preparing a styrene-free modified BMC molding compound according to claim 5, characterized in that: The first stirring rod is provided with a first gear, the first gear is matched with a second gear, the second gear is provided with a second stirring rod, and the first stirring rod and the second stirring rod are matched with each other.

7. The method for preparing a styrene-free modified BMC molding compound according to claim 5, characterized in that: A guide plate is arranged in the shell, and the guide plate is located at the lower side of the movable plate.

8. The method for preparing a styrene-free modified BMC molding compound according to claim 4, characterized in that: The kneading mechanism includes a shell, a kneading motor is provided on the outer side of the shell, the kneading motor drives the first S kneading rod to rotate, the first S kneading rod is provided with a third gear, the third gear is matched with a fourth gear, the fourth gear is provided with a second S kneading rod, and the first S kneading rod and the second S kneading rod are matched.

9. The method for preparing a styrene-free modified BMC molding compound according to claim 8, characterized in that: The shell comprises a jacket, and a heating coil is arranged in the jacket.

10. The method for preparing a styrene-free modified BMC molding compound according to claim 8, characterized in that: The shell is provided with a protrusion at the middle gap between the first S kneading rod and the second S kneading rod.

Images