CN105461908A - Forming technology of additive for optimizing bulk molding compound forming technology - Google Patents

Abstract

The invention provides a preparation method of an additive for optimizing a bulk molding compound forming technology. The additive is prepared from, by mass, 10%-30% of long-chain dihydric alcohol, 30%-40% of short-chain dihydric alcohol, 10%-25% of saturated dibasic acid, 20%-40% of unsaturated dibasic acid and 0.1%-0.6% of an organic tin catalyst. The bulk molding compound forming technology additive which is prepared by all the raw materials through a polycondensation reaction is added into a bulk molding compound, and compression molding is performed to prepare a molding product. According to the prepared bulk molding compound forming technology additive, the flowing property in the compression molding process can be well improved, and the pressure needed by compression molding is reduced. Meanwhile, the prepared product has the good mechanical property and surface smoothness and is suitable for the application field of automobiles, ships, decoration accessories and the like.

Description

An Additive Molding Process for Optimizing the Molding Process of Bulk Molding Compounds

technical field

The invention belongs to the technical field of improving molding processing technology of bulk molding compound (BMC), and in particular refers to the synthesis of modified and added resin that has a special thickening effect on the BMC system.

Background technique

BMC is usually made of highly active unsaturated polyester resin or its modified resin as the base, adding low shrinkage additives, chopped glass fibers, inorganic fillers, initiators, mold release agents and colorants, etc. molding compound. BMC bulk molding compound has excellent electrical properties, mechanical properties, heat resistance, and chemical corrosion resistance, and is mainly used in transportation (especially the automotive industry), electronics, electrical appliances and construction fields.

There are currently three main types of BMC molding processes, namely compression molding (compression) molding technology, transfer (die-casting) molding technology and injection molding technology. Currently more commonly used is the molding process and injection molding process. Generally speaking, compression molding is suitable for the production of large and medium-sized products, while die-casting molding, especially injection molding, is suitable for large-scale production of small and medium-sized products. These three processes can form products with smooth surfaces on both sides, and the dimensional accuracy of the products can reach a very high level.

In the daily molding production process, a relatively high pressure is usually required to make the BMC material flow in the cavity, which not only is not conducive to the dispersion of fibers in the system, but also affects the uniformity of its distribution; at the same time, the higher pressure also means that A series of problems such as the loss of the mold, the cost of the production process, and the production efficiency. Therefore, the traditional compression molding process of bulk molding compound can no longer meet the current society's requirements for energy saving, environmental protection, and high efficiency. Research and development of a new thickening modifier is suitable for the current transportation (especially the automobile industry), electronics, electrical appliances It has very important research significance and practical application value.

Contents of the invention

Aiming at the above-mentioned problems existing in the existing compression molding technology, the present invention provides a thickening modifier which can improve the fluidity of the bulk molding compound during the pressing process, and has a melting point of 40-80°C. The invention adopts an additive for optimizing the molding process of the bulk molding compound, which can greatly improve the flow performance of the BMC during the molding process, and meanwhile maintain good mechanical properties and surface smoothness of the BMC product.

The present invention is achieved through the following technical solutions: an additive for optimizing the forming process of bulk molding compound, the material is prepared from the following components in mass percentage: long-chain dihydric alcohol is 20%~50%; short-chain dihydric alcohol is 20%~50%; Alcohol is 5%~30%; saturated dibasic acid is 10%~50%; unsaturated dibasic acid is 5%~50%; organic tin catalyst is 0.1%~0.6%.

The long-chain diol may be neopentyl glycol, 1,6-hexanediol and 1,4-butanediol.

The short-chain diols are ethylene glycol, 1,2-propanediol, and 1,3-propanediol, which have a good linear structure.

The saturated dibasic acid is terephthalic acid, isophthalic acid and adipic acid.

The unsaturated dibasic acid may be glutaconic acid, maleic anhydride, fumaric acid.

The organotin catalyst can be dibutyltin dilaurate, dibutyltin diacetate, stannous octoate.

The present invention also discloses a method for preparing the above-mentioned additive for optimizing the molding process of bulk molding compound, which is prepared by the following steps:

(1) First add long-chain diols, short-chain diols, and organotin catalysts into the reaction kettle at a temperature of 80-100°C, at a speed of 400-500 rpm, and the reaction time is 2-3 hours;

(2) Add the saturated dibasic acid into the reaction kettle, the temperature is 140~160℃, and the reaction time is 4~5 hours.

(3) Add the unsaturated dibasic acid into the reaction kettle, the temperature is 170~190℃, and the reaction time is 3~5 hours;

(4) In the step (3), the additives for the molding process of the bulk molding compound are obtained, and are uniformly mixed with the BMC raw materials.

The melting point of the additives for the molding process of the bulk molding compound prepared in the step (4) is 40-80°C.

The beneficial effects of the present invention are:

(1) A kind of thickening aid synthesized by the present invention has rich sources of different types of alcohol and acid raw materials; the synthesis process is simple, and the operation is convenient and safe;

(2) A thickening aid synthesized by the present invention can effectively improve the fluidity of BMC in the molding process, reduce energy consumption in production, and prolong the service life of the mold.

Specific implementation method:

The preparation method of an additive for optimizing the molding process of the bulk molding compound of the present invention will be described in detail through examples below, which do not limit the scope of the present invention.

Example 1:

According to the mass ratio, the formula is: 23 parts of neopentyl glycol, 17 parts of 1,2-propanediol, 37 parts of terephthalic acid, 23 parts of maleic anhydride, and 0.2 part of dibutyltin dilaurate. The preparation steps are as follows:

(1) First add neopentyl glycol, 1,2-propanediol, and dibutyltin dilaurate into the reaction kettle at a temperature of 80°C at a speed of 400 rpm for a reaction time of 2 hours;

(2) Add terephthalic acid into the reaction kettle, the temperature is 140°C, and the reaction time is 4 hours;

(3) Add maleic anhydride into the reaction kettle, the temperature is 170°C, and the reaction time is 3 hours;

(4) The additive for the molding process of the bulk molding compound obtained in step (3) is uniformly mixed with the BMC raw material;

The additive for the molding process of the prepared bulk molding compound has a melting point of 51°C; without adding the thickening and modifying additive, the BMC spiral flow length is 85cm, and the spiral length is 100cm when the material is molded and flows Length increased by 18%.

Example 2:

According to the mass ratio, the formula is: 11 parts of 1,4-butanediol, 23 parts of ethylene glycol, 18 parts of isophthalic acid, 48 parts of fumaric acid, and 0.4 parts of dibutyltin diacetate. The preparation steps are as follows:

(1) First add 1,4-butanediol, ethylene glycol, and dibutyltin diacetate into the reaction kettle at a temperature of 89°C at a speed of 460 rpm for a reaction time of 2.5 hours;

(2) Add isophthalic acid into the reaction kettle, the temperature is 150°C, and the reaction time is 4.5 hours;

(3) Add fumaric acid into the reaction kettle, the temperature is 182°C, and the reaction time is 4 hours;

(4) The additive for the molding process of the bulk molding compound obtained in step (3) is uniformly mixed with the BMC raw material;

The additive for the molding process of the prepared bulk molding compound has a melting point of 64°C; without adding the thickening and modifying additive, the BMC spiral flow length is 85cm, and the spiral length is 104cm when the material is molded and flows Length increased by 22%.

Example 3:

According to the mass ratio, the formula is: 35 parts of 1,6-hexanediol, 7 parts of 1,3-propanediol, 49 parts of adipic acid, 9 parts of glutaconate, and 0.6 part of stannous octoate. The preparation steps are as follows:

(1) First add 1,6-hexanediol, 1,3-propanediol, and stannous octoate into the reaction kettle at a temperature of 98°C at a speed of 480 rpm for a reaction time of 2.7 hours;

(2) Add adipic acid into the reaction kettle, the temperature is 157°C, and the reaction time is 5 hours;

(3) Add glutaconic acid into the reaction kettle, the temperature is 185°C, and the reaction time is 5 hours;

(4) The additive for the molding process of the bulk molding compound obtained in step (3) is uniformly mixed with the BMC raw material;

The additive for the molding process of the prepared bulk molding compound has a melting point of 72°C; without adding the thickening and modifying additive, the BMC spiral flow length is 85cm, and the spiral length is 102cm when the material is molded and flows Length increased by 20%.

Example 4:

According to the mass ratio, the formula is: 29 parts of neopentyl glycol, 11 parts of 1,2-propanediol, 46 parts of terephthalic acid, 14 parts of maleic anhydride, and 0.2 part of dibutyltin dilaurate. The preparation steps are as follows:

(1) First add neopentyl glycol, 1,2-propanediol, and dibutyltin dilaurate into the reaction kettle at a temperature of 80°C at a speed of 400 rpm for a reaction time of 2 hours;

(2) Add terephthalic acid into the reaction kettle, the temperature is 140°C, and the reaction time is 4 hours;

(3) Add maleic anhydride into the reaction kettle, the temperature is 170°C, and the reaction time is 3 hours;

(4) The additive for the molding process of the bulk molding compound obtained in step (3) is uniformly mixed with the BMC raw material;

The additive for the molding process of the prepared bulk molding compound has a melting point of 55°C; the measured BMC spiral flow length is 85cm without adding the thickening and modifying additive, and the spiral length is 106cm when the material is molded and flows Length increased by 25%.

The above is only a specific example of the embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements can also be made without departing from the technical principles of the present invention. It is regarded as the protection scope of the present invention.

Claims (8)

1. optimize an additive for Bulk Molding Compound moulding process, it is characterized in that the massfraction of contained raw material and each raw material is: long chain diol is 20% ~ 50%; Short chain glycol is 5% ~ 30%; Monounsaturated dicarboxylic acid is 10% ~ 50%; Unsaturated dibasic acid is 5% ~ 50%; Organotin catalysts is 0.1% ~ 0.6%.

2. a kind of additive optimizing Bulk Molding Compound moulding process according to claim 1, is characterized in that described long chain diol is neopentyl glycol, 1,6-hexylene glycol and BDO.

3. a kind of additive optimizing Bulk Molding Compound moulding process according to claim 1, is characterized in that described short chain glycol is ethylene glycol, 1,2-PD, 1,3-PD.

4. a kind of additive optimizing Bulk Molding Compound moulding process according to claim 1, is characterized in that described monounsaturated dicarboxylic acid can be terephthalic acid, m-phthalic acid, hexanodioic acid.

5. a kind of additive optimizing Bulk Molding Compound moulding process according to claim 1, is characterized in that described unsaturated dibasic acid can be propene dicarboxylic acid, MALEIC ANHYDRIDE, FUMARIC ACID TECH GRADE.

6. a kind of additive optimizing Bulk Molding Compound moulding process according to claim 1, is characterized in that described organotin catalysts can be dibutyl tin laurate, dibutyltin diacetate, stannous octoate.

7. a kind of preparation method optimizing the additive of Bulk Molding Compound moulding process according to claim 1, is characterized in that concrete steps are as follows:

(1) first by long chain diol, short chain glycol, organotin catalysts, adds in reactor, and temperature is 80 ~ 100 DEG C, with the rotating speed of 400-500 rev/min, 2 ~ 3 hours reaction times;

(2) monounsaturated dicarboxylic acid is added in reactor, temperature is 140 ~ 160 DEG C, and the reaction times is 4 ~ 5 hours;

(3) add in reactor by unsaturated dibasic acid, temperature is 170 ~ 190 DEG C, and the reaction times is 3 ~ 5 hours;

(4) in the optimization Bulk Molding Compound moulding process additive that step (3) obtains, with BMC raw material Homogeneous phase mixing.

8. preparation method according to claim 7, is characterized in that the fusing point of the optimization Bulk Molding Compound moulding process additive of preparation in described step (4) is 40 ~ 80 DEG C.