CN103131164B - The method of injection moulding white PA additives for plastics and injection moulding white PA plastic component - Google Patents

Abstract

The present invention relates to the method for injection moulding white PA additives for plastics and injection moulding white PA plastic component.This additive comprises one or more of siloxane polymer resin and modified siloxane fluoropolymer resin, and described siloxane polymerization resin is or/and the weight percent of modified polyorganosiloxane fluoropolymer resin, white PA plastics is respectively: siloxane polymerization resin is or/and modified polyorganosiloxane fluoropolymer resin: 2 ‰ ~ 5 ‰; White PA plastics: surplus.The present invention, by adding siloxane polymerization resin or/and modified siloxane fluoropolymer resin in white PA plastics, can make white PA plastics there will not be mold sticking when the injection moulding demoulding.The viscosity of white PA plastisol can also be improved, improve surface gloss and the wear resistance of white PA plastic injection piece.

Description

Additive for injection molding white PA plastics and method for injection molding white PA plastics

【Technical field】

The invention belongs to the technical field of chemical industry and relates to an additive for injection molding white PA plastics and a method for injection molding white PA plastic parts.

【Background technique】

PA is the chemical abbreviation of Polyamide. Polyamide is a tough angular translucent or milky white crystalline resin. The molecular weight of polyamide as an engineering plastic is generally 15,000-30,000. Polyamide has high mechanical strength, high softening point, heat resistance, low coefficient of friction, wear resistance, self-lubrication, shock absorption and noise reduction, oil resistance, weak acid resistance, alkali resistance and general solvents, good electrical insulation, Self-extinguishing, non-toxic, odorless, good weather resistance, poor dyeing. The disadvantage is that it has high water absorption, which affects dimensional stability and electrical properties. Fiber reinforcement can reduce the water absorption of the resin, so that it can work under high temperature and high humidity.

Due to the strong polarity of PA, it has strong hygroscopicity and poor dimensional stability, but it can be improved by modification. Adding carbon black and other UV-absorbing additives to PA can greatly enhance the self-lubricating property of PA. PA without any additives will stick to the mold due to its strong hygroscopicity, but for the black PA plastic with black masterbatch, it will not stick to the mold. In view of the current problem of white PA plastic sticking to the mold, the industry generally applies a lubricant to the injection mold cavity, or chemically or physically modifies the white PA plastic by adding other chemical additives and mixing it with white PA. , but these chemical additives are either complicated to add, or their cost is high, or they will bring new physical defects to PA plastics, such as color changes and strength decline. Therefore, a very suitable additive for white PA plastics has not been found so far, which can improve the self-lubricating properties and other properties of white PA plastics at a very low cost.

【Content of invention】

Purpose of the present invention is exactly in order to solve the problem that prior art exists, has proposed a kind of additive for injection molding white PA plastic, after adding the additive of the present invention, the phenomenon of sticking mold no longer occurs in white PA plastic when injection molding.

Concrete technical scheme of the present invention is as follows:

The invention provides an additive for injection molding white PA plastics, characterized in that the additive includes one or more of siloxane polymer resin and modified siloxane polymer resin, and the siloxane polymer resin Or/and the percentage by weight of modified polysiloxane polymer resin, white PA plastics is respectively:

Silicone polymer resin or/and modified polysiloxane polymer resin: 2‰～5‰;

White PA plastic: margin.

The siloxane polymer resin is one or more of polymethylsiloxane, polydimethylsiloxane, and polytrimethylsiloxane, and the modified siloxane polymer resin is One or more of amino-modified polysiloxane, epoxy polysiloxane and phenyl-modified polysiloxane.

The degree of polymerization of the two polymers of the siloxane polymer resin and the modified polysiloxane polymer resin is 1-1000.

Preferably, the degree of polymerization of the two polymers is 3-100.

The present invention also provides a method for injection molding white PA plastic parts, characterized in that the method comprises:

In parts by weight, add 2 to 5 parts of additives to 995 to 998 parts of the white PA plastic to be processed, stir and mix evenly;

Put the mixture of white PA plastic and additives into the barrel of the injection molding machine;

The injection molding machine heats and melts the white PA plastic and additives and injects them into the cavity of the mold after stirring evenly.

The method further includes:

Put the mixture of white PA plastic and additives into the feed port of the screw extruder, and put the plastic masterbatch extruded by the screw extruder into the injection molding machine for injection molding.

The additive includes one or more of siloxane polymer resin and modified siloxane polymer resin.

The siloxane polymer resin is one or more of polymethylsiloxane, polydimethylsiloxane, and polytrimethylsiloxane, and the modified siloxane polymer resin is One or more of amino-modified polysiloxane, epoxy polysiloxane, and phenyl-modified polysiloxane.

The additive for injection molding white PA plastics according to claim 7, characterized in that the degree of polymerization of the two polymers of the siloxane polymer resin and the modified polysiloxane polymer resin is 1-1000.

Preferably, the degree of polymerization of the two polymers is 3-100.

Compared with the prior art, by adding silicone polymer resin or/and modified silicone polymer resin in the white PA plastic, the present invention can prevent the white PA plastic from sticking to the mold during injection molding , At the same time, it will not change the color of the white PA plastic, nor will it change other physical and chemical properties of the white PA plastic. Not only that, but also improve the surface gloss and wear resistance of white PA plastic injection molded parts. On the other hand, it also reduces the viscosity of white PA plastic when it is melted in the injection molding machine or extruder, and reduces the resistance of screw extrusion, which is beneficial for the molten rubber to enter the cavity of the mold, saving energy and increasing the service life of the equipment.

【Detailed ways】

In order to make the object, technical solution and advantages of the invention clearer, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Example 1

An additive for injection molding white PA plastics, the additive is polymethylsiloxane, the weight percentages of polymethylsiloxane and white PA plastics are respectively 2‰ and 998‰, according to the above weight percentages, the Polymethylsiloxane and white PA plastics are put into a mixer and stirred evenly, and then the mixture is put into the cylinder of the injection molding machine. Polymethylsiloxane and white PA plastics are melted in the injection molding machine and then injected through the injection molding machine. The nozzle is injected into the cavity of the mold for injection molding. After the injection molded parts are injection molded, the injection molded parts are demoulded. The injection molding machine will not stick to the mold when it is demoulded, and the surface is smooth.

Example 2

An additive for injection molding white PA plastics, the additive is polymethylsiloxane, polydimethylsiloxane and polytrimethicone, polymethylsiloxane, polydimethylsiloxane The weight percentages of polytrimethicone and white PA plastics are 1‰, 1‰, 1‰ and 997‰ respectively. According to the above weight percentages, the polymethylsiloxane, polydimethylsiloxane Oxane, polytrimethicone and white PA plastics are put into a mixer and stirred evenly, and then the mixture is put into the cylinder of the injection molding machine, polymethylsiloxane, polydimethylsiloxane, polytrimethicone Methylsiloxane and white PA plastics are melted in the injection molding machine and then injected into the cavity of the mold through the nozzle of the injection molding machine for injection molding. After the injection molded parts are injection molded, the injection molded parts are demoulded. The injection molding machine will not stick to the mold when it is demoulded, and the surface is smooth.

Example 3

An additive for injection molding white PA plastics, the additive is amino-modified polysiloxane and epoxy polysiloxane, and the weight percentages of polysiloxane and epoxy polysiloxane to white PA plastics are 2‰ respectively , 2‰ and 996‰, according to the above weight percentage, put the polysiloxane, epoxy polysiloxane and white PA plastic into the mixer and stir evenly, then put the mixture into the plastic extruder and extrude White PA plastic masterbatch mixed with polysiloxane and epoxy polysiloxane. The above-mentioned plastic masterbatch is put into the cylinder of the injection molding machine, and the plastic masterbatch is melted in the injection molding machine and then injected into the cavity of the mold through the nozzle of the injection molding machine for injection molding. After the injection molded parts are injection molded, the injection molded parts are demoulded. The injection molding machine will not stick to the mold when it is demoulded, and the surface is smooth.

Example 4

An additive for injection molding white PA plastics, the additive is amino-modified polysiloxane, epoxy polysiloxane and phenyl-modified polysiloxane, amino-modified polysiloxane, epoxy polysiloxane The weight percentages of alkane, phenyl-modified polysiloxane and white PA plastic are 2‰, 2‰, 1‰ and 995‰ respectively. According to the above weight percentages, the amino-modified polysiloxane, epoxy Polysiloxane, phenyl-modified polysiloxane and white PA plastic are put into a mixer and stirred evenly, and then the mixture is put into a plastic extruder to extrude and mixed with amino-modified polysiloxane, epoxy polysiloxane White PA plastic masterbatch of oxane and phenyl modified polysiloxane. The above-mentioned plastic masterbatch is put into the cylinder of the injection molding machine, and the plastic masterbatch is melted in the injection molding machine and then injected into the cavity of the mold through the nozzle of the injection molding machine for injection molding. After the injection molded parts are injection molded, the injection molded parts are demoulded. The injection molding machine will not stick to the mold when it is demoulded, and the surface is smooth.

Example 5

An additive for injection molding white PA plastics, the additive is 1,3,5-trimethyl-1,1,3,5,5-pentaphenyltrisiloxane, 1,3,5-trimethyl -The weight percentages of 1,1,3,5,5-pentaphenyltrisiloxane and white PA plastics are 5‰ and 995‰ respectively, according to the above weight percentages, the 1,3,5-trimethyl Base-1, 1, 3, 5, 5-pentaphenyltrisiloxane and white PA plastic are put into a mixer and stirred evenly, then put the mixture into a plastic extruder and extrude to mix 1, 3, 5 - White PA plastic masterbatch of trimethyl-1,1,3,5,5-pentaphenyltrisiloxane. The above-mentioned plastic masterbatch and color masterbatch are put into the cylinder of the injection molding machine together, and the plastic masterbatch and color masterbatch are melted in the injection molding machine and then injected into the cavity of the mold through the nozzle of the injection molding machine for injection molding. After the injection molded part is injection molded, the injection molded part is demoulded. The injection molding machine will not stick to the mold when it is demoulded. The surface is smooth and the gloss is good.

The above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the spirit and scope of the technical solutions of the present invention, all of them should be included in the scope of the claims of the present invention.

Claims (7)

1. the additive of injection moulding white PA plastics, it is characterized in that, this additive comprises one or more of siloxane polymer resin and modified siloxane fluoropolymer resin, and described siloxane polymerization resin is or/and the weight percent of modified polyorganosiloxane fluoropolymer resin, white PA plastics is respectively:

Siloxane polymerization resin is or/and modified polyorganosiloxane fluoropolymer resin: 2 ‰ ~ 5 ‰;

White PA plastics: surplus;

Described modified siloxane fluoropolymer resin is that amino modified polysiloxane is or/and epoxy polysiloxane;

Described siloxane polymerization resin is polymethyl siloxane, polydimethylsiloxane and poly-trimethicone, and the ratio of described polymethyl siloxane, polydimethylsiloxane and poly-trimethicone is 1:1:1.

2. the additive of injection moulding white PA plastics according to claim 1, it is characterized in that, the polymerization degree of described siloxane polymerization resin and these two kinds of polymkeric substance of modified polyorganosiloxane fluoropolymer resin is 1 ~ 1000.

3. the additive of injection moulding white PA plastics according to claim 2, it is characterized in that, the polymerization degree of two kinds of polymkeric substance is 3 ~ 100.

4. a method for injection moulding white PA plastic component, it is characterized in that, the method comprises:

With parts by weight, in 995 ~ 998 parts of white PA plastics to be processed, add 2 ~ 5 parts of additives, be uniformly mixed;

The mixture of white PA plastics and additive is dropped in the barrel of injection moulding machine;

Injection moulding machine by white PA plastics and additive heating and melting and be expelled to mould after stirring die cavity in injection moulding;

This additive comprises one or more of siloxane polymer resin and modified siloxane fluoropolymer resin; Described modified siloxane fluoropolymer resin is that amino modified polysiloxane is or/and epoxy polysiloxane;

Described siloxane polymerization resin is polymethyl siloxane, polydimethylsiloxane and poly-trimethicone, and the ratio of described polymethyl siloxane, polydimethylsiloxane and poly-trimethicone is 1:1:1.

5. the method for injection moulding white PA plastic component according to claim 4, it is characterized in that, the method comprises further:

The mixture of white PA plastics and additive is dropped into the opening for feed of screw extrusion press, the plastic master batch extruded by screw extrusion press puts into injection moulding machine injection moulding.

6. the method for injection moulding white PA plastic component according to claim 4, it is characterized in that, the polymerization degree of described siloxane polymerization resin and these two kinds of polymkeric substance of modified polyorganosiloxane fluoropolymer resin is 1 ~ 1000.

7. the method for injection moulding white PA plastic component according to claim 6, it is characterized in that, the polymerization degree of two kinds of polymkeric substance is 3 ~ 100.