阅读说明：本技术 一种pet复合材料及其制备方法和应用 (PET composite material and preparation method and application thereof ) 是由 边策 唐帅 刘峰 吕孝腾 曹金波 于 2019-12-11 设计创作，主要内容包括：本发明提供了一种PET复合材料及其制备方法和应用,属于复合材料技术领域。本发明提供的PET复合材料包括以下质量百分含量的制备原料：40～60％的PET；1～3％的乙烯-(甲基)丙烯酸盐类成核剂；1～3％的小分子酯类增塑剂；3～5％的增韧剂,0.5～2％的抗氧剂,10～30％的玻璃纤维,5～20％的矿物填充物。本发明以PET为基体材料,在添加成核剂的基础上同时添加增塑剂,能够使PET的冷结晶温度明显向低温区移动,热结晶温度及熔点明显向高温区移动,提高PET的结晶速度,分子链排列更加规则,形成的晶体更加完善,脱模效果明显改善,且形成的晶体不会再重新排列,有利于使制件尺寸更加稳定。(The invention provides a PET composite material and a preparation method and application thereof, belonging to the technical field of composite materials. The PET composite material provided by the invention comprises the following preparation raw materials in percentage by mass: 40-60% of PET; 1-3% of an ethylene- (meth) acrylate nucleating agent; 1-3% of a small molecular ester plasticizer; 3-5% of a toughening agent, 0.5-2% of an antioxidant, 10-30% of glass fiber and 5-20% of a mineral filler. According to the invention, the PET is used as a base material, the plasticizer is added on the basis of adding the nucleating agent, the cold crystallization temperature of the PET can obviously move to a low-temperature region, the hot crystallization temperature and the melting point of the PET can obviously move to a high-temperature region, the crystallization speed of the PET is improved, the molecular chain arrangement is more regular, the formed crystal is more perfect, the demolding effect is obviously improved, the formed crystal can not be rearranged, and the size of a finished piece is more stable.)

1. The PET composite material is characterized by comprising the following preparation raw materials in percentage by mass:

40-60% of PET; 1-3% of an ethylene- (meth) acrylate nucleating agent; 1-3% of a small molecular ester plasticizer; 3-5% of a toughening agent, 0.5-2% of an antioxidant, 10-30% of glass fiber and 5-20% of a mineral filler.

2. The PET composite according to claim 1 wherein the PET has an intrinsic viscosity of 0.6 to 1.0 dL/g.

3. The PET composite material of claim 1 wherein the ethylene- (meth) acrylate-based nucleating agent comprises one or more of ethylene- (meth) acrylate zinc salt, ethylene- (meth) acrylate sodium salt, and ethylene- (meth) acrylate lithium salt.

4. The PET composite of claim 1, wherein the small molecule ester plasticizer comprises neopentyl glycol diphenyl esters and/or derivatives of neopentyl glycol diphenyl esters.

5. The PET composite of claim 1, wherein the toughening agent comprises one or more of ethylene methyl (meth) acrylate, ethylene ethyl (meth) acrylate, and ethylene butyl (meth) acrylate.

6. The PET composite material according to claim 1, wherein the antioxidant comprises one or more of tris [2, 4-di-tert-butylphenyl ] phosphite, pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite.

7. The PET composite of claim 1, wherein the glass fibers have a diameter of 11 μ ι η and a length of 3 mm; the glass fiber is alkali-free untwisted glass fiber treated by a coupling agent.

8. The PET composite of claim 1, wherein the mineral filler comprises phlogopite and/or silver mica with a particle size of 100 mesh.

9. A process for the preparation of a PET composite material according to any one of claims 1 to 8, comprising the steps of:

mixing PET, an ethylene- (methyl) acrylate nucleating agent, a toughening agent and an antioxidant to obtain a first mixed material;

mixing the micromolecule ester plasticizer with the mineral filler to obtain a second mixed material;

and carrying out melt mixing, extrusion and grain cutting on the first mixed material, the second mixed material and the glass fiber to obtain the PET composite material.

10. Use of the PET composite material according to any one of claims 1 to 8 or the PET composite material prepared by the preparation method according to claim 9 in preparing a motor shell of an automobile air conditioner.

Technical Field

The invention relates to the technical field of composite materials, in particular to a PET composite material and a preparation method and application thereof.

Background

Polyethylene terephthalate (PET) is a resin with excellent properties and low cost, and is mainly used for preparing fibers, films, hollow containers and the like at present. Because PET resin contains a large number of benzene rings in molecules, the rigidity of the molecules is high, the mobility is poor, the glass transition temperature is high, the crystallization speed is low, the molding period is long, the molding is easy to stick to the mold, the molding shrinkage rate is high, the dimensional stability of a workpiece is poor, and the crystallized molding is brittle, so that the application range of the PET resin is limited.

The glass transition temperature of the PET resin is about 75 ℃, the temperature rising crystallization temperature (namely, cold crystallization temperature) is about 145 ℃, the melting point is about 210 ℃, and the temperature lowering crystallization temperature (namely, hot crystallization temperature) is about 242 ℃. In order to achieve rapid molding and no sticking of the PET, the PET resin needs to be modified by making the glass transition temperature as low as possible, the melting point and the thermal crystallization temperature as high as possible, and the cold crystallization temperature as low as possible. At present, the following two methods are mainly used for modifying the PET resin:

first, blending with other resins such as PBT, PC, PA and LCP, etc., although it improves the moldability of PET to some extent, it increases the cost and is not ideal.

Secondly, the crystallization performance of PET is improved by adding a nucleating agent; the nucleating agent is mainly used for adjusting the crystallization rate of PET, so that a melt can be crystallized at a higher temperature, nucleation points of the melt are increased, and the size of spherulites of the melt is reduced, thereby improving the performance of various aspects and shortening the molding period. The nucleating agents mainly used at present are mainly classified into inorganic nucleating agents and organic nucleating agents. The inorganic nucleating agent mainly comprises: talcum powder, zinc powder, aluminum powder, graphite and the like, and the nucleating agent can improve the crystallization speed of PET to a certain extent, but has limited reduction of the cold crystallization temperature, and is difficult to reduce to below 120 ℃, so that the mold sticking problem of PET cannot be well solved. The organic nucleating agent mainly comprises: monocarboxylate, benzoic acid and alkali metal salts of the benzoic acid, wherein the nucleating agent mainly breaks chains of PET molecular chains under the action of the carboxylate to achieve the purpose of rapid crystallization; however, this process has a great influence on the mechanical properties of PET, and such nucleating agents cause more severe mold sticking.

Disclosure of Invention

The invention aims to provide a PET composite material, and a preparation method and application thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a PET composite material, which comprises the following preparation raw materials in percentage by mass:

40-60% of PET; 1-3% of an ethylene- (meth) acrylate nucleating agent; 1-3% of a small molecular ester plasticizer; 3-5% of a toughening agent, 0.5-2% of an antioxidant, 10-30% of glass fiber and 5-20% of a mineral filler.

Preferably, the PET has an intrinsic viscosity of 0.6 to 1.0 dL/g.

Preferably, the ethylene- (meth) acrylate nucleating agent comprises one or more of ethylene- (meth) acrylate zinc salt, ethylene- (meth) acrylate sodium salt and ethylene- (meth) acrylate lithium salt.

Preferably, the small-molecule ester plasticizer comprises neopentyl glycol diphenyl ester and/or derivatives of neopentyl glycol diphenyl ester.

Preferably, the toughening agent comprises one or more of ethylene methyl (meth) acrylate, ethylene ethyl (meth) acrylate and ethylene butyl (meth) acrylate.

Preferably, the antioxidant comprises one or more of tris [2, 4-di-tert-butylphenyl ] phosphite, pentaerythritol tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite.

Preferably, the glass fiber has a diameter of 11 μm and a length of 3 mm; the glass fiber is alkali-free untwisted glass fiber treated by a coupling agent.

Preferably, the mineral filler comprises phlogopite and/or silver mica with a particle size of 100 mesh.

The invention provides a preparation method of the PET composite material in the technical scheme, which comprises the following steps:

mixing PET, an ethylene- (methyl) acrylate nucleating agent, a toughening agent and an antioxidant to obtain a first mixed material;

mixing the micromolecule ester plasticizer with the mineral filler to obtain a second mixed material;

and carrying out melt mixing, extrusion and grain cutting on the first mixed material, the second mixed material and the glass fiber to obtain the PET composite material.

The invention provides an application of the PET composite material in the technical scheme or the PET composite material prepared by the preparation method in the technical scheme in preparing an automobile air conditioner motor shell.

The invention provides a PET composite material, which comprises the following preparation raw materials in percentage by mass: 40-60% of PET; 1-3% of an ethylene- (meth) acrylate nucleating agent; 1-3% of a small molecular ester plasticizer; 3-5% of a toughening agent, 0.5-2% of an antioxidant, 10-30% of glass fiber and 5-20% of a mineral filler. According to the invention, PET is used as a base material, and a plasticizer is added on the basis of adding a nucleating agent, so that the cold crystallization temperature of the PET can obviously move to a low-temperature region, the hot crystallization temperature and the melting point can obviously move to a high-temperature region, the crystallization speed of the PET is improved, the molecular chain arrangement is more regular, the formed crystal is more perfect, the demolding effect is obviously improved, the formed crystal can not be rearranged, and the size of a finished piece is more stable; meanwhile, the PET composite material provided by the invention has excellent mechanical properties and low-temperature impact resistance. The PET composite material provided by the invention can be used for preparing the motor shell of an automobile air conditioner, and can not become soft and deform after being used for a long time at the temperature of 140 ℃, so that the comprehensive performance is excellent.

Detailed Description

The invention provides a PET composite material, which comprises the following preparation raw materials in percentage by mass:

40-60% of PET; 1-3% of an ethylene- (meth) acrylate nucleating agent; 1-3% of a small molecular ester plasticizer; 3-5% of a toughening agent, 0.5-2% of an antioxidant, 10-30% of glass fiber and 5-20% of a mineral filler.

The PET composite material comprises, by mass, 40-60% of PET, preferably 50-60% of PET, more preferably 54-57% of PET, wherein the intrinsic viscosity [ η ] of the PET is preferably 0.6-1.0 dL/g.

The PET composite material comprises 1-3% of ethylene- (methyl) acrylate nucleating agent, preferably 2-3%. In the invention, the ethylene- (meth) acrylate nucleating agent preferably comprises one or more of ethylene- (meth) acrylate zinc salt, ethylene- (meth) acrylate sodium salt and ethylene- (meth) acrylate lithium salt, and more preferably ethylene- (meth) acrylate sodium salt; in an embodiment of the present invention, the ethylene- (meth) acrylic acid sodium salt is purchased from dupont with the specific model SURLYN 8920. The nucleating agent of the kind is preferably adopted in the invention, and can form ion clusters with PET resin in the melting processing process, spherical crystals with uniform size are formed by taking the ion clusters as nucleation points, so that the cold crystallization temperature of the PET composite material is favorably moved to a low temperature region, and the melting point and the hot crystallization temperature are favorably moved to a high temperature region, thereby improving the crystallization speed of the PET composite material, and simultaneously, the PET resin cannot be degraded like a carboxylate nucleating agent.

The PET composite material comprises 1-3% of micromolecular ester plasticizer, preferably 2-3%. In the invention, the small molecular ester plasticizer preferably comprises neopentyl glycol diphenyl ester and/or derivatives of neopentyl glycol diphenyl ester, and more preferably neopentyl glycol diphenyl ester; in an embodiment of the invention, the neopentyl glycol diphenyl ester was purchased from langerhans, with the specific model number Uniplex 512. The nucleating agent is only added to mainly improve the forming speed of crystal nucleus, and the later crystal growth process is slow due to poor mobility of a PET molecular chain, so that the crystallization speed of the PET resin cannot be effectively improved, the change of increasing the content of the nucleating agent and the crystallization speed is not ideal, the demoulding effect of a finished piece is not ideal, and the size is larger; according to the invention, the plasticizer is added on the basis of adding the nucleating agent, the PET molecular chain starts to thaw, the molecular chain becomes active, the regular arrangement of the molecular chain is accelerated, the crystal is more perfect, the crystal growth speed starts to be accelerated, the cold crystallization temperature of the PET composite material can obviously move to a low temperature region, the hot crystallization temperature and the melting point obviously move to a high temperature region, and the demolding effect is obviously improved. The traditional low-hardness high polymer materials with lower melting points, such as TPEE, PEG100, PEG2000 and the like, are used as plasticizers, the use effect of the matching nucleating agent is limited, the cold crystallization temperature of PET can only be reduced to about 110 ℃, the cold crystallization temperature of the PET can not be further reduced (when the cold crystallization temperature of the PET composite material is between 98 ℃ and 105 ℃, the PET composite material is not adhered to a mold any more), and the performance of the PET composite material can be adversely affected along with the increase of the addition amount of the plasticizer; although polyethylene glycol as a plasticizer can well improve the movement capability of PET molecules, the polyethylene glycol contains active functional groups, so that PET is easily degraded, and the performance of the PET composite material is adversely affected. The invention adopts the micromolecular ester compound as the plasticizer, can effectively reduce the cold crystallization temperature of the PET, simultaneously ensures that the performance of the PET is not reduced, and leads the crystal of the PET composite material to be more perfect.

The PET composite material comprises 3-5% of toughening agent, preferably 3-4%. In the present invention, the toughening agent preferably includes one or more of ethylene methyl (meth) acrylate (E/nMA/GMA), ethylene ethyl (meth) acrylate (E/nEA/GMA), and ethylene butyl (meth) acrylate (E/nBA/GMA), more preferably ethylene methyl (meth) acrylate, ethylene ethyl (meth) acrylate, or ethylene butyl (meth) acrylate, and further preferably ethylene butyl (meth) acrylate; in the examples of the present invention, ethylene butyl (meth) acrylate was specifically used as a toughening agent, purchased from dupont, with a specific model number PTW. The invention utilizes the toughening agent to improve the compatibility of the PET resin, is beneficial to improving the strength, impact resistance (toughness) and the dispersibility of the mineral filler in the PET composite material.

The preparation raw materials of the PET composite material comprise 0.5-2% of antioxidant, preferably 0.5-1%, in the invention, the antioxidant preferably comprises one or more of tris [ 2.4-di-tert-butylphenyl ] phosphite (antioxidant 168), tetrakis [ β - (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester (antioxidant 1010) and bis (2, 4-di-tert-butylphenol) pentaerythritol diphosphite, more preferably the antioxidant 168 and the antioxidant 1010, and when the antioxidant is the antioxidant 168 and the antioxidant 1010, the mass ratio of the antioxidant 168 to the antioxidant 1010 is preferably 2: 3.

The PET composite material comprises 10-30% of glass fiber, and preferably 20-30%. In the present invention, the glass fiber preferably has a diameter of 11 μm and a length of 3 mm; the glass fiber is preferably alkali-free untwisted glass fiber treated by a coupling agent, the coupling agent is preferably KH560, and the alkali-free untwisted glass fiber treated by the coupling agent can form a better phase interface with PET resin, improve the compatibility of the glass fiber and the PET resin and be beneficial to improving the mechanical property of the PET composite material; in an embodiment of the present invention, the glass fibers are purchased from Taishan glass fibers, Inc. with the specific model number ECS 11-3.0-T436H.

The raw materials for preparing the PET composite material comprise 5-20% of mineral fillers, and preferably 5%, 10%, 15% or 20%. In the present invention, the mineral filler preferably comprises phlogopite and/or silver mica, preferably of 100 mesh size; in an embodiment of the invention, the mineral filler is purchased in particular from the Yan lake mining industry.

The invention provides a preparation method of the PET composite material in the technical scheme, which comprises the following steps:

mixing PET, an ethylene- (methyl) acrylate nucleating agent, a toughening agent and an antioxidant to obtain a first mixed material;

mixing the micromolecule ester plasticizer with the mineral filler to obtain a second mixed material;

and carrying out melt mixing, extrusion and grain cutting on the first mixed material, the second mixed material and the glass fiber to obtain the PET composite material.

In the present invention, the PET is preferably dried before use so that the moisture content thereof is 0.05% or less; the drying condition is not specially limited, and the moisture content of the PET is ensured to be below 0.05 percent, for example, the PET can be dried for 5 hours at the temperature of 140 ℃. Mixing dried PET, an ethylene- (methyl) acrylate nucleating agent, a toughening agent and an antioxidant to obtain a first mixed material; the invention has no special limitation on the mixing, and the preparation raw materials are uniformly mixed.

Mixing a small molecular ester plasticizer with a mineral filler to obtain a second mixed material; according to the invention, the micromolecule ester plasticizer and the mineral filler are preferably placed in a high-speed mixer, and the materials are uniformly mixed and then cooled for 1h under the condition of 2000r/min to obtain a second mixed material.

After the first mixed material and the second mixed material are obtained, the first mixed material, the second mixed material and the glass fiber are subjected to melting, mixing, extruding and granulating to obtain the PET composite material. In the present invention, the melt-kneading and extrusion process is preferably carried out in a twin-screw extruder; the first mixed material is added from a main feed opening of the double-screw extruder, the second mixed material is added from a first side feed opening of the double-screw extruder, and the glass fiber is added from a second side feed opening of the double-screw extruder and then is melted and kneaded in the double-screw extruder. According to the invention, the small molecular ester plasticizer and the mineral filler are mixed and added from the side feeding port, so that the residence time of the plasticizer in the double-screw extruder can be reduced, the maintenance of the content of the plasticizer is facilitated, and the plasticizer can fully play a role.

In the present invention, the process parameters of the melt kneading are preferably: the double-screw extruder is divided into eleven temperature zones, wherein the temperature of the first zone is 270-275 ℃, the temperature of the second zone is 270-275 ℃, the temperature of the third zone is 265-270 ℃, the temperature of the fourth zone is 265-270 ℃, the temperature of the fifth zone is 260-265 ℃, the temperature of the sixth zone is 260-265 ℃, the temperature of the seventh zone is 255-260 ℃, the temperature of the eighth zone is 255-260 ℃, the temperature of the ninth zone is 255-260 ℃, the temperature of the tenth zone is 250-255 ℃, and the temperature of the eleventh zone is 250-255 ℃; the temperature of the machine head is 250-255 ℃, and the rotating speed of the double-screw extruder is 220-340 rpm.

After the melting, mixing and extrusion are finished, the obtained material is preferably cooled, air-dried and then cut into particles; the pellets of the present invention are not particularly limited, and may be produced by a method known to those skilled in the art. After the grain cutting is finished, the obtained material is preferably dried to obtain the PET composite material; the drying is not particularly limited, and the granulated material can be fully dried, for example, the granulated material can be dried for 5 hours in a blast drying oven at 120 ℃.

The invention provides an application of the PET composite material in the technical scheme or the PET composite material prepared by the preparation method in the technical scheme in preparing an automobile air conditioner motor shell.

The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The following raw materials are specifically used in the examples and comparative examples of the present invention:

PET: purchased from certified chemical fiber companies, with a specific model number FG 600;

antioxidant 168 and antioxidant 1010: purchased from saint leikott chemical ltd;

silver mica powder: purchased from Yanhu mining with a particle size of 100 mesh;

glass fiber: purchased from Taishan fiberglass Co., Ltd, with the specific model number ECS 11-3.0-T436H;

plasticizer: purchased from lucent corporation with a specific model of Uniplex 512;

a toughening agent: purchased from dupont, specific model PTW;

nucleating agent: purchased from dupont, with the specific model SURLYN 8920.