CN105647088A - Thermally conductive plastics and preparation method thereof - Google Patents

Abstract

The invention discloses thermally conductive plastics. The thermally conductive plastics are prepared from a plastic substrate, thermally conductive filler, a solvent, a coupling agent and a plastic modifier, wherein the coupling agent is polyethyleneimine and accounts for 1%-5% by mass of the thermally conductive plastics. The invention further discloses a preparation method of the thermally conductive plastics. The preparation method comprises steps of material weighing, coupling agent treatment, mixing and extrusion. According to the scheme, the thermally conductive plastics can form a better heat channel, and is high in thermally conductive efficiency and good in mechanical properties.

Description

A kind of heat-conducting plastic and preparation method thereof

Technical field

The present invention relates to a kind of organic high molecular compound, be specifically related to a kind of heat-conducting plastic and preparation method thereof.

Background technology

Along with commercial production and scientific technological advance, the thermal environment of instrument and equipment changes rapidly to high temperature direction, the heat that now electronic equipment produces accumulates rapidly, making electronic device work with remaining to reliability under using ambient temperature, timely heat-sinking capability becomes the key factor affecting its operational reliability.

In Heat Conduction Material field, pure macromolecular material is generally the non-conductor of heat, generally cannot meet the requirement of heat radiation. Typically require the good conductor adding heat, for instance metal or metal-oxide. Machine-shaping cheap, easy can be obtained by the method filled, can apply to the heat conduction requirement of some special dimension through suitable PROCESS FOR TREATMENT or formula adjustment.

The heat conductivility of heat-conducting plastic is determined by its heat conductivity. Its heat conductivity depends on the combined effect of plastics and heat filling. The heat filling being scattered in resin has the shapes such as granular, lamellar, threadiness. When consumption is less, though filler can be uniformly dispersed in plastics, but still can not form contact to each other and interact, thus now the heat conductivity of material improves little; When amount of filler brings up to more than 20%, filler forms the network being interconnected in the plastic, is greatly improved the heat conductivity of material.

Heat-conducting plastic is mainly made up of plastic substrate and metal or metal oxide filler. Due to the difference of the physical characteristic of two kinds of materials, between biphase, it is hardly formed good contact, easily forms island type structure between plastic substrate and filler, it is impossible to forming good thermal pathways, cause that thermal conductivity is relatively low, mechanical performance is poor simultaneously.

Summary of the invention

It is an object of the invention to provide a kind of heat-conducting plastic and preparation method thereof, the heat-conducting plastic of the present invention program can form good thermal pathways, and not only heat transfer efficiency is high, and good mechanical property.

For reaching above-mentioned purpose, the base case of the present invention is as follows:

A kind of heat-conducting plastic, including plastic substrate, heat filling, solvent, coupling agent and plastic modifier, described coupling agent is polymine, and the mass percent accounting for raw material total amount is 1��5%.

The principle of this programme: the end group imine group in polymine can produce chemical bonding effect with the surface oxygen atoms in heat filling and the ester group in plastic substrate, thus the interaction force that improve between plastic substrate and heat filling, improve the interaction between heat filling, thus being effectively increased conductivity and mechanical performance simultaneously.

The advantage of this programme is: adopting mass percent is that the polymine of 1��5% is as coupling agent, can increase between plastic substrate and heat filling, and the interaction force between heat filling, so that conductive plastics has higher heat conductivility and mechanical strength.

Prioritization scheme 1, the further optimization to base case, it is 3% that described polymine accounts for the mass percent of raw material total amount. Inventor finds through test, and during polymine accounting 3%, the interface cohesion of heat filling and plastic substrate is tight, and heat conductivity and the heat conductivility of the heat-conducting plastic prepared are the best.

Prioritization scheme 2, the further optimization to base case, described polymine adopts the one in L-PEI, branched polymine or mixture. It is respectively adopted the polymine of above two type or both mixing all can reach the effect of the present invention.

Prioritization scheme 3, the further optimization to base case, described plastic substrate selects the one in polymethyl methacrylate and polyethylene terephthalate or mixture; Described heat filling selects the one in aluminium oxide, magnesium oxide or silicon dioxide; The one in isopropanol, ethanol, toluene, dimethylbenzene or ethylene glycol monomethyl ether selected by described solvent; Plastic modifier selects the one of SEBS-g-MA or SEBS-1615. When each raw material selects in the manner described above, can be achieved with the purpose of the present invention.

The preparation method that the present invention also provides for a kind of heat-conducting plastic, comprises the following steps:

S1: carry out weighing, plastic substrate 30��90%, heat filling 5��50%, polymine 1��5%, plastic modifier 0.5��10%, solvent 3��12% according to following mass percent;

S2: be 50��100 DEG C in temperature by polymine, heat filling and solvent, stirs when mixing speed is 100��300r/min, the heat filling that then sucking filtration processed;

S3: plastic substrate, plastic modifier and the heat filling processed are mixed, obtains mixture;

S4: mixture is transferred to extruder, temperature range 150-200 DEG C of extrusion.

In above-mentioned preparation method, adopt polymine as coupling agent treatment heat filling, improve the interaction force between plastic substrate and heat filling, improve the interaction between heat filling simultaneously. Detect discovery by experiment, adopt the electric conductivity of heat-conducting plastic prepared by above-mentioned preparation method, mechanical performance to be significantly better than the electric conductivity of existing heat-conducting plastic, mechanical performance.

Detailed description of the invention

Below by detailed description of the invention, the present invention is further detailed explanation:

The step of preparation is described below in detail for embodiment 1. Wherein the proportioning of embodiment 1 and other embodiments embodies in Table 1, and except the difference of the proportioning in table 1 or index, the preparation process of other embodiments is identical with embodiment 1.

In the present invention, solvent can select isopropanol, ethanol, toluene, dimethylbenzene, ethylene glycol monomethyl ether. In following example, isopropanol selected by solvent.

In the present invention, plastic substrate can select the one in polymethyl methacrylate and polyethylene terephthalate or mixture. In following example, plastic substrate selects polymethyl methacrylate.

In the present invention, plastic modifier can select SEBS-g-MA, SEBS-1615, and in following example, plastic modifier selects polymethyl methacrylate.

Embodiment 1

The preparation method that the present embodiment discloses a kind of heat-conducting plastic, specifically includes following steps:

S1: carry out weighing, polymethyl methacrylate 50%, aluminium oxide 27%, polymine 3%, SEBS-g-MA10% and isopropanol 10% according to following mass percent;

S2: be about 80 DEG C in temperature by polymine, aluminium oxide and solvent, stirs 1 hours when mixing speed is 200r/min, the aluminium oxide that then sucking filtration processed;

S3: by polymethyl methacrylate, SEBS-g-MA and the aluminium oxide mix homogeneously that processed, obtain mixture.

S4: mixture is transferred to extruder, at temperature range 150-200 DEG C of extruding pelletization, finally prepares heat-conducting plastic product by the plastic grain obtained by injector.

Comparative example 1

The difference part of comparative example 1 and embodiment 1 is only that, in the preparation process of embodiment 1, the step using coupling agent related to is omitted.

Comparative example 2

Comparative example 2 is distinguished by with embodiment 1, and the coupling agent in embodiment 1 is replaced with titanate coupling agent, and other steps are constant.

Table 1

Detecting the heat conductivity of heat-conducting plastic, the tensile strength that adopt each embodiment, comparative example to prepare respectively, testing result is as shown in table 2:

Table 2

Contrast conclusion:

1. comparative example 1 compares with comparative example 1, comparative example 2, differs primarily in that comparative example 1 is in the process preparing conductive plastics, is provided without coupling agent polymine; Comparative example 2 adopts titanate coupling agent. Comparative example 1 detects the electrical conductivity of the conductive plastics obtained, tensile strength all only have the electrical conductivity of conductive plastics of embodiment 1, tensile strength 1/10th; In comparative example 2, the electrical conductivity of conductive plastics, tensile strength are also significantly lower than embodiment 1. As can be seen here, electric conductivity and the tensile property of conductive plastics are played an important role by the polymine used in the embodiment of the present invention.

2. as can be seen from Table 1 and Table 2, the electrical conductivity of embodiment 1 heat-conducting plastic, tensile strength the difference of slightly higher three embodiments of performance essentially consist in polymine, isopropanol accounting different, isopropanol uses mainly as solvent, the performance of heat-conducting plastic is substantially free of impact, so the consumption differring primarily in that coupling agent of three, from the result of embodiment 1-3 it can be seen that the effect that ratio is 3% of polymine more preferably.

3. embodiment 1-5 is compared with comparative example 2, and the raw material of each embodiment adopts different ratios, but adopts titanate coupling agent effect more preferably in the ratio comparative example 2 that electrical conductivity, tensile strength properties are generally. Generally, significantly it is distinctive in that the embodiment 1-5 coupling agent adopted is different from the coupling agent that comparative example 2 adopts.

Above-described is only embodiments of the invention, and in scheme, the general knowledge such as known characteristic does not do too much description at this. Should be understood that; for a person skilled in the art, without departing from the inventive concept of the premise, it is also possible to make some deformation and improvement; these also should be considered as protection scope of the present invention, and these are all without affecting effect of the invention process and practical applicability. The protection domain that this application claims should be as the criterion with the content of its claim, and the detailed description of the invention in description etc. records the content that may be used for explaining claim.

Claims (5)

1. a heat-conducting plastic, including plastic substrate, heat filling, solvent, coupling agent and plastic modifier, it is characterised in that described coupling agent is polymine, and the mass percent accounting for raw material total amount is 1��5%.

2. heat-conducting plastic according to claim 1, it is characterised in that it is 3% that described polymine accounts for the mass percent of raw material total amount.

3. heat-conducting plastic according to claim 1, it is characterised in that described polymine includes the one in L-PEI, branched polymine or mixture.

4. heat-conducting plastic according to claim 1, it is characterised in that described plastic substrate selects the one in polymethyl methacrylate and polyethylene terephthalate or mixture; Described heat filling selects the one in aluminium oxide, magnesium oxide or silicon dioxide; The one in isopropanol, ethanol, toluene, dimethylbenzene or ethylene glycol monomethyl ether selected by described solvent; Plastic modifier selects the one of SEBS-g-MA or SEBS-1615.

5. the preparation method of heat-conducting plastic described in any one of claim 1-4, it is characterised in that comprise the following steps:

S1: carry out weighing, plastic substrate 30��90%, heat filling 5��50%, polymine 1��5%, plastic modifier 0.5��10%, solvent 3��12% according to following mass percent;

S2: be 50��100 DEG C in temperature by polymine, heat filling and solvent, stirs when mixing speed is 100��300r/min, the heat filling that then sucking filtration processed;

S3: plastic substrate, plastic modifier and the heat filling processed are mixed, obtains mixture;

S4: mixture is transferred to extruder, temperature range 150-200 DEG C of extrusion.