阅读说明：本技术 一种高密度导电聚氨酯泡棉及其制备方法、及胶带 (High-density conductive polyurethane foam, preparation method thereof and adhesive tape ) 是由 蒋可可 于 2020-07-31 设计创作，主要内容包括：本发明提供一种高密度导电聚氨酯泡棉及其制备方法以及胶带。所述制备方法包括以下步骤：将1,3-二甲基咪唑磷酸二甲酯盐和水加入到反应釜中,混合均匀后升温至45～52℃,然后加入石墨烯,混合均匀后,将反应釜降至35～40℃,再加入依次聚醚多元醇、份扩链剂,混合均匀后,将反应釜降至常温,再将催化剂、泡沫稳定剂依次加入到反应釜中混合均匀得到A料；称取二苯甲烷二异氰酸酯作为B料加入冰水浴锅中,将所述A料和所述B料搅拌均匀得到预聚体；将所述预聚体加入到超声微波协同萃取设备中进行反应得到高密度导电聚氨酯泡棉。采用本发明的方法制备的聚氨酯泡棉具有高密度和高导电性。(The invention provides high-density conductive polyurethane foam, a preparation method thereof and an adhesive tape. The preparation method comprises the following steps: adding 1, 3-dimethyl imidazole dimethyl phosphate and water into a reaction kettle, uniformly mixing, heating to 45-52 ℃, then adding graphene, uniformly mixing, cooling the reaction kettle to 35-40 ℃, adding polyether polyol and a chain extender in sequence, uniformly mixing, cooling the reaction kettle to normal temperature, sequentially adding a catalyst and a foam stabilizer into the reaction kettle, and uniformly mixing to obtain a material A; weighing diphenylmethane diisocyanate as a material B, adding the material B into an ice water bath, and uniformly stirring the material A and the material B to obtain a prepolymer; and adding the prepolymer into ultrasonic microwave synergistic extraction equipment for reaction to obtain the high-density conductive polyurethane foam. The polyurethane foam prepared by the method has high density and high conductivity.)

1. A preparation method of high-density conductive polyurethane foam is characterized by comprising the following steps:

the method comprises the following steps: adding 15-35 parts of ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate and 5-10 parts of water into a reaction kettle, uniformly mixing, heating to 45-52 ℃, adding 25-50 parts of graphene, uniformly mixing, cooling the reaction kettle to 35-40 ℃, sequentially adding 70-110 parts of polyether polyol and 6-10 parts of chain extender, uniformly mixing, cooling the reaction kettle to normal temperature, sequentially adding 0.5-1 part of catalyst and 1-4 parts of foam stabilizer into the reaction kettle, and uniformly mixing to obtain a material A, wherein the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is 1: (1.2-2);

step two: weighing 150 parts by weight of diphenylmethane diisocyanate as a material B, adding the material A into an ice water bath kettle at the temperature of 1-3 ℃, cooling the material B to 1-3 ℃, adding the material A obtained in the step one into the ice water bath kettle, and uniformly stirring the material A and the material B to obtain a prepolymer, wherein the stirring speed is 1200-1600 r/min;

step three: and (3) adding the prepolymer obtained in the step (II) into ultrasonic microwave synergistic extraction equipment for reaction to obtain high-density conductive polyurethane foam, wherein the ultrasonic microwave reaction time is 10-16 min, the ultrasonic microwave reaction temperature is 35-45 ℃, and the ultrasonic output power is 150-170W.

2. The method for preparing high-density conductive polyurethane foam according to claim 1, wherein the weight ratio of the 1, 3-dimethylimidazole dimethyl phosphate to the graphene is 1: 1.5.

3. the method for preparing high-density conductive polyurethane foam according to claim 1, wherein the polyether polyol comprises polyether polyol 1, polyether polyol 2 and polyether polyol 3, and the weight ratio of polyether polyol 1, polyether polyol 2 and polyether polyol 3 is 1: (0.2-0.5): (0.05-0.1), wherein the polyether polyol 1 is prepared by ring-opening polymerization of a mixture of sucrose, sorbitol and glycerol and oleic acid as an initiator and propylene oxide as a polymerization monomer, and the hydroxyl value is 480-620 mgKOH/g; the polyether polyol 2 is prepared by ring-opening polymerization of a mixture of mannitol and xylitol and glycerol as an initiator and propylene oxide as a polymerization monomer, wherein the hydroxyl value is 420-600 mgKOH/g; the polyether polyol 3 is flame-retardant polyether polyol, and the acid value is 1.1-1.5 mgKOH/g.

4. The method for preparing high-density conductive polyurethane foam according to claim 1, wherein the catalyst added in the first step is a mixture of amine catalyst and tin catalyst.

5. The method for preparing high-density conductive polyurethane foam according to claim 4, wherein the catalyst is a mixture of diethanolamine and dibutyltin dilaurate, and the weight ratio of the diethanolamine to the dibutyltin dilaurate is (0.6-0.8): 1.

6. the method for preparing high-density conductive polyurethane foam according to claim 1, wherein the chain extender is one or more of ethylene glycol, 1, 4-butanediol and glycerol.

7. The method for preparing high-density conductive polyurethane foam according to claim 1, wherein the foam stabilizer is polydimethylsiloxane.

8. A high-density conductive polyurethane foam, which is prepared by the preparation method of the high-density conductive polyurethane foam as claimed in any one of claims 1 to 7.

9. An adhesive tape, comprising a substrate layer, an adhesive layer arranged on the surface of the substrate layer and a release film, wherein the adhesive layer is sandwiched between the substrate layer and the release film, and the adhesive tape is characterized in that the substrate layer is the high-density conductive polyurethane foam of claim 8.

Technical Field

The invention relates to a polyurethane foam product, in particular to high-density conductive polyurethane foam, a preparation method thereof and an adhesive tape.

Background

The polyurethane foam material is an organic polymer material which is obtained by reacting polyisocyanate and polyol and contains a plurality of urethane chain segments. The polyurethane material has excellent mechanical, acoustic, electrical and chemical medium resistance, wide hardness range, good flexibility, bonding performance, wear resistance, low temperature resistance, radiation resistance and the like. The polyurethane material is widely applied in the fields of automobiles, machinery, electronics, packaging, buildings, medical treatment, aerospace and the like.

Polyurethane foam is difficult to form an effective conductive path therein due to its low density, small cell wall and pillar size, and it is more difficult to improve its conductive properties. At present, some conductive fillers (such as carbon black and the like) are filled into a polyurethane matrix so as to improve the conductivity, but the polyurethane foaming is an in-situ polymerization reaction, which brings difficulty to the dispersion of the conductive fillers in the polyurethane matrix. More importantly, the size among the cells in the polyurethane foam is gradually reduced from the central part to the edge of the pillar, the large-size conductive filler is difficult to disperse at the edge part far away from the pillar, so that a conductive path is difficult to form, and the density of the polyurethane foam is reduced by adding the conductive material such as carbon black. In the prior art, no effective method for improving the density and the conductivity of the polyurethane foam simultaneously exists.

Disclosure of Invention

The invention provides high-density conductive polyurethane foam and a preparation method thereof, and aims to solve the technical problems that the density of the conductive polyurethane foam is low or the high-density polyurethane foam is not uniformly distributed and has poor conductivity in the prior art.

The embodiment of the invention provides a preparation method of high-density conductive polyurethane foam, which comprises the following steps:

the method comprises the following steps: adding 15-35 parts of ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate and 5-10 parts of water into a reaction kettle, uniformly mixing, heating to 45-52 ℃, adding 25-50 parts of graphene, uniformly mixing, cooling the reaction kettle to 35-40 ℃, sequentially adding 70-110 parts of polyether polyol and 6-10 parts of chain extender, uniformly mixing, cooling the reaction kettle to normal temperature, sequentially adding 0.5-1 part of catalyst and 1-4 parts of foam stabilizer into the reaction kettle, and uniformly mixing to obtain a material A, wherein the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is 1: (1.2-2);

step two: weighing 150 parts by weight of diphenylmethane diisocyanate as a material B, adding the material A into an ice water bath kettle at the temperature of 1-3 ℃, cooling the material B to 1-3 ℃, adding the material A obtained in the step one into the ice water bath kettle, and uniformly stirring the material A and the material B to obtain a prepolymer, wherein the stirring speed is 1200-1600 r/min;

step three: and (3) adding the prepolymer obtained in the step (II) into ultrasonic microwave synergistic extraction equipment for reaction to obtain high-density conductive polyurethane foam, wherein the ultrasonic microwave reaction time is 10-16 min, the ultrasonic microwave reaction temperature is 35-45 ℃, and the ultrasonic output power is 150-170W.

Further, the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is 1: 1.5.

further, the polyether polyol comprises polyether polyol 1, polyether polyol 2 and polyether polyol 3, and the weight ratio of polyether polyol 1, polyether polyol 2 and polyether polyol 3 is 1: (0.2-0.5): (0.05-0.1), wherein the polyether polyol 1 is prepared by ring-opening polymerization of a mixture of sucrose, sorbitol and glycerol and oleic acid as an initiator and propylene oxide as a polymerization monomer, and the hydroxyl value is 480-620 mgKOH/g; the polyether polyol 2 is prepared by ring-opening polymerization of a mixture of mannitol and xylitol and glycerol as an initiator and propylene oxide as a polymerization monomer, wherein the hydroxyl value is 420-600 mgKOH/g; the polyether polyol 3 is flame-retardant polyether polyol, and the acid value is 1.1-1.5 mgKOH/g.

Further, the catalyst added in the first step is a mixture of an amine catalyst and a tin catalyst.

Further, the catalyst is a mixture of diethanolamine and dibutyltin dilaurate, and the weight ratio of the diethanolamine to the dibutyltin dilaurate is 0.6-0.8): 1.

further, the chain extender is one or more of ethylene glycol, 1, 4-butanediol and glycerol.

Further, the foam stabilizer is polydimethylsiloxane.

The embodiment of the invention also provides the high-density conductive polyurethane foam which is prepared by the preparation method of the high-density conductive polyurethane foam.

The embodiment of the invention also provides an adhesive tape, which comprises a substrate layer, an adhesive layer and a release film, wherein the adhesive layer and the release film are arranged on the surface of the substrate layer, the adhesive layer is sandwiched between the substrate layer and the release film, and the substrate layer is the high-density conductive polyurethane cotton.

The invention has the following beneficial effects:

according to the high-density conductive polyurethane foam provided by the invention, a specific amount of graphene and a specific amount of a 1, 3-dimethyl imidazole dimethyl phosphate salt raw material are added into a material A, and the reaction temperature of the graphene and the ionic liquid is controlled, so that the polyurethane foam has high density and high conductivity at the same time. The ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate has high conductivity, a wide electrochemical window, lubricity and miscibility, interacts with pi-pi bonds on the surface of graphene, a layer of ionic liquid is assembled and modified on the surface of the graphene, the graphene can be rapidly dispersed into the ionic liquid due to good bonding and charge attraction capacities between the ionic liquid and the graphene, the ionic liquid can enable the graphene to be stripped to a certain extent, the graphene can generate more large pi bonds and lone pair electrons, and later-stage polyurethane cotton is connected with a large pi conjugated system of the graphene, so that the conductivity is better. Due to the dispersion and stripping effects of the ionic liquid, the graphene and the ionic liquid can be better dispersed on the edge part, far away from the support, of the polyurethane foam, so that the polyurethane foam can still form a three-dimensional through conductive path even at the far edge part. In addition, although the ionic liquid is added in the preparation process, due to the good structural stability of the graphene and the pi-pi effect of the graphene, the graphene and the polyurethane foam can be stably combined together, so that the effects of improving the density of the polyurethane foam and improving the conductivity of the polyurethane foam can be achieved at the same time.

Secondly, a prepolymer obtained by uniformly mixing the material A and the material B is put into ultrasonic microwave synergistic extraction equipment to perform ultrasonic-microwave multiple circulation to prepare polyurethane cotton, on one hand, cavitation effect and other nonlinear phenomena of ultrasonic waves are caused, and cavitation bubbles in an ionic liquid medium radiated by ultrasonic waves are expanded and compressed to generate localized hot spots, so that the ionic liquid, graphene and isocyanate raw materials are subjected to ultrasonic chemical reaction, and the graphene and polyurethane cotton are combined more stably; on the other hand, the mechanical disturbance and cavitation of the ultrasonic wave can increase the closed cell rate of the foam and improve the density of the polyurethane foam. In addition, microwave heating can generate polarization effect on the electric property and magnetism of the ionic liquid, graphene, isocyanate and other raw materials, and the electric conductivity is improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are some, but not all, embodiments of the present 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 invention is further described below with reference to specific embodiments.

The embodiment of the invention provides a preparation method of high-density conductive polyurethane foam, which comprises the following steps:

the method comprises the following steps: adding 15-35 parts of ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate and 5-10 parts of water into a reaction kettle, uniformly mixing, heating to 45-52 ℃, adding 25-50 parts of graphene, uniformly mixing, cooling the reaction kettle to 35-40 ℃, sequentially adding 70-110 parts of polyether polyol and 6-10 parts of chain extender, uniformly mixing, cooling the reaction kettle to normal temperature, sequentially adding 0.5-1 part of catalyst and 1-4 parts of foam stabilizer into the reaction kettle, and uniformly mixing to obtain a material A, wherein the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is 1: (1.2-2);

step two: weighing 150 parts by weight of diphenylmethane diisocyanate as a material B, adding the material A into an ice water bath kettle at the temperature of 1-3 ℃, cooling the material B to 1-3 ℃, adding the material A obtained in the step one into the ice water bath kettle, and uniformly stirring the material A and the material B to obtain a prepolymer, wherein the stirring speed is 1200-1600 r/min;

step three: and (3) adding the prepolymer obtained in the step (II) into ultrasonic microwave synergistic extraction equipment for reaction to obtain high-density conductive polyurethane foam, wherein the ultrasonic microwave reaction time is 10-16 min, the ultrasonic microwave reaction temperature is 35-45 ℃, and the ultrasonic output power is 150-170W.

The pz orbital of each carbon atom of graphene perpendicular to the plane of the layer can form a large pi bond of multiple atoms throughout the layer, and thus has excellent conductive and optical properties and a very stable structure. The ionic liquid has higher conductivity, wider electrochemical window and high stability, and the conductive high molecular material obtained in the ionic liquid usually has better electrochemical activity and stability. The ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate has the characteristics of high conductivity, nonvolatility, nonflammability, good thermal stability and the like, and has the characteristics of good dissolving capacity on a plurality of inorganic salts and organic matters.

Specific amounts of ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate and graphene are added into the material A at the same time, the material A and the material B are mixed and then are put into ultrasonic wave microwave synergistic extraction equipment for ultrasonic wave-microwave multiple circulation to prepare the polyurethane cotton, and finally the purposes of improving the density and the conductivity of the polyurethane cotton are achieved at the same time.

Due to the lubricity and miscibility of the ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate, when graphene and the ionic liquid are mixed at 45-52 ℃, the ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate interacts with pi-pi on the surface of the graphene, a layer of ionic liquid is self-assembled and modified on the surface of the graphene, due to the good bonding and charge attraction capacity between the ionic liquid and the graphene, the graphene can be rapidly dispersed into the ionic liquid, the ionic liquid can enable the graphene to be stripped to a certain degree, the graphene can generate more large pi bonds and lone pair electrons, and the later-stage polyurethane cotton is connected with a large pi conjugated system of the graphene, so that the conductivity is better. Due to the dispersion and stripping effects of the ionic liquid, the graphene and the ionic liquid can be better dispersed on the edge part, far away from the support, of the polyurethane foam, so that the polyurethane foam can still form a three-dimensional through conductive path even at the far edge part.

The effect of ultrasonic waves on chemical reaction mainly comes from cavitation effect and other nonlinear phenomena, and cavitation bubbles in an ionic liquid medium radiated by ultrasonic waves are expanded and compressed to generate localized hot spots, so that the ionic liquid, graphene and isocyanate raw materials are subjected to ultrasonic chemical reaction, and the graphene and polyurethane cotton are combined more stably; in addition, the mechanical disturbance and cavitation of the ultrasonic waves can increase the closed cell rate of the foam and improve the density of the polyurethane foam. The microwave heating has the main effects of generating polarization and electric conduction on the electric property and magnetism of substances on ionic liquid, graphene, isocyanate and other raw materials. Due to the non-thermal effect of the micro-wave, the reaction activation energy can be further reduced, and the strength of molecular chemical bonds can be weakened, so that the chemical reaction is accelerated.

In addition, the applicant finds through experiments that when the ultrasonic waves and the microwaves exist simultaneously, the mechanical disturbance and the cavitation of the ultrasonic waves and the specific thermal effect and non-thermal effect of the microwave field are combined together, a synergistic effect is generated between the mechanical disturbance and the cavitation, the chemical reaction is more favorably carried out, and the energy utilization rate is higher compared with a conventional mechanical stirring mode and a conventional heating mode. Ultrasonic wave and microwave two act on whole reaction process simultaneously, and not alone or act on the reaction process in proper order, the respective unique action of full play two promptly, the synergistic effect between the full play two again, graphite alkene all can be dispersed more evenly in each position, and compare mechanical stirring mode and heating method, relatively more graphite alkene can be added to reaction system, the poor problem of stability can not appear yet, therefore, electric conductive property can further promote.

In the invention, the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is 1: (1.2-2), when the addition amount of the graphene is too small, the conductivity is poor; when the graphene is added in an excessive amount, the conductivity is increased, but the stability is poor, so that the density of the prepared polyurethane foam is reduced.

Preferably, the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is 1: 1.5, when the ratio of the density of the polyurethane foam to the conductivity of the polyurethane foam is in the same range, the density and the conductivity index of the prepared polyurethane foam are optimal.

In the invention, the reaction temperature of the 1, 3-dimethyl imidazole dimethyl phosphate and the graphene is 45-52 ℃, and when the reaction temperature exceeds 52 ℃, the structural stability is damaged; when the reaction temperature is lower than 45 ℃, the ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate and graphene cannot be well dispersed and stripped, so that the conductivity is poor.

In this embodiment, the polyether polyol includes polyether polyol 1, polyether polyol 2, and polyether polyol 3, and the weight ratio of polyether polyol 1, polyether polyol 2, and polyether polyol 3 is 1: (0.2-0.5): (0.05-0.1), wherein the polyether polyol 1 is prepared by ring-opening polymerization of a mixture of sucrose, sorbitol and glycerol and oleic acid as an initiator and propylene oxide as a polymerization monomer, and the hydroxyl value is 480-620 mgKOH/g; the polyether polyol 2 is prepared by ring-opening polymerization of a mixture of mannitol and xylitol and glycerol as an initiator and propylene oxide as a polymerization monomer, wherein the hydroxyl value is 420-600 mgKOH/g; the polyether polyol 3 is flame-retardant polyether polyol, and the acid value is 1.1-1.5 mgKOH/g.

The density of the polyurethane foam is increased by adding specific polyols.

In this embodiment, the catalysts added in the first step are amine catalysts and tin catalysts.

In this embodiment, the catalyst is a mixture of diethanolamine and dibutyltin dilaurate, and the weight ratio of diethanolamine to dibutyltin dilaurate is (0.6-0.8): 1. the method comprises the following steps of preparing a polyurethane foaming agent, preparing a catalyst for polyurethane reaction, and controlling the ratio of diethanol amine to dibutyltin dilaurate to ensure that gel reaction and foaming reaction can be balanced.

In this embodiment, the chain extender is one or more of monoethylene glycol, 1, 4-butanediol, and glycerol.

In this example, the foam stabilizer was polydimethylsiloxane.

The polydimethylsiloxane can stabilize the foam performance, can also improve the extensibility of polyurethane foam, and is also synergistic in flame retardance.

The embodiment of the invention also provides the high-density conductive polyurethane foam which is prepared by the preparation method of the high-density conductive polyurethane foam.

The embodiment of the invention also provides an adhesive tape, which comprises a substrate layer, an adhesive layer and a release film, wherein the adhesive layer and the release film are arranged on the surface of the substrate layer, the adhesive layer is sandwiched between the substrate layer and the release film, and the substrate layer is the high-density conductive polyurethane cotton.