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 唐勇军 于 2020-08-04 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、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；将所述预聚体注入到预热的模具中进行发泡得到聚氨酯泡棉。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 injecting the prepolymer into a preheated mold for foaming to obtain the 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:

adding 10-35 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 ℃, then adding 15-30 parts of graphene, uniformly mixing, cooling the reaction kettle to 35-40 ℃, then 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 1-3 parts of catalyst and 2-5 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 (0.5-1.5): 1;

weighing 120 parts by weight of diphenylmethane diisocyanate as a material B, adding the diphenylmethane diisocyanate 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 1200-2200 r/min;

and step three, injecting the prepolymer obtained in the step two into a preheated mold for foaming to obtain polyurethane foam, wherein the surface temperature of the preheated mold is 45-55 ℃, and the foaming time is 20-30 minutes.

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 0.8: 1.

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 preparation method of the high-density conductive polyurethane foam according to claim 4, wherein the catalyst is a mixture of an amine catalyst triethylene diamine and a tin catalyst stannous octoate, and the weight ratio of the triethylene diamine to the stannous octoate is (0.4-0.6): 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 and a release film, wherein the adhesive layer is arranged on the surface of the substrate layer, and 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:

adding 10-35 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 ℃, then adding 15-30 parts of graphene, uniformly mixing, cooling the reaction kettle to 35-40 ℃, then 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 1-3 parts of catalyst and 2-5 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 (0.5-1.5): 1;

weighing 120 parts by weight of diphenylmethane diisocyanate as a material B, adding the diphenylmethane diisocyanate 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 1200-2200 r/min;

and step three, injecting the prepolymer obtained in the step two into a preheated mold for foaming to obtain polyurethane foam, wherein the surface temperature of the preheated mold is 45-55 ℃, and the foaming time is 20-30 minutes.

Further, the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is 0.8: 1.

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 an amine catalyst triethylene diamine and a tin catalyst stannous octoate, and the weight ratio of the triethylene diamine to the stannous octoate is (0.4-0.6): 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 raw material of 1, 3-dimethyl imidazole dimethyl phosphate are added into the material A, and the reaction temperature of the graphene and the raw material 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.

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 10-35 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 15-30 parts of graphene, uniformly mixing, cooling the reaction kettle to 35-40 ℃, adding 70-110 parts of polyether polyol and 6-10 parts of chain extender in sequence, uniformly mixing, cooling the reaction kettle to normal temperature, adding 1-3 parts of catalyst and 2-5 parts of foam stabilizer in sequence 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 (0.5-1.5): 1;

step two: weighing 120 parts by weight of diphenylmethane diisocyanate as a material B, adding the material B 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 1200-2200 r/min;

step three: and (3) injecting the prepolymer obtained in the step (II) into a preheated mold for foaming to obtain polyurethane foam, wherein the surface temperature of the preheated mold is 45-55 ℃, and the foaming time is 20-30 minutes.

The pz orbit of each carbon atom of graphene perpendicular to the layer plane can form a large pi bond of multiple atoms throughout the layer, so that the graphene has excellent conductive and optical properties and a graphene structure is very stable. 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, good dissolving capacity for a plurality of inorganic salts and organic matters and the like.

A specific amount of ionic liquid 1, 3-dimethyl imidazole dimethyl phosphate and graphene are added into the material A at the same time, so that the conductivity can be improved, and the density of the prepared polyurethane foam can be improved. 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. 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 polyurethane foam has high density and strength although more conductive paths are formed at the edge part. Namely, the effects of improving the density of the polyurethane foam and improving the conductivity of the polyurethane foam can be simultaneously achieved.

In the invention, the weight ratio of the 1, 3-dimethyl imidazole dimethyl phosphate to the graphene is (0.5-1.5): 1, when the addition amount of the 1, 3-dimethyl imidazole dimethyl phosphate is too small, the dispersibility of graphene is influenced, and the conductivity is poor; when the 1, 3-dimethylimidazole dimethyl phosphate is added in an excessive amount, the conductivity is increased, but the stability is deteriorated, 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 0.8: 1, when the two are in the ratio, the density and the conductivity index of the prepared polyurethane cotton 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 catalyst added in the first step is a mixture of an amine catalyst and a tin catalyst.

In this embodiment, the catalyst is a mixture of an amine catalyst triethylene diamine and a tin catalyst stannous octoate, and the weight ratio of triethylene diamine to stannous octoate is (0.4-0.6): 1.

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.