CN113861497B

CN113861497B - Self-heating foam, preparation method thereof and adhesive tape

Info

Publication number: CN113861497B
Application number: CN202111073609.8A
Authority: CN
Inventors: 丁泽成; 王文广; 周东珊; 蒋义赏; 彭伟
Original assignee: Zhejiang Yasha Decoration Co Ltd
Current assignee: Zhejiang Yasha Decoration Co Ltd
Priority date: 2021-09-14
Filing date: 2021-09-14
Publication date: 2023-03-03
Anticipated expiration: 2041-09-14
Also published as: CN113861497A

Abstract

The invention belongs to the technical field of foam adhesive tapes, and particularly discloses self-heating foam, a preparation method thereof and an adhesive tape, wherein the self-heating foam is prepared by mixing and foaming at least the following raw materials in parts by weight: 40-50 parts of acrylic ester, 30-50 parts of solvent, 0.5-3 parts of curing agent, 1-10 parts of foaming microspheres, 0.1-3 parts of dispersing agent and 1-10 parts of heating substance; the heating substance is energy storage particles which generate heat through deformation under the action of pressing or microcapsules wrapped with a heating composition which reacts with oxygen to generate heat, and the microcapsules are provided with shells which can be broken under the action of pressing. The invention can provide a base material with a self-heating function for the foam adhesive tape, so that the foam adhesive tape still has good viscosity in a low-temperature environment, and a heating device is not needed to be used for field heating.

Description

Self-heating foam, preparation method thereof and adhesive tape

Technical Field

The invention relates to the technical field of foam adhesive tapes, in particular to self-heating foam, a preparation method thereof and an adhesive tape.

Background

The foam adhesive tape is manufactured by using foam (such as EVA, PE, PU, acrylic foam and the like) as a base material, coating solvent type (or hot melt type) pressure-sensitive adhesive on one surface or two surfaces of the base material and compounding release paper, has the characteristics of firm adhesion, quick use and the like, can play roles in heat insulation, water resistance, shock absorption, sealing, sound absorption and the like, and is widely applied to the fields of automobile accessories, electronic devices, mobile phone accessories, office tools and the like.

The acrylic foam adhesive tape has strong and lasting cohesiveness, can realize permanent structural fixation between materials with different surface characteristics even if used between the materials, can avoid punching compared with connection modes such as riveting, screw/bolting, and accords with the processing characteristics of assembly type decoration, so the acrylic foam adhesive tape is widely used in the field of building decoration. However, the acrylic foam adhesive tape generally needs to be kept at 15-40 ℃ in use, the viscosity of the acrylic foam adhesive tape is obviously reduced in a low-temperature environment such as winter, an adherend is easy to fall off, and at present, foam is heated by adopting a heating device to meet the requirement of use viscosity, but the method is very inconvenient to operate and wastes time and labor.

Disclosure of Invention

One of the objectives of the present invention is to provide a self-heating foam, which can provide a substrate with self-heating function for a foam tape, so that the foam tape still has good adhesion in a low temperature environment, and does not need to be heated in situ by a heating device.

In order to achieve the purpose, the invention adopts the following specific technical scheme:

the self-heating foam is prepared from the following raw materials in parts by weight: 40-50 parts of acrylate, 30-50 parts of solvent, 0.5-3 parts of curing agent, 1-10 parts of foaming microsphere, 0.1-3 parts of dispersing agent and 1-10 parts of heating monomer; the heating monomer is an energy storage particle which is deformed to release heat by pressing or a microcapsule wrapped with a heating composition which reacts with oxygen to release heat, and the microcapsule is provided with a shell which can be broken under the pressing action.

The self-heating foam is prepared by blending heating monomers and other foam raw materials and then heating and foaming, each energy storage particle or microcapsule in the prepared self-heating foam is used as a heating unit for supplying heat, and the heat in the heating unit can be released by pressing the self-heating foam. In the foam raw material, the foaming microspheres are spherical plastic particles with thermoplastic acrylate polymer as the shell and alkane gas as the core, and the foaming microspheres are used as foaming agents, so that on one hand, the foaming microspheres have good compatibility with the main raw material, namely acrylate, and are easy to combine, and the strength and toughness of foam can be effectively improved; on the other hand, compared with the conventional foaming agent, the foaming microspheres have small impact on the heat-generating monomer, and can reduce the condition that the heat-generating monomer deforms or cracks in advance to release heat due to foaming extrusion.

Preferably, the foaming microspheres are medium-low temperature foaming microspheres with the foaming temperature less than or equal to 150 ℃, and the commercial products such as Aksu 031DU40, american Borken Polychem 120DU15, japanese Songben MSL-3030 and the like. The medium-low temperature foaming microspheres are mild in foaming, and can effectively reduce the influence of foaming on the heating monomer.

Preferably, the weight of the heat-generating monomer is 1-10% of the total weight of the raw materials. The using amount of the heating monomer is less than 1 percent, the heat release of the foam is insufficient, and the adhesive force of the foam adhesive tape can not meet the use requirement; the amount of the heat-generating monomer exceeds 10%, on one hand, the dispersion difficulty is increased, and on the other hand, the toughness of the foam is reduced, so that the pressing resistance is increased.

Preferably, the curing agent is one or more of an isocyanate curing agent, an epoxy curing agent and a pyridine curing agent.

Preferably, the dispersing agent is a condensate of aliphatic alcohol and ethylene oxide and/or a nonionic high molecular block copolymer.

Preferably, the solvent is one or more of ethyl acetate, butyl acetate, dimethyl carbonate, toluene and isopropanol.

Preferably, the energy storage particles are strip-shaped lambda-titanium pentoxide. The energy stored by the strip lambda-titanium pentoxide is large, and the crystals are converted into beta-titanium pentoxide after being pressed, so that heat is generated; and the initial state of the lambda-titanium pentoxide is strip-shaped, the distribution of the foam is wide, the coverage area is large, and the pressing stress is facilitated.

Preferably, the heat-generating composition includes at least, by weight: 40-65% of iron powder, 2-25% of activated carbon, 0.5-10% of inorganic salt, 0.5-10% of water-absorbing resin and 5-20% of water. After pressing the foam, the shell of the microcapsules is broken and the composition comes into contact with air, causing an exothermic reaction.

Preferably, the shell is a spherical plastic film with a hollow interior, and the inner diameter of the plastic film is 0.3-0.8mm.

The invention also aims to provide a preparation method of the self-heating foam, which comprises the following steps:

a. premixing acrylate, a solvent and a dispersant, and uniformly stirring;

b. premixing the curing agent, the foaming microspheres and the heating monomer, and uniformly stirring at a stirring speed of 20-100r/min;

c. adding the premix obtained in the step b into the premix obtained in the step a, stirring while adding, controlling the stirring speed at 20-100r/min, and stirring for at least 30min;

d. and d, coating the mixture obtained in the step c on release paper, and heating and foaming to obtain the heating foam.

According to the preparation method of the self-heating foam, the dispersion level of the powder, particularly the heating monomer, is improved by controlling the feeding sequence, so that the temperature difference of different parts of the foam after the heating monomer releases heat is reduced; and the stirring speed must be strictly controlled during mixing, so as to avoid the heat-generating composition from being exposed to an exothermic reaction too early due to the damage of the microcapsules caused by high-speed shearing.

The invention also aims to provide the adhesive tape, which comprises a substrate layer, adhesive layers respectively arranged on the upper surface and the lower surface of the substrate layer and an isolation layer arranged on the surface of at least one side of the adhesive layer far away from the substrate layer, wherein the substrate layer is the self-heating foam prepared according to the composition formula and the preparation method. The isolation layer covers on the glue film surface, tears when the cotton sticky tape of bubble uses, and the isolation layer can be PET from type paper, PP from type paper, PLA from type paper, PE from type paper etc.. Make the monomer heat release that generates heat through pressing down the sticky tape during use, then the heat is transmitted to the glue film by the substrate layer, and then makes the glue film heat up and avoid the viscidity decline problem of glue film under the low temperature environment.

The invention has the following beneficial effects:

1. according to the invention, the foaming raw material and the heating monomer are blended and then foamed to prepare the self-heating foam, and the heating monomer selects energy storage particles which deform under pressure to release heat or microcapsules coated with heating substances which react with oxygen to release heat, so that the pressing heat release of the foam is realized; the self-heating foam is used as a base material of the foam adhesive tape, so that the foam adhesive tape still has good viscosity in a low-temperature environment, an object can be firmly bonded without using a heating device, the operation is convenient, and the connection efficiency of components is greatly improved in assembly decoration.

2. According to the invention, the medium-low temperature foaming microspheres are used as the foaming agent, so that the influence of the foaming process on the heating monomer is effectively reduced, and the possibility of early heat release of the foaming monomer is reduced; and can be matched with acrylic ester which is a main raw material of the foam, so that the strength and the toughness of the foam are improved.

3. The invention ensures the sufficiency of heat release of the foam by strictly controlling the dosage (1-10 wt%) of the heating monomer, and simultaneously does not cause pressing difficulty.

4. The preparation method of the self-heating foam can ensure that the heating monomer has good dispersion level and reduce the mechanical damage of the heating monomer in the preparation process, and the self-heating foam with sufficient and uniform heat release function is prepared by combining the formula design.

Drawings

FIG. 1: the adhesive tape is structurally and schematically shown.

In the figure: 1-a substrate layer, 2-a glue layer, 3-an isolation layer and 11-a heating unit.

Detailed Description

The invention is further described below with reference to the following figures and specific examples.

Example 1

The self-heating foam is prepared from the following raw materials in parts by weight: 45 parts of acrylate, 40 parts of solvent, 2 parts of curing agent, 5 parts of foaming microsphere, 2 parts of dispersing agent and 6 parts of heating monomer; the solvent is ethyl acetate, the curing agent is an isocyanate curing agent, the foaming microspheres are Ackso low-temperature foaming microspheres 031DU40, the dispersing agent is a condensation product of fatty alcohol and ethylene oxide, and the heating monomer is strip-shaped lambda-titanium pentoxide.

Weighing the raw materials according to the formula, and then preparing the self-heating foam according to the following steps:

a. premixing acrylate, a solvent and a dispersant, and uniformly stirring;

b. premixing a curing agent, foaming microspheres and a heating monomer, and uniformly stirring, wherein the stirring speed is controlled at 50r/min;

c. adding the premix obtained in the step b into the premix obtained in the step a, stirring while adding, controlling the stirring speed at 50r/min, and stirring for 35min;

d. and c, coating the mixture obtained in the step c on release paper, and heating and foaming at 130 ℃ to obtain the heating foam.

Example 2

The self-heating foam is prepared from the following raw materials in parts by weight: 50 parts of acrylate, 50 parts of solvent, 3 parts of curing agent, 10 parts of foaming microspheres, 3 parts of dispersing agent and 10 parts of heating monomer; the solvent is ethyl acetate, the curing agent is an isocyanate curing agent, the foaming microspheres are Ackso low-temperature foaming microspheres 031DU40, the dispersing agent is a condensation product of fatty alcohol and ethylene oxide, and the heating monomer is a microcapsule wrapped with a heating composition which reacts with oxygen to release heat; the heat-generating composition comprises the following components in percentage by weight: 50% of iron powder, 20% of activated carbon, 8% of sodium chloride, 8% of water-absorbent resin and 14% of water; the microcapsule has a shell which can be broken under the action of pressure, the shell is a spherical plastic film with a hollow interior, the inner diameter of the plastic film is 0.5mm, the film thickness is 10 mu m, and the spherical plastic film is filled with the heat-generating composition.

a. premixing acrylate, a solvent and a dispersant, and uniformly stirring;

b. premixing a curing agent, foaming microspheres and a heating monomer, and uniformly stirring, wherein the stirring speed is controlled at 100r/min;

c. adding the premix obtained in the step b into the premix obtained in the step a, stirring while adding, controlling the stirring speed at 100r/min, and stirring for 35min;

Example 3

The self-heating foam is prepared from the following raw materials in parts by weight: 40 parts of acrylic ester, 30 parts of solvent, 0.5 part of curing agent, 1 part of foaming microsphere, 0.1 part of dispersing agent and 1 part of heating monomer; the solvent is toluene, the curing agent is phenol-aldehyde amine epoxy curing agent, the foaming microspheres are American Pollacon low-temperature foaming microspheres Polychem 120DU15, the dispersing agent is PEO-PPO-PEO block copolymer, and the heating monomer is strip-shaped lambda-titanium pentoxide.

a. premixing acrylate, a solvent and a dispersant, and uniformly stirring;

b. premixing a curing agent, foaming microspheres and a heating monomer, and uniformly stirring, wherein the stirring speed is controlled at 20r/min;

c. adding the premix obtained in the step b into the premix obtained in the step a, stirring while adding, controlling the stirring speed at 20r/min, and stirring for 30min;

d. and c, coating the mixture obtained in the step c on release paper, and heating and foaming at 135 ℃ to obtain the heating foam.

Example 4

A self-heating foam, substantially as in example 1, except that: in this embodiment, the amount of the heating monomer is different, and specifically, the self-heating foam is prepared from the following raw materials in parts by weight: 45 parts of acrylic ester, 36 parts of solvent, 2 parts of curing agent, 5 parts of foaming microspheres, 2 parts of dispersing agent and 10 parts of heating monomer. The self-heating foam is prepared in the same manner as in example 1.

Example 5

A self-heating foam, substantially as in example 1, except that: in this embodiment, the amount of the heating monomer is different, and specifically, the self-heating foam is prepared from the following raw materials in parts by weight: 45 parts of acrylate, 45 parts of solvent, 2 parts of curing agent, 5 parts of foaming microsphere, 2 parts of dispersing agent and 1 part of heating monomer. The self-heating foam is prepared in the same way as in example 1.

Comparative example 1

A foam, substantially as in example 1, differing only in that: the comparative example is not added with a heating monomer, and specifically, the foam is prepared from the following raw materials in parts by weight: 45 parts of acrylic ester, 46 parts of solvent, 2 parts of curing agent, 5 parts of foaming microspheres and 2 parts of dispersing agent. Weighing the raw materials according to the formula, mixing, stirring uniformly, heating and foaming at 130 ℃ to obtain the foam.

Comparative example 2

A foam, substantially as in example 1, differing only in that: the heating monomer adding amount of the comparative example is less than 1%, and specifically, the foam is prepared from the following raw materials in parts by weight: 45 parts of acrylate, 45.5 parts of solvent, 2 parts of curing agent, 5 parts of foaming microspheres, 2 parts of dispersing agent and 0.5 part of heating monomer. The preparation method of the foam is the same as that of example 1.

Comparative example 3

A foam, substantially as in example 1, differing only in that: the heating monomer in the comparative example is added by more than 10 percent, and specifically, the foam is prepared from the following raw materials in parts by weight: 45 parts of acrylic ester, 31 parts of solvent, 2 parts of curing agent, 5 parts of foaming microspheres, 2 parts of dispersing agent and 15 parts of heating monomer. The preparation method of the foam is the same as that of example 1.

Comparative example 4

A foam, substantially as in example 1, differing only in that: this comparative example uses a conventional chemical blowing agent ADC instead of the foamed microspheres of example 1. The preparation method of the foam is basically the same as that of the embodiment 1, and the difference is that: the temperature for heating and foaming is 150 ℃.

The foam obtained in examples 1 to 5 and comparative examples 1 to 4 was used to prepare an adhesive tape having a structure shown in FIG. 1 by the following method: foam with the thickness of 1.2mm is used as a substrate layer 1, and each energy storage particle or microcapsule is used as a heating unit 11 in the substrate layer 1 to release heat; respectively arranging glue layers 2 with the thickness of 0.3mm on the upper surface and the lower surface of a substrate layer 1, wherein the glue layers 2 are made of acrylate pressure-sensitive glue, and then arranging an isolation layer 3 on the outer surface of one glue layer 2, wherein the isolation layer 3 is PE isolation paper; the glue layer 2 without the PE release paper is bent inwards and attached to the outer surface of the PE release paper to form the roll-shaped adhesive tape.

The prepared adhesive tape was subjected to adhesion test as follows: the pvc foam board and the steel section (5 x 5cm in size) were bonded at ambient temperatures of 25 c, 15 c, 5c, -5 c using the foam tapes prepared in examples 1-5 and comparative examples 1-4, respectively, the pressing force was removed after a pressing time of 10s at 150N, the whole was lightly shaken and bonded, whether the steel section was peeled off was observed, the test was repeated 20 times, and the peeling probability of the steel section bonded by different foams at different temperatures was calculated. The test results are shown in the following table 1, and it can be seen that the foam tapes of examples 1 to 5 can firmly adhere objects at various temperatures, the applicability in low-temperature environment is good, the heating monomer endows the foam tapes with good self-heating function, and the effect is remarkable; and the type of the foaming agent and the using amount of the heating monomer have great influence on the bonding effect of the foam tape.

TABLE 1 bonding test results of foam tapes at different ambient temperatures

This detailed description is to be construed as illustrative only and is not to be taken as limiting the invention, as any changes that may be made by a person skilled in the art after reading the present specification will be protected by the patent laws within the scope of the appended claims.

Claims

1. A self-heating foam is characterized in that: the material is prepared from the following raw materials in parts by weight: 40-50 parts of acrylic ester, 30-50 parts of solvent, 0.5-3 parts of curing agent, 1-10 parts of foaming microspheres, 0.1-3 parts of dispersing agent and 1-10 parts of heating substance; the heating substance is energy storage particles which generate heat through deformation under the action of pressing or microcapsules coated with a heating composition which reacts with oxygen to release heat, and the microcapsules are provided with shells which can be broken under the action of pressing;

the energy storage particles are strip-shaped lambda-titanium pentoxide;

the heat-generating composition at least comprises the following components in percentage by weight: 40-65% of iron powder, 2-25% of activated carbon, 0.5-10% of inorganic salt, 0.5-10% of water-absorbing resin and 5-20% of water.

2. The self-heating foam according to claim 1, wherein: the foaming microspheres are medium-low temperature foaming microspheres with the foaming temperature of less than or equal to 150 ℃.

3. The self-heating foam according to claim 1, wherein: the weight of the heat-generating substance accounts for 1-10% of the total weight of the raw materials.

4. The self-heating foam according to claim 1, wherein: the curing agent is one or more of isocyanate curing agent, epoxy curing agent and pyridine curing agent.

5. The self-heating foam according to claim 1, wherein: the dispersing agent is a condensation product of fatty alcohol and ethylene oxide and/or a nonionic high-molecular block copolymer.

6. The self-heating foam according to claim 1, wherein: the solvent is one or more of ethyl acetate, butyl acetate, dimethyl carbonate, toluene and isopropanol.

7. The self-heating foam according to claim 1, wherein: the shell is a spherical plastic film with a hollow interior, and the inner diameter of the plastic film is 0.3-0.8mm.

8. A process for preparing a self-heating foam as claimed in any one of claims 1 to 7, wherein: the method comprises the following steps:

a. premixing acrylate, a solvent and a dispersant, and uniformly stirring;

b. premixing the curing agent, the foaming microspheres and the heating substance, and uniformly stirring at a stirring speed of 20-100r/min;

c. c, adding the premix obtained in the step b into the premix obtained in the step a, stirring while adding, controlling the stirring speed at 20-100r/min, and stirring for at least 30min;

d. and c, coating the mixture obtained in the step c on release paper, and heating and foaming to obtain the heating foam.

9. The utility model provides an adhesive tape, includes substrate layer (1), sets up respectively glue film (2) and setting at least one of the surface about substrate layer (1) glue film (2) are kept away from substrate layer (1) one side surface's isolation layer (3), its characterized in that: the substrate layer (1) is the self-heating foam as defined in any one of claims 1 to 7.