阅读说明：本技术 一种低温汽车膨胀胶及其制备方法 (Low-temperature automobile expansion adhesive and preparation method thereof ) 是由 罗李华 于 2019-09-28 设计创作，主要内容包括：本发明公开了一种低温汽车膨胀胶,所述低温汽车膨胀胶由包含下述重量份的各原料制成：高分子聚合物100份、过氧化物硫化剂3～5份、硫化助剂0.5～3份、发泡剂5～15份、发泡活化剂0.5～8份、填料1～10份、增粘剂2～15份、润滑剂0.5～3份、抗氧剂0～2份、阻燃剂0～10份。本发明的低温汽车膨胀胶的,通过精选原料组成,优化各原料含量,制得的低温汽车膨胀胶,发泡倍率高,制品密度小,可填充大的空腔；膨胀胶与铝片和ABS骨架件的粘结强度高；高温烘烤稳定性好,发泡后的膨胀胶不易出现塌陷收缩问题；低温发泡性能与高温发泡倍率得到很好的平衡；存储稳定性好,产品品质稳定,存放周期较长。(The invention discloses a low-temperature automobile expansion adhesive which is prepared from the following raw materials in parts by weight: 100 parts of high molecular polymer, 3-5 parts of peroxide vulcanizing agent, 0.5-3 parts of vulcanizing assistant, 5-15 parts of foaming agent, 0.5-8 parts of foaming activator, 1-10 parts of filler, 2-15 parts of tackifier, 0.5-3 parts of lubricant, 0-2 parts of antioxidant and 0-10 parts of flame retardant. The low-temperature automobile expansion adhesive disclosed by the invention is prepared by selecting raw materials and optimizing the content of each raw material, and the prepared low-temperature automobile expansion adhesive is high in foaming multiplying power, small in product density and capable of being filled in a large cavity; the bonding strength of the expansion glue, the aluminum sheet and the ABS framework piece is high; the high-temperature baking stability is good, and the foamed expansion glue is not easy to collapse or shrink; the low-temperature foaming performance and the high-temperature foaming multiplying power are well balanced; the storage stability is good, the product quality is stable, and the storage period is long.)

1. The low-temperature automobile expansion glue is characterized by being prepared from the following raw materials in parts by weight:

100 parts of high molecular polymer, 3-5 parts of peroxide vulcanizing agent, 0.5-3 parts of vulcanizing assistant, 5-15 parts of foaming agent, 0.5-8 parts of foaming activator, 1-10 parts of filler, 2-15 parts of tackifier, 0.5-3 parts of lubricant, 0-2 parts of antioxidant and 0-10 parts of flame retardant.

The high polymer is any one or a mixture of more of ethylene-vinyl acetate copolymer with 26-28 VA content, ethylene-vinyl acetate copolymer with 40 VA content, low-density polyethylene, ethylene-methyl methacrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, butadiene rubber and ethylene propylene diene monomer rubber.

2. The low-temperature automobile expansion glue according to claim 1, wherein the high-molecular polymer is a composition of ethylene-vinyl acetate copolymer with VA content of 28, low-density polyethylene and ethylene-butyl acrylate copolymer, wherein the ethylene-vinyl acetate copolymer with VA content of 28 comprises 40-80 parts, LDPE resin comprises 10-30 parts, and EBA resin comprises 10-30 parts.

3. The low-temperature automobile expansion glue according to claim 1, wherein the peroxide vulcanizing agent is any one or a mixture of more of dicumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, 1-di-tert-butylperoxy-3, 3, 5-trimethylcyclohexane, 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane, 1, 3-bis (tert-butylperoxyisopropyl) benzene, 1-di-tert-butylperoxy-3, 3, 5-trimethylcyclohexane; preferably, the total usage amount of the peroxide vulcanizing agent is 3-4 parts.

4. The low-temperature automobile expansion glue of claim 1, wherein the vulcanization aid is any one or a mixture of trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, N, N' -p-phenylene bismaleimide, zinc diacrylate, zinc dimethacrylate, triallyl cyanurate, triallyl isocyanurate, 1, 2-polybutadiene and sulfur; the total amount of the vulcanization auxiliary agent is 0.5-3 parts.

5. The low-temperature automobile expansion glue of claim 1, wherein the foaming agent is one or more of azodicarbonamide, sodium bicarbonate, 4 'oxybisbenzenesulfonylhydrazide, p-toluenesulfonylaminourea, N' -dinitrosopentamethylenetetramine, urea and its derivatives, p-toluenesulfonylhydrazide, benzenesulfonylhydrazide, p-toluenesulfonylacetone hydrazone, diisopropyl azodicarboxylate, barium azodicarboxylate, biurea, biuret, nitrourea, carbohydrazide, nitroguanidine, ammonium bicarbonate, citric acid and its derivatives, sodium dihydrogen phosphate, and an expanded microsphere foaming agent; the total amount of the foaming agent is 7-9 parts; preferably, the foaming agent is a composition of azodicarbonamide, 4 'oxybis-benzenesulfonyl hydrazide, urea and derivatives thereof, and the mixture ratio of the azodicarbonamide is 5-7 parts, the 4, 4' oxybis-benzenesulfonyl hydrazide is 2-3 parts, and the urea and derivatives thereof are 0.5-2 parts.

6. The low temperature automobile expansion glue of claim 1, wherein the foaming activator is any one or a mixture of several of zinc oxide, zinc carbonate, basic zinc carbonate, zinc stearate, calcium stearate, zinc oleate, calcium oleate, zinc glycerolate, calcium glycerolate, zinc acetate, zinc citrate, citric acid, zinc benzene sulfinate, zinc p-toluene sulfinate, zinc formate, zinc isooctanoate, zinc diacrylate, zinc dimethacrylate, zinc diethyldithiocarbamate, zinc 2-mercaptobenzothiazole, zinc dimethyldithiocarbamate, zinc fluoride, urea and derivatives thereof; the total amount of the foaming activator is 1-3 parts.

7. The low-temperature automobile expansion glue according to claim 1, characterized in that the filler is one or a mixture of more of calcium carbonate, talcum powder, wollastonite, montmorillonite, bentonite, glass fiber, magnesium carbonate, kaolin and nano calcium carbonate; the total amount of the filler is 1-10 parts.

8. The low-temperature automobile expansion glue according to claim 1, wherein the tackifier is any one or a mixture of more of petroleum resin, EVA hot melt glue, amorphous alpha-olefin copolymer and zinc isooctanoate; preferably, the total using amount of the tackifier is 4-8 parts.

9. The low-temperature automobile expansion glue according to claim 1, wherein the lubricant is one or a mixture of stearic acid, zinc stearate, calcium stearate, epoxidized soybean oil, mineral oil, polyethylene glycol, amide wax, hydrocarbon wax, fatty alcohol and carboxylic ester; preferably, the total using amount of the lubricant is 0.8-1.5 parts; the antioxidant is any one or a mixture of several of antioxidant 1010, antioxidant 1076 and antioxidant BHT; preferably, the total dosage of the antioxidant is 0.1-0.5 part; the flame retardant is any one or a mixture of more of antimony trioxide, magnesium hydroxide, aluminum hydroxide, alkyl phosphate, aryl phosphate, octabromodiphenyl oxide, pentabromoethylbenzene, tetrabromobisphenol A, tris (dibromopropyl) phosphate, borate, triazine and derivatives thereof, melamine, tellurium compounds and hydroxyl aluminum; preferably, the total using amount of the flame retardant is 3-5 parts.

10. A method for preparing the low-temperature automobile expansion glue according to any one of claims 1 to 9, characterized by comprising the following steps:

(1) adding a high molecular polymer into an internal mixer for pre-mixing;

(2) sequentially adding a lubricant, a foaming agent, an antioxidant, a filler, a tackifier and a flame retardant into an internal mixer, and mixing the materials into blocks to enter the next step;

(3) adding a vulcanizing agent, a vulcanizing assistant and a foaming activator, and then continuously mixing; during the mixing period, the materials at the feeding port are turned over and cleaned for more than 3 times;

(4) after mixing uniformly, unloading under the condition that the temperature of the material is not more than 90 ℃, and feeding the material into an extruder for granulation;

(5) and packaging the granular expansion glue, namely the low-temperature automobile expansion glue.

Technical Field

The invention relates to the field of expansion glue, and particularly relates to low-temperature automobile expansion glue and a preparation method thereof.

Background

With the rapid development of national economy, the living standard of people is greatly improved, various high-grade passenger cars become necessities of families, and the autonomous brand and the foreign brand cars have a large gap in engine technology, so that the autonomous brand is successively frustrated in the middle-high-end market. The research and development investment is increased, the riding comfort of the automobile is improved, and the control of the production cost becomes urgent. Among many parameters of automobiles, NVH (Noise, Vibration, Harshness) is of great concern because the bypass cavity of the automobile body generates high velocity airflow when traveling at high speeds, resulting in strong Noise and Vibration.

The current industrial solution is to use expansion glue and sponge to obstruct the air flow in the inner and outer door panels of the automobile, but still has a plurality of problems:

(1) the traditional expansion glue has low foaming ratio and high product density, and cannot fill large cavities;

(2) the bonding strength of the expansion glue, the aluminum sheet and the ABS framework piece is too low, and the sagging and peeling problem is easy to occur under the process condition;

(3) the high-temperature baking stability is poor, and the foamed expansion glue is easy to collapse and contract;

(4) with the gradual reduction of the temperature and time of the baking process of the preheating furnace, higher requirements are put forward on the low-temperature foaming performance of the expansion glue.

(5) The coordination between the low-temperature foaming performance and the high-temperature foaming rate is a difficult problem in the industry, and enterprises are difficult to balance between the low-temperature foaming performance and the high-temperature foaming rate.

(6) The storage stability is poor, the product quality is unstable, the storage period is short, enterprises cannot set safe stocks with reasonable periods, and the productivity cannot complete orders in time.

Based on the situation, the invention provides a low-temperature automobile expansion adhesive and a preparation method thereof, which can effectively solve the problems.

Disclosure of Invention

The invention aims to provide a low-temperature automobile expansion adhesive and a preparation method thereof. The low-temperature automobile expansion adhesive is prepared by selecting raw materials, optimizing the content of each raw material, and selecting a high-molecular polymer, a peroxide vulcanizing agent, a vulcanizing aid (also called an auxiliary crosslinking agent), a foaming agent, a foaming activator, a filler, a tackifier, a lubricant and the like in a proper proportion, and has the advantages of high foaming ratio, low product density and capability of being filled in a large cavity; the bonding strength of the expansion glue, the aluminum sheet and the ABS framework piece is high; the high-temperature baking stability is good, and the foamed expansion glue is not easy to collapse or shrink; the low-temperature foaming performance and the high-temperature foaming multiplying power are well balanced; the storage stability is good, the product quality is stable, and the storage period is long.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the low-temperature automobile expansion glue is prepared from the following raw materials in parts by weight:

100 parts of high molecular polymer, 3-5 parts of peroxide vulcanizing agent, 0.5-3 parts of vulcanizing assistant (also called assistant crosslinking agent), 5-15 parts of foaming agent, 0.5-8 parts of foaming activator, 1-10 parts of filler, 2-15 parts of tackifier, 0.5-3 parts of lubricant, 0-2 parts of antioxidant and 0-10 parts of flame retardant.

The high polymer is any one or a mixture of more of ethylene-vinyl acetate copolymer (EVA resin) with 26-28 VA content, ethylene-vinyl acetate copolymer (EVA resin) with 40 VA content, low-density polyethylene (LDPE), ethylene-methyl methacrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-butyl acrylate copolymer (EBA), Butadiene Rubber (BR) and Ethylene Propylene Diene Monomer (EPDM).

When the antioxidant and the flame retardant are added in 0 part, the antioxidant and the flame retardant are not added.

The low-temperature automobile expansion adhesive is prepared by selecting raw materials, optimizing the content of each raw material, and selecting a high-molecular polymer, a peroxide vulcanizing agent, a vulcanizing aid (also called an auxiliary crosslinking agent), a foaming agent, a foaming activator, a filler, a tackifier, a lubricant and the like in a proper proportion, and has the advantages of high foaming ratio, low product density and capability of being filled in a large cavity; the bonding strength of the expansion glue, the aluminum sheet and the ABS framework piece is high; the high-temperature baking stability is good, and the foamed expansion glue is not easy to collapse or shrink; the low-temperature foaming performance and the high-temperature foaming multiplying power are well balanced; the storage stability is good, the product quality is stable, and the storage period is long.

The inventor finds out through a large number of experiments that: different kinds of polymers are selected to be compounded with EVA, so that the defects of insufficient single EVA fluidity and insufficient melt strength can be overcome, the polymer also has better fluidity in a low-temperature paint baking section, and simultaneously, the high-temperature paint baking section can have higher melt strength. Preferably, the high molecular polymer is a composition of ethylene-vinyl acetate copolymer (EVA resin) with VA content of 28, low-density polyethylene (LDPE) and ethylene-butyl acrylate copolymer (EBA), wherein the ethylene-vinyl acetate copolymer with VA content of 28 is 40-80 parts, the LDPE resin is 10-30 parts, and the EBA resin is 10-30 parts.

The mixed polymer (high molecular polymer) can be prepared by firstly mixing the mixed polymer with an internal mixer to form mixed rubber and then granulating the mixed rubber by a granulator for standby, or can be prepared by directly adding each polymer particle and other materials into the internal mixer to mix and then granulating.

Preferably, the peroxide vulcanizing agent is any one or a mixture of more of dicumyl peroxide (DCP), di-tert-butyl peroxide (DTBP), Benzoyl Peroxide (BPO), 1-di-tert-butylperoxy-3, 3, 5-trimethylcyclohexane (BPMC), 2, 5-dimethyl-2, 5-bis (tert-butylperoxy) hexane (DBPMH), 1, 3-bis (tert-butylperoxyisopropyl) benzene (BIPB), 1-di-tert-butylperoxy-3, 3, 5-trimethylcyclohexane (3M);

more preferably, the total amount of the peroxide vulcanizing agent is 3-4 parts.

In order to meet the requirements of crosslinking degree in low-temperature foaming and high-temperature foaming stages, the vulcanizing agent is used according to the principle that a high-temperature vulcanizing agent and a low-temperature vulcanizing agent are matched, such as high-temperature vulcanizing agent DCP, BIPB, low-temperature vulcanizing agent BPO and low-temperature vulcanizing agent 3M are used together, formula adjustment is carried out according to actual requirements and cost budget, and DCP and BPO or 3M are selected and used together according to low cost and general environmental protection requirements, such as 2 parts of DCP and 1 part of BPO or 3M; BIPB and 3M can be selected and used together, for example, 1.5 parts of BIPB and 1 part of 3M are used together, which has no higher requirement on cost but has higher requirement on environmental protection; the specific scheme can be flexibly changed according to actual requirements so as to meet the requirements of cost and environmental protection at the same time.

Preferably, the vulcanization aid (also called as an auxiliary crosslinking agent) is any one or a mixture of more of trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTAMA), Ethylene Glycol Diacrylate (EGDA), Ethylene Glycol Dimethacrylate (EGDMA), N' -p-phenylene bismaleimide (PDM or HVA-2), Zinc Diacrylate (ZDA), Zinc Dimethacrylate (ZDMA), triallyl cyanurate (TAC), triallyl isocyanurate (TAIC), 1, 2-polybutadiene (1,2-PBR) and sulfur;

more preferably, the total amount of the vulcanization aid is 0.5-1 part.

The vulcanizing assistant is an activator of a peroxide crosslinking agent, can improve the decomposition rate and the crosslinking degree of peroxide, and can obviously reduce the consumption of the peroxide and improve the comprehensive mechanical property of the foamed polymer by adding a small amount of the assistant. The vulcanization aid is selected in consideration of the coordination between crosslinking and foaming, since different vulcanization aids have different activating effects on peroxides and foaming agents. The invention preferably selects trimethylolpropane trimethacrylate (TMPTAMA) or triallyl isocyanurate (TAIC) which is easily obtained and has low price, and a small amount of Zinc Diacrylate (ZDA) or Zinc Dimethacrylate (ZDMA) can be selected and used together with the TMPTAMA or the TAIC for readers who need to inhibit excessive crosslinking under high temperature. The feasible scheme of the invention is not limited to the examples in the claims, and the formula combination has larger elastic space, thereby meeting the implementation of various cost performance expansion glue cases.

Preferably, the foaming agent is one or a mixture of more of azodicarbonamide (foaming agent ADC), sodium bicarbonate, 4 'oxybis-benzenesulfonylhydrazide (foaming agent OBSH/OT), p-toluenesulfonyl urea (foaming agent RA), N' -dinitrosopentamethylenetetramine (foaming agent DPT and foaming agent H), urea and its derivatives (foaming agent BK), p-toluenesulfonyl hydrazine (foaming agent TSH), benzenesulfonyl hydrazide (foaming agent BSH), p-toluenesulfonyl acetone hydrazone, diisopropyl azodicarboxylate, barium azodicarboxylate, biuret, nitrourea, carbohydrazide, nitroguanidine, ammonium bicarbonate, citric acid and its derivatives, sodium dihydrogen phosphate and an expanded microsphere foaming agent;

more preferably, the total amount of the foaming agent is 7-9 parts;

more preferably, the foaming agent is a composition of azodicarbonamide (foaming agent ADC), 4 'oxybis-benzenesulfonyl hydrazide (foaming agent OBSH/OT), and urea and its derivatives (foaming agent BK), and the mixture ratio is 5-7 parts of azodicarbonamide (foaming agent ADC), 2-3 parts of 4, 4' oxybis-benzenesulfonyl hydrazide (foaming agent OBSH/OT), and 0.5-2 parts of urea and its derivatives (foaming agent BK).

The invention is not limited to the examples, and the specific embodiment is a combination system of a high-temperature foaming agent (rapid decomposition temperature is higher than 180 ℃) and a medium-temperature foaming agent (decomposition temperature is 150-180 ℃) and a low-temperature foaming agent (decomposition temperature is lower than 150 ℃), such as foaming agent ADC + foaming agent OBSH + foaming agent BK, foaming agent DPT + foaming agent OBSH + foaming agent BK, ADC + foaming agent H + foaming agent OBSH + foaming agent BK, ADC + foaming agent RA + foaming agent OBSH + foaming agent BK. The combination of various proportions can cause the high-temperature foaming agent to be changed into a medium-temperature foaming agent or even a low-temperature foaming agent, such as a foaming agent ADC: when the foaming agent OBSH is 1:1 (mass ratio), the decomposition temperature of the mixed foaming agent is reduced to 160-180 ℃; foaming agent DPT: when the blowing agent BK is 1:1 (mass ratio), the decomposition temperature of the mixed blowing agent is reduced to 120 ℃; thus, formulation design is by no means simple to sum and should be adjusted to the practical dilemma faced, for example, reducing the amount of blowing agent OBSH to less than 15% of blowing agent ADC would produce a better additive effect rather than an activating effect.

Preferably, the foaming activator is any one or a mixture of several of zinc oxide, zinc carbonate, basic zinc carbonate, zinc stearate, calcium stearate, zinc oleate, calcium oleate, zinc glycerolate, calcium glycerolate, zinc acetate (zinc acetate), zinc citrate, citric acid, zinc benzene sulfinate (activator ZBS/BM), zinc p-toluene sulfinate (activator ZTS/TM), zinc formate (foaming activator ZF), zinc isooctanoate, Zinc Diacrylate (ZDA), Zinc Dimethacrylate (ZDMA), zinc diethyldithiocarbamate (accelerator ZDEC), zinc 2-mercaptobenzothiazole (accelerator ZMBT), zinc dimethyldithiocarbamate (accelerator ZDMC), zinc fluoride, urea and derivatives (BK) thereof;

more preferably, the total amount of the foaming activator is 1 to 3 parts.

The selection of the activator is matched with the crosslinking, and the activation capability of the activator on the foaming agent and the peroxide crosslinking agent and the influence on the mechanical property of the material need to be examined. For example, zinc carbonate is more active than zinc oxide, but zinc carbonate can reduce the compression set property of the foamed polymer, which results in poor dimensional stability of the material, and zinc carbonate can greatly activate a peroxide crosslinking agent, which results in excessive crosslinking and embrittlement and even surface collapse of the material in a high-temperature vulcanization stage. Therefore, the dosage of the activating agent needs to be strictly screened and controlled, and the reasonable proportion not only can greatly reduce the production cost, but also greatly contributes to the improvement of the performance of the expansion glue. Preferred activators are zinc oxide, zinc benzenesulfinate, urea and derivatives thereof, and the like, although other combinations are possible, the combination principle is that the decomposition temperature of the high-temperature foaming agent is slightly reduced, and the temperatures of the medium-temperature foaming agent and the low-temperature foaming agent are greatly reduced, different activators can be selected for different foaming agents, and the foaming agent is specifically selected by considering the action of the activator. The invention focuses on low-temperature foaming performance, so that the dosage of the low-temperature foaming agent and the low-temperature foaming auxiliary agent can be properly increased (of course, the microsphere foaming agent with lower expansion temperature is also a good choice); and considering the decomposition temperature of the high-temperature foaming agent, a small amount of a conventional activator such as zinc oxide is added. The foaming process is subject to special requirements and can be suitably modified by the person skilled in the art.

Preferably, the filler is one or a mixture of more of calcium carbonate, talcum powder, wollastonite, montmorillonite, bentonite, glass fiber, magnesium carbonate, kaolin and nano calcium carbonate;

more preferably, the total amount of the filler is 1 to 3 parts.

The above-mentioned fillers act as nucleating agents and reduce costs.

Preferably, the tackifier is any one or a mixture of more of petroleum resin (rosin and derivatives thereof, terpene resin, polymeric resin and condensation resin), EVA hot melt adhesive, amorphous alpha-olefin copolymer (APAO) and zinc isooctanoate;

more preferably, the total amount of the tackifier is 4-8 parts.

The adhesion between the metal aluminum sheet and the metal aluminum sheet is preferably petroleum resin, and other adhesion promoters are required for the adhesion between the metal aluminum sheet and the resin framework.

Preferably, the lubricant is any one or a mixture of more of stearic acid, zinc stearate, calcium stearate, epoxidized soybean oil, mineral oil, polyethylene glycol, amide wax, hydrocarbon wax, fatty alcohol and carboxylic ester;

more preferably, the total using amount of the lubricant is 0.8-1.5 parts;

preferably, the antioxidant is one or a mixture of several of antioxidant 1010, antioxidant 1076 and antioxidant BHT;

more preferably, the total amount of the antioxidant is 0.1-0.5 part;

preferably, the flame retardant is any one or a mixture of more of antimony trioxide, magnesium hydroxide, aluminum hydroxide, alkyl phosphate, aryl phosphate, octabromodiphenyl oxide, pentabromoethyl benzene, tetrabromobisphenol A, tris (dibromopropyl) phosphate, borate, triazine and derivatives thereof, melamine, tellurium compounds and aluminum hydroxide;

more preferably, the total amount of the flame retardant is 3-5 parts.

The invention also provides a preparation method of the low-temperature automobile expansion glue, which comprises the following steps:

(1) adding a high molecular polymer into an internal mixer for pre-mixing;

(2) sequentially adding a lubricant, a foaming agent, an antioxidant, a filler, a tackifier and a flame retardant into an internal mixer, and mixing the materials into blocks to enter the next step;

(3) adding a vulcanizing agent, a vulcanizing assistant and a foaming activator, and then continuously mixing; during the mixing period, the materials at the feeding port are turned over and cleaned for more than 3 times;

(4) after mixing uniformly, unloading under the condition that the temperature of the material is not more than 90 ℃, and feeding the material into an extruder for granulation;

(5) and packaging the granular expansion glue, namely the low-temperature automobile expansion glue.

The low-temperature automobile expansion glue is mainly used for sound insulation and noise reduction of passenger automobiles.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the invention uses the high-temperature foaming agent, the medium-temperature foaming agent and the low-temperature foaming agent together, and solves the foaming problem of the expansion glue at different baking varnish temperatures.

(2) The invention selects different activators respectively for the high-temperature foaming agent, the medium-temperature foaming agent and the low-temperature foaming agent, ensures that various foaming agents can be completely decomposed at corresponding working section temperatures, and achieves the foaming ratio required by the process.

(3) The invention increases the consumption of the foaming agent, simultaneously combines the high-temperature vulcanizing agent and the low-temperature vulcanizing agent, ensures the crosslinking problem at different baking finish temperatures, and ensures that the expansion glue can be properly vulcanized in both low-temperature and high-temperature working sections.

(4) The invention introduces the vulcanizing assistant to make up the defects of the decomposition rate and the crosslinking degree of the low-temperature vulcanizing agent in the low-temperature working section, so that the low-temperature vulcanizing agent has excellent performance in the low-temperature paint baking working section.

(5) The invention selects different polymers to be compounded with EVA, overcomes the defects of insufficient fluidity and melt strength of single EVA, ensures that the polymer has better fluidity in a low-temperature paint baking section, and simultaneously has higher melt strength in a high-temperature paint baking section. Meanwhile, the bonding strength of the expansion glue to the framework and the metal member is greatly improved by compounding different polymers, so that the NVH effect of the passenger vehicle in a high-speed driving state is still excellent.

(6) The invention adds proper amount of lubricant to improve the processing performance of the materials in the procedures of mixing, granulating and injection molding; in addition, the lubricant plays the role of a separant at the same time, so that the reaction among various additives can be effectively blocked, the product storage time and the product quality are more stable, and the product quality guarantee period is longer.

(7) The invention adds proper amount of fire retardant to improve the fire-retardant grade of the expansion glue, so that the expansion glue meets the industrial requirements of passenger vehicles.

(8) The compounded expansion glue has lower processing temperature, and the problem of unstable quality caused by overhigh banburying and granulating temperature is solved.

(9) The low-temperature automobile expansion adhesive is prepared by selecting raw materials, optimizing the content of each raw material, and selecting a high-molecular polymer, a peroxide vulcanizing agent, a vulcanizing aid (also called an auxiliary crosslinking agent), a foaming agent, a foaming activator, a filler, a tackifier, a lubricant and the like in a proper proportion, and has the advantages of high foaming ratio, low product density and capability of being filled in a large cavity; the bonding strength of the expansion glue, the aluminum sheet and the ABS framework piece is high; the high-temperature baking stability is good, and the foamed expansion glue is not easy to collapse or shrink; the low-temperature foaming performance and the high-temperature foaming multiplying power are well balanced; the storage stability is good, the product quality is stable, and the storage period is long.

Detailed Description

In order that those skilled in the art will better understand the technical solutions of the present invention, the following description of the preferred embodiments of the present invention is provided in connection with specific examples, which should not be construed as limiting the present patent.

The test methods or test methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials, unless otherwise indicated, are conventionally obtained commercially or prepared by conventional methods.