JPS6345713B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to an aerosol adhesive composition,
In particular, it relates to products with improved storage stability, anti-occlusion properties, adhesive properties, and other properties. There are various methods for applying adhesive to an adherend, such as brush application, spray application, and roll application. ) etc., it is widely used in construction-related and other fields because it can perform the desired coating operation relatively easily and efficiently and does not require special coating equipment. By the way, when applying an adhesive by such spray coating, the adhesive sprayed onto the surface of the adherend is required to stay on the surface of the adherend without penetrating into the inside of the adherend. However, if the adhesive penetrates into the adherend, a good adhesive film will not be formed on the surface of the adherend, and "leakage" at the adhesive interface will not only deteriorate, but also reduce the adhesive strength. This is because, in some cases, the physical properties of the adherend may change (for example, become hard). In addition, spray adhesives, that is, aerosol adhesives, can be freely formed into various patterns depending on the purpose of adhesion, such as round patterns, oval patterns, spider web patterns, etc. There are demands to be met, and for this purpose it is necessary that the adhesive liquid be well atomized in the desired width during spraying. Due to these circumstances and various requests depending on the purpose of adhesion, aerosol adhesives use partial gel type elastomers with predetermined properties as a base material in a predetermined ratio, or tackifiers, isoform fillers, and other adhesives. However, in these compositions, the increase in viscosity or the addition of similar substances can cause the components to aggregate, solidify and precipitate, and cause phase separation. This may cause problems with stability during storage, and may also clog the nozzle of the spray equipment, causing dust to become clogged, and in some cases causing problems such as making spraying operations extremely difficult. It is. Moreover, depending on the properties and amount of the additives added, the spray pattern may become narrow or no longer patterned, making it difficult and flexible in designing the composition of each component in such aerosol adhesives. They had various problems, such as being small in size and requiring strict control over their addition ratio and storage conditions. The present invention was made for the purpose of providing an adhesive composition that corrects the various drawbacks mentioned above in aerosol type adhesives, and its gist is that SBR is used as a main ingredient to improve the adhesive function. The aerosol type adhesive composition contains a tackifying agent for retaining the tackifier and a volatile organic solvent for dissolving them to form a solution. ~350
An adhesive composition containing 0.1 to 1.8% by weight of ultrafine anhydrous silica of m ² /g, with a viscosity of 100 to 10,000 centipoise, and a structural viscosity coefficient of 0.1 to 0.8. That is, the adhesive composition according to the present invention adds a predetermined amount of ultrafine anhydrous silica having predetermined properties and a particle size range to an SBR adhesive composition conventionally suitably used for aerosols, and also improves its viscosity and structural viscosity. The coefficient has been adjusted to a predetermined value, so it not only has excellent storage stability and anti-occlusion properties, but also can be atomized to a desired width and form a wide variety of spray patterns when spraying. In addition, an aerosol adhesive composition has been provided which forms an appropriate and uniform film on the surface of the adherend without penetrating into the adherend after being applied, thereby providing good adhesive strength. It is. The various conditions mentioned above for the present invention were not determined theoretically, but were obtained as a result of trials based on numerous experiments, and therefore, at present, the causal relationship with the above effects is not necessarily clear. Although this is not the case, it is presumed to be something like the following. That is, the anhydrous silica used in the present invention is
Anhydrous and
SiO ₂ of high purity (99.8% or more), highly finely granulated [specifically, commercially available as Aerosil from Nippon Aerosil Co., Ltd.], and the addition of such anhydrous silica. This action suppresses agglomeration of adhesive component particles and maintains a uniform dispersion state. As a result, the storage stability is improved without precipitation or phase separation, and the adhesive can be easily sprayed. When the composition is ejected from the nozzle, the slipperiness of the composition is improved and the composition flows smoothly through the nozzle.
It is understood that along with atomization, there is no caking in the nozzle, and the clogging phenomenon is effectively avoided even in a nozzle with a relatively large diameter. Furthermore, based on the thickening effect of ultrafine anhydrous silica and its surface activity, the composition applied to the adherend maintains an appropriate viscosity and does not penetrate into the adherend. It stays on the surface and forms a film with a predetermined thickness and excellent adhesiveness, thereby increasing the adhesive strength, while its thixotropic property gives the adhesive composition a large structural viscosity coefficient (structural viscosity coefficient). (The significance of which will be explained in detail later) allows for maintaining a suitable viscosity with excellent atomization properties during spraying operations, allowing for an appropriate spray pattern according to the purpose without sacrificing good workability. It is inferred that this can be formed. However, these effects based on the addition of anhydrous silica only depend on the viscosity, properties, and other properties of the adhesive composition as a whole, as well as the types of solvents and other various additives.
This is realized by the correlation with conditions such as properties, that is, by promoting, reducing, or cooperating with the effects of each component, and in the present invention, these conditions are as follows. It is necessary to be selected. First, the adhesive composition applicable in the present invention is an SBR adhesive composition conventionally suitable for aerosol use, and is a partially crosslinked (gelled) SBR (styrene-butadiene rubber) that has a predetermined property. , pulverized to a predetermined particle size and used as a base material, or partially crosslinked or non-crosslinked CR (chloroprene rubber), NR (natural rubber),
The base material is SBR (non-crosslinked type), etc., and a suitable adhesion agent, filler, etc.
It is composed by adding a viscosity stabilizer, an anti-aging agent, a vulcanizing agent, a specified solvent, etc. in appropriate proportions depending on the purpose of use. Any of the adhesion agents, other additives, solvents, etc. used in conventional SBR adhesive compositions can be used.More specifically, as the adhesion agent, petroleum resin, Rosin and rosin esters, rosin derivatives such as hydrogenated rosin esters, rosin-modified phenolic resins, phenolic resins, terpene-phenolic resins, and others can be used. Organic solvents include toluene, hexane, benzene, MEK (methyl ethyl ketone), and MIBK. (methyl isobutyl ketone), alcohol, acetone, etc. In addition, morpholin is used as a viscosity stabilizer, and BHT (butylated) is used as an anti-aging agent.
Examples include magnesia (MgO) and zinc white (ZnO) as vulcanizing agents, but of course the types of these components,
The ratio is appropriately selected in relation to the type, ratio, compatibility, and other properties of the base material and other components. For example, MgO as a vulcanizing agent,
ZnO is necessary when CR is used as a base material. Next, as mentioned above, ultrafine anhydrous silica is commercially available with various particle sizes, surface areas, and properties, but the anhydrous silica used in the present invention has a particle size of 15 mμ or less and a surface area ( (as measured by the BET method) must be selected within the range of 150 m ² /g to 350 m ² /g. If particles with a particle size exceeding 15 mμ and/or a surface area of less than 150 m ² /g are used, the stability during storage may be impaired, such as the adhesive composition being susceptible to phase separation during storage. 350
If a material exceeding m ² /g is used, the pattern area becomes narrow during spraying, making it difficult to freely form a pattern in a desired shape. Among the above ranges of surface area conditions, a desirable range for maximizing the effects of the present invention is 170 to 300 m ² /g. The amount of anhydrous silica to be added must be adjusted within the range of 0.1 to 1.8% by weight (hereinafter referred to as % by weight) based on the entire composition containing the silica. If it is less than 0.1%, hardly any effect can be expected from the addition of anhydrous silica, and if it exceeds 1.8%, the adhesive strength will drop sharply, and good results cannot be obtained in either case. Within this range, a more desirable range is 0.4% to 1.2%. Furthermore, the adhesive solution composed of such ultrafine anhydrous silica needs to have an overall viscosity adjusted to a predetermined value, which ranges from 100 to 10,000 centipoise (cps). .
If the viscosity is lower than 100 cps, the adhesive sprayed on the surface of the adherend will penetrate into the inside of the adherend, causing changes in its physical properties or a decrease in adhesiveness, causing the various problems mentioned above. . Moreover, when it exceeds 10,000 cps, spray workability becomes significantly worse. Among these, the range that yields the best results,
That is, a more desirable range is 1200 to 5000 cps.
Note that these viscosities are all measured using a B-type rotational viscometer based on JIS-K-6838. Next, it is an essential condition for the adhesive composition according to the present invention that its overall structural viscosity coefficient be adjusted to a range of 0.1 to 0.8. Here, the structural viscosity coefficient refers to the viscosity measured using a B-type viscometer at a temperature of 25°C and a rotor rotation speed of 2 rpm and 20 rpm (η ₁ and η ₂
The absolute value of the slope of the straight line when connecting both measuring points with a straight line, with the logarithm of the rotation speed on the vertical axis and the logarithm of the rotation speed on the horizontal axis, that is, |(logη ₁ −logη ₂ )/(logr ₁ −
logr ₂ ) | (r is the number of rotations, r ₁ =2 and r2 = 20, respectively). This structural viscosity coefficient indicates the degree of so-called thixotropic property or thixotropy, and is imparted exclusively by the effect based on the addition of anhydrous silica. In other words, it maintains a high viscosity in a static state, but the viscosity decreases in a dynamic state, for example when a spray can is shaken, and this allows for good workability. In the present invention, this structural viscosity coefficient is suppressed within the range of 0.1 to 0.8, which imparts good adhesive film-forming ability. That is, if the coefficient is smaller than 0.1, the above effects of the present invention will not be achieved, and if it exceeds 0.8, it will be difficult to appropriately set good workability, storage stability, and other properties in a well-balanced manner. be. In particular, within the above range, 0.2
~0.6 is a more desirable range, and when the adhesive composition is adjusted within this range, it satisfies various required properties as an adhesive and brings about good results. All of the conditions detailed above are essential for the present invention, and a composition that satisfies them will exhibit the excellent effects described above, but in order to further improve the properties of the composition, It is desirable to select the rubber content and nonvolatile content to be included as follows. First of all, as for the rubber content, if the amount (content) is lower than 8%, the adhesive strength will decrease, so it is desirable to contain it at the same value or more, and attention should be paid to ensuring an optimal spray pattern. More preferably, the content is in the range of 9 to 12%. Next, regarding non-volatile content, an amount of 25% to 38% is good for normal adherends, but if the adherend is a highly water-absorbing material,
A range of 29 to 35% is more desirable. This range is a range in which the adhesive applied to the adherend does not penetrate into the interior of the adherend even if the material is highly water-absorbing, and the best spray pattern is also ensured. When filling a spray can with adhesive, a propellant such as LPG or dimethyl ether is also filled at the same time, but the pressure of these propellants must be adjusted to an appropriate value depending on the type of spray can, adhesive viscosity, etc. is set. By the way, with conventional aerosol adhesives, the pattern adjustment is greatly affected by the viscosity of the adhesive, and when the viscosity increases, it becomes difficult to form an appropriate spray pattern. It has been experimentally confirmed that even when the viscosity of the above adhesive increases to a certain extent, the spray pattern can be appropriately adjusted by adjusting the gas pressure and gas ratio of the propellant. It also exhibits the advantage that quality control is easier than with conventional adhesive compositions. As described above, the aerosol adhesive composition according to the present invention has excellent storage stability and anti-occlusion properties by controlling its viscosity, structural viscosity coefficient, properties of the anhydrous silica added, and other conditions within predetermined ranges. The present invention has various effects as described above, such as improved properties, workability, adhesion, etc., and excellent pattern shape performance. This will be explained by giving examples. In addition, all parts and percentages in the examples are based on weight unless otherwise specified. Example 1

【table】

[Table] Partially crosslinked emulsion polymerized solid SBR [Hot
SBR#1009: manufactured by Nippon Zeon Co., Ltd.] was dissolved in hexane and toluene as a solvent, and then rosin ester [Ester Gum 105: manufactured by Arakawa Chemical Industries, Ltd.] was dissolved in hexane and toluene as a solvent.
Furthermore, ultrafine anhydrous silica with an average particle diameter of 12 mμ and a surface area of 200±25 m ² /g [Aerosil #200: manufactured by Nippon Aerosil Co., Ltd.] was dispersed in hexane as a dispersion medium. Then, after adding morpholine as a viscosity stabilizer, further solvent was added to obtain an adhesive composition with a viscosity of 300 cps, a structural viscosity coefficient of 0.2, and a final composition as shown in Table 1 above. I prepared something. Next, add this to LPG (7.0Kg/cm ² ) as a propellant.
JIS-
When the adhesive peel strength in the 90 degree direction was measured according to the test method specified in K-6854, it was 2.0Kg/in.
I got a result of (width). Example 2

[Table] Following the same procedure as in the previous example, the viscosity was
An adhesive composition of 4000 cps, a structural viscosity coefficient of 0.6, and a final composition as shown in Table 2 above was prepared. In Table 2, Ester Gum A and HP are rosin ester and hydrogenated rosin ester, respectively, and both are commercially available from Arakawa Chemical Industry Co., Ltd. The adhesive obtained in this way is used as a jetting agent.
A sample similar to the above was prepared by filling a spray can with LPG (7.0Kg/cm ² ) and then spraying, and the adhesive peeling strength was measured. ) results were obtained. Example 3

[Table] Viscosity was determined by the same procedure as in the above example.
900cps, structural viscosity coefficient 0.35, final composition is the third above.
Adhesive compositions as shown in the table were prepared. still,
In this example, a partial gel type was used as the base material.
SBR (hot SBR#1009), NR, non-gel type
SBR [Hot SBR #1013: manufactured by Nippon Zeon Co., Ltd.] was used, and hydrogenated rosin ester (Ester Gum 105) and rosin ester [Super Ester S-115: manufactured by Arakawa Chemical Industry Co., Ltd.] were used as adhesion agents. ] was used. A sample similar to the above was prepared using such an adhesive, and its adhesive peel strength was measured, and it was found to be 3.0.
The result was obtained in Kg/in (width). Example 4

【table】

[Table] Partial gel type SBR (hot
SBR#1009), partial gel type CR [Skyplane Y-
20E: manufactured by Toyo Soda Kogyo Co., Ltd.], non-gel type CR [Skyprene G-40T: manufactured by Toyo Soda Kogyo Co., Ltd.], phenolic resin as an adhesion agent (Tamanol 515: manufactured by Arakawa Chemical Industry Co., Ltd.) , terpene-phenol resin (Tamanol 803: manufactured by Arakawa Chemical Industry Co., Ltd.) was used, and MgO and ZnO were used as CR vulcanizing agents, and BHT was used as anti-aging agent.
An adhesive composition having a viscosity of 500 cps, a structural viscosity coefficient of 0.15, and a final composition as shown in Table 4 above was prepared using the same procedure as in the above example. Next, this was sprayed onto the same material as above using a jetting agent LPG (7.0Kg/cm ² ) to prepare a sample, and then the adhesive peeling strength was measured.
A result of 4.0Kg/in (width) was obtained. It was confirmed that the adhesives prepared in these Examples had no problems with storage stability or anti-occlusion properties, and were able to form a good spray pattern. As shown in these results, the present invention is applicable to adhesives containing various SBR base materials, tackifiers, etc., and adhesives composed according to the present invention are It is understood that it has various excellent properties.

Claims (1)

[Claims] 1. An aerosol adhesive composition containing SBR as the main ingredient and a tackifying agent to maintain the adhesive function and a volatile organic solvent to form a solution.
Furthermore, the average particle size is 15 mμ or less and the surface area is
Contains 0.1 to 1.8% by weight of ultrafine anhydrous silica of 150 to 350 m ² /g, and increases the viscosity to 100 to 1.8% by weight.
10,000 centipoise and structural viscosity coefficient of 0.1~
Aerosol type adhesive composition adjusted to 0.8.