JPS6111966B2 - - Google Patents

Description

[Detailed description of the invention]

TECHNICAL FIELD The present invention relates to adhesive materials, particularly crosslinkable adhesive materials and methods for their production. In recent years, with advances in synthetic polymer production chemistry, synthetic resins have been used for a variety of purposes, including adhesives, putties, sealants, caulking materials, safety tire sealants, etc. Further, chemical processing, such as cross-linking, is being applied to the material. There are various methods for making this type of sticky substance, but acrylic monomers or vinyl monomers are selected and subjected to solution polymerization or emulsion polymerization, and the resulting polymer is directly used as is.
Alternatively, there is a method of partially crosslinking to obtain a polymer. However, in this method, after carrying out the above polymerization,
the need to recover the solvent, the associated loss of solvent, and during solvent recovery;
There are problems such as the fact that they tend to cause pollution problems.
Furthermore, when water is used, in addition to the pollution problem of how to treat wastewater, water has an adverse effect on the physical properties of the obtained polymer. Furthermore, when making a polymer obtained from the above acrylic monomer into an adhesive substance,
There is a limit to the range in which the physical properties can be changed.
It is not possible to meet the demand for adhesive substances with physical properties that meet the diversification of uses in recent years. Therefore, the present inventors conducted intensive studies on the acquisition of adhesive substances that could overcome the above problems, assuming the use of acrylic monomers, and as a result, they arrived at the present invention. can be polymerized without using water or solvents,
That is, the objective is to obtain an adhesive substance using an acrylic polymer that has physical properties that can be applied in a wide range of applications, using a method that does not require water or solvent recovery and does not affect the physical properties of the polymer. In order to achieve this object, the present invention consists of a liquid polymer (A) and a copolymer (B) as main components, and the copolymer (B) contains one or more acrylic monomers. 2 to 5 of the acrylic monomer (b) having an epoxy group and/or the vinyl monomer (c) having an epoxy group per 100 parts by weight of (a)
The gist is an adhesive substance characterized in that it is obtained by copolymerizing parts by weight. Furthermore, the present invention provides an acrylic monomer (b) having an epoxy group and an acrylic monomer (b) having an epoxy group per 100 parts by weight of one or more acrylic monomers (a) in the presence of a liquid polymer (A) without using a solvent. The gist of the present invention is a method for producing an adhesive substance, characterized by copolymerizing 2 to 5 parts by weight of a vinyl monomer (c) having/or an epoxy group. The present invention will be specifically described in detail below. First, the method for producing the adhesive substance according to the present invention will be described, and then the composition, physical properties, effects, etc. of the adhesive substance according to the present invention obtained by that method will be described. state First, prepare a liquid polymer (A). Liquid polymers with a viscosity range of 10 ² to 10 ⁷ cps are used for controlling the viscosity of the acrylic monomer copolymerization system, stability in the polymerization system, processability of the obtained polymer mixture, workability, etc. described below. are selected taking into consideration. Such liquid polymers include saturated polymers such as polybutene, polyisobutylene, polyether polyol, polyester polyol, polyurethane, polysulfide, silicone, epichlorohydrin rubber, as well as chloroprene, polybutadiene, polyisoprene, SBR, IIR,
It is possible to use unsaturated liquid polymers such as NBR. Moreover, these are not only used singly, but also in various combinations depending on the purpose. In other words, it is possible to use it in such a way that one part takes advantage of its high tackiness and the other part takes advantage of its function as a surfactant to improve dispersion. Furthermore, mixed liquid polymers in which various rubbers are dissolved in these liquid polymers can also be used. The most preferred polymers for the liquid polymer (A) include polybutene, liquid butyl rubber, and a mixture of polybutene and liquid butyl rubber. Next, the acrylic monomer (a) used in the present invention includes 2-ethylhexyl acrylate, ethyl acrylate, n-butyl acrylate, N-n-butoxymethyl acrylamide, methyl acrylate, methyl methacrylate, ethyl methacrylate, and butyl methacrylate. , isobutyl acrylate, isobutyl methacrylate, hexyl methacrylate, 2-butyl acrylate, t-butyl acrylate, cyclohexyl acrylate, cyclohexyl methacrylate, octyl acrylate, octyl methacrylate, dodecyl acrylate, dodecyl methacrylate, phenyl methacrylate, lauryl methacrylate, as an amide, acrylamide, Methacrylamide, 2-aminomethoxy ethyl acrylate, decyl octyl methacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diacetone acrylamide, 2-hydroxymethyl methacrylate with a hydroxyl group, hydroxymethyl acrylate, N- with a methylol group Examples include methylol acrylamide and hydroxylmethyldiacetone-acrylamide. Among these, 2-ethylhexyl acrylate, ethyl acrylate, N-n-butoxymethylacrylamide, and N-butyl acrylate are preferably selected. On the other hand, acrylic monomers with epoxy groups
As (b) and/or the vinyl monomer (c) having an epoxy group, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, etc. are selected, and glycidyl methacrylate is preferably selected. Next, the monomers (a), (b) and/or (c) are copolymerized in the presence of the liquid polymer (A). In this case, the amount of liquid polymer (A) used varies depending on the intended use of the final adhesive material and the degree of crosslinking, but it is generally an acrylic copolymer.
The amount is 5 to 2000 parts by weight, particularly preferably 20 to 500 parts by weight, per 100 parts by weight. If the amount is less than 5 parts by weight, the copolymerization of the acrylic monomers (a) to (c) cannot be carried out smoothly, and if it is more than 2000 parts by weight, the tackiness due to the acrylic copolymer (B) may occur. I can't expect that. In addition, the copolymerization ratio of the acrylic monomer (a) and the acrylic monomer (b) having an epoxy group and/or the vinyl monomer (c) having an epoxy group is based on 100 parts by weight of the acrylic monomer (a). The amount of the epoxy group-containing monomer (b) and/or (c) is 0.5 to 30 parts by weight, preferably 2 to 5 parts by weight. This is because as the content of epoxy groups increases, the degree of crosslinking increases, but on the other hand, the adhesiveness becomes poor, and conversely, as the content of epoxy groups decreases, the degree of crosslinking decreases, resulting in poor heat resistance. Polymerization is carried out in the presence of a known polymerization initiator such as benzoyl peroxide or azobisisobutylnitrile at 50 to 150°C, preferably 70 to 130°C in a closed system for 3 to 30 hours at normal pressure, increased pressure, or reduced pressure. It takes place below. In this case, the liquid polymer (A) may be present in the polymerization system prior to the start of polymerization, or may be mixed into the system during the polymerization process after the polymerization of the acrylic monomer has progressed to some extent. In the latter case, the polymerization up to that point is carried out, for example, in bulk. Furthermore, an epoxy curing agent and a filler are added to this polymerization system.
Stabilizers etc. may be added. Of course, it is also possible to add during or after polymerization. In particular, it is better to add and mix the epoxy curing agent at the stage of using the adhesive material obtained by the present invention to effect crosslinking. There are various types of epoxy curing agents. For example, amines, acid anhydrides, polyamide resins, polysulfide resins, boron trifluoride amine complexes, synthetic resin initial condensates, etc. can be used. Among amines, examples of aliphatic amines include diethylenetetramine and triethylenetetramine, and examples of aromatic amines include metaphenylenediamine,
Diaminodiphenylmethane, diaminodiphenyl sulfone, dimethylaminodiphenylaminomethylolphenol as secondary and tertiary amines,
These include tris(dimethylaminomethyl)phenol and piperidine, and effective acid anhydrides include phthalic anhydride, hexahydrophthalic anhydride, methylnadic anhydride, pyromellitic anhydride, and maleic anhydride. The amount added may be sufficient as long as it is sufficient to cure the epoxy group, but it is preferably 0.05 to 10 parts by weight per 100 parts by weight of the acrylic copolymer. As the filler, silica, alumina, talc, zinc white, titanium oxide, carbon black, powdered rubber, glass fiber, carbon fiber, pigment, dye, etc. are selected. By adding these, flow prevention, reinforcement, heat resistance, and colorability can be imparted to the obtained polymer composition. Adding eg silica as a filler to the composition obtained according to the invention can impart thixotropy to it and give it an anti-flow effect. Thus, the polymer composition obtained by the method of the present invention is a mixed polymer in which the liquid polymer (A) and the acrylic copolymer (B) are mixed with each other, and is generally fluid. Both polymers in the mixed polymer have better compatibility than when both polymers are once formed and then mixed, which is far beyond the expected compatibility based on the compatibility parameter values. I can't. This point is also a feature of the present invention. Probably, because a specific monomer containing an epoxy group is used as a monomer to be copolymerized with the acrylic monomer, the entanglement of the molecular chains,
This is thought to be due to some grafting and crosslinking. In order to confirm this, the present inventors prepared a polymer composition (mixing ratio: (1:1) was measured by GPC. The result is the first
According to the diagram shown in the figure, the peak of the liquid polymer, which accounts for one half of the polymer composition obtained in the present invention, shows a sharp peak when used alone, but in this case, it is on the high molecular weight side. It is noteworthy that it has moved to In other words, it is difficult to think that this indicates a simple mixed system of liquid polymer and acrylic copolymer in the polymerization system, but entanglement of liquid polymer acrylic copolymer or grafting of acrylic to liquid polymer has occurred. It should be considered that this indicates that As described above, in the present invention, a homogeneous system with very good compatibility can be created by radical polymerizing a liquid polymer and an acrylic monomer, which originally have poor compatibility, in a mixed system thereof. In addition, FIG. 2 shows a comparison between the polymer composition obtained by the present invention and a composition obtained by prepolymerizing a liquid polymer and an acrylic copolymer, respectively, and mixing them. , showed the results of the same measurements as above. This makes it even clearer that they have distinctly independent molecular weight distributions. As described above, the adhesive substance obtained in the present invention can be used in various fields and applications as it is or after being crosslinked by mixing with other substances such as solvents. Examples of usage patterns are as follows. (1) Store the adhesive substance in a container, add an epoxy curing agent at the time of use, apply it to the object to be coated, and then cure at room temperature or by heating if necessary to form a coating agent. (2) Apply the adhesive substance to the backing as described above, cover it with a liner, and peel off the liner before use. (3) Store the adhesive substance in a container, add an appropriate epoxy hardener when using it, and apply it as a caulking material. (4) Add an appropriate amount of filler, knead and use as a sticky putty. Finally, describing the effects of the present invention, the present invention can achieve the following effects. When producing an adhesive substance, a liquid polymer is used as a medium without using a solvent or a solvent such as water, so the product after the polymerization reaction can be used as it is. Further, problems such as loss of solvent, toxicity of the solvent, fear of fire caused by the solvent, and pollution problems due to waste of solvent and water do not occur. Adhesive substances have a low viscosity and are easy to process before being molded into the required shape, and after being molded, the required viscosity and strength can be obtained through crosslinking. The adhesive substance of the present invention consists of a liquid polymer (A) and a copolymer polymer (B) as main components, and the copolymer polymer (B) is used to develop adhesiveness.
In (B), acrylic monomer (a) is mainly used (100 parts by weight). In addition, in order to provide crosslinking points (epoxy groups) in the copolymer (B) and provide the necessary strength to the adhesive material, an acrylic monomer (b) having a small amount of epoxy group and/or an epoxy group A vinyl monomer (c) is used (2 to 5 parts by weight). Note that the epoxy group is bonded to the molecules of the copolymer (B) in a branched manner and serves as a crosslinking point.
For this reason, if the acrylic monomer (b) and/or vinyl monomer (c) is less than 2 parts by weight, there will be too few crosslinking points and no strength will be obtained, whereas if it exceeds 5 parts by weight, the acrylic monomer (c) will be relatively weak. a) decreases and the adhesiveness decreases. In the present invention,
It strikes a balance between adhesion and strength. The physical properties after crosslinking can be changed arbitrarily depending on the type and amount of liquid polymer contained in the system before crosslinking, as well as the type and composition ratio of the acrylic monomer, so it is an adhesive material with a very wide range of physical properties. can be obtained. If necessary, inorganic and organic fillers can be added to the adhesive substance of the present invention during or after the reaction, thereby improving and controlling the physical properties. As described above, an extremely wide range of applications is possible by selecting the types and controlling the amounts of various liquid polymers, acrylic monomers, fillers, etc. Therefore, it can be applied to general adhesives, sealants, caulking materials, putty, etc., and one application that takes advantage of its excellent adhesiveness and suitable heat resistance is a sealant for safety tires. As explained above, polymerization is easy, there is no danger, various disadvantages in the production of adhesive compositions are eliminated, and a wide range of physical properties can be controlled, so it has the advantage of being very widely applicable. The present invention will now be explained in more detail with reference to Examples, and the physical property testing methods described in the Examples are as follows. (1) Adhesiveness...J.Dow method 32 with diameter from 1/32 inch to 32/32 inch
Prepare different types of steel balls and run on a slope with an inclination of 30°.
Roll the steel ball over a distance of 10 cm, and the maximum diameter of the steel ball that stops on the adhesive coated surface within 10 cm is taken as a measure of its adhesiveness. (2) Adhesive strength...180° constant speed peeling (ASTMD1000) A piece of tape with a sample width of 25 mm is attached to a polished stainless steel plate, and the tape piece is peeled off from the stainless steel plate at a constant speed of 300 mm/min at an angle of 180°. (Kg/25mm) (3) Heat resistance... Drop test 50mm x 50 in the center of a 100mm x 200mm release paper
A sample with a thickness of 3 mm is applied, hung vertically in an oven, and the flow state is examined after 5 hours at 120°C. Examples 1 to 7 As liquid polymers, Polybutene 2000H manufactured by Idemitsu Petrochemical Co., Ltd. and Polybutene SV- manufactured by Nisseki Chemical Co., Ltd.
7000 was selected and a polymerization reaction was carried out in a system in which acrylic monomer was added with the composition shown in the table below. Numbers in the table represent parts by weight.

[Table] The reaction of the above composition was carried out in the following manner. That is,
Put the desired liquid polymer into a three-necked separable flask equipped with a stirring bar and a reflux condenser, add the monomers with the composition shown in the table, stir and mix, then add benzoyl peroxide and control the temperature to 80℃. Polymerization was carried out in a heated bath with stirring. The reaction system is initially a low viscosity liquid, but as the monomer polymerization progresses, it becomes a highly viscous whitening liquid after 2 to 5 hours. At this stage, stirring was discontinued, and after further aging for 3 hours, the reaction was terminated. The resulting composition was a sticky substance having a viscosity of 620,000 cps to 5,960,000 cps at 25°C, depending on the composition of the charged polybutene. Among these series of Examples, SV-7000 was particularly effective in imparting adhesiveness and stretchability to the resulting composition. Examples 8 to 13 Select the compositions of Examples 2, 4, and 6 from Examples 1 to 7, add and mix an epoxy curing agent,
After crosslinking at room temperature or an appropriate temperature, the physical properties were measured and compared with the uncrosslinked compositions of Examples 2, 4, and 6. The results are shown in the table below. The numbers at the top of the table represent parts by weight.

【table】

[(Note 1): Amine catalyst for room temperature curing manufactured by Sanwa Kagaku Co., Ltd.]

Examples 14-20 The reaction system was adjusted according to the method described in Examples 1-7 to obtain compositions in which the type of acrylic monomer was mainly changed. The numbers in the upper row of the table represent parts by weight.

[Table] As shown in the above table, good highly viscous and cloudy compositions were obtained in all cases. Moreover, the obtained composition 100
1.0 parts of Sanmide 315 was added to the 1.0 parts of Sanmide 315, mixed well, left to stand at room temperature for 24 hours, and then subjected to a heat sag test at 120°C. As a result, no sagging phenomenon was observed in the compositions of any of the examples. The results were obtained. or,
In the adhesion test using the J.Dow method, excellent results were obtained, with values ranging from 26/32 to 32/32. Examples 21 to 23 The compositions obtained in Examples 15 and 17 were mixed as shown in the following table, and immediately after being thoroughly mixed, it was applied to the inner surface of the tie to a thickness of 3 mm, and after being left for 24 hours, it was applied to a nail. A test (Note 2) was conducted to examine the sealing performance of the composition.

【table】

[Table] As mentioned above, these compositions have excellent properties as tire sealant materials.
These compositions also have excellent adhesion to rubber and good heat resistance as described in Examples 14-20. Examples 24 to 29 Liquid chloroprene and polyether were selected as liquid polymers, and acrylic polymers were polymerized using them as a medium. The reaction procedure is as in Example 1.
The method described in sections 7 to 7 was followed. When a polyether type polymer is used as the liquid polymer, it has good compatibility with the acrylic polymer and generally becomes a highly transparent viscous composition. Furthermore, with the liquid polymers used in these Examples, the viscosity of the resulting compositions was relatively low. However, these compositions are treated with the amine curing agent Sanmide 315.
When cross-linked at room temperature by adding 1.0 part, relatively good results were obtained in a 5-hour sagging test at 120°C.
In particular, no sagging phenomenon was observed after crosslinking in the compositions obtained in Examples 24 and 29. Therefore, such a composition is suitable as an adhesive material that is soft during processing and requires comparative heat resistance and hardness through crosslinking treatment.

[Table] Examples 30 to 32 A reaction system was prepared with the mixture composition shown in the following table, and after thorough stirring and mixing, 1 part by weight of benzoyl peroxide was added, and the reaction was carried out with stirring in a hot bath controlled at 65°C. Ivy. The reaction time was 5 hours from the end of the induction period and the start of the polymerization reaction, with stirring. After adding 0.5 parts by weight of tris(dimethylaminomethyl)phenol to these compositions and thoroughly mixing them, the mixture was coated on a polyester film to a thickness of 0.2 mm, and then crimped onto a 25 mm wide stainless steel plate at 120°C.
The adhesive strength was measured using a sample that had been heat-treated for 15 minutes and cross-linked. As shown in the table below, these compositions exhibited excellent adhesive strength. From the above, these compositions have the potential to become suitable materials for adhesive tapes.

【table】

[Table] Examples 33 to 39 and Reference Example 1 Changes in properties were investigated when various fillers were mixed into the composition (Example 28), which exhibited some sagging phenomenon at high temperatures even after completion of crosslinking. The composition and characteristic values are shown in the table below. The numbers at the top of the table represent parts by weight.

[Table] As shown in the table above, silica, carbon, and powdered rubber are effective in preventing sagging at high temperatures, but the effects of other substances are somewhat small. Also, fillers
Example 35 containing 100 parts becomes a putty-like composition,
Adhesiveness decreased. Furthermore, the composition containing 150 parts (see Reference Example 1) was dry and difficult to use as an adhesive material.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are diagrams showing the results of GPC measurements of adhesive substances obtained by the method of the present invention and the conventional method.

Claims (1)

[Claims] 1 The main components are a liquid polymer (A) and a copolymer (B), and the copolymer (B) contains 100% by weight of one or more acrylic monomers (a). Acrylic monomer (b) having an epoxy group and/or vinyl monomer having an epoxy group
An adhesive substance obtained by copolymerizing 2 to 5 parts by weight of (c). 2 In the presence of liquid polymer (A) without using a solvent,
Copolymerization of 2 to 5 parts by weight of an acrylic monomer (b) having an epoxy group and/or a vinyl monomer (c) having an epoxy group to 100 parts by weight of one or more acrylic monomers (a). A method for producing a sticky substance, characterized by: