JPH0337593B2 - - Google Patents

Description

[Detailed description of the invention]

[Object of the Invention] The present invention relates to a reaction-curable pressure-sensitive adhesive composition comprising a polyether containing at least one reactive silicon group and a resin compatible with the polyether. In particular, the present invention relates to a pressure-sensitive adhesive composition that has a good balance of tack, adhesion, and holding power, has excellent tack at low temperatures, has excellent holding power at high temperatures, and has good removability and adhesion to non-polar adherends. [Prior art and problems to be solved by the invention] Conventionally, the most widely used method for manufacturing adhesive products is to add tackifying resins, plasticizers, anti-aging agents, etc. to natural rubber or synthetic rubber. and dissolved uniformly in organic solvent (solid content concentration 20-35
%), or a solution of the acrylic polymer is applied onto a support such as a plastic film, and the solvent is removed by evaporation by heating and drying. This method requires a step to remove a large amount of organic solvent, which requires expensive thermal energy to evaporate the solvent and equipment to recover it.
There are also problems in the working environment, disaster prevention, and pollution. On the other hand, acrylic emulsion type adhesives and hot melt type adhesives have been introduced to solve these problems, but the former has shortcomings in water resistance and acrylic acid odor, while the latter has shortcomings in heat resistance and tack. Yes, it is not completely satisfactory. On the other hand, among solvent-type adhesives, rubber-based adhesives have the drawback of insufficient holding power at high temperatures, and acrylic-based adhesives have insufficient tackiness at low temperatures. The present inventors have already carried out extensive studies to obtain an adhesive that can be applied without using any or very little solvent, is odorless, has good water resistance and heat resistance, and has excellent adhesive properties. , at least 1
It has been discovered that a pressure-sensitive adhesive composition free from the above-mentioned drawbacks can be obtained by using a composition which is fluid at room temperature and whose main component is a polyether containing two reactive silicon groups. A tackifying resin may be used in combination with this pressure-sensitive adhesive composition, and among the tackifying resins, rosin ester resin is inexpensive, has good compatibility with polyether, and is easy to use. However, it has been found that when a rosin ester resin is used in combination with a polyether containing reactive silicon groups, there is a problem in that the polyether containing reactive silicon groups becomes difficult to cure.
Especially when using a large amount of rosin ester resin,
Adhesive compositions that exhibit this tendency are used for adhesive tapes, etc., but when manufacturing adhesive tapes using this adhesive composition, the composition is coated on the adhesive tape, cured, and then the tape is removed. It will be rolled up. Adhesive tape is usually long, so
Unless the curing time is short, productivity will be extremely poor. [Structure of the Invention] As a result of intensive studies, the present inventors have come to solve this problem. That is, the present invention provides (a) polyether 100 containing at least one reactive silicon group;
parts by weight, and (b) a rosin ester resin having a softening point (ring and ball method) of 100°C or less and an acid value (KOHmg/g) of 10 or less, and the above polyether having a softening point of 100°C or higher. Mixture with melting resin 10~
140 parts by weight, (c) 0.1 to 10 parts by weight of a curing catalyst, and (d) 0 to 150 parts by weight of an additive, wherein the above-mentioned softening point of (b) is 100°C polyether. Compatible resins, that is, tackifier resins include aromatic petroleum resins, aliphatic/aromatic copolymer petroleum resins, alicyclic petroleum resins, low molecular weight polystyrene resins, coumaron resins, terpene-phenol resins, and phenolic resins. and xylene resin. The composition of the present invention has an excellent feature that curing of the composition proceeds easily despite using a rosin ester which is inexpensive, has good compatibility, and is easy to use. In the present invention, the polyether containing at least one reactive silicon group must contain at least one reactive silicon group at the end of the molecule or in the side chain. Preferably, it is bonded to the terminal end of the molecule. This is because better adhesive properties can be obtained. The reactive silicon group has the general formula (where ^, or 3, b is 0, 1
or an integer selected from 2, provided that 1≦a+b≦4,
(m is an integer selected from 0 to 18) Any group represented by the following may be used. In addition to a hydroxyl group, a hydrolyzable group can also be used as X, but specific examples include a halogen group, a hydride group, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an aminooxy group, an alkenyloxy group, etc. These include, but are not limited to. In particular, the X group is preferably an alkoxy group. The concentration of reactive silicon groups is preferably 75% or more, more preferably 80% or more, based on all terminals. Such a concentration of reactive silicon groups is advantageous in dissolving the tackifier resin uniformly and in large quantities in the polyether, and thus the adhesive properties can be adjusted over a wide range and the curing speed can be increased. This is because it is advantageous in terms of productivity. The main chain of the polyether used is essentially -
R ¹ -O- (where R ¹ is a divalent organic group,
It is most effective when most of the groups are hydrocarbon groups having 1 to 4 carbon atoms. Specifically, R ¹ is −CH ₂ −, −CH ₂ CH ₂ −, −CH (CH ₃ )
CH ₂ −, −CH(C ₂ H ₅ )CH ₂ −, −
_{CH2CH2CH2CH2- ,} -C _{( CH3} ) _{2CH2- , etc.} are mentioned. Only one type of repeating unit may be used, or a polyether consisting of two or more types of repeating units is effectively used. -CH( _CH3 ) _CH2- is particularly preferred. Polyether having a molecular weight of 500 to 15,000 can be effectively used. The polyether containing a reactive silicon group used is disclosed in JP-A-53-129247 and JP-A-54-6097.
No. 82123, JP 55-82123, JP 55-82123, JP 55-82123, JP 55-
123620, JP 55-137129, JP 55-137129, JP
55-135185, JP 55-125121, JP 45-36319, JP 46-12154,
It can be specifically produced by methods described in Japanese Patent Publication No. 46-30711, Japanese Patent Publication No. 48-36960, etc., but is not limited thereto. In the present invention, an easy-to-use rosin ester resin is used in combination with component (a). Some rosin ester resins have excellent adhesive properties in terms of tack and holding power, but do not have sufficient adhesive strength.
One component is a rosin ester resin having a temperature of 0.degree. C. or less and an acid value (KOHmg/g) of 10 or less. Further, as another resin component, a resin having a softening point of 100° C. or higher as determined by the ring and ball method is used in combination.
In this case, it is possible to obtain a pressure-sensitive adhesive composition that is highly balanced not only in adhesive strength but also in tack and holding power. As resin components with a softening point of 100°C or higher, aromatic petroleum resins, aliphatic/aromatic copolymer petroleum resins, alicyclic petroleum resins, low molecular weight polystyrene resins, coumarone resins, Tetsupen-phenol resins, and phenolic resins. and xylene resins. Among these resins, especially low molecular weight polystyrene resins and alicyclic petroleum resins,
An adhesive with good color and weather resistance can be obtained. Further, when a combination of terpene and phenol resins is used, particularly excellent adhesion properties are exhibited. The rosin ester resin used in the present invention has an acid value (KOHmg/g) of 10 or less. If the acid value exceeds 10, even if other resins are blended, the curability becomes unstable when the adhesive composition is applied and then cured, and curing may not be completed within the desired time. This is because it is difficult to obtain stable performance. Generally, rosin ester resin refers to esterified products of rosins with various alcohols, and also includes derivatives such as hydrogenated products and disproportionated products. Examples of such rosin ester resins that are easily available as commercial products include Steverite Ester 7, Fuoral 85 (manufactured by Hercules), Ester Gum H, Ester Gum AAG,
Super Ester A-100 (manufactured by Arakawa Chemical Co., Ltd.),
Examples include Ester EG8000 (manufactured by Tokushima Oil Co., Ltd.). The terpene phenol resin used in the present invention is a copolymer of tempel and phenol, and examples of easily available commercial products include YS Polyster T series, S-145,
There are #2000 series and Mighty Ace, etc. The molecular weight used is about 400 to 1200, and the number of OH groups in one molecule is about 1.0 to 2.0. The aromatic petroleum resin used in the present invention is obtained by polymerization with the so-called _C9 fraction of a mixture of styrene, α-methylstyrene, vinyltoluene, indene, etc. as the main component, and the molecular weight is
Something between 600 and 1000 is good. The aliphatic/aromatic petroleum resin used in the present invention is obtained by copolymerizing a so-called _C5 fraction and a so-called _C9 fraction as main components, and has a molecular weight of about 500 to 1000. Good. The alicyclic petroleum resin used in the present invention includes those obtained by polymerizing cyclopentadiene or dicyclopentadiene, or hydrogenating aromatic petroleum resin, and derivatives thereof. These petroleum resins mentioned above are commercially available products such as Neopolymer E-100 (manufactured by Nippon Petrochemicals),
Examples include Petrozin-80, PTR-6100, Tatsuku Ace (manufactured by Mitsui Petrochemicals), and Quinton 1500 (manufactured by Nippon Zeon). The low molecular weight polystyrene resin used in the present invention is a styrene polymer having a molecular weight of about 300 to 1,000, and examples of commercially available products include Vicolastic A-75 (manufactured by Hercules). The Cumaron resin used in the present invention is produced from coal tar, and examples of commercially available products include Cumaron G-90 (manufactured by Nippon Steel Chemical Co., Ltd.). The amount of (b) resin used is preferably 10 to 140 parts by weight based on 100 parts by weight of the polyether. If the amount is less than this, the adhesive strength will be insufficient, and if it is more than this, the tack will be insufficient. In the present invention, a catalyst can be used for the purpose of accelerating the curing reaction due to the bonding of reactive silicon groups of polyether. This curing catalyst is
dibutyltin dilaurate, tin dioctylate,
Dioctyltin maleate, a reaction product of dibutyltin oxide and phthalate ester, dibutyltin diacetylacetonate, carboxylic acid metal salts such as alkyl titanates, amine salts such as dibutylamine-2-ethylhexoate, and other acidic catalysts, Known silanol condensation catalysts such as basic catalysts can be mentioned. The amount of these catalysts used is 0.1 to 10 parts by weight per 100 parts by weight of polyether. 0.1
If the amount is less than 10 parts by weight, the catalytic effect will be low, and if it exceeds 10 parts by weight, curing will be too rapid, which will adversely affect the workability of coating onto the support. In the present invention, if necessary, plasticizers or softeners such as dioctyl phthalate, butylbenzyl phthalate, polypropylene glycol, chlorinated paraffin, liquid polybutadiene, calcium carbonate, clay, talc, titanium oxide, zinc white, silica, Fillers such as diatomaceous earth and barium sulfate, antioxidants, ultraviolet absorbers, pigments, surfactants, and the like can be added as appropriate. The adhesive composition of the present invention is different from the conventional solution type which uses a large amount of organic solvent, and can be used in a type that uses substantially no or almost no solvent. For dissolution into the rubber polymer component (polyether), the tackifying resin may be dissolved in a solvent in advance and then mixed with the polyether, or the mixture of the tackifying resin and polyether may be directly dissolved in the tackifying resin. A completely solvent-free adhesive composition can be produced by heating to around the softening point or kneading with a kneader, roller, or the like. Although the adhesive composition of the present invention is essentially solvent-free, it is also possible to use a small amount of a solvent for the purpose of adjusting viscosity. Adhesive products can be produced from this adhesive composition, for example, by the following method, but the method is not limited to the following method. For example, a tackifying resin and, if necessary, a plasticizer, a filler, an anti-aging agent, etc. are added to a liquid polyether containing at least one hydrolyzable silicon group in a predetermined amount, and the mixture is used in a Banbury mixer, a kneader, a roll, etc. Dissolve the mixture uniformly using a kneader, and finally add the curing catalyst and mix uniformly. Next, this liquid composition is applied onto a support with a rotor to a certain thickness, cured at room temperature to 150°C for 80 seconds to 5 minutes, and then wound into a roll. In addition, for example, when manufacturing in larger quantities, the catalyst may be separately coated on the support from the viewpoint of viscosity stability of the adhesive, or the catalyst or water may be sprayed after the adhesive is applied. There are other methods such as spraying. [Example] The present invention will be specifically described below with reference to Examples. Reference Example 1 800 g of polypropylene oxide (manufactured using polypropylene glycol as a starting material) with an average molecular weight of 8000 containing 97% allyl ether groups at the terminals was placed in a pressure-resistant reaction vessel equipped with a stirrer, and methyl dimethoxy Add 20 g of silane, followed by a catalyst solution of chloroplatinic acid (H ₂ PtCl ₆ .
After adding 0.34 ml of a solution of 8.9 g of 6H ₂ O dissolved in 18 ml of isopropyl alcohol and 160 ml of tetrahydrofuran, the mixture was reacted at 80° C. for 6 hours. As a result of quantifying the reaction rate from gas chromatography and IR spectrum, it was found that 83% of the terminals had reacted, and the (CH ₃ O) ₂ (CH ₃ )Si-CH ₂ CH ₂ CH ₂ O- group was Polypropylene oxide was obtained. Examples 1 to 10 Rosin ester resin (trade name: Stevelite Ester 7, manufactured by Hercules Co., Ltd., softening point 77°C,
acid value 3), and terpene-phenol resin (trade name: YS Polyster T-145, manufactured by Yasushi Oil Co., Ltd., softening point 145°C, and trade name: YS Polyster T-115,
(manufactured by Yasushi Oil Co., Ltd., softening point 115°C) was added and dissolved in toluene to obtain a high solids solution with a solid content concentration of 80% and a viscosity of several tens of poise (at room temperature). Add 5 parts by weight of a tin-based curing catalyst (trade name: No. 918, manufactured by Sankyoki Gosei Co., Ltd.) to 100 parts by weight of polyether, mix uniformly, and apply it on a 25μ thick polyester film using a coater. It was applied so that the adhesive thickness after drying was 25 μm, and heat treated at 110° C. for 10 minutes to obtain an adhesive tape. When we measured the adhesive properties of this adhesive tape, we found that
As shown in Table 1, it can be seen that adhesive properties with highly balanced tack, adhesive strength, and holding power are exhibited. In addition, almost the same results were obtained when the heat treatment time was set to 2 minutes. The test method for the characteristics in Table 1 is as follows. Measurement of tack: Measured using the J. Dow rolling ball tack method. Run-up distance 10cm, inclination angle 30
degrees, temperatures of 23°C and 0°C, and the maximum diameter of a stationary ball (x 1/32 inch). Measurement of adhesive strength: Pasted on stainless steel plate adherend, 60
After standing at 23°C for minutes, 180° peel strength was tested at a tensile rate of 30 mm/min at a temperature of 23°C. Measurement of holding force: 25mm x 25 on stainless steel plate adherend
They were bonded together in an area of mm, and at a temperature of 40°C, a 1 kg weight was suspended as a static load, and the displacement distance was measured after 60 minutes.

[Table] Comparative Example 1 Same as Example 1 except that instead of using the mixture of rosin ester resin and terpene-phenol resin, 100 parts by weight of rosin ester resin was used and the heat treatment time was 2 minutes. An adhesive tape was obtained in the same manner. However, in this case, the polymer was insufficiently cured and had no holding power at all, making it impossible to even measure it. [Effects of the Invention] The pressure-sensitive adhesive composition of the present invention is inexpensive and has good compatibility, so it has an excellent effect that the curing of the composition progresses even though it uses a rosin ester resin that is easy to use.

Claims (1)

[Scope of Claims] 1 (a) 100 parts by weight of a polyether containing at least one reactive silicon group; (b) a softening point (ring and ball method) of 100°C or less and an acid value (KOHmg/g) A mixture of a rosin ester resin having a softening point of 10 or less and a resin compatible with the above polyether having a softening point of 100°C or more 10 to 140
parts by weight, (c) 0.1 to 10 parts by weight of a curing catalyst, and (d) 0 to 150 parts by weight of an additive, the pressure-sensitive adhesive composition comprising (b) a polyether having a softening point of 100°C or higher. The compatible resins are aromatic petroleum resins, aliphatic/aromatic copolymer petroleum resins, alicyclic petroleum resins, low molecular weight polystyrene resins, coumaron resins, terpene-phenolic resins, phenolic resins, and xylene resins. An adhesive composition characterized in that it is selected from the group. 2. The pressure-sensitive adhesive composition according to claim 1, wherein the resin having a softening point of 100°C or higher is a terpene-phenol resin. 3. The adhesive composition according to claim 1, wherein the reactive silicon group is an alkoxysilyl group. 4. The pressure-sensitive adhesive composition according to claim 1, wherein the polyether is polypropylene oxide.