JP3425524B2 - Pressure-sensitive adhesive composition for pressure-sensitive adhesive tape and pressure-sensitive adhesive tape using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive composition for an adhesive tape and an adhesive tape using the same.

[0002]

2. Description of the Related Art Adhesive tapes are used for the purpose of bundling and protecting automobile electric wires. Water-based adhesives are used as the adhesives for tapes because of their excellent safety and health, and as a base (natural rubber latex / styrene butadiene latex / acrylate resin emulsion)
It is composed of a mixed system, a terpene phenol resin emulsion as a tackifier, and a low molecular weight polyisoprene latex as a softening agent. In the wire harness after taping, the tape end portion is easily peeled off due to vibration, stress, etc. during operation or assembly into a car, so tape with strong adhesiveness is preferred. A tackifier with a high softening point is used to increase the adhesive strength, but it is difficult for the tackifier particles to melt in the rubber during the tape drying process and the heat drying process compared to those with a low softening point, and it does not even melt into the rubber. Absent. Therefore, there is a problem that tackiness is lacking immediately after drying and the adhesive tape surface cannot be adhered to the winding core during the winding process to produce an adhesive tape. In addition, the tackiness immediately after drying is improved by using a low softening point tackifier or the addition amount of the softening agent with respect to the water-based pressure-sensitive adhesive, but the pressure-sensitive adhesive composition causes a decrease in the adhesive strength and a decrease in the cohesive strength. It is accompanied by problems such as transfer to the adherend.

[0003]

DISCLOSURE OF THE INVENTION The present invention is for an adhesive tape which is excellent in the sticking property of the tape adhesive surface to the winding core during the production of the adhesive tape and has a good balance of the adhesive force, tackiness and cohesive force. An object is to provide an adhesive composition and an adhesive tape using the same.

[0004]

According to the present invention, a mixed latex containing natural rubber latex and styrene-butadiene rubber latex is used as component A, and a terpene phenol resin emulsion having a softening point of 100 to 135 ° C. is used as component B and butyl acrylate resin. The present invention relates to a pressure-sensitive adhesive composition for a pressure-sensitive adhesive tape, which comprises as a D component a mixed emulsion with a C component which is a terpene phenol resin having a softening point of 60 to 80 ° C. The present invention also relates to a pressure-sensitive adhesive tape, which is obtained by applying the pressure-sensitive adhesive composition for a pressure-sensitive adhesive tape on a tape substrate made of vinyl chloride resin and drying the composition.

Hereinafter, in the present specification, a "terpene phenol resin having a softening point of 100 to 135 ° C." used in the present invention is referred to as a "high softening point terpene phenol resin",
The “terpene phenol resin having a softening point of 60 to 80 ° C.” is also referred to as a “low softening point terpene phenol resin”.
Also, natural rubber is NR and styrene butadiene rubber is SB.
R and butyl acrylate are also referred to as BA.

The present invention relates to a pressure-sensitive adhesive composition characterized by containing at least A component, B component and D component, and in particular characterized by using D component, by which the above problems are solved. It is a thing. That is, the high softening point terpene phenolic resin as the B component secures the adhesive force and cohesive force over time, and the C component contained in the D component, that is, the low softening point terpene phenolic resin, makes the tape sticky to the core immediately after drying. To secure.

The component D of the present invention is not particularly limited in its production method as long as it is an emulsion in which the BA resin and the component C are uniformly compatible with each other. Examples include those produced by mixing a softening point terpene phenol resin, polymerizing, and then emulsifying. The adhesive composition of the present invention preferably uses an emulsion in which a BA resin and a C component are previously mixed as the D component, but a dispersion state similar to that of the D component is obtained in the mixing and dispersion process with the A component. If there is, B
The A resin and the C component can be used separately.

By the way, generally, when the pressure-sensitive adhesive composition is applied to a tape substrate and then dried, the pressure-sensitive adhesive composition goes through the steps of water evaporation, fusion of each polymer particle, and diffusion of each polymer. Since the component D is an emulsion as described above, the component C is particularly the component A,
It is considered that the B component and the BA resin are mixed with other polymers, and good adhesiveness can be obtained even immediately after drying.

The pressure-sensitive adhesive composition of the present invention may further contain optional additives such as a softening agent, an antioxidant, a filler and a water resistant agent in addition to the above components. It is preferable to include. Moreover, polyisoprene latex is mentioned as a preferable softening agent. This polyisoprene preferably has a low molecular weight, for example, 30,
The range of 000-50,000 is mentioned.

The WET weight ratio of the pressure-sensitive adhesive composition of the present invention can be variously changed according to the purpose, but the A component: B component:
D component: softening agent = 100: 60: 20 to 40: 5 is preferable. When the content of the component D is less than 20% by weight relative to the amount of the component A, the tackiness immediately after drying is reduced, and when it exceeds 40% by weight, the cohesive force is reduced and the adhesive composition is transferred to an adherend at high temperature. Wearing is easy to occur. Further, in the D component, the WET weight ratio of the mixed emulsion of the BA resin and the C component is preferably BA resin: C component = 100: 100. Further, in the component A, the WET weight ratio of NR latex and SBR latex is NR: SBR.
= 100: 100 is preferable.

The composition components used in the pressure-sensitive adhesive composition of the present invention are known, and their molecular weight or softening point, latex or latex are appropriately selected so that adhesive properties with various physical properties can be obtained depending on the application of the pressure-sensitive adhesive tape. The molecular dispersion state in the emulsion (solid content ratio, type of emulsifier and other additives, adjusted by selection of addition amount) can be selected. In addition, each of the above components may be a commercially available product.

The terpene phenol resin as the component B or C used in the present invention can be obtained by reacting terpene and various phenols with a Friedel-Crafts type catalyst, or by condensing this with formalin. Say what can be done. The softening points of the B component and the C component are measured by the ring and ball method (Ball & Ring method) and refer to the heat distortion temperature of the resin.

A pressure-sensitive adhesive tape can be produced by coating the pressure-sensitive adhesive composition of the present invention on a tape substrate by a conventional method, drying and winding it on a winding core. Here, as the drying condition, preferably, air of 100 to 120 ° C. is 5 to
A treatment of applying for 3 minutes can be mentioned. In particular, the pressure-sensitive adhesive composition of the present invention exhibits good characteristics when a vinyl chloride resin is selected as the tape base material. This is because the adhesive property at the interface between the pressure-sensitive adhesive composition of the present invention and the vinyl chloride resin is good. Further, the pressure-sensitive adhesive tape of the present invention has an advantage that the range of selection of the core material is wider than that of the conventional one. Examples of the core material that is preferably used in the present invention include paper and polyethylene.

The vinyl chloride resin used in the pressure-sensitive adhesive tape of the present invention contains not only polyvinyl chloride (PVC) but also a copolymer with other copolymerizable monomers, and is a part of polyvinyl chloride. Can be those copolymers.
The monomer constituting the copolymer includes at least one selected from ethylene, vinyl acetate, acrylic acid, acrylic acid ester and the like. The PVC preferably has an average degree of polymerization p = 800 to 1300. The vinyl chloride resin can usually contain a plasticizer, a stabilizer, a filler, an antioxidant, an ultraviolet absorber, a flame retardant, a pigment and the like. Further, it is obvious that the pressure-sensitive adhesive composition of the present invention can be applied to labels, sheets and the like as well as tapes.

[0015]

EXAMPLES Hereinafter, specific examples of the present invention will be described.
The present invention should not be limited to this. Examples 1 and 2 and Comparative Examples 1 to 3 Composition components described in Table 1 (numerical values are WET parts by weight (however, the antioxidant is solid parts by weight)) are mixed and dispersed under the same conditions to obtain an adhesive tape. The composition was prepared, applied to a vinyl chloride resin, and dried to prepare each adhesive tape having an adhesive layer thickness of 20 μm.

Their properties were evaluated. The details of the composition of the adhesive composition and the evaluation method are as follows. Composition of adhesive composition NR latex; Standard (manufactured by Guthrie Co., Ltd.) Solid content 60 wt% SBR latex; T091A (Nippon Synthetic Rubber Co., Ltd.)
50% by weight solids BA resin emulsion; AE200 (manufactured by Japan Synthetic Rubber Co., Ltd.) 50% by weight solids B component (high softening point terpene phenol resin emulsion); Nanolet G1250 (Yasuhara Chemical Co., Ltd.)
50% by weight solids, 125 ° C. softening point C component (low-softening point terpene phenol resin); Nanolet T800 (Yasuhara Chemical Co., Ltd.) 50% by weight solids, softening point 70-80 ° C. D component (with BA resin) Mixed emulsion with low softening point terpene phenol resin); Celbest Gamma 2000 (Hoechst Synthetic Co., Ltd.) solid content 50% by weight, BA resin / low softening point terpene phenol resin (softening point 70 to 80 ° C.)
≈ 1/1 (weight ratio) Softener; LIR (Kuraray Co., Ltd.) Solid content 60 wt% Antioxidant; Tinuvin B75 (Ciba Specialty Chemicals Co., Ltd.)

Evaluation method Finger touch: The adhesive composition was applied and dried, and the paste surface immediately after that was subjected to a sensory test by touch (◎: excellent, ○: good,
X: inferior). Adhesive strength: The adhesive composition was applied, dried, and held at 70 ° C. for 1 hour, and then the tape was measured according to JIS C2107. Cohesion: The pressure-sensitive adhesive composition was applied, dried, and held at 70 ° C. for 1 hour, and then the tape was measured according to JIS C2107. However, the pasting area between glue surfaces is 19 × 10mm ²
The time until falling at 23 ° C. under a load of 1 kg was measured.

[0018]

[Table 1]

It can be seen from Table 1 that Examples 1 and 2 using the pressure-sensitive adhesive composition of the present invention show excellent performances in both finger tack immediately after drying and pressure-sensitive adhesive strength and cohesive strength after aging at high temperature. On the other hand, Comparative Examples 1 to 3 show examples in which the D component of the present invention is not used. Comparative Example 1 was inferior in finger touch tack, and Comparative Example 3 was improved in finger touch tack when the amount of the softening agent was increased, but the adhesive strength after time decreased and the tendency of the adhesive composition to transfer to the test plate was observed. Was given. Comparative Example 2 is a low-softening-point terpene phenol resin that can also be used as the C component in the D component (however, the manufacturer is different from the C component in the D component used in the examples, so it cannot be absolutely said that they are the same) and BA. Since the resin was separately mixed and dispersed with the other components, it can be seen that the dispersibility of the component C is poor under the same dispersion conditions as in the example, and the adhesive force and cohesive force are inferior to those in the example.

[0020]

EFFECTS OF THE INVENTION The pressure-sensitive adhesive composition of the present invention has excellent tackiness immediately after drying and good sticking property to the core during tape production. In addition, the pressure-sensitive adhesive tape using the pressure-sensitive adhesive composition of the present invention has an excellent balance of adhesive force and cohesive force.

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Claims (6)

(57) [Claims] 1. A mixed latex containing a natural rubber latex and a styrene-butadiene rubber latex as a component A, and a terpene phenol resin emulsion having a softening point of 100 to 135 ° C. with a B component and a butyl acrylate resin at a softening point of 60 to 80 ° C. A pressure-sensitive adhesive composition for a pressure-sensitive adhesive tape, comprising a mixed emulsion with a component C which is a terpene phenol resin as a component D. 2. The adhesive tape according to claim 1, wherein the component D is produced by mixing a butyl acrylate monomer with a low softening point terpene phenol resin, polymerizing the mixture, and then emulsifying the mixture. Adhesive composition. 3. The pressure-sensitive adhesive composition for pressure-sensitive adhesive tapes according to claim 1, further comprising polyisoprene latex as a softening agent. 4. The weight ratio of WET is A component: B component: D.
Ingredient: Softening agent = 100: 60: 20 to 40: 5, The pressure-sensitive adhesive composition for pressure-sensitive adhesive tapes according to any one of 1 to 3, characterized in that: 5. In the D component, the WET weight ratio is butyl acrylate resin: C component = 100: 100.
The pressure-sensitive adhesive composition for pressure-sensitive adhesive tapes according to any one of claims 1 to 4, wherein 6. A pressure-sensitive adhesive tape, which is obtained by applying the pressure-sensitive adhesive composition for pressure-sensitive adhesive tape according to any one of claims 1 to 5 onto a tape base material made of vinyl chloride resin and drying the composition.