JPH10140118A - Pressure-sensitive adhesive for use on vinyl chloride resin tape and composition for pressure-sensitive adhesive - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pressure-sensitive adhesive which can form a pressure- sensitive adhesive layer improved in both pressure-sensitive adhesives and tack and therefor having well-balanced pressure-sensitive adhesive properties, and an aqueous composition for a pressure-sensitive adhesive and suitable for forming such a pressure-sensitive adhesive and used on a vinyl chloride resin tape. SOLUTION: This adhesive comprises 100 pts.wt. rubber base comprising a mixture of a natural rubber with a synthetic rubber, 40-70 pts.wt. rosin ester tackifier and 5-20 pts.wt. low-molecular-weight polyisoprene. The tackifier should comprises 85-50wt.% rosin ester resin having a softening point of 90-105 deg.C and 12-50wt.% maleinized rosin ester resin having a softening point of 120-135 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive for a soft vinyl chloride resin pressure-sensitive adhesive tape, and more particularly to a water-based pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer in producing such a pressure-sensitive adhesive tape. .

[0002]

2. Description of the Related Art Soft vinyl chloride resin adhesive tapes are widely used for electrical insulation and for binding electric wires, and such adhesive tapes are formed by nitrile rubber on a support made of a plasticized soft vinyl chloride sheet. It is usually manufactured by providing an undercoat layer mainly composed of a base material and the like, and further applying a pressure-sensitive adhesive layer composed of a tackifier, a softener, an antioxidant and the like to a rubber base polymer. In order to form such a pressure-sensitive adhesive layer, a solution-type pressure-sensitive adhesive composition using an organic solvent or an aqueous emulsion-type pressure-sensitive adhesive composition is generally applied to the tape surface, and further dried to remove the solvent and the like. The method of removing is adopted. However, recently, from the viewpoint of occupational health, prevention of environmental pollution, and resource saving, aqueous emulsion-type pressure-sensitive adhesive compositions are becoming mainstream.

As an aqueous emulsion-type pressure-sensitive adhesive composition used for producing such a vinyl chloride pressure-sensitive adhesive tape, for example, a carboxyl-modified styrene-butadiene-based latex, a natural rubber latex, and a styrene-butadiene-based latex are expressed in terms of solid content weight ratio. 80: 20-50: 5
With respect to the base polymer mixed at 0, an emulsion of a resin having a softening point of 110 to 140 ° C. of a pentaerythritol ester of partially maleated disproportionated rosin and / or a pentaerythritol ester of partially fumarated disproportionated rosin is prepared. 80:20 to 50: 5 in terms of solid content conversion weight ratio.
An aqueous pressure-sensitive adhesive composition blended in the range of 0 has been proposed (JP-A-63-275885).

[0004]

Such a vinyl chloride resin tape is generally preferred to be adhered to an adherend, that is, a tape having a high adhesive strength. By using a resin having a high softening point as the rosin ester resin, the adhesive strength is increased. However, in this case, there is a problem that tack at a low temperature is reduced. Therefore, a method such as increasing the blending amount of a softening agent is used to further improve the low temperature tack. However, since an increase in the amount of the softening agent leads to a decrease in the adhesive strength, it has been difficult to improve both the adhesive strength and the low-temperature tack at the same time.

Accordingly, the present invention is intended to improve both the adhesive strength and the tack of the adhesive layer of the vinyl chloride resin tape so as to realize a balanced adhesive property. It is an object of the present invention to provide a water-based pressure-sensitive adhesive composition for a vinyl chloride resin tape, which is suitable for use as a pressure-sensitive adhesive.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
Rubber base material 100 made of a mixture of natural rubber and synthetic rubber
Rosin ester-based tackifier 40 to 7 parts by weight
An adhesive containing 0 parts by weight and 5 to 20 parts by weight of a low molecular weight polyisoprene, wherein the rosin ester-based tackifier has a softening point of 90 to 105 ° C.
This can be achieved by a pressure-sensitive adhesive for a vinyl chloride resin tape, which comprises a weight percentage of 15 to 50 weight% of a maleated rosin ester resin having a softening point of 120 to 135 ° C.

Further, the pressure-sensitive adhesive layer of the vinyl chloride resin tape has a rosin ester-based tackifier as a solid with respect to 100 parts by weight of a base latex made of a mixture of a natural rubber latex and a synthetic rubber latex. 40
An aqueous emulsified liquid pressure-sensitive adhesive composition containing rosin ester-based tackifier having a softening point of 90 to 10 parts by weight.
85 to 50% by weight of rosin ester resin at 5 ° C and softening point 1
Maleated rosin ester resin at 20-135 ° C 15-
It can be easily formed by using a pressure-sensitive adhesive composition for a vinyl chloride resin tape, which is characterized by comprising 50% by weight.

Further, in the pressure-sensitive adhesive composition of the present invention, when the low-molecular-weight polyisoprene-based emulsion as a softener is contained in an amount of 5 to 20 parts by weight, based on 100 parts by weight of the solid of the base latex, Further, the composition for an adhesive has an excellent balance of performance.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The base material of the composition for forming the pressure-sensitive adhesive for vinyl chloride resin tape of the present invention is preferably in the form of a latex or an emulsion. Polymer latex, acrylic ester copolymer latex, acrylic
Butadiene copolymer latex, synthetic rubber-based latex such as styrene / isoprene latex, and natural rubber latex are used.However, natural rubber latex and synthetic rubber latex are used in terms of flexibility and cohesion as an adhesive layer. It is preferable to use a mixture of The mixing ratio is suitably about 7: 3 to 5: 5 as a solid as in the prior art.

The rosin ester-based tackifier compounded in the pressure-sensitive adhesive comprises a rosin ester resin having a relatively low softening point and a maleated rosin ester resin having a relatively high softening point. The softening point of the ester resin is preferably in the range of 90 to 105 ° C, and the softening point of the maleated rosin ester resin is preferably in the range of 120 to 135 ° C. The amount of the rosin ester resin in the total rosin ester-based tackifier was 85 to 50% by weight, and the remainder was a maleated rosin ester resin. If the compounding amount of the rosin ester resin in the rosin ester-based tackifier falls outside this range and falls below 50% by weight, the adhesive strength remains at a high value, but the low-temperature tack decreases sharply. The amount of ester resin is 8
If it exceeds 5% by weight, further improvement of the low-temperature tack is hardly observed, but the adhesive strength tends to decrease, which is not preferable.

When the rosin ester-based tackifier is blended with the base latex, the tackifier is also preferably in the form of an emulsion, and the rosin ester resin and the maleated rosin ester resin in the form of an aqueous emulsion are It is preferable that each of the compositions is mixed at a predetermined mixing ratio and then mixed with the base latex to obtain a composition for an adhesive.

The pressure-sensitive adhesive of the present invention contains 5 to 20 parts by weight of a low molecular weight polyisoprene as a softening agent for a rubbery base material, but the amount is not particularly limited. It can be determined appropriately within a range necessary for adjustment. In addition, when blending such a low molecular weight polyisoprene, it is preferable to use an aqueous emulsion and mix it with the base latex so that the solid content becomes a predetermined blending ratio.

[0013]

Example: DOP to 100 parts by weight of vinyl chloride resin
A 0.15 mm thick soft vinyl chloride resin tape obtained by blending 80 parts by weight, 100 parts by weight of a calcium carbonate-based filler, and 3 parts by weight of a calcium-zinc-based heat stabilizer was prepared, and an NBR-based undercoat was prepared. The coating was applied to a thickness of about 3 μm and dried to prepare a tape support. Next, a styrene-butadiene copolymer latex (manufactured by Nippon Synthetic Rubber, T
No. 091A, solid content 50% by weight) and natural rubber latex (Standard, manufactured by Guthrie Co., solid content 60% by weight) were blended in the same weight and a base latex having a solid content of 55% by weight was obtained. .

A rosin ester resin aqueous emulsion having a softening point of 125 ° C. (Arakawa Chemical Industries, Superester E725, solid content 50% by weight) as a tackifier is added to the above-mentioned base latex, and the softening point is 100 ° C. Rosin ester resin aqueous emulsion (Arakawa Chemical Industries, Super Ester E
720, a solid content of 50% by weight) and an aqueous emulsion of a maleated rosin ester resin having a softening point of 125 ° C. (100 parts by weight of Marquid No. 1 manufactured by Arakawa Chemical Industry Co., Ltd.) are dissolved in an equal amount of toluene, and 15% by weight of dodecylbenzene is dissolved. The mixture was emulsified by stirring and poured into an aqueous solution of sodium sulfonate, treated with a homogenizer, and then desolvated under reduced pressure to a solid content of 50% by weight). A low molecular weight polyisoprene latex (Kuraray , LIR700, solid content 50% by weight) were mixed according to the formulation shown in Table 1, using an aqueous emulsion of a hindered phenol-based antioxidant as an antioxidant, respectively. Compositions A to H were prepared.

[0015]

[Table 1]

Each of the pressure-sensitive adhesive compositions A to H is uniformly coated on the above-mentioned tape support, dried with hot air, and is a vinyl chloride resin tape having a pressure-sensitive adhesive layer having a thickness of about 30 μm. It was created. The vinyl chloride resin tape thus obtained was allowed to stand in a room at a humidity of 65% for 24 hours or more, and the values of the adhesive strength and the low-temperature tack were measured by the following methods. The results are shown in Table 1.

Adhesion test: 25 mm wide according to the adhesion test method of JIS C 2107 “Testing method of electric insulating adhesive tape”.
Cut out a 250mm long sample, and polish 125mm long polished SU
A half of the sample is adhered to the upper surface of the S steel plate and pressed.
Turn over 80 ° and leave for 30 minutes. Thereafter, 180 ° peeling was performed at a speed of 300 mm / min using a tensile tester, and the tensile load value at this time was changed from a width of 25 mm to a width of 10 mm.
And converted to the adhesive strength (N). The measured values thus obtained were shown as the average of the results of five samples.

Low temperature tack test: Morgan Quick Stick Tes
Cut a 25 mm wide x 125 mm long sample in accordance with the t method, make the adhesive side outward, fix both ends with tape of 18 mm wide, form a loop-shaped test piece, and grasp the upper part of the tensile tester in a 5 ° C environment at 5 ° C. Attach the above tape stop. A polished SUS steel plate is attached horizontally to the lower grip and gradually raised, and when the contact surface between the test piece and the polished steel plate becomes 25 mm x 25 mm, peeling is performed at a speed of 300 mm / min in the opposite direction, The tensile load value (N) at this time is defined as a low temperature tack (5 ° C. loop tack). The measured values thus obtained were shown as the average of the results of five samples.

According to the results shown in Table 1, when a rosin ester resin having a softening point of 100 ° C. and a rosin ester resin having a softening point of 125 ° C. are blended, the adhesive strength and the low temperature tack are proportional to the blending ratio. On the other hand, when a rosin ester resin having a softening point of 100 ° C. and a maleated rosin ester resin having a softening point of 125 ° C. are used, the compounding ratio is 85:
It can be seen that when the ratio is in the range of 15 to 50:50, a synergistic effect of having both high adhesive strength and high low temperature tack is exhibited.

[0020]

EFFECTS OF THE INVENTION The pressure-sensitive adhesive for vinyl chloride resin tape of the present invention is superior to a rosin ester resin having a relatively low softening point and a maleated rosin ester resin having a relatively high softening point. Because it contains a rosin ester-based tackifier blended in an amount, it exhibits high tackiness while having a high low-temperature tack. .

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09J 193: 04)

Claims (3)

[Claims] 1. A rosin ester-based tackifier of 40 to 70 parts by weight and a low molecular weight polyisoprene 5 based on 100 parts by weight of a rubber base comprising a mixture of natural rubber and synthetic rubber.
A rosin ester-based tackifier comprising 85 to 50% by weight of a rosin ester resin having a softening point of 90 to 105C and a maleated rosin ester resin having a softening point of 120 to 135C. An adhesive for vinyl chloride resin tape, comprising 50% by weight. 2. An aqueous emulsion containing 40 to 70 parts by weight of a rosin ester-based tackifier as a solid, based on 100 parts by weight of a solid of a base latex comprising a mixture of a natural rubber latex and a synthetic rubber latex. Wherein the rosin ester-based tackifier has a softening point of 90 to 105 ° C and a rosin ester resin of 85 to 50% by weight.
And 15 to 50% by weight of a maleated rosin ester resin having a softening point of 120 to 135 ° C. 3. A low molecular weight polyisoprene-based emulsion as a softener is contained in an amount of 5 to 20 parts by weight as a solid with respect to 100 parts by weight of the solid of the base latex.
The composition for a pressure-sensitive adhesive according to item 1.