JPS63275685A - Aqueous pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To provide the title compsn. whose pressure-sensitive adhesive properties such as adhesive strength and tack, do not change after the lapse of time, and which comprises a base polymer composed of a mixture of a particular copolymer latex with a natural rubber latex and a tackifier composed of a particular resin emulsion. CONSTITUTION:An aq. pressure-sensitive adhesive compsn. for soft polyvinyl chloride, which comprises a base polymer composed of a mixture of a styrene- butadiene copolymer latex with a natural rubber latex and a tackifier composed of a resin emulsion comprising as a disperse phase a pentaerythritol ester of partially maleinized disproportionated rosin and/or a pentaerythritol ester of partially fumaric-modified disproportionated rosin having a softening point of 110-140 deg.C. The pressure sensitive adhesive properties, such as adhesive strength and tack, exhibited by the present compsn. upon manufacturing thereof do not lower after the lapse of time. The compsn. can be advantageously used for preparing tape, sheet, label, etc. comprising as a substrate soft polyvinyl chloride, which are for use in electrical insulation, electrical wire binding, sundries, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a novel aqueous adhesive composition for soft vinyl chloride whose adhesive properties such as adhesive strength and tack do not change over time.

BACKGROUND OF THE INVENTION PRIOR ART AND THEIR PROBLEMS Adhesives are usually applied to paper, plastic films, etc., and applied to tapes, sheets, labels, etc. Water-based emulsion type adhesives have various advantages over organic solvent type adhesives, such as no air pollution, superior safety and hygiene, and resource conservation.
In recent years, there has been a rapid shift from organic solvent type to aqueous emulsion type. In this way, water-based emulsion-type adhesives have been used in a variety of applications, but recently, soft chlorinated The development of water-based emulsion type adhesives is also desired for adhesives to be applied to tapes, sheets, labels, etc. that use vinyl as a support.

Conventionally, water-based emulsion type adhesives generally use acrylic emulsion type adhesives, styrene-butadiene copolymer latex (hereinafter referred to as SBR latex), natural rubber latex (hereinafter referred to as NR latex), etc. as a base polymer, and rosin, non-containing polymers, etc. Latex adhesives made by adding a tackifier resin emulsion such as glycerin ester of homogenized rosin, terpene resin, petroleum resin, etc. are known, and adhesive tapes using paper, polyester film, cellophane, etc. as a support are known. Useful for labels and sheets. However, when these conventional water-based emulsion-type adhesives are used for tapes, sheets, labels, etc. with soft vinyl chloride as a support, they have excellent adhesive properties such as adhesive strength and tack immediately after production, but A problem arises in that the plasticizer originating from the soft vinyl chloride support migrates from the soft vinyl chloride side to the adhesive layer, resulting in a significant decrease in adhesive properties such as adhesive force and tack of the adhesive. Therefore, an aqueous emulsion-type adhesive that can be used for tapes, sheets, labels, etc. using soft vinyl chloride as a support has not yet been obtained.

Means for Solving the Problems The present inventors have solved the above-mentioned problems of conventional water-based emulsion-type adhesives, namely, by applying water-based emulsion-type adhesives to tapes, sheets, labels, etc. using soft vinyl chloride as a support. As a result of extensive research in order to solve the problem that the adhesive properties deteriorate significantly over time when used, we used a mixture of SBR latex and NR latex as the base polymer, and developed a tackifier resin with a specific high softening point. The present invention was completed based on the discovery that when using a tackifier resin emulsion, the adhesive properties immediately after production do not deteriorate over time even when used in tapes, sheets, labels, etc. with soft vinyl chloride as a support. I ended up doing it.

That is, the present invention provides a pressure-sensitive adhesive composition comprising a base polymer and a tackifier, in which (1) the base polymer is a mixture of styrene-butadiene copolymer latex and natural rubber latex, and (2) the tackifier is partially maleic. a pentaerythritol ester of a fumarated disproportionated rosin and/or a pentaerythritol ester of a partially fumarated disproportionated rosin,
The present invention relates to a water-based adhesive composition for soft vinyl chloride, which is a resin emulsion containing a resin having a softening point of 110 to 140°C as a dispersing element.

In the present invention, a mixture of SBR latex and NR latex is used as the base polymer.

Here, SBR latex refers to SBR latex and/or
or carboxy-modified SBR latex, usually
Commercially available adhesives can be used. S.B.
Considering the provision of rubber elasticity and low-temperature physical properties, R latex has a styrene/butadiene bond ratio of 25/75 by weight.
45155 is preferred. When the amount of styrene is less than 25 parts by weight, the glass transition point (hereinafter referred to as Tg) is lowered, so that sufficient cohesive force cannot be obtained. If it exceeds 45 parts by weight, the Tg will increase and the tackiness will decrease.

In addition, the gel fraction (toluene insoluble content weight %) is 35 to 65
%, and if the gel fraction is less than 35%, the cohesive force is low. If it exceeds 65%, sufficient tack cannot be obtained. The modification rate of carboxy-modified SBR latex is generally 0.5 to 7% by weight. One kind of SBR latex and carboxy-modified SBR latex can be used, or two or more kinds having different bound styrene amounts, gel fractions, and carboxy modification rates can be used together in any ratio. Examples of commercially available products include rP L-20 manufactured by Polycer Co., Ltd. for carboxy-modified SBR latex.
8J, rPL-222J, and the like.

In addition, as the NR latex, any of those used in this type of composition can be used, and it may be either depolymerized or non-depolymerized, but the cohesive force, cost, etc. when made into vinyl chloride tape etc. can be used. Considering this, it is better to use one that does not depolymerize.

The mixing ratio of SBR latex and NR latex is preferably used in the range of 80:20 to 50:50 in solid content weight ratio. Particularly preferably 70:30
~60:40, and it is more preferable to use the amount of bound styrene in the mixture of SBR latex and NR latex from 20 to 32%. When the amount of bound styrene in SBR latex is small, the blending ratio of NR latex may be lowered, and when the amount of bound styrene in SBR latex is large, the blending ratio of NR latex may be increased.

If the amount of styrene is too small, the adhesive force will decrease, and if it is too large, the transfer of the plasticizer will significantly reduce the cohesive force.

On the other hand, as the tackifier resin used in the resin emulsion which is one component in the composition of the present invention, one or two types of pentaerythritol ester of partially maleated disproportionated rosin and pentaerythritol ester of partially fumarated disproportionated rosin are used. It must be a mixture of the above. That is, the object of the present invention is achieved by using the above tackifier resin.

Here, the pentaerythritol ester of pentazine of the partially maleated disproportionated rosin is obtained by the method shown below. That is, 1 to 5 parts by weight of at least one of maleic anhydride, maleic acid, and fumaric acid is added to 100 parts by weight of at least one of tall oil rosin, wood rosin, and gum rosin, and then a disproportionation catalyst is added. disproportionality in the presence of Furthermore, in the presence or absence of an esterification catalyst such as methanesulfonic acid, 8 to 8 to 10 pentaerythritol is added to 100 parts by weight of the partially maleated disproportionated rosin and/or partially fumarated disproportioned rosin obtained above. It is obtained by esterifying all of the 15 polymers. Incidentally, the disproportionation reaction and the esterification reaction can be performed in this order, in the reverse order, or at the same time. In this gap, if the amount of at least one of maleic anhydride, maleic acid, and fumaric acid used is less than 1 part by weight, the softening point tends not to be sufficiently high;
If the amount is more than 1 part by weight, the softening point tends to become too high and the compatibility tends to decrease, which is not preferable. The softening point of the tackifier resin thus obtained is 110~
The temperature is preferably 140°C, particularly preferably 120 to 130°C. When the softening point is less than 110°C, the rate of oral decrease in adhesive strength is large. When the temperature exceeds 140°C, the tack becomes low.

Next, the resin is emulsified. Emulsifiers used at this time include α-olefin sulfonates, alkyl sulfates, alkylphenyl sulfates,
Examples include anionic emulsifiers such as polyoxyethylene alkylphenyl ether sulfate, Hafester salt of sulfosuccinic acid of polyoxyethylene aralkylphenyl ether, rosin soap, and nonionic emulsifiers such as polyoxyethylene alkylphenyl ether.

Further, the amount of emulsifier is not particularly limited, but is usually about 1 to 10 parts by weight in terms of solid content per 100 parts by weight of resin.
Preferably it is 1 to 5 parts by weight.

If it exceeds 10 parts by weight, the water resistance and adhesive strength of the adhesive will decrease. If the amount is less than 1 part by weight, the stability of the resin emulsion will deteriorate.

As a method for obtaining a high softening point tackifier resin emulsion, the above-mentioned high softening point tackifier resin was dissolved in a solvent such as benzene or toluene, and then the above-mentioned emulsifier and soft water were added, and the mixture was emulsified using a high-pressure emulsifier. After that, the solvent is removed under reduced pressure. A small amount of solvent such as benzene or toluene is mixed so that the softening point of the resin is about 90℃ or less, an emulsifier is kneaded in, and hot water is gradually added. After phase emulsification to obtain an emulsion, the solvent is removed under reduced pressure or used as is, or the temperature is raised to above the softening point of the resin in an autoclave, an emulsifier is kneaded in, and hot water is gradually added. Examples include a method of emulsifying the two phases to form an emulsion, and any of these methods may be used.

The aqueous adhesive composition of the present invention has a base polymer of S
The blending ratio of the mixture of BR latex and NR latex and the tackifier is 80:20 to 80:20 in terms of solid content weight ratio.
It is preferable to use a blend in the range of 50:50. Particularly preferred is 70:30 to 50:50. Addition amount of high softening point tackifier resin emulsion is 20
If the amount is less than 50 parts by weight, sufficient adhesiveness cannot be imparted, and if it exceeds 50 parts by weight, the cohesive force is significantly reduced, which is not preferable.

The aqueous adhesive composition of the present invention may optionally contain an antifoaming agent,
Some thickeners, fillers, antioxidants, waterproofing agents, film-forming aids, etc. may be used.

Effects of the Invention The aqueous adhesive composition of the present invention can be suitably applied to tapes, sheets, labels, etc. with soft vinyl chloride as a support used for electrical insulation, wire binding, miscellaneous goods, etc., and can be applied immediately after production. Adhesive properties such as adhesive force and tack do not decrease even after oral administration.

EXAMPLES Hereinafter, the present invention will be explained in detail with reference to production examples, working examples, and comparative examples, but the present invention is not limited to these examples. In each example, all parts and percentages are based on weight unless otherwise specified.

Production Example Pentaerythritol ester of partially fumarated disproportionated rosin (fumarization rate: 23.5% by weight, softening point: 125°C) 1
After dissolving 00 parts in 60 parts of toluene at 100°C for about 1 hour, it was cooled to 80°C, and 3 parts of an anionic emulsifier (dodecylbenzenesulfonic acid sodium salt) and 160 parts of water were added in terms of solid content. Preliminary emulsification was carried out by stirring at a temperature of 1 hour. The obtained preliminary emulsion was high-pressure emulsified at a pressure of 300 kg/cm 2 using a high-pressure emulsifier (manufactured by Manton Galarin) to obtain an emulsion. Next, 200 parts of the emulsion was charged into a vacuum distillation apparatus, and vacuum distillation was carried out for 6 hours at 50°C and 100 mmHg to obtain 123 parts of pentaerythritol ester resin emulsion (solid content: 50%) of partially fumarated disproportionated rosin. I got it.

Example 1 30 parts (solid content equivalent) of pentaerythritol ester resin emulsion of partially fumarated disproportionated rosin obtained in Production Example and carboxy-modified SBR latex (R
PL-222J, bound styrene content 42%, non-volatile content 5
2%) (solid content equivalent) and NR latex (non-volatile content 62%) 21 parts (solid content equivalent) were mixed, and as an acrylic thickener, "Primal ASE-604 (manufactured by Japan 7 Krill Co., Ltd., A water-based adhesive composition was obtained by adding 0.5 part (in terms of solid content) of 28% non-volatile content to 5% and increasing the viscosity.

Example 2 40 parts (solid content equivalent) of pentaerythritol ester resin emulsion of partially fumarated disproportionated rosin obtained in Production Example and carboxy-modified SBR latex (Polycer Co., Ltd. r
PL-222J, bonded styrene 42%, non-volatile content 5
2%) (solid content equivalent) and NR latex (non-volatile content 62%) 24 parts (solid content equivalent) were mixed, and further, as an acrylic thickener [Primal ASE-60J
(manufactured by Nippon Acrylic Co., Ltd., used after diluting 28% non-volatile content to 5%) 0.5 part (in terms of solid content) was added to increase the viscosity to obtain an aqueous adhesive composition.

Example 3 In the production example, pentaerythritol ester of partially maleated disproportionated rosin (maleated An emulsion was obtained by carrying out exactly the same operation as in the production example, except that the concentration was 1.5% by weight and the softening point was 115°C. Next, an aqueous adhesive composition was obtained using this emulsion and the same formulation as in Example 1.

Comparative Example 1 In the production example, glycerin ester of disproportionated rosin (softening point 100°C, "Superester A-
An emulsion was obtained by carrying out exactly the same operation as in the production example except that 100J (manufactured by Arayo Kagaku Kogyo Co., Ltd.) was used. next,
Using this emulsion, an aqueous adhesive composition was obtained in the same manner as in Example 1.

Comparative Example 2 In the production example, petroleum resin (softening point 100
C1 [Finton D-100J, manufactured by Nippon Zeon Co., Ltd.] was used, but the same operation as in the production example was performed to obtain an emulsion. Next, an aqueous adhesive composition was obtained using this emulsion and the same formulation as in Example 1.

Comparative Example 3 In the production example, a polyterpene resin (softening point 115°C, “YX-Resin Px #1150J,
An emulsion was obtained by carrying out exactly the same operation as in the production example except that the emulsion was used (manufactured by Yasuyu Kagaku Kogyo Co., Ltd.). Next, an aqueous adhesive composition was obtained using this emulsion and the same formulation as in Example 1.

Comparative Example 4 In the production example, pentaerythritol ester of maleated rosin (softening point 150°C, "Marquid Nα5", manufactured by Arayo Kagaku Kogyo Co., Ltd.) was used in place of pentaerythritol ester of partially fumarated disproportionated rosin. An emulsion was obtained by carrying out the same operation as in the production example except for the following. Next, an aqueous adhesive composition was obtained using this emulsion and the same formulation as in Example 1.

Comparative Example 5 In the production example, pentaerythritol ester of polymerized rosin (softening point 121°C, "Pensel C") was used instead of pentaerythritol ester of partially fumarated disproportionated rosin.
An emulsion was obtained by carrying out exactly the same operation as in the production example except for using Arayo Kagaku Kogyo Co., Ltd.). Next, an aqueous adhesive composition was obtained using this emulsion and the same formulation as in Example 1.

How to make vinyl chloride tape Apply "Hiker 1571CJ (B, F)" as a primer to a 150 μm thick soft vinyl chloride tape.

Goodrich) / rPL-222” = 1/1
(Weight ratio) was applied to a dry weight of 2 to 3 g/m2, and then dried in a circulating air dryer at 70°C for 3 minutes.
It was left in a room with a temperature of 20° C. and a relative humidity of 65% for 2 hours.

Furthermore, the weight of the aqueous adhesive composition after drying is 28 to 30 g.
/m2, dried in a circulating air dryer at 105°C for 3 minutes, and immediately wound up to prepare a vinyl chloride tape. Thereafter, the value measured after being left in a room at a temperature of 20° C. and a relative humidity of 65% for 24 hours was taken as the value immediately after manufacture. In addition, the vinyl chloride tape obtained above was left in a circulating air dryer at 70°C for 72 hours, then taken out, and placed in a room with a temperature of 20°C and relative humidity of 65% for 24 hours.The values measured immediately after aging were determined as the values after aging. did. Incidentally, all rates of change were determined using the following formulas.

Rate of change (%) = Value immediately after manufacture Various tests are conducted using the following methods.

1. Adhesion crab measurement temperature 20℃, tensile speed 300mm/m
The adhesive strength (g/cm) was measured by peeling at 180°. The object to be adhered to is a stainless steel plate.

2. Tack: J listed in JIS Z 0237
, was measured by the Dow method at a slope of 30° and a measurement temperature of 20°C. The numbers in Table 1 are Ba1lNo.

shows.

3.Agglomerated crab bonding area 19X2Onon2, load 1
Attach the adhesive sides of vinyl chloride tape together using 20 kg.
Expressed as holding time (min) at °C.

Claims (1)

[Scope of Claims] [1] A pressure-sensitive adhesive composition comprising a base polymer and a tackifier, wherein (1) the base polymer is a mixture of a styrene-butadiene copolymer latex and a natural rubber latex, and (2) a tackifier. is a pentaerythritol ester of a partially maleated disproportionated rosin and/or a pentaerythritol ester of a partially fumarated disproportionated rosin,
An aqueous adhesive composition for soft vinyl chloride, characterized in that it is a resin emulsion comprising a resin to be dispersed having a softening point of 110 to 140°C. [2] The blending ratio of styrene-butadiene copolymer latex and natural rubber latex is 80 in terms of solid content weight ratio.
The aqueous adhesive composition according to claim 1, which has a ratio of: 20 to 50:50. [3] The aqueous adhesive composition according to claim 1, wherein the blending ratio of the base polymer and the tackifier is from 80:20 to 50:50 in solid content weight ratio.