JPH0782541A - Pressure-sensitive adhesive composition - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide an acrylic pressure-sensitive adhesive composition which is particularly excellent in repulsion resistance without impairing the balance of adhesive strength, holding power, and physical properties of tack. . [Composition] Terpenes obtained by adding phenols to a mixture of terpenes and rosins in the presence of an acidic catalyst.
Compared to the case where rosin phenol resin is used as tackifier resin and rosin phenol resin and terpene phenol resin are used in combination as tackifier resin, the adhesive strength, holding power, and physical property balance of tack are excellent, and especially the repulsion resistance is excellent. Acrylic pressure-sensitive adhesive composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an acrylic pressure-sensitive adhesive composition useful for the production of pressure-sensitive adhesive tapes or sheets, and more specifically, it has excellent balance of adhesive strength and holding power and physical properties of tack, and particularly The present invention relates to an acrylic pressure-sensitive adhesive composition having excellent repulsion resistance.

[0002]

2. Description of the Related Art Conventionally, as a pressure-sensitive adhesive for a non-polar substrate, an adhesive is improved by adding a tackifier such as a rosin resin or a terpene phenol resin to an acrylic pressure-sensitive adhesive. It is known to cause. However, the above-mentioned resin used as a tackifier usually has a low molecular weight and tends to have poor adhesive properties at high temperatures. Therefore, in the invention described in JP-A-1-306483, a technique has been proposed in which a tackifier having poor compatibility with a base polymer is used to control plasticization of the polymer to improve adhesive properties at high temperatures. There is.

[0003]

However, this technique attaches too much importance to the adhesive property at high temperature, so that the plasticization rate at normal temperature becomes low and the adhesive property to the rough surface is impaired. Particularly, in the application of curved surface adhesion of double-sided tape such as adhesion of urethane foam in the interior of automobiles and adhesion of heat insulating material around ducts for air conditioning in home appliances, an adhesive having excellent repulsion resistance is desired. Therefore, an object of the present invention is to provide an acrylic pressure-sensitive adhesive composition that is particularly excellent in repulsion resistance without impairing the balance of adhesive strength, holding power, and physical properties of tack.

[0004]

[Means for Solving the Problems] As a result of intensive studies to achieve the above object, a terpene / rosin phenol resin obtained by adding phenols to a mixture of terpenes and rosins in the presence of an acidic catalyst. When used as a tackifying resin to produce pressure-sensitive adhesive tapes or sheets, compared to the case of using a rosin phenol resin and a terpene phenol resin in combination as a tackifying resin, the adhesive strength, holding power, and physical property balance of tack are improved. Excellent,
In particular, they have found that the repulsion resistance is excellent. The present invention has been completed based on such new findings, and is an acrylic pressure-sensitive adhesive composition obtained by blending an acrylic polymer with a tackifying resin, wherein the tackifying resin is a terpene / rosin phenol resin. It is an acrylic pressure-sensitive adhesive composition characterized by being present.

[0005]

In the acrylic pressure-sensitive adhesive composition of the present invention, the object of the present invention is achieved by using the terpene / rosin phenol resin as the tackifying resin. That is, an acrylic pressure-sensitive adhesive composition in which a terpene / phenolic resin is added to an acrylic polymer exhibits good adhesive properties, is particularly excellent in repulsion resistance, and has a good balance of adhesive strength, holding power, and tack physical properties. Excellent results are obtained. The reason for this is unknown, but the compatibility with the acrylic polymer is more affected when the terpene-rosin phenol resin is used than when only the rosin-based tackifying resin or the terpene-based tackifying resin is used. , The stress resistance of pressure-sensitive adhesive is improved, the curved surface adhesiveness and the adhesiveness to non-polar adherend are improved, and the softening point of terpene / rosin phenol resin is high. It is considered that this is due to the fact that there is little decrease in the holding force because the internal cohesive force of the entire agent is increased.

The terpene / rosin phenol resin according to the present invention can be produced by using the known reaction between terpenes and phenols and reaction between rosins and phenols, that is, phenols are aromatic such as toluene and xylene. Group hydrocarbons, or halogenated hydrocarbons such as dichloroethane or chloroform, ethers, aliphatic hydrocarbons, carbon disulfide, etc.
It is obtained by gradually dropping terpenes and rosins in the temperature range of ℃ to 200 ℃. To further explain, the presence of an acidic catalyst such as sulfuric acid, hydrochloric acid, phosphoric acid, polyphosphoric acid, boron trifluoride, aluminum trichloride, zinc chloride, paratoluenesulfonic acid, methanesulfonic acid in a mixture of terpenes and rosins. A phenol is added to the terpene / rosin mixture by reacting it with a phenol under the following conditions, and the polymer may be polymerized by further heating this.

The mixing ratio of the terpenes and the rosins is preferably such that the rosins are used in an amount of 0.2 to 5 times the weight of the terpenes 1 by weight. When the amount of rosin is small, the repulsion resistance is poor, and when the amount of rosins is large, both the holding power and the repulsion resistance are poor. On the other hand, the mixture ratio of terpenes and rosins and phenols is preferably 10 to 50 parts by weight of phenols per 100 parts by weight of the mixture.
When the amount of phenols is low, the holding power is poor, and when the amount of phenols is high, the resin is hard and the tack and repulsion resistance are poor, and unreacted phenols are also high, which is industrially uneconomical.

The reaction temperature and time vary depending on the raw materials used, the type of catalyst and the compound produced, but are 0 to 200 ° C. and 3 to
It is usually done for about 30 hours, especially at 20 to 120 ° C for 6 hours.
It is preferable to carry out the reaction for about 15 hours. When the reaction is over,
At the same time as removing the solvent by distillation or the like, the catalyst is decomposed and removed.

The terpene / rosin phenol resin thus obtained is characterized by reaction temperature, reaction time, kind and amount of acidic catalyst, mixing ratio of terpenes and rosins, mixture of terpenes and rosins and phenols. Various resins can be obtained depending on the usage ratio, etc., but in general, in HPLC analysis, there is also an absorption peak with the same retention time as longines phenol resin and terpene phenol resin, but both resins have their own absorption peaks. A peak is recognized, and it can be recognized that the resin has a different composition from the rosin phenol resin and the terpene phenol resin. Also, GPC from rosin phenol resin
It has been confirmed in the analysis that the molecular weight distribution is wide and the average molecular weight is large, while it is smaller than the average molecular weight of the terpene phenol resin. As for the physical properties, the average molecular weight may be in the range of 600 to 2000 (GPC analysis), and the softening point may be 100 ° C. or higher.

Examples of the terpenes include pinene, limonene, isolimonene, camphene, terpinene, terpinolene, ferrandrene, bornylene and the like, and a mixture of them such as α-pinene and β-pinene-based gum terpine oil, pine oil, d- Examples include cyclic monoterpenes such as dipentene mainly composed of limonene.

Examples of rosins include natural rosins such as gum rosin, wood rosin and tall oil rosin, polymerized rosins,
Various known modified rosins such as maleated rosin, fumarized rosin, and formylated rosin can be used.

The phenols include phenol, cresol, t-butylphenol, octylphenol,
Examples thereof include alkyl-substituted phenols and alkoxy-substituted phenols such as nonylphenol and phenylphenol, catechol, resorcinol, hydroquinone, polyhydric phenols such as pyrogallol, halogenated phenols such as chlorophenol and bromophenol, naphthol and dioxynaphthalene. These phenols are
It is selected in consideration of the performance as a tackifying resin and the manufacturing cost, but it is most preferable to use phenol.

In the acrylic pressure-sensitive adhesive composition of the present invention, the composition of the acrylic polymer is not particularly limited, and various known homopolymers or copolymers can be used as they are. That is, acrylic acid 2-
Various acrylate esters such as ethylhexyl, n-butyl acrylate, ethyl acrylate, methyl acrylate,
Methacrylic acid esters such as 2-ethylhexyl methacrylate, n-butyl methacrylate, ethyl methacrylate, and methyl methacrylate, various acrylic acid esters and methacrylic acid esters having a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, and vinyl acetate. It is possible to use a copolymer in which styrene, etc. are used in combination. The method for producing the acrylic polymer is not particularly limited, and the acrylic polymer can be easily produced by appropriately selecting a radical polymerization method such as a solution polymerization method, a suspension polymerization method, or a bulk polymerization method.

A curing agent such as a polyisocyanate compound, a polyamine compound, a melamine resin or an epoxy resin may be added to the acrylic pressure-sensitive adhesive composition of the present invention. Further, if necessary, a filler, an antioxidant, an ultraviolet absorber or the like may be added appropriately.

The present invention will be described below with reference to examples.
The present invention is not limited to each of these examples.

Example 1 Phenol 6 was added to a 1 L four-necked flask.
After 9.2 g (0.74 mol) and 150 g of xylene were charged and dissolved in a nitrogen atmosphere, 56.3 g (0.19 mol) of an ethyl ether complex of boron trifluoride was added. To a 500 ml dropping funnel, 200 g of a 50% solution of gum rosin in xylene (0.30 mol, acid value of gum rosin of 16
9.2) and 100g (0.74mol) of Chinese gum turpentine
Was charged, the dropping was started at an internal temperature of 50 ° C., and the entire amount was dropped in 2 hours. After the dropping was completed, the temperature was raised to 80 ° C. and the reaction was carried out for 2 hours, then cooled to 50 ° C. and 300 g of water was added. 1
Transfer to a L separating funnel, remove the aqueous layer, and add water 30
After washing the xylene layer twice with 0 g, transfer it to a 1 L eggplant flask and reduce the pressure to a vacuum degree of 5 to 10 mmHg on an oil bath at 140 ° C. to recover xylene, unreacted phenol and low boiling point resin. Then, 232.2 g (yield 86.3%) of a terpene / rosin phenol resin was obtained. The resin thus obtained had an acid value of 69 and a softening point of 116 ° C. Acrylic polymer is manufactured by charging 592 parts by weight of ethyl acetate and 592 parts by weight of toluene into a 5 L four-necked flask.
Under a nitrogen atmosphere, 400 parts by weight of 2-ethylhexyl acrylate, 600 parts by weight of n-butyl acrylate, 5 parts of acrylic acid
0 parts by weight, benzoyl peroxide (BPO) 3.2
A part by weight was added, the temperature was raised to 80 ° C., and the reaction was performed for 10 hours. After the reaction was completed, 100 parts by weight of toluene was added to adjust the nonvolatile content. The viscosity of the obtained acrylic resin solution is 60.
The nonvolatile content was 45.1% at 00 cp (25 ° C).
100 parts by weight of the acrylic resin solution thus obtained,
9 parts by weight of the terpene-rosin phenol resin and 1.5 parts by weight of Coronate L (45% nonvolatile content, manufactured by Nippon Polyurethane Industry Co., Ltd.) as a curing agent were mixed to obtain a pressure-sensitive adhesive composition solution. This pressure-sensitive adhesive composition solution is applied to release paper and dried, and then rayon nonwoven fabric (14 g
/ M ² ) was double-sided transferred so that the coating amount on one side was 65 g / m ² to prepare a double-sided tape test piece. The double-sided tape test piece was crosslinked and aged at 20 ° C. for 7 days, and a performance test was conducted.

Example 2 As in Example 1, 69.4 g of phenol
(0.74 mol), xylene 150 g, 97% sulfuric acid 1
3.9 g (0.14 mol) was charged, the internal temperature was raised to 50 ° C., and 100 g of a 50% xylene solution of gum rosin (0.
15 mol) and 100 g (0.74 mol) of Chinese gum turpentine were added dropwise over 2 hours. After completion of the dropping, the mixture was reacted at 80 ° C. for 2 hours, then gradually heated to 250 ° C. while decompressing to a vacuum degree of 100 to 150 mmHg, and xylene, unreacted phenol, and low boiling point resin were collected, and terpene. 194.3 g (yield 88.6%) of phenol resin was obtained. The acid value of the obtained resin was 37 and the softening point was 124 ° C. The production of the acrylic polymer, the preparation of the adhesive composition, and the performance test were performed in exactly the same manner as in Example 1.

[Example 3] 56.5 g (0.60 mol) of phenol
Except that the terpene
Production of rosin phenol resin and acrylic polymer, preparation of adhesive composition, and performance test were conducted. The terpene
The yield of rosin phenol resin is 91.8% and the acid value is 3
2. The softening point was 142 ° C.

Example 4 43.4 g (0.46 mol) of phenol
Except that the terpene
Production of rosin phenol resin and acrylic polymer, preparation of adhesive composition, and performance test were conducted. The terpene
The yield of rosin phenol resin is 92.6% and the acid value is 3
4. The softening point was 143 ° C.

Example 5 A 300% solution of gum rosin in 50% xylene was used.
Except having changed to g (0.45 mol), terpene / rosin phenol resin, acrylic polymer production, adhesive composition preparation, and performance test were conducted in the same manner as in Example 1. The yield of terpene / rosin phenol resin is 9
The acid value was 4.7%, the acid value was 65, and the softening point was 133 ° C.

Example 6 A 50% solution of gum rosin in xylene was added to 150
Except for changing to g (0.23 mol), terpene / rosin phenol resin, acrylic polymer production, adhesive composition preparation, and performance test were conducted in the same manner as in Example 1. The yield of terpene / rosin phenol resin is 8
The softening point was 9.8%, the acid value was 44, and the softening point was 134 ° C.

Example 7 43.4 g (0.46 mol) of phenol and 200 g of 50% gum rosin in xylene.
A terpene / rosin phenol resin, an acrylic polymer were prepared, an adhesive composition was prepared, and a performance test was conducted in the same manner as in Example 2 except that the amount was changed to (0.30 mol).
The yield of terpene / rosin phenol resin was 92.
The acid value was 3%, the acid value was 54, and the softening point was 141 ° C.

Example 8 40 g of 50% xylene solution of gum rosin
(0.06 mol)), terpene / rosin phenol resin, acrylic polymer production, adhesive composition preparation, and performance test were conducted in the same manner as in Example 1. The yield of terpene / rosin phenol resin is 8
The acid number was 7.8%, the softening point was 125 ° C.

Example 9 Phenol 52.3 g (0.56 mol), 97% sulfuric acid 7.0 g (0.07 mol), gum rosin 50% xylene solution 300 g (0.45 mol), Chinese gum turpentine 50 g Instead of (0.37 mol), terpene / rosin phenol resin, acrylic polymer production, adhesive composition preparation, and performance test were conducted in the same manner as in Example 1. The yield of the terpene / rosin phenol resin was 91.0%, the acid value was 88, and the softening point was 133 ° C.

Comparative Example 1 A performance test was conducted in the same manner as in Example 1 except that a commercially available terpene phenol resin A (acid value 0, softening point 120 ° C.) was used instead of the terpene / rosin phenol resin.

Comparative Example 2 A performance test was conducted in the same manner as in Example 1 except that a commercially available terpene phenol resin B (acid value 0, softening point 135 ° C.) was used instead of the terpene / rosin phenol resin.

Comparative Example 3 A performance test was conducted in the same manner as in Example 1 except that a commercially available terpene phenol resin C (acid value 0, softening point 147 ° C.) was used instead of the terpene / rosin phenol resin.

Comparative Example 4 Commercially available rosin phenol resin D (acid value 5
6. A performance test was conducted in exactly the same manner as in Example 1 except that a terpene / rosin phenol resin having a softening point of 152 ° C. was used instead of the terpene / rosin phenol resin.

[Comparative Example 5] 1: 1 mixture of commercially available terpene phenol resin C and rosin phenol resin D (acid value 28, softening point 1
A performance test was conducted in exactly the same manner as in Example 1 except that (48 ° C.) was used instead of the terpene / rosin phenol resin.

Comparative Example 6 20 g of a 50% xylene solution of gum rosin
A terpene / rosin phenol resin, an acrylic polymer were prepared, an adhesive composition was prepared, and a performance test was conducted in the same manner as in Example 1 except that the amount was changed to (0.03 mol).
The terpene / rosin phenol resin yield was 81.
The acid value was 7%, the acid value was 11, and the softening point was 110 ° C.

Comparative Example 7 Phenol 52.3 g (0.56 mol), 97% sulfuric acid 7.0 g (0.07 mol), gum rosin 50% xylene solution 350 g (0.53 mol), Chinese gum turpentine 25 g Instead of (0.19 mol), terpene / rosin phenol resin, acrylic polymer production, adhesive composition preparation, and performance test were conducted in exactly the same manner as in Example 1. The yield of the terpene / rosin phenol resin was 89.4%, the acid value was 105, and the softening point was 138 ° C.

[Comparative Example 8] 14.5 g (0.15 mol) of phenol
A terpene / rosin phenol resin, an acrylic polymer were prepared, an adhesive composition was prepared, and a performance test was conducted in the same manner as in Example 1 except that The yield of terpene / rosin phenol resin is 69.2% and the acid value is 7
5, the softening point was 112 ° C.

[Comparative Example 9] A terpene / rosin phenol resin and an acrylic polymer were produced in exactly the same manner as in Example 2 except that the amount of phenol was changed to 172.5 g (1.83 mol).
An adhesive composition was prepared and a performance test was conducted. The yield of the terpene / rosin phenol resin was 75.1%, the acid value was 28, and the softening point was 116 ° C. Examples 1 to 9 above
The performance tests of Comparative Examples 1 to 9 were examined in the following manner. The results are shown in Table 1. (Tack) A steel ball with a ball number of 20 was rolled from an inclined surface with an angle of 21.5 degrees by the ball rolling method, and the rolling distance of the ball was measured. (Adhesive strength) A polypropylene plate is used as an adherend, and
One side of the mm-width tape was reciprocated once on a polypropylene plate with a 2 kg hand roller to press it, and the strength when peeled at a 180-degree angle and a pulling speed of 300 mm / min was measured. The unit is g / 20 mm width. (Holding power) Adhesive area 20 on SUS304 stainless steel plate
The test tape is reciprocated once with a 2 kg hand roller so as to have a size of 20 mm, pressure-bonded and laminated, and then 1 at 80 ° C in an atmosphere.
The displacement distance was measured after a static load of 1 kg was applied for a period of time. (Repulsion resistance) A test tape having a tape width of 25 mm is reciprocated once with a hand roller of 2 kg to an aluminum plate having a width of 25 mm to perform pressure bonding and bonding. Then tape one side to a length of 150
A 2 kg hand roller is reciprocated once on a plate made of ABS resin having a size of 2 mm, so that it is bonded by pressure. Bend the ABS plate to 140
A curved surface was attached so as to have a height of 30 mm (height: about 30 mm), and the state was maintained in an atmosphere of 60 ° C. for 24 hours, and then the distance lifted from the ABS plate was measured.

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryoichi Fujii 4 Harima Kasei Co., Ltd. at 671 Mizusui, Noguchi Town, Kakogawa City, Hyogo Prefecture

Claims (4)

[Claims] 1. An acrylic pressure-sensitive adhesive composition obtained by blending an acrylic polymer with a tackifying resin, wherein the tackifying resin is a terpene / rosin phenol resin. Agent composition. 2. The terpene-rosin phenol resin is added to a mixture of terpenes and rosins in the presence of an acidic catalyst,
The acrylic pressure-sensitive adhesive composition according to claim 1, which is a product obtained by reacting phenols and heating to polymerize them. 3. The weight ratio of terpenes and rosins, which are constituent components of the terpene / rosin phenol resin, is 1:
The acrylic pressure-sensitive adhesive composition according to claim 1, which is 0.2 to 1: 5. 4. The terpene / rosin phenol resin is a terpene / rosin mixture to which phenol is added in an amount of 10 to 50% by weight, and the resin softening point is 100.
The acrylic pressure-sensitive adhesive composition according to claim 1, which has a temperature of not less than ° C.