JPS5814474B2 - Soft PVC molded body for pressure-sensitive adhesive - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a soft PVC molded body for pressure-sensitive adhesives that is widely used as pressure-sensitive adhesive sheets, films, tapes, etc., and its main purpose is to improve adhesiveness, holding power, weather resistance, etc. The object of the present invention is to provide the above-mentioned molded product having excellent properties.

Conventionally, compositions mainly consisting of synthetic or natural rubber and low-molecular-weight firefighter resins have often been used as pressure-sensitive adhesive components in soft PVC moldings for pressure-sensitive adhesives, such as pressure-sensitive polyvinyl chloride tapes and sheets. However, these have the disadvantage that they have insufficient weather resistance and aging resistance, resulting in significant deterioration when used at high temperatures or outdoors for long periods of time.

On the other hand, in adhesive compositions that use conventional acrylic polymer-based compositions, which have excellent weather resistance and aging resistance by themselves, the cohesive force is significantly reduced by the plasticizer, and There is a drawback that the holding power is significantly deteriorated due to the blended plasticizer and the plasticizer that is transferred orally from the soft polyvinyl chloride resin molding that is the support to the adhesive side, and in order to improve this. There was a problem in that when a large amount of crosslinking agent was used, the initial adhesive properties deteriorated.

As a result of intensive research in light of the above-mentioned circumstances, the inventors discovered that an addition polymer obtained by addition-polymerizing a specific acrylic polymer with a specific ethylenically unsaturated monomer and a plasticizer. In a soft polyvinyl chloride molded product for pressure-sensitive adhesive use, in which a pressure-sensitive adhesive composition containing the pressure-sensitive adhesive composition is applied to the surface of a soft polyvinyl chloride-based resin molded product, there is almost no significant decrease in cohesive force due to the above-mentioned plasticizer, and the adhesive composition is The present inventors have discovered that the adhesive composition has excellent properties and also has good anchoring properties to a support, leading to the completion of this invention.

That is, this invention consists of a soft polyvinyl chloride resin molded body and a pressure-sensitive adhesive composition applied to the surface of the molded body,
The pressure-sensitive adhesive composition contains 50 to 99.95% by weight of a main monomer consisting of an ester of acrylic acid or methacrylic acid and an aliphatic alcohol having 8 or less carbon atoms, and 0% by weight of an unsaturated monomer having a polar group. Glass transition of a homopolymer or copolymer is added to an acrylic polymer having an average molecular weight of about 100,000 or more, consisting of 0.05 to 20% by weight and O to 30% by weight of a vinyl monomer copolymerizable with these monomers. 2 points
The present invention relates to a soft vinyl chloride molded article for pressure-sensitive adhesive use, characterized in that it contains an addition-polymerizable polymer obtained by addition-polymerizing at least one ethylenically unsaturated monomer that can have a temperature of 73°K or more, and a plasticizer.

The acrylic polymer used in this invention has acrylic acid or meccrylic acid as main monomers and 8 carbon atoms.
Esters with the following aliphatic alcohols are used.

The reason why the number of carbon atoms in the aliphatic alcohol is set to be 8 or less is that if the number of carbon atoms is larger than this, the adhesiveness of the adhesive composition to the soft polyvinyl chloride resin molded body will be significantly reduced.

Such main monomers include aliphatic alcohols whose alkyl groups are methyl, ethyl, butyl, isobutyl,
Examples include esters of acrylic acid or methacrylic acid consisting of hexyl group, heptyl group, octyl group, inoctyl group, 2-ethylhexyl group, and the like.

These are used in a proportion of 50 to 99.95% by weight based on the total monomers.

The unsaturated monomer with a polar group used together with this main monomer is intended to improve the adhesion of the acrylic polymer to the soft polyvinyl chloride resin molded body.
Examples of polar groups include those that can impart polarity to the acrylic polymer, such as carboxyl groups, hydroxyl groups, amide groups, nitrile groups, epoxy groups, substituted amino and amide groups (for example, N-hydroxyalkylamide and N-alkoxyalkylamide). Widely applicable.

Specifically, acrylic acid, meccrylic acid, crotonic acid, maleic acid, itaconic acid, 2-hydroxypropyl acrylate, 2-methylhydroxyethyl acrylate, N
．． N-dimethyl (ethyl) acrylate, bis-N. N
-dimethylaminoethyl maleate, (meth)acrylamide, N-methylolacrylamide, glycidyl (
Examples include meth)acrylate and acrylonitrile.

These unsaturated monomers with polar groups account for 0.0 of the total monomers.
It is used in a proportion of 5 to 20% by weight.

In addition, if necessary, an arbitrary vinyl monomer that can be copolymerized with the above-mentioned main monomers and unsaturated monomers having polar groups is added in an amount of O to 30% by weight based on the total monomers. You can also use

Examples include vinyl acetate, vinyl propionate, styrene and its derivatives, vinyl chloride, and the like.

The acrylic polymer (hereinafter referred to as base polymer) consisting of such a monomer structure is sticky at room temperature, but its molecular weight is about 100,000 or more, preferably about 200,000 to 1,000,000. It is necessary to have an average molecular weight.

When the average molecular weight is lower than 100,000, the cohesive force decreases significantly, which is inappropriate.

Next, in this invention, it is important to further add-polymerize a specific ethylenically unsaturated monomer to the above-mentioned pace polymer, and by this addition polymerization, a large cohesive force that cannot be obtained with the pace polymer alone is obtained. The force-increasing effect makes the reduction in cohesion by the plasticizer almost negligible, with very good results for the adhesive properties.

On the other hand, if a homopolymer (or copolymer) is made alone from a specific ethylenically unsaturated monomer used for addition polymerization and blended with a pace polymer, no significant improvement in cohesive force is observed. Moreover, the decrease in adhesive strength cannot be ignored, and the adhesive composition cannot be made suitable.

Furthermore, if a specific ethylenically unsaturated monomer used for addition polymerization is added during the synthesis of the base polymer and copolymerized at the same time, either adhesive strength, adhesive strength, or cohesive strength will be extremely low. It is also not suitable.

The specific ethylenically unsaturated monomer used for addition polymerization is one or more unsaturated monomers whose homopolymer or copolymer has a glass transition point of 273°K or higher, preferably 300°K or higher. It is a monomer.

Here, if the glass transition point of the homopolymer or copolymer is lower than 273°K, a sufficient effect of improving the cohesive force cannot be obtained.

Among the two or more unsaturated monomers that can make the copolymer have a glass transition point of 273°K or more, there are monomer mixtures that can make the homopolymer of each monomer have a glass transition point of 273°K or more. It also includes a mixture of an unsaturated monomer whose homopolymer has a glass transition point of 273°K or higher and an unsaturated monomer whose homopolymer has a glass transition point of lower than 273°K.

The latter monomer mixture may be one that can exhibit a glass transition point of 273°K or higher when formed into a copolymer depending on its composition ratio.

For example, n-butyl acrylate (below 273°K): methyl methacrylate (above 300°K): itaconic acid (
A monomer mixture of 300'K or higher) = 15:65:15 is applicable because the glass transition point of the copolymer is 273°K or higher.

The inventors have discovered that the unsaturated monomer is selected from the group of styrene, vinyl acetate, acrylonitrile and mecrylonitrile, and the glass transition point of the homopolymer thereof can be 300°K or more. Is it a monomer?
Alternatively, an unsaturated monomer whose glass transition point can be 273°K or higher in a homopolymer selected from the group of acrylic esters, methacrylic esters, or styrene derivatives (hereinafter, unsaturated monomers belonging to both groups are referred to as component A). We have found that monomers (referred to as monomers) are particularly suitable.

Specific examples of unsaturated monomers belonging to the latter group include cyclohexyl acrylate (289°K), methyl acrylate (279°K), and n-butyl methacrylate (293°K).
), N. N dimethylaminoethyl methacrylate (28
9°K), hexadecyl methacrylate (288°K),
2-Me1-xyethyl methacrylate (286°K), 4
- unsaturated monomers whose homopolymer glass transition temperature can be 273°K or higher, such as butylstyrene (279'K), and 2-butyl meccrylate (318°K), 3.
3-dimethylbutyl methacrylate (318°K), 3
・3-dimethyl-2-butyl methacrylate (381°K), ethyl methacrylate (338°K), glycidyl methacrylate (319°K), isobornyl methacrylate (383°K), isobutyl methacrylate (326°K)
°K), isopropyl methacrylate (354 °K),
Methyl meccrylate (378°K), phenyl methacrylate (378°K), n-probyl meccrylate (3
08°K), inbornyl acrylate (367°K)
, 4-tert-butylstyrene (403°K), 2.
4-Diisopropylstyrene (441°K), 2,5-
Dimethylstyrene (416°K), 3,4-diethylstyrene (382'K), 2-hydroxymethylstyrene (433°K), 4-methylstyrene (366°K),
There are unsaturated monomers such as 2-methylstyrene (366°K) whose homopolymer glass transition temperature can be 300°K or higher.

Among these unsaturated monomers belonging to the latter group, those whose homopolymer glass transition point can be 300°K or higher are desirable, and among these, methyl methacrylate is most preferred.

In this invention, it is preferable to use one or more of these A component monomers selected from one or both of the two groups depending on the type of pace polymer.
Furthermore, an unsaturated monomer (hereinafter referred to as a component B monomer) which can be copolymerized with these component A monomers and whose copolymer has a glass transition point of 273°K or higher is used in combination. Good too.

Such B component monomers include unsaturated monomers whose homopolymers can have a glass transition temperature of 273°K or higher, such as acrylic acid, methacrylic acid, and iconic acid, as well as n-butyl acrylate and ethyl acrylate. , the glass transition temperature of its homopolymers such as 2-ethylhexyl acrylate is 2.
One or more monomers used in general acrylic pressure-sensitive adhesives, such as unsaturated monomers with a temperature lower than 73°K, are used.

The amount of these component B monomers to be used is one of the factors that determines the glass transition point of the copolymer, so it may be determined appropriately according to the types of both component monomers A and B, taking this point into consideration. Generally, 95% by weight or less, preferably 3% by weight in all monomers.
It is preferable to set it to 0 weight ratio or less.

In this invention, when addition polymerizing such an ethylenically unsaturated monomer to a pace polymer, either a solution polymerization method in which an organic solvent is included in the addition polymerization system or a bulk polymerization method in which no solvent is used at all is adopted. It's okay.

The solution polymerization method not only provides good polymerization workability, but also allows the organic solvent used to effectively act as a chain transfer agent during the polymerization reaction, suppressing excessive addition polymerization reactions, and reducing the molecular weight of the paste polymer from its original value. Such organic compounds have very good results in preventing gelation during polymerization reactions, such as when polymerization is high, and in controlling the addition polymer and the homopolymer (or copolymer) partially formed together with this polymer to a suitable molecular weight. Examples of solvents are toluene, benzene,
xylene, hexane, hepkun, n-octane, isooctane, ethyl acetate, acetone, methyl ethyl ketone,
Examples include methanol, ethanol, isopropanol, and the like.

Note that the organic solvent used for forming the base polymer may be used as is.

The amount of organic solvent used is usually 5 to 900 parts by weight, preferably about 25 to 400 parts by weight, based on 100 parts by weight of the base polymer. If this amount is too large, the amount of addition polymerization polymer formed will be small. Since a large amount of homopolymer is produced, the effect of the present invention cannot be obtained sufficiently.

When determining the amount to be used, take into consideration the type of ethylenically unsaturated monomer, the ease of chain transfer of the organic solvent to the monomer radical, the composition or molecular weight of the base polymer, and other factors such as the amount of polymerization initiator. For example, when vinyl acetate is used as an ethylenically unsaturated monomer, the amount should be usually 5 to 70 parts by weight per 100 parts by weight of the pace polymer. When using a component A monomer other than vinyl, the proportion is preferably 5 to 4 pO parts by weight.

In addition, it is generally preferable to use organic solvents such as ethyl acetate and benzene, which have small chain transfer constants, or to use a large amount of solvent for acrylic polymers with very high molecular weights; conversely, toluene, which has a large chain transfer constant, It is better to use a smaller amount of solvent when using an organic solvent such as isopropanol or for a base polymer with a relatively low molecular weight.

On the other hand, in such a bulk polymerization method that does not contain a solvent, a base polymer with the lowest possible molecular weight is selected, and when a base polymer with a high molecular weight is used, an appropriate chain transfer agent is included in the polymerization system. Care should be taken to prevent gelation during polymerization and to prevent the addition polymerization reaction from proceeding excessively.

The above-mentioned chain transfer agents include a wide variety of conventionally known chain transfer agents such as thioglycol, thioglycolic acid, butylmercabutane, and laurylmercabutane.

The amount used may be about 0.01 to 0.1 part by weight, preferably about 0.03 to 0.6 part by weight, per 100 parts by weight of the ethylenically unsaturated monomer.

In such solution polymerization or bulk polymerization, the blending ratio of the base polymer and the ethylenically unsaturated monomer is generally 5 to 200 parts by weight, preferably 5 to 200 parts by weight of the ethylenically unsaturated monomer to 100 parts by weight of the base polymer. The amount is 10 to 150 parts by weight.

If this amount is too large, even if the cohesive force can be improved, the adhesive force will be significantly reduced.

Of course, the amount used depends on the composition and molecular weight of the pace polymer used, the type of ethylenically unsaturated monomer, and the solution weight, in order to prevent gelation during the polymerization reaction and to prevent the addition polymerization reaction from proceeding too much. The optimum range should be appropriately determined depending on whether a bulk polymerization method or a bulk polymerization method is used, and in the case of a solution polymerization method, the type of organic solvent used, and the optimum range differs considerably depending on various embodiments.

In general, when a base polymer with a high molecular weight is used, compared to when a pace polymer with a low molecular weight is used, and when the above A component monomer other than vinyl acetate is used as an ethylenically unsaturated monomer, the same is true. Compared to when vinyl acetate is used as a monomer, when bulk polymerization is used, compared to when solution polymerization is used, and when an organic solvent with a small chain transfer constant is used in solution polymerization. It is better to use a smaller amount of ethylenically unsaturated monomer than when using a monomer with a large number of identifications.

In addition, some ethylenically unsaturated monomers have strong reactivity between the functional groups contained in them and the functional groups contained in the base polymer, and in such cases gelation due to the reaction between the two may be prevented. The amount used must be set within an appropriate range from the viewpoint of

Although the addition polymerization initiation reaction of the present invention can be carried out using energy such as light or electron beam, it may be carried out using a general radical polymerization catalyst that is normally used for forming the base polymer.

This catalyst contains azo compounds such as azobisisobutyronitrile and various organic peroxides, and the use of organic peroxides has particularly good results in improving adhesion and cohesion. be done.

Examples of such organic peroxides include penzoyl peroxide, cumene hydroperoxide, and di-tert-
Examples include butyl peroxide, tert-butyl peroxybenzoate, lauroyl peroxide, ketone peroxide, tert-butyl peroxy 2-ethylhexanoate, methyl ethyl ketone peroxide, and cyclohexanone peroxide.

The amount of polymerization catalysts such as organic peroxides and azo compounds used is about 0.01 to 5 parts by weight, preferably about 0.05 to 3 parts by weight, based on 100 parts by weight of the ethylenically unsaturated monomer. be.

The temperature of the addition polymerization reaction greatly affects the molecular weight of the addition polymerized polymer obtained as well as the amount of polymerization catalyst used, so it is best to set it appropriately depending on the required molecular weight, but generally the temperature is about 50 to 90°C. You can do it with

Of course, it is also possible to carry out the addition polymerization reaction using a redox catalyst, and in this case it may be carried out at about room temperature.

The polymerization reaction product obtained in this manner contains some homopolymers or copolymers of ethylenically unsaturated monomers as a polymer component, but mainly contains an addition-polymerized polymer obtained by addition-polymerizing the base polymer.

The molecular weight of the adduct in this addition polymerization almost corresponds to the molecular weight of the homopolymer or copolymer, and can be varied depending on the selection of the conditions of the addition polymerization reaction, but is generally about 1,000 to 100,000, preferably about 1,000 to 100,000. It is about 5,000 to 70,000.

Note that this molecular weight is determined by G. P. C. It can be easily determined from the molecular weight distribution curve obtained by the method.

As mentioned above, the pressure-sensitive adhesive composition used in the present invention contains a plasticizer as an essential component together with the above-mentioned addition polymer.

This plasticizer imparts appropriate tackiness to the adhesive composition to provide good adhesion to the adherend, and when used together with the addition polymerization polymer, the soft polyvinyl chloride resin molded support. However, the reduction in cohesive force of the addition-polymerized polymer due to this plasticizer is negligible.

Examples of the plasticizer include dioctyl phthalate,
Low molecular plasticizers such as dibutyl phthalate, diisodecyl phthalate, dihexyl phthalate, dioctyl sebacate, dioctyl adipate, diisononyl phthalate, adipic acid polyester, sebacic acid polyester having a molecular weight of about 1,000 to 3,000. , polymeric plasticizers such as adelic acid polyester and phthalic acid polyester, epoxy plasticizers such as epoxidized soybean oil and epoxidized fatty acids, and trimellitic acid ester plasticizers. The amount is usually 2 to 30 parts by weight, preferably 5 to 20 parts by weight, based on 100 parts by weight of the base polymer.

A pressure-sensitive adhesive composition containing such an addition polymer and a plasticizer can be applied as it is to the surface of a flexible polyvinyl chloride resin molded product to create a pressure-sensitive adhesive with excellent adhesive properties. Although it can be a vinyl chloride molded product, it may also contain a general crosslinking agent in order to further increase the cohesive force of the adhesive composition and improve its adhesive properties.

Examples of the crosslinking agent include ethyl etherified methylolmelamine, butyl etherified methylolmelamine,
Tolylene diisocyanate, hexamethylene diinocyanate, alkylphenol, zinc acetate, tin chloride,
Examples include calcium oxide, penzoyl peroxide, and diglycidyl ether of bisphenol A.

The amount of these compounded may be small, and the amount of the base polymer used
About 0.001 to 1.5 parts by weight per 100 parts by weight is sufficient.

Furthermore, the pressure-sensitive adhesive composition used in the present invention may contain various additives such as colorants, fillers, anti-aging agents, and tackifiers, if necessary.

The soft polyvinyl chloride resin molded body to which the above-mentioned pressure-sensitive adhesive composition is applied may be soft polyvinyl chloride resin molded into various shapes such as sheets, films, tapes, or vinyl chloride-acetic acid. Includes copolymers of vinyl chloride and other monomers such as vinyl copolymers, which contain various plasticizers such as dioctyl phthalate and dibutyl phthalate, as well as stabilizers, fillers, colorants, and flame retardants. , impact-resistance-modifying polymers, and other various commonly used ingredients may be appropriately blended as needed.

This invention will be explained in more detail with reference to Examples below.
This invention is not limited to these, and various modifications can be made without departing from the technical idea of this invention.

In the examples, parts mean parts by weight, and adhesive strength, holding power, and weather resistance were measured by the following methods.

<Adhesive Strength> The 180° peeling adhesive strength (g/19 mm) was measured based on JISC-2336.

<Holding power> Polyester adhesive tape (Nitto Denko A31B) on the back
) on a Bakelite board.
A load of 300 g was applied at 40° C., and the time (minutes) until the loaded object fell was measured.

Weather Resistance The sample tape was left in a weather meter under accelerated conditions for 216 hours, equivalent to one year of outdoor exposure, and the time until the adhesive composition hardened and lost its tackiness was measured.

Example 1 100 parts of a monomer mixture consisting of 70 parts of n-butyl acrylate, 30 parts of 2-ethylhexyl acrylate, and 3 parts of acrylic acid, 200 parts of toluene, and 0.1 part of penzoyl peroxide were charged into a three-necked flask. After stirring for 60 minutes while purging with nitrogen, the temperature was raised to 62°C and a polymerization reaction was carried out for 7 hours.

The obtained polymer solution contained an acrylic polymer having an average molecular weight of about 250,000 and was sticky at room temperature.

Next, after cooling this polymer solution to 50°C, 30 parts of n-butyl methacrylate (glass transition point of homopolymer 293' K) and this monomer 1
After adding 1 part of penzoyl peroxide to 00 parts, and purging the system with nitrogen for 30 minutes, the temperature was raised to 75°C.
A time addition polymerization reaction was performed.

The addition polymer thus obtained has a molecular weight of G. P. C. It was 25,000.

To the solution containing this addition polymerization polymer, 10 parts of dioctyl phthalate as a plasticizer and 0.2 parts of zinc acetate as a crosslinking agent were added to 100 parts of the acrylic polymer to prepare an adhesive composition.

This adhesive composition was applied to a PVC film with a thickness of 0.15 mm having a composition in which 50 parts of dioctyl phthalate, 0.8 parts of cadmium stearate, and 0.8 parts of barium stearate were mixed with 100 parts of polyvinyl chloride resin. 2 on top
Apply to a dry film thickness of 5 to 32μ and heat at 130°C.
After drying for 5 minutes, it was wrapped around a core to obtain a pressure-sensitive adhesive polyvinyl chloride tape.

Example 2 As a monomer for addition polymerization, n-butyl methacrylate 30
A monomer mixture consisting of 9.98 parts of n-butyl methacrylate and 1 part of n-probyl methacrylate (glass transition point of the copolymer: 294°K)
A pressure-sensitive adhesive polyvinyl chloride tape was prepared in the same manner as in Example 1, except that .

Comparative Example 1 In the acrylic polymer solution obtained by the method of Example 1,
An adhesive composition was prepared by adding 10 parts of dioctyl fucrate and 0.2 parts of zinc acetate to 100 parts of the acrylic polymer, and using this adhesive composition, a polychloride for pressure-sensitive adhesive was prepared in exactly the same manner as in Example 1. Made of vinyl table.

Comparative Example 2 Into the acrylic polymer solution obtained by the method of Example 1,
To 100 parts of acrylic polymer, 10 parts of dioctyl phthalate, 1 part of zinc acetate, and 0.2 parts of Epicoat 828 (manufactured by Ciba Geigy, liquid epoxy crosslinking agent) were added to prepare an adhesive composition, and this adhesive A pressure-sensitive adhesive polyvinyl chloride tape was prepared using the composition in exactly the same manner as in Example 1.

Comparative Example 3 The monomer mixture for addition polymerization described in Example 1 was
An acrylic polymer having an average molecular weight of about 220,000 and consisting of n-butyl acrylate, 2-ethylhexyl acrylate, and n-butyl meccrylate is added together to the polymerization system when forming the acrylic polymer solution described in . A polymer solution containing 100% of the above polymer is added to this solution.
10 parts of dioctyl phthalate and 0.2 parts of zinc acetate were added to prepare an adhesive composition. Using this adhesive composition, a polyvinyl chloride tape for pressure-sensitive adhesive was prepared in exactly the same manner as in Example 1.

Comparative Example 4 SBR (manufactured by Nippon Zeon Co., Ltd., Nipol #1502) 5
0 parts, 50 parts of natural rubber, tackifier (Yasu Oil Co., Ltd. YS
An adhesive composition was prepared consisting of 60 parts of #900 (terpene type), 3 parts of an anti-aging agent (Sumilizer BHT, manufactured by Sumitomo Chemical Co., Ltd.), 5 parts of dioctyl phthalate, and 300 parts of toluene.

Next, the surface of the PVC film described in Example 1 was undercoated in accordance with a conventional method, and the above adhesive composition was applied thereon so that the dry film thickness was 25 to 32μ, and then heated at 130°C. After drying for 5 minutes, it was wrapped around a core to obtain a pressure-sensitive adhesive polyvinyl chloride tape.

The following table shows the results of measuring the adhesive properties and weather resistance of each of the polyvinyl chloride tapes for pressure-sensitive adhesives obtained in the above Examples and Comparative Examples.

As is clear from the above table, the sample tapes of Examples 1 and 2, which are PVC molded products for pressure-sensitive adhesives of the present invention, have excellent adhesive strength, holding power, and weather resistance, but they do not contain specific ethylene as an adhesive component. Comparative Example 1, which uses an acrylic polymer without addition polymerization of sexually unsaturated monomers, has extremely poor holding power. Comparative Example 3, in which an ethylenically unsaturated monomer was used as a copolymerization component of an acrylic polymer rather than an addition polymer, had very weak adhesive strength, and a comparison using an ordinary rubber adhesive composition Example 4
The weather resistance of these materials is significantly inferior to that of the above-mentioned examples.

Claims (1)

[Scope of Claims] 1. Consisting of a soft polyvinyl chloride resin molded body and a pressure-sensitive adhesive composition applied to the surface thereof, the pressure-sensitive adhesive composition is composed of acrylic acid or methacrylic acid and carbon Main monomer consisting of ester with aliphatic alcohol of number 8 or less, 50 to 99.95 weight percent, unsaturated monomer having polar group 0.05 to 20 weight percent, and copolymerized with these monomers. An acrylic polymer having an average molecular weight of about 100,000 or more and consisting of a possible vinyl monomer of 0 to 30% by weight, and an ethylenically unsaturated monomer that can have a homopolymer or copolymer glass transition temperature of 273°K or more. A soft vinyl chloride molded article for pressure-sensitive adhesive use, characterized in that it contains an addition-polymerized polymer obtained by addition-polymerizing at least one polymer, and a plasticizer. 2. The soft vinyl chloride molded article for pressure-sensitive adhesive use according to claim 1, which contains 2 to 30 parts by weight of a plasticizer based on 100 parts by weight of an acrylic polymer having an average molecular weight of about 100,000 or more.