JP2000273262A - Acrylic plastisol composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acrylic plastisol which can solve troubles which can occur when functional groups are introduced into the plastisol to cross-link the formed coating films, and can realize improved storage stability and coating film physical properties, and especially to provide an acrylic plastisol which can give sufficient coating film physical properties, even when mixed with a filler, and has a high utility value also in practical uses. SOLUTION: This acrylic plastisol composition contains as essential components (A) acrylic polymer particles which contain reactive functional groups (F1) in core portions, do not contain reactive functional groups that can react with the reactive functional groups (F1) at <=200 deg.C and are different from the reactive functional groups (F1), and have core-shell structures, (B) a plasticizer, and (C) an organic compound which contains two or more reactive functional groups (F2) capable of reacting with the reactive functional groups (F1) at <=200 deg.C and can dissolve or disperse the plasticizer B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a plastisol in which thermoplastic polymer particles are dispersed in a plasticizer. More specifically, the present invention relates to a non-chlorine-based plastisol that does not generate toxic gas or the like during combustion. More specifically, it relates to an acrylic plastisol that achieves excellent physical properties such as storage stability and coating film strength.

[0002]

2. Description of the Related Art Plastisols obtained by dispersing thermoplastic polymer particles in a plasticizer have been used in a wide variety of industrial fields by utilizing their excellent processability and coating film properties. In particular, a plastisol using a vinyl chloride-based polymer is known as a vinyl chloride-based sol (hereinafter, abbreviated as “vinyl sol”). It is widely used in a wide range of industrial fields such as toys and miscellaneous goods. However, in recent years, the adverse effects on the environment of hydrogen chloride gas, dioxin, and the like generated when incinerating a vinyl chloride-based polymer have come to be regarded as a social problem, and the demand for alternative materials to PVC sols has increased. Accordingly, acrylic plastisols (hereinafter abbreviated as acrylic sols) in which acrylic polymer particles are dispersed in a plasticizer have been developed and have attracted attention. Acrylic sol is regarded as a promising alternative to PVC sol in that it has the same form, workability and processability as PVC sol. However, coating films obtained by heating conventional acrylic sols are inferior to PVC sols in terms of strength, durability, rubber elasticity, and the like. It needed to be improved.

[0003] In order to improve the physical properties of the coating film, several methods have been proposed for forming a cross-linking reaction by using heat at the time of forming an acrylic sol. For example, JP-A-6-3222
In JP-A-18, an acrylic polymer particle containing a reactive functional group such as a carboxyl group, an epoxy group, a methylol group, or an etherified methylol group, and a compound capable of reacting therewith, for example, a liquid epoxy compound, a polyamine compound It has been proposed that by blending a polyamideamine compound or the like with a plasticizer as a cross-linking agent, an effect of improving physical properties of a coating film such as creep resistance can be obtained. The invention described in this publication is characterized in that the above-mentioned reactive functional group is present in the shell portion of the acrylic polymer particle. JP-A-7-157622 discloses an acrylic polymer particle having a reactive functional group such as a carboxyl group, an amide group, a hydroxyl group, an amino group, an epoxy group, a methylol group, or an etherified methylol group, and reacts with the acrylic polymer particles. It has been proposed that by blending a polymer which can be used as a crosslinking agent together with a plasticizer, an effect of improving the properties of the coating film such as creep resistance can be obtained. JP-T 8-510277 and JP-A-7-25953 propose a plastisol containing a compound capable of participating in a crosslinking reaction with a polymer at a gelation temperature. However, it is not clarified here what specific compound or functional group is effective to use in what form. Also, in fact, simply blending a compound and a polymer containing a functional group that reacts at the gelation temperature,
In fact, the formation of an effective cross-linking does not progress, and the effect of improving the physical properties of the coating film cannot be obtained unless strict conditions are set.

A common feature of the methods proposed in these publications is that the polymer particles contain a reactive functional group in the whole or in the surface layer (shell portion) and crosslink with the reactive compound present in the plasticizer. It is assumed that.

[0005]

However, the methods proposed by these publications have some serious problems. The first problem is that the reactive functional group is present on the surface layer of the polymer particles. For this reason,
Exists directly in contact with the curing agent compound dissolved or dispersed in the plasticizer, and the reaction progresses gradually during storage of the plastisol, increasing the viscosity over time Or, if it is significant, it gels. That is, the storage stability as a plastisol is extremely poor. Such time-dependent thickening cannot be used except in a very special case where heating and film formation are completed immediately after the plastisol is blended, and the practicability is extremely poor. Generally, the level of storage stability required for plastisols is 35 ° C. or 40 ° C., and sometimes over a week to 10
The degree of thickening over a long period of time, up to one day or one month, is extremely severe, being within tens of percent of the initial viscosity. If the storage stability of the plastisol is insufficient, the plastisol gels inside piping for producing and supplying the plastisol, leading to an abnormal situation such as stopping the production line. In the case where the viscosity increases with time, it is natural that stability and reproducibility cannot be obtained in operations such as coating, and stable process control cannot be performed. Thus, plastisols with poor storage stability cannot be used as substitutes for PVC sols and have low industrial utility. Conversely, when the reactivity of the reactive functional group is suppressed with an emphasis on storage stability, the formation of cross-linking upon heating becomes insufficient, and the effect of cross-linking, which should be expected, is diminished. I will. After all, it is difficult to achieve both the storage stability of plastisol and high reactivity during heating by the method proposed in the above publication.

[0006] The second problem is that the crosslinking speed is too high, so that the process of melting the thermoplastic polymer particles, which is the essence of the plastisol, is not sufficiently performed. According to the above publication, polymer particles containing a reactive functional group are actually produced, and the resulting plastisol is heated to form a coating film and its physical properties are measured, as compared with the case where no reactive functional group is contained. Therefore, strength and elongation are rather reduced. It should be particularly noted that when a filler is added to the plastisol, the physical properties of the coating film are remarkably reduced, and it has been found that, in extreme cases, the film formation itself may not even proceed. It is pointed out that the reason why the physical properties of the coating film deteriorates despite the introduction of the reactive functional group is that the balance between the rate of thermal melting of the polymer particles and the reaction rate of the reactive functional group is not properly controlled. Is done. The formation of a plastisol means that the rate at which the thermoplastic polymer particles absorb the plasticizer by heating is dramatically accelerated, and eventually melts into the plasticizer and becomes uniform, resulting in a physical polymer chain. Entanglement occurs to form a tough continuous coating film. Here, if the cross-linking reaction is to proceed ideally, the cross-linking should be formed after the melting of the polymer particles has completely progressed.

However, in the method proposed by the above publication, since the reactive functional group is present on the surface layer of the polymer particles, the polymer particles react with the crosslinking agent in the plasticizer immediately without melting. , Forming a cross-linking bond. Alternatively, since reactive functional groups capable of reacting with each other coexist in individual polymer particles, a cross-link is formed inside the particles immediately when the polymer particles start to swell.
This behavior is particularly remarkable when a self-crosslinkable functional group proposed in the above-mentioned publication, that is, a methylol group, an etherified methylol group, or the like is used. In this case, the functional groups cannot be expected to crosslink after the polymer particles are melted, and the crosslinking reaction proceeds almost quantitatively inside the particles. In this way, the polymer particles in which cross-links are formed while the polymer particles are still in their morphology, absorb the plasticizer no matter how much heating is applied, and swell, or even heat melt. And a high-quality continuous coating film in which polymer chains are uniformly entangled cannot be formed. It is clear that such film formation failure significantly impairs the properties of the coating film expected from the basic behavior of plastisol.

[0008] The behavior observed in the method proposed in the above-mentioned publication, in which the more the filler is added, the more the film formation state becomes poor, can be easily explained from the mechanism described above. That is, as the filler content increases, the performance as a binder expected from the polymer is more important, and it is necessary that the degree of entanglement of the polymer chains is higher. That is, by maintaining the molten state for a sufficiently long time, the molten polymer molecules can sufficiently fill the voids of the filler, leading to an improvement in the performance as a binder. However, in the method proposed by the above publication, the crosslinking reaction proceeds immediately without waiting for the melting of the polymer particles when heated, suppressing the heat melting of the polymer particles, and a polymer enough to sufficiently fill the voids of the filler. It is considered that a significant film formation failure occurs due to the inability of molecular movement of the molecules. Looking at the current applications of PVC sols, it has been found that in most applications, a large amount of filler such as calcium carbonate is blended for various purposes such as cost reduction and improvement of hardness, or weight increase depending on the application. General. Therefore, when a filler is compounded, it is extremely inconvenient that the coating film strength is remarkably reduced, and its industrial utility value is extremely low.

As described above, although the introduction of a reactive functional group is expected to be effective in improving the properties of a coating film if used properly, it has been proposed in the methods proposed so far. In addition, the storage stability of the plastisol was reduced, and the physical properties of the coating film were reduced due to insufficient thermal melting of the polymer particles, and no improvement effect was obtained.

As another example of blending a reactive compound into a plastisol, for example, JP-A-6-506710, JP-A-5-279439, and the like have suggested that an adhesive agent be blended. . However, the gist of the technology proposed in these publications is to impart reactivity with a base material by blending an adhesive compound, and no consideration is given to reactivity with a polymer.
Therefore, it is not intended to form a cross-linked bond in the coating film after heating, and it is not possible to obtain an effect of improving the physical properties such as the strength and elongation of the coating film and rubber elasticity.

The present invention has been made to solve the above-mentioned problems, and has been made to solve the above-mentioned adverse effects that have occurred when a reactive functional group is introduced into a plastisol to form a crosslink in a coating film. The present invention proposes an acrylic plastisol that realizes improved storage stability and coating film properties. In particular, the present invention proposes an acrylic plastisol which can provide sufficient coating film properties even when a filler is blended and is highly useful in industrial practical use.

[0012]

Means for Solving the Problems As a result of intensive studies on the above-mentioned problems, the present inventors have found that when plastisols have functional groups that can react with each other, the reaction rate is lower than the chemical reaction rate between the functional groups. Have also been found to be largely governed by the location of the functional groups. as a result,
For the different reactive functional groups (F1) and (F2) that can react with each other, one reactive functional group (F1) is present in the center of the polymer particle, that is, the core, and the other reactive functional group (F1) By making F2) dissolved or dispersed in the plasticizer, the balance between the rate of thermal melting of the polymer particles and the rate of formation of the crosslinking reaction was successfully optimized. Further study the combination of reactive functional groups in detail, and from the viewpoint of reaction rate and stability,
It is particularly preferable that a ketoester group and a hydroxyl group are present in the core portion of the polymer particles, and at the same time, a compound containing two or more amino groups and blocked isocyanate groups in a molecule is dissolved or dispersed in a plasticizer. Preferably, they have found that there is a clear improvement effect on the strength and elongation of the coating film, rubber elasticity, and the like, and have reached the present invention.

That is, the acrylic plastisol composition of the present invention comprises (A) a reactive functional group (F1) which contains a reactive functional group (F1) in the core and which can react with the reactive functional group (F1) at 200 ° C. or lower. Are acrylic polymer particles having a core-shell structure not containing a different reactive functional group; (B) a plasticizer; (C) the reactive functional group (F1) at 200 ° C. or lower.
An organic compound containing two or more reactive functional groups (F2) in the molecule capable of reacting with the organic compound and dissolving or dispersing in the plasticizer (B). . Here, (A) the acrylic polymer particles having a core-shell structure have an average primary particle diameter of 400 nm or more, and the ratio of the core portion to the shell portion is converted into the molar ratio of the monomer forming these. Part / shell part = 3
It is desirable to be 0/70 to 70/30. As a combination of the reactive functional group (F1) and the reactive functional group (F2),
(F1) + (F2) in this order: epoxy group + amino group, epoxy group + carboxyl group, β-ketoester group + block isocyanate group, β-ketoester group + epoxy group, carboxyl group + epoxy group, hydroxyl group + block Desirably, any one of an isocyanate group, a hydroxyl group and an epoxy group｝ is preferable, and particularly, any one of an epoxy group + an amino group, a β-ketoester group + blocked isocyanate group, and a hydroxyl group + blocked isocyanate group is preferable.

(A) The monomer composition forming the core of the acrylic polymer particles having a core-shell structure is such that the amount of the monomer containing the reactive functional group (F1) is determined by the total amount of the monomers forming the core. 0.1 to 10.0 mol%
It is desirable that In particular, (A) the monomers forming the core portion and the shell portion of the acrylic polymer particles are the following monomer mixtures (Mc) and (Ms), respectively, and the molar ratio of (Mc) to (Ms) is ( Mc) /
(Ms) = 30/70 to 70/30, and the main component of the (B) plasticizer is preferably a C6-C10 aliphatic alcohol diester of phthalic acid. (Mc) Total 1
Methyl methacrylate: 20 to 84.9 mol% C2 to C8 aliphatic and / or aromatic alcohol (meth) acrylate: 15 to 79.9 mol% Monomer containing reactive functional group (F1): 0.1-1
0.0 mol% Other copolymerizable monomers: 20 mol% or less (Ms) The total is set to 100 mol%. Methyl methacrylate: 50 to 95 mol% (C2 to C8 aliphatic and / or aromatic alcohol (meth) acrylate): 5 to 50 mol% Other copolymerizable monomer: 20 mol% or less

Among them, (B) the main component of the plasticizer is C8-C
It is a phthalic acid diester of an aliphatic alcohol of No. 9 and preferably the following monomer mixtures (Mc) and (Ms). (Mc) The total is 100 mol%, and methyl methacrylate: 20 to 69.9 mol% n-butyl (meth) acrylate and / or i-butyl (meth) acrylate: 30 to 79.9 mol% epoxy group or hydroxyl group or β-keto ester Group-containing monomer: 0.1 to 10.0 mol% Other copolymerizable monomer: 20 mol% or less (Ms) Total is 100 mol%, methyl methacrylate: 60 to 95 mol% n-butyl (meth) acrylate and / or i -Butyl (meth) acrylate: 5 to 40 mol% Other copolymerizable monomer: 20 mol% or less

[0016]

DETAILED DESCRIPTION OF THE INVENTION According to the study of the present inventors, when there are functional groups that react with each other in a plastisol, these reaction rates are largely controlled by where the functional groups are present. Specifically, [1] when the mutually reactive functional groups coexist in the core portion or the shell portion, the reaction is the fastest. [2] When the functional groups reacting with each other are separately localized in the core and the shell, the reaction rate is slightly lower than in [1]. [3] When the functional groups reacting with each other are present separately in the particle and outside the particle, that is,
When one type of functional group is present in the particle and another type of functional group that reacts with it is present in a state of being dissolved or dispersed in the plasticizer independently of the particle, the reaction rate is from [2]. Is further reduced. Among the cases of [3], the case where the functional group present in the particles is localized in the shell part ([3a]) and the case where the functional group is localized in the core part ([3b]) are as follows.
The reaction speed of [b] is much lower than that of [3a].
In summary, the reaction rate was [1]> [2] >> [3a] >>
It was observed that the order was [3b]. That is, it was confirmed that in the plastisol cross-linking reaction, even if the chemical reactivities were the same, the physical factor of the state of separation between the functional groups largely controlled the reaction rate. It was also confirmed that this factor had an effect that exceeded the chemical reactivity in some cases.

The reason why the reaction rate greatly varies depending on the location of the functional group is that the particles start to swell by heating the plastisol, and finally melt to destroy the morphology of the core-shell structure. It can be understood by considering the process. In other words, it takes much longer time for the plastisol particles to sufficiently melt by heat as compared with the chemical reaction rate between the functional groups. This comparison of reaction rates is confirmed by measuring the rheological behavior of each plastisol when heated.

The fact that the reaction rate of cross-linking in a plastisol is too high means that the cross-links are formed while the thermal melting of the polymer particles is insufficient. Such a crosslinking reaction does not meet the original purpose of introducing the crosslinking. Originally, the purpose of cross-linking is to bond the entire coating to form an integrated and tough coating, and to uniformly bond polymer chains that originally existed in different particles It is necessary to let However, if the cross-linking proceeds too quickly, the particles still retain their shape due to incomplete melting of the particles, and the functional groups cross-link with the closest functional groups, i.e., within the same particle. A bond will be formed. As a result, the heating process is intended to convert the polymer particles themselves into crosslinked particles that are not thermally melted, while aiming at the thermal melting of the polymer particles. Once crosslinked inside the particles, the crosslinked particles cannot be melted by heat no matter how much heating is applied, and therefore, no matter how much heating is applied, the film formation state does not progress.

From these observations, it is suggested that in the design of polymer particles for plastisols, it is ideal to isolate functional groups that react with each other in a place where they cannot react until thermal melting is sufficient. It is concluded. That is,
One functional group is located at the center of the particle, that is, the core, and the other functional group is present in the plasticizer. Therefore, in the present invention, a combination of reactive functional groups (F1) and (F2) capable of reacting in a temperature range of 200 ° C. or less, which is a general plastisol film forming condition, is selected. It is important that (F1) is present in the core of the polymer particles (A) and that the reactive functional group (F2) is not present in the polymer particles (A), and that the reactive functional group is used as a plasticizer. It is necessary that two or more of the dissolved or dispersed compounds (C) exist in one molecule. The reason that two or more reactive functional groups (F2) are required in one molecule of the compound (C) is to form a crosslink.

In the present invention, another reason why the reactive functional group (F1) is not present in the shell portion of the polymer particles (A) is to maintain the storage stability of the plastisol.
That is, when the reactive functional group (F1) is present in the shell portion, that is, when the reactive functional group is exposed on the particle surface, the reactive functional group (F1) and the reactive functional group (F1) are dissolved or dispersed in the plasticizer. The reactive functional group (F2) present in the compound (C) present gradually reacts during storage of the plastisol to form a bond, and the entire plastisol is increased in molecular weight by cross-linking to increase its viscosity, and finally to gelation This is because
Therefore, in order to maintain good storage stability of plastisol, it is necessary that the reactive functional groups do not come into contact with each other during storage. For this purpose, the reactive functional groups (F1) must be present on the surface of the polymer particles. Instead, it must be present in the core.

The acrylic polymer particles (A) having a core-shell structure used in the present invention have an average primary particle size of 4%.
The core part (Mc) / shell part (Ms) = 30/70 to 70/30 in terms of the molar ratio of the monomers forming the core part and the shell part.
It is preferred that The intention is that the reactive functional group (F1) contained in the core part is completely covered by the shell part having a sufficient thickness, the storage stability as a plastisol can be maintained, and the melting rate during heating is reduced. This is to prevent excessive reduction. When the ratio of the core portion is less than 30%, the crosslink density in the coating film is lowered due to the shortage of the absolute amount of the reactive functional group (F1), and the improvement effect cannot be expected. Is too high, the time required for the polymer particles to melt and expose the reactive functional group (F1) in the heating film formation process becomes too long, and crosslinks are formed within the prescribed heating conditions. It is not preferable because adverse effects such as the inability to perform such operations occur. Conversely, when the ratio of the core portion is higher than 70%, the thickness of the substantial shell portion becomes insufficient, and it becomes difficult to completely cover the core portion. Therefore, the reactive functional group (F1) is exposed on the particle surface. Increase the storage stability of the plastisol. Also, the timing of exposing the reactive functional group (F1) in the heating film formation process becomes too fast,
It is not preferable because adverse effects such as insufficient realization of thermal melting of the polymer particles are likely to occur.

On the other hand, when the average primary particle size of the polymer particles (A) is less than 400 nm, the thickness of the substantial shell portion becomes insufficient, and the timing of exposing the reactive functional group (F1) in the heating film forming process is reduced. Since the speed is too high, the adverse effect that sufficient thermal melting of the polymer particles cannot be realized is likely to occur. Further, the average primary particle diameter of the polymer particles (A) is 400
In the case of less than nm, the specific surface area of the polymer giving a constant mass is significantly larger than in the case where the particle diameter is larger than this, so that there is an adverse effect that the viscosity of the plastisol increases and the workability decreases, so that it is preferable. Absent.

The preferred combination of the reactive functional group (F1) and the reactive functional group (F2) in the present invention is (F1) + (F
In the order of 2), epoxy group + amino group, epoxy group + carboxyl group, β-ketoester group + blocked isocyanate group, β-ketoester group + epoxy group, carboxyl group + epoxy group, hydroxyl group + blocked isocyanate group, hydroxyl group + epoxy Group. More preferably, (F
1) In the order of + (F2), there are an epoxy group + amino group, β-ketoester group + blocked isocyanate group, hydroxyl group + blocked isocyanate group. The combination of these functional groups has sufficiently high reactivity, and has the ability to rapidly form a cross-linking at a plastisol film formation temperature of 200 ° C. or less. At the same time, since these reactive functional groups (F1) have substantially no self-crosslinking properties, it is possible to prevent the polymer particles from forming crosslinks in the particles before melting. In these respects, the above functional groups are suitable in the gist of the present invention. Unsuitable reactive functional groups (F1) are self-crosslinkable functional groups such as methylol groups,
And etherified methylol groups. These functional groups correspond to the case [1] described above, and can react with each other no matter where they are present in the polymer particles, and thus hinder the melting of the polymer particles. Considering that the method for producing polymer particles having a core-shell structure as used in the present invention is generally emulsion polymerization of an aqueous medium, the functional groups that decompose or deactivate by reacting with water are reactive. Functional group (F
Not suitable as 1). The functional group mentioned here as the reactive functional group (F1) can be contained in the polymer particles relatively stably during the emulsion polymerization. Readily available.
Many types of the functional groups listed here as the reactive functional group (F2) are industrially prepared as compounds that can be dissolved or dispersed in a plasticizer. Therefore, it can be selected widely according to the intended use and required performance of the plastisol, and is suitable for optimizing physical properties.

In the present invention, the amount of the monomer containing the reactive functional group (F1) among the monomers forming the core of the acrylic polymer particles (A) having a core-shell structure is determined by the amount of the monomer forming the core. 0.1 to the total amount
It is preferably 10.0 mol%. If the amount of the reactive functional group (F1) is less than 0.1 mol%, a sufficient cross-linking density cannot be obtained, and the effect of improving the physical properties of the coating film is hardly observed. Conversely, a reactive functional group (F1)
When the amount is more than 10.0 mol%, the crosslinking density becomes too high, and the coating film is not plasticized well, loses flexibility and becomes hard and brittle. Therefore, it is not preferable because physical properties such as flexibility and rubber elasticity, which are characteristics of the plastisol coating film, cannot be obtained. At the same time, since a coating film having a too high crosslinking density has a low plasticizer retention, a phenomenon in which the plasticizer bleeds out with time is observed. This is not preferred because it not only impairs the physical properties of the coating film but also causes contamination with a plasticizer.

The preferred range of the monomer composition for forming the core is that the total of the monomers for forming the core is 100 mol.
1%, methyl methacrylate is 20 to 8
4.9 mol%, (meth) acrylic acid ester of C2-C8 aliphatic and / or aromatic alcohol is 15-79.
9 mol%, the monomer containing the reactive functional group (F1) is 0.1 to 10.0 mol%, and the other copolymerizable monomer is 20 mol%. When the ratio of methyl methacrylate is lower than 20 mol%, or C2 to C8
When the ratio of the (meth) acrylate of the aliphatic and / or aromatic alcohol is higher than 79.9 mol%, the compatibility of the core with the plasticizer is too high,
During storage of the sol, the core absorbs the plasticizer and swells, which tends to increase the sol viscosity. Conversely, when the ratio of methyl methacrylate is higher than 84.9 mol%, or when the ratio of (meth) acrylate of C2 to C8 aliphatic and / or aromatic alcohol is lower than 15 mol%, the plasticity of the core portion is reduced. Since the compatibility with the agent is too low, the plasticizer retainability of the coating film becomes insufficient, and the plasticizer tends to bleed out. Other copolymerizable monomers are selected according to the required performance depending on the application, but the copolymerization ratio is at most 20 mol%, and if the ratio is increased further, the compatibility of the core with the plasticizer is optimized. It is likely to be out of range. A more preferable range of the monomer composition is as follows: when the total of the monomers forming the core portion is 100 mol%, methyl methacrylate is 20 to 69.9 mol%, and n-butyl (meth) is used.
Acrylate and / or i-butyl (meth) acrylate is 30 to 79.9 mol%, and epoxy group or hydroxyl group or β-keto ester group-containing monomer is 0.1 to 10.
0 mol%, 20 mol of other copolymerizable monomers
1% or less. In this case, the storage stability of the plastisol can be satisfied even under the strict requirement of 10 days or more at 40 ° C., and a coating film excellent in plasticizer retention is formed.

The preferred range of the monomer composition for forming the shell portion is that when the total of the shell monomers is 100 mol%, the methyl methacrylate content is 50 to 95 mol%.
%, (Meth) acrylic acid ester of C2 to C8 aliphatic and / or aromatic alcohol is 5 to 50 mol%, and other copolymerizable monomers are 20 mol% or less.
When the ratio of methyl methacrylate is lower than 50 mol%, or when the (meth) acrylate of a C2 to C8 aliphatic and / or aromatic alcohol is higher than 50 mol%, the compatibility of the shell part with the plasticizer is too high. Therefore, during storage of the sol, the shell part absorbs the plasticizer and swells, causing an increase in the sol viscosity, or the resin particles are likely to be completely dissolved in the plasticizer and gelled. Conversely, when the ratio of methyl methacrylate is higher than 95 mol%, or when the (meth) acrylate of a C2 to C8 aliphatic and / or aromatic alcohol is 5 mol%
%, The compatibility of the shell part with the plasticizer is too low, and the plasticizer retention of the coating film becomes insufficient.
It tends to cause the plasticizer to bleed out. Other copolymerizable monomers are selected according to the required performance depending on the application, but the copolymerization ratio is 2 at the maximum.
If the ratio is further increased, the compatibility of the shell portion with the plasticizer is likely to be out of the optimum range. A more preferable range of the monomer composition is as follows: when the total of the shell monomers is 100 mol%, methyl methacrylate is 60 to 95 mol%, and n-butyl (meth) acrylate and / or i-butyl (meth) acrylate is 5 to 40 mol%. The amount of other copolymerizable monomers is 20 mol% or less. In this case, the storage stability of the plastisol can be satisfied even under the strict requirement of 10 days or more at 40 ° C., and the plasticizer has excellent plasticizer retention. Form a film.

The method for producing the acrylic polymer particles (A) having a core-shell structure used in the present invention is not particularly limited.
It can be widely used such as emulsion polymerization, dispersion polymerization, fine suspension polymerization, suspension polymerization, etc. Especially, a method of producing an aqueous emulsion by polymerization in an aqueous medium, drying it and recovering polymer solids Is common. As a polymerization method in an aqueous medium, emulsion polymerization, in particular, seed polymerization in which seed particles are polymerized stepwise is generally used. As a method for recovering the polymer solid content, a spray drying method, a coagulation method, a freeze drying method and the like are known, and among them, the spray drying method is general.

The plasticizer (B) used in the present invention is not particularly limited, and plasticizers and the like used in PVC sols can be widely used. Specifically, dimethyl phthalate,
Diethyl phthalate, dibutyl phthalate, di-n-hexyl phthalate, di-n-octyl phthalate, di-
Dialkyl phthalate plasticizers such as 2-ethylhexyl phthalate, di-i-nonyl phthalate and di-i-decyl phthalate; alkylbenzyl phthalate plasticizers such as butyl benzyl phthalate; other phthalate plasticizers; di-2-ethylhexyl Aliphatic dibasic acid ester plasticizers such as azelate, dimethyl adipate, dibutyl adipate, di-2-ethylhexyl adipate, di-i-decyl adipate, dibutyl sebacate, di-2-ethylhexyl sebacate, dibutyl glycol adipate, etc. Ether-containing plasticizer, trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl-2-ethyl Phosphate-based plasticizers such as hexyl phosphate, further benzoic acid ester plasticizers, polyester plasticizers such as phthalate esters and adipic acid esters, such as epoxy-based plasticizers are available. It is also possible to use a plurality of these plasticizers in combination. In particular, it is desirable to use a phthalic acid diester of a C6 to C10 aliphatic alcohol as a main component (50% by weight or more). Further, it is more desirable that a phthalic acid diester of a C8-C9 aliphatic alcohol be a main component (50% by weight or more).

The monomer having a reactive functional group (F1) used in the present invention is not particularly limited. For example, when the reactive functional group (F1) is an epoxy group, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether and the like can be used. Available. In addition, the reactive functional group (F1) has β
In the case of a ketoester group, acetoacetoxyethyl methacrylate, acetoacetoxyethyl acrylate and the like can be used. When the reactive functional group (F1) is a hydroxyl group, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxypropyl acrylate,
-Hydroxybutyl methacrylate, 4-hydroxybutyl acrylate and the like can be used. When the reactive functional group (F1) is a carboxyl group, methacrylic acid, acrylic acid, itaconic acid, crotonic acid and the like can be used.

Examples of (meth) acrylates of C2 to C8 aliphatic and / or aromatic alcohols used in the present invention include ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) Acrylate,
s-butyl (meth) acrylate, t-butyl (meth)
Acrylate, cyclohexyl (meth) acrylate,
Examples include 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, and phenyl (meth) acrylate. Examples of other copolymerizable monomers used in the present invention include styrene, α-methylstyrene, vinyl acetate, acrylonitrile, acrylamide and the like. These are selected according to different required performances depending on the application. For example, when importance is placed on hardness, styrene is preferred, and when importance is placed on flexibility, vinyl acetate is preferred.

The organic compound (C) which contains two or more reactive functional groups (F2) in the molecule and which can be dissolved or dispersed in the plasticizer (B) and which satisfies the above requirements is used in the present invention. If it is, there is no particular limitation. For example, when the reactive functional group (F2) is an amino group, aliphatic polyamines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine; fatty acid-modified polyamidoamines obtained by amidating polyamines such as ethylenediamine with a fatty acid dimer; In addition, among compounds generally used as a curing agent for an epoxy resin, those satisfying the above-mentioned conditions and the like can be arbitrarily used.
When the reactive functional group (F2) is a blocked isocyanate group, examples thereof include compounds obtained by reacting an aromatic isocyanate such as tolylene diisocyanate or an aliphatic isocyanate such as alkylene diisocyanate with an alkyl-substituted phenol or the like as a blocking component. Can be When the reactive functional group (F2) is an epoxy group, a bisphenol A type epoxy resin or the like can be used. When the reactive functional group (F2) is a carboxyl group, examples thereof include a carboxyl group-containing polymer obtained by copolymerizing a carboxyl group-containing monomer with another monomer.

The plastisol composition of the present invention can contain various fillers and the like according to the intended use. Examples of fillers include calcium carbonate, aluminum hydroxide, paraiter, clay, colloidal silica, mica powder,
Examples include silica sand, diatomaceous earth, kaolin, talc, glass powder, and aluminum oxide. Examples of additives other than the above, pigments such as titanium oxide and carbon black,
Diluents such as mineral terpenes and mineral spirits, as well as defoamers, fungicides, antibacterial agents, deodorants, surfactants, lubricants, UV absorbers, fragrances, foaming agents, leveling agents, adhesives, etc. It is possible.

The plastisol composition of the present invention can be used in many of the same applications as for PVC sols. Examples of applications include car body sealers, car undercoats, wallpaper, cushion floors, cosmetics, flooring materials such as tile carpet backings, toys, food samples,
Miscellaneous goods, adhesives, steel plate paints, dip coat paints, and the like. Examples of the method for processing the plastisol composition of the present invention include calendering, slashing, dipping, spraying, and rolling.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. The evaluation methods in the examples are as follows unless otherwise specified.

[Viscosity] The prepared plastisol was heated at 25 ° C.
After adjusting the temperature, the viscosity was measured using a BH type viscometer (Pa · s).
Was measured (No. 7 rotor, 20 rpm). For the reading of the scale of the viscometer, a value one minute after the start of rotation was used. The evaluation criteria are as follows. When a filler is blended ：: less than 20 ：: 20 or more and less than 30 ：: 30 or more and less than 50 ×: 50 or more When no filler is blended ◎: less than 15 ○: 15 or more and less than 25 Δ: 25 or more and less than 40 ×: 40 or more

[Storage stability] After the viscosity of the prepared plastisol was measured, it was sealed and stored in a thermostat at 40 ° C for 10 days. Then, after taking out from the thermostat and adjusting the temperature to 25 ° C., the viscosity was measured, and the thickening rate (%) with respect to the initial viscosity was determined by the following formula. Thickening rate = ([viscosity after storage] − [initial viscosity]) / [initial viscosity] × 100 Evaluation criteria are as follows. When a filler is added ◎: less than 30% ○: 30% or more and less than 60% ：: 60% or more and less than 100% ×: 100% or more When no filler is added ◎: less than 50% ：: 50% or more and less than 100 Δ: 100% or more and less than 150% ×: 150% or more

[Preparation of Coating Film and Measurement of Strength and Elongation] A glass plate (thickness: 2) coated with a releasing agent was applied to the prepared plastisol.
mm) to a uniform thickness of 2 mm.
This was heated in an oven at 140 ° C. for 20 minutes to obtain a coating film. This was cut into a dumbbell No. 3 shape, and a tensile test (tensile speed: 200 mm / min) was performed using a Tensilon measuring instrument to measure the strength (MPa) and elongation (%). The evaluation criteria are as follows. Strength When a filler is blended ２: 2.0 or more ○: 1.5 or more and less than 2.0 Δ: 1.0 or more and less than 1.5 ×: less than 1.0 When no filler is blended ◎: 3.5 ○: 2.5 or more and less than 3.5 Δ: 1.5 or more and less than 2.5 ×: less than 1.5 Elongation When a filler is blended ：: 200 or more 以上: 150 or more and less than 200 △: 100 or more and 150 or less Less than ×: less than 100 When no filler is blended ：: 200 or more ○: 150 or more and less than 200 Δ: 100 or more and less than 150 ×: less than 100

[Plasticizer Retention] The coating film obtained by the above method was stored at 25 ° C. for one week, and then the bleed out of the plasticizer from the coating film surface was visually evaluated. The evaluation criteria are as follows, both with and without the filler. ○: No bleed-out ×: Bleed-out

Example 1 <Preparation of Acrylic Polymer Particles (A1)> A 5-liter four-necked flask was equipped with a stirring blade, a thermometer, a cooling pipe, and a nitrogen ventilation pipe, and pure water (1200 g) was added thereto. ) And 150
Nitrogen gas was sufficiently ventilated while stirring at rpm. Thereafter, methyl methacrylate (24.0 g) and n-butyl methacrylate (24.0 g) were added, and the internal temperature was 80
The temperature was raised to ° C. When the internal temperature reached 80 ° C., potassium persulfate (0.60 g) was added to pure water (24.0 g).
And an aqueous solution of the initiator dissolved therein was added to initiate polymerization. The inner solution became cloudy within a few minutes, giving seed particles having excellent monodispersibility. 30 minutes after the addition of the aqueous initiator solution, methyl methacrylate (336.7 g), n-butyl methacrylate (341.3 g), glycidyl methacrylate (34.1 g), sodium dialkyl sulfosuccinate (trade name: Perex O) -TP (Kao Corporation), 6.
00g) and pure water (300.0 g) were added dropwise over 2 hours while maintaining the internal temperature at 80 ° C, and then maintained for 1 hour to complete polymerization of the core. Subsequently, methyl methacrylate (499.0 g), n-butyl methacrylate (145.1 g), sodium dialkyl sulfosuccinate (trade name: Perex O-TP (Kao Corporation), 6.00 g), pure water (300.0 g) ) Was added dropwise over 2 hours while maintaining the internal temperature at 80 ° C., and then maintained for 1 hour to complete polymerization of the shell portion. The obtained acrylic polymer emulsion had a solid content of 44%, a volume average particle diameter of 660 nm, and a number average particle diameter of 6%.
40 nm, volume average particle diameter / number average particle diameter =
1.03, indicating high monodispersity. Next, this acrylic polymer emulsion was pulverized using a spray dryer to obtain dried acrylic polymer particles (A1) having a residual moisture content of less than 1.0% by weight.

<Evaluation of plastisol and evaluation of coating film>
Based on 100 parts by weight of the obtained acrylic polymer particles (A1), 140 parts by weight of diisononyl phthalate, 100 parts by weight of calcium carbonate, and 5.0 parts by weight of a fatty acid dimer-modified polyamidoamine are blended, and heat is not applied by a disper mixer. The mixture was stirred with care and defoamed under reduced pressure to obtain a plastisol in which the polymer particles (A1) were well dispersed in a plasticizer. The viscosity of the obtained plastisol is 16.2 Pa · s, and the storage stability is 17%.
And was good. The strength of the coating film obtained from this plastisol was 2.5 MPa, the elongation was 380%, and the plasticizer retention was good.

[Examples 2 to 25] <Production of polymer particles (A2) to (A21)> In the same manner as in the case of the acrylic polymer particles (A1), the polymerization was carried out according to the monomer composition shown in Table 1. United particles (A2) to (A
21) was obtained. The average particle diameter of the primary particles of these polymer particles is also shown in Table 1. Using these polymer particles, a plastisol was prepared according to the formulation shown in Tables 2 to 4 and evaluated. Table 5 shows the results.
However, in Example 25, a plastisol was prepared without blending a filler and evaluated, and the results are shown in Table 6.

Comparative Examples 1 to 11 The polymer particles (A22) to (A26) used in Comparative Examples 1 to 11 were prepared as follows. <Preparation of polymer particles (A22) to (A23)>
Polymer particles (A22) were prepared in the following manner, roughly according to the method described in JP-A-322218. That is, after preparing seed particles in the same manner as in Example 1, methyl methacrylate (475.0) was used.
g) and a mixture of glycidyl methacrylate (25.0 g) was dropped into the seed particle dispersion to perform polymerization. Sodium hydroxide was added at 4% by weight based on the solid content of the obtained polymer emulsion, and hydrolysis was carried out at 95 ° C. for 5 hours to obtain a dispersion of polymer particles having carboxyl groups distributed on the particle surface. The pH was adjusted to acidic with dilute hydrochloric acid, and the solid content was recovered by a coagulation method to obtain polymer particles (A22). In the same manner, the monomer composition was changed to methyl methacrylate (400.0 g), n-butyl acrylate (6
0.0 g), N-methylolacrylamide (50.0 g)
g) to obtain polymer particles (A23).

<Preparation of Polymer Particles (A24) to (A25)> The polymer particles (A24) were prepared in the following manner substantially according to the method described in JP-A-7-157622.
Was prepared. That is, methyl methacrylate (36
0.0g), styrene (50.0g), acrylic acid (1
5.0 g), 2-hydroxyethyl methacrylate (2
5.0 g) of the mixture was subjected to fine suspension polymerization in the presence of a dispersant to obtain a polymer dispersion. This was spray-dried in the same manner as in Example 1 to obtain polymer particles (A24).
I got In a similar manner, the monomer composition was changed to methyl methacrylate (350.0 g), styrene (50.0 g),
Polymer particles (A25) were obtained by changing to n-butyl acrylate (35.0 g), acrylic acid (15.0 g), and N-butoxymethylacrylamide (25.0 g).

<Preparation of polymer particles (A26)>
Approximately following the method described in US Pat.
Polymer particles (A26) were prepared. That is, the first embodiment
For the seed particles prepared by the same method as described above, styrene (150.0) was used as a monomer for forming the core.
g), and styrene (70.0 g) and methyl methacrylate (15.0 g) as monomers forming a shell portion.
g), a mixture of methacrylic acid (15.0 g) was added dropwise,
Polymerization was performed. The obtained polymer emulsion was prepared in Example 1.
Spray-dry by the same method as described above, and polymer particles (A
26) was obtained. <Evaluation of plastisol and evaluation of coating film> Comparative Example 1,
Nos. 4, 6, 8, and 10 prepared plastisols without blending a filler and evaluated. Comparative Examples 2, 3, 5, 7, 9,
In No. 11, a plastisol was prepared by blending a filler and evaluated. For Comparative Examples 1 to 11, the polymer (A2
2) to (A26), the same plasticizers as those described in the publications referred to when preparing (A26) were used. The formulation of the plastisol is shown in Table 4. Table 6 shows the physical properties of the obtained plastisol and the coating film.

[0045]

[Table 1]

The abbreviations in Table 1 are as follows. MMA: methyl methacrylate nBMA: n-butyl methacrylate GMA: glycidyl methacrylate AAEM: acetoacetoxyethyl methacrylate 4HBA: 4-hydroxybutyl acrylate MAA: methacrylic acid

[0047]

[Table 2]

The abbreviations in Table 2 are as follows. DINP: diisononyl phthalate DOP: di-2-ethylhexyl phthalate CaCO ₃ : calcium carbonate

[0049]

[Table 3]

The abbreviations in Table 3 are as follows. DINP: diisononyl phthalate CaCO ₃ : calcium carbonate

[0051]

[Table 4]

The abbreviations in Table 4 are as follows. DINP: diisononyl phthalate BPBG: butyl phthalyl butyl glycolate BBP: butyl benzyl phthalate ATBC: acetyl tributyl citrate CaCO ₃ : calcium carbonate

[0053]

[Table 5]

[0054]

[Table 6]

[Consideration of Examples and Comparative Examples] <Examples 1, 2, and 3> In Example 1, an epoxy group was used as a reactive functional group in the core portion, and a fatty acid dimer-modified polyamidoamine was used as a compound that reacted with the epoxy group. Is used. The viscosity of the plastisol was 16.2 Pa · s, and the storage stability was good at 17%. The strength of the coating film obtained from this plastisol was extremely good at 2.5 MPa,
Elongation and plasticizer retention were good. Example 2 used a β-ketoester group as a reactive functional group in the core,
In this case, a blocked isocyanate is used as a compound that reacts with this. The other polymer composition was obtained in Example 1.
Is the same as Also in this case, both the viscosity and storage stability of the plastisol were good, and the strength of the coating film was very good. Elongation and plasticizer retention were good.
Example 3 uses a hydroxyl group as a reactive functional group in the core portion,
In this case, a blocked isocyanate is used as a compound that reacts with this. The other polymer composition was obtained in Example 1.
Is the same as Also in this case, both the viscosity and storage stability of the plastisol were good, and the strength of the coating film was very good. Elongation and plasticizer retention were good.

Example 4 In Example 4, the same polymer (A1) as in Example 1 was used, and the plasticizer was changed from diisononyl phthalate to di-2-ethylhexyl phthalate. In this case as well, the viscosity and storage stability of the plastisol were both very good, and the strength and elongation of the coating film and the plasticizer retention were also very good.

<Examples 5 and 6> Examples 5 and 6 are examples in which the composition of the polymer was changed. In the fifth embodiment, n
-Increase the butyl methacrylate ratio, n-
The butyl methacrylate ratio was lowered. In Example 6, conversely, the ratio of n-butyl methacrylate in the core portion was decreased, and the ratio of n-butyl methacrylate in the shell portion was increased. In each case, the viscosity, storage stability, and the strength, elongation, and plasticizer retention of the coating film of the plastisol were extremely good, and it was found that the physical properties were extremely good within this composition range.

Examples 7 and 8 Examples 7 and 8 are examples in which the composition of the polymer was changed and i-butyl methacrylate was used instead of n-butyl methacrylate. In Example 7, the i-butyl methacrylate ratio in the core was high,
The i-butyl methacrylate ratio in the shell is low. Conversely, in Example 8, the i-butyl methacrylate ratio in the core portion was low, and the i-butyl methacrylate ratio in the shell portion was high. In each case, the viscosity, storage stability, and strength, elongation, and plasticizer retention of the coating film were very good, and it was found that the physical properties were very good within this composition range.

<Examples 9 and 10> Examples 9 and 10 are examples in which the ratio of the core part to the shell part of the polymer was changed.
The ninth embodiment has a core portion ratio of 70 mol%, and the tenth embodiment has a core portion ratio of 30 mol%. In each case, the viscosity, storage stability, and strength, elongation, and plasticizer retention of the coating film were very good, and it was found that the physical properties were very good within this composition range.

<Embodiments 11 and 12> Embodiments 11 and 1
2 is an example in which the composition of the polymer was changed. In Example 11, the ratio of n-butyl methacrylate in the core portion was further lower than that in Example 5. In this case, the viscosity of the plastisol, the storage stability, the strength of the coating film, and the retention of the plasticizer were very good. The elongation of the coating film was slightly lower than that of Example 5, but was good. Example 12 is an example in which the ratio of n-butyl methacrylate in the shell portion was higher than that in Example 6. In this case, the elongation of the coating film was extremely good. The viscosity, storage stability, and strength of the coating film of plastisol were slightly lower than those of Example 6, but were good.

Examples 13, 14, 15, 16 Examples 13 to 16 are also examples in which the composition of the polymer was changed. In the thirteenth embodiment, the n-butyl methacrylate ratio of the core portion is lower than that in the eleventh embodiment. In this case, the viscosity of the plastisol, the storage stability, the strength of the coating film, and the retention of the plasticizer were very good. Although the elongation of the coating film was slightly lowered, it was good. In Example 14, n-
The ratio of butyl methacrylate is higher than in Example 5. In this case, the viscosity of the plastisol and the elongation of the coating film were very good. The storage stability of the plastisol and the strength of the coating film were slightly reduced but good. Example 15 is a case where n-butyl methacrylate in the shell part was deleted. In this case, the viscosity, storage stability, and strength of the coating film of the plastisol were very good. Although the elongation of the coating film was slightly lowered, it was good. Example 16 is a case where the ratio of n-butyl methacrylate in the shell portion was further higher than that in Example 12.
In this case, the elongation of the coating film was extremely good. The plastisol viscosity, storage stability, and coating strength were slightly reduced but good.

Example 17 Example 17 is an example in which the average particle size of the polymer particles was reduced. The composition of the polymer is the same as in Example 1. In this case, the strength, elongation, and plasticizer retention of the coating film were extremely good. The viscosity and storage stability of plastisol were slightly reduced but good.

Embodiments 18 and 19 Embodiments 18 and 1
Reference numeral 9 denotes an example in which the ratio between the core and the shell is changed. In Example 18, the ratio of the core portion was further reduced to 20 mol% as compared with the case of Example 10. In this case, the viscosity, storage stability, and strength of the coating film of the plastisol were very good. The elongation of the coating film was slightly reduced but good. In Example 19, the ratio of the core portion was further increased to 80 mol% as compared with the case of Example 9. In this case, the elongation of the coating film was extremely good. The viscosity of plastisol,
The storage stability and the strength of the coating film were slightly reduced but good.

<Embodiments 20 and 21> Embodiments 20 and 2
1 is an example in which the amount of the reactive functional group in the core portion was changed. Examples 20 and 21 both use an epoxy group as the reactive functional group. The amount of glycidyl methacrylate, which is a monomer that gives an epoxy group, was 0.05 mol% in Example 20 and 15.0 mol% in Example 21 with respect to the total amount of monomers forming the core portion. In Example 20, the viscosity, storage stability, and elongation of the coating film of the plastisol were extremely good. The strength of the coating film was slightly lower than that of Example 1 but good. In Example 21, the plastisol viscosity, storage stability, and coating film strength were extremely good. Although the elongation of the coating film was lower than that of Example 1, it was good.

Example 22 Example 22 is an example in which the combination of the reactive functional groups (F1) and (F2) was changed. In Example 1, an epoxy group and an amino group were used as a more preferable combination example. In Example 22, a carboxyl group and an epoxy group were used. Methacrylic acid was used as a monomer providing a carboxyl group, and bisphenol type epoxy resin was used as a compound having an epoxy group. In this case, the viscosity, storage stability, and elongation of the coating film of the plastisol were very good. The strength of the coating film was slightly lower than that of Example 1, but was good.

<Examples 23 and 24> Examples 23 and 2
4 is an example in which the same polymer (A1) as in Example 1 was used and the compound to be reacted therewith was changed. In Example 23, ethylenediamine was used instead of the fatty acid-modified polyamidoamine, and in Example 24, hexamethylenediamine was used instead of the fatty acid-modified polyamidoamine. In each case, the viscosity, storage stability, strength and elongation of the plastisol were very good.

Example 25 Example 25 is an example in which the same polymer (A1) as in Example 1 was evaluated without blending a filler. In this case, the strength of the coating film was more excellent than that of Example 1.

<Comparative Examples 1, 2, 3, 4, 5> Comparative Examples 1
5 are polymer particles (A22) and (A2) prepared according to the method described in JP-A-6-322218.
This is an example in which 3) was used to separately evaluate the case where a filler was compounded and the case where no filler was compounded. However, since it is necessary to select a plasticizer suitable for the composition of the polymer, the plasticizer specified in the above publication was used. Comparative Example 1 is an example evaluated using polymer particles (A22) without compounding a filler. In this case, the storage stability of the plastisol was poor, and the strength of the coating film was slightly insufficient. It is considered that the reason why the storage stability of the plastisol was poor was that a carboxyl group was present on the surface of the polymer particles and reacted with the epoxy resin mixed in the plastisol.
Comparative Example 2 is an example in which a filler was blended using the same polymer (A22). In this case, the strength of the coating film was significantly reduced. The storage stability of plastisol was also poor. This is the same when the reactive compound to be blended was changed from an epoxy resin to a fatty acid-modified polyamidoamine (Comparative Example 3), and the strength of the coating film was significantly reduced. The reason why the strength of the coating film is remarkably reduced when the filler is blended in this way is that the melting of the polymer particles is reduced due to the presence of the reactive functional group in the shell portion of the polymer particles, and the gap between the fillers is reduced. This is probably because the polymer molecules are prevented from penetrating into the polymer. Comparative Example 4 is an example evaluated using the polymer particles (A23) without blending a filler. In this case, the storage stability of the plastisol was poor, and the strength of the coating film was slightly insufficient. Comparative Example 5 is an example in which a filler was blended using the same polymer particles (A23) and evaluated. Also in this case, the coating film strength was significantly reduced as compared with Comparative Example 4.

Comparative Examples 6, 7, 8, and 9 Comparative Examples 6 to 9 are examples using polymer particles (A24) and (A25) prepared according to the method described in JP-A-7-157622. It is. However, since it is necessary to select a plasticizer suitable for the composition of the polymer, the plasticizer specified in the above publication was used. Comparative Examples 6 and 7 were polymer particles (A2
This is an example using 4). A carboxyl group and a hydroxyl group are used as reactive functional groups, and a bisphenol A type epoxy resin is blended as a reactive compound. Comparative Example 6 is an example evaluated without a filler. In this case, the storage stability of the plastisol was poor, and the coating strength was slightly reduced. Comparative Example 7 is an example in which a filler was blended using the same polymer particles (A24). In this case, the strength of the coating film was significantly reduced as compared with Comparative Example 6. Comparative Examples 8 and 9 are examples using the polymer particles (A25). A carboxyl group and an etherified methylol group are used as reactive functional groups, and a bisphenol A type epoxy resin is blended as a reactive compound. Comparative Example 8 is an example evaluated without adding a filler. In this case, the storage stability of the plastisol was poor, and the coating film strength was reduced. Comparative Example 9 is an example in which a filler was blended using the same polymer particles (A25). In this case, the strength of the coating film was significantly reduced as compared with Comparative Example 8.

<Comparative Examples 10 and 11> Comparative Examples 10 and 1
No. 1 is an example using polymer particles (A26) prepared according to the method described in JP-A-7-25953. A carboxyl group is used as a reactive functional group, and a bisphenol A type epoxy resin is used as a reactive compound. However, since it is necessary to select a plasticizer suitable for the composition of the polymer, the plasticizer specified in the above publication was used. Comparative Example 10 was an example evaluated without blending a filler, in which the storage stability of plastisol was poor and the strength of the coating film was slightly insufficient. Comparative Example 11 was an example in which a filler was compounded and evaluated. In this case, the strength of the coating film was significantly reduced as compared with Comparative Example 10.

[0071]

As described in detail above, the acrylic plastisol of the present invention can improve the storage stability and the strength of the coating film, which have become problems when introducing a crosslinking system with a reactive functional group. . In particular, the effect is remarkable even when a large amount of filler is blended, and the industrial significance and effect are remarkable.

In particular, when the acrylic polymer particles (A) have an average primary particle diameter of 400 nm or more and a specific ratio of the core to the shell, the reactive functional group contained in the core is obtained. (F1) is completely covered by the shell portion having a sufficient thickness, so that the storage stability as a plastisol can be maintained at a higher level, and the melting rate during heating can be prevented from excessively decreasing. In addition, a reactive functional group (F
By making the combination of 1) and the reactive functional group (F2) specific, the reactivity becomes higher, and a cross-linking can be rapidly formed at a plastisol film formation temperature of 200 ° C. or less. In addition, it is possible to prevent the formation of cross-links in the polymer particles before the particles are melted. Further, the amount of the monomer containing the reactive functional group (F1) among the monomers forming the core of the acrylic polymer particles (A) is 0.1 to 1
By setting the amount to 0.0 mol%, the effect of improving the properties of the coating film is increased by making the crosslinking density sufficient, and the coating film can be plasticized well to have flexibility. Therefore, physical properties such as flexibility and rubber elasticity, which are characteristics of the plastisol coating film, can be obtained. In addition, bleeding out of the plasticizer over time can be prevented.

In particular, when the monomer forming the core of the acrylic polymer particles (A) is the one described in claim 6, the swelling due to the absorption of the plasticizer in the core during storage of the sol and the sol viscosity The rise can be prevented. Moreover, the plasticizer retainability of the coating film is good, and bleed out of the plasticizer can be prevented. Further, the compatibility of the core with the plasticizer is preferable. Further, by providing (A) the monomer forming the shell portion of the acrylic polymer particles as described in claim 6, the compatibility of the shell portion with the plasticizer is appropriate, and the plasticity of the shell portion during storage of the sol is improved. Swelling due to absorption of the agent,
An increase in sol viscosity or gelation can be prevented. And,
The plasticizer retainability of the coating film is sufficient, and bleed out of the plasticizer can be prevented. Further, the compatibility of the shell portion with the plasticizer becomes appropriate. In particular, by satisfying the condition of claim 7, the storage stability of plastisol is 1 at 40 ° C.
Strict requirements such as 0 days or more can be satisfied, and a coating film excellent in plasticizer retention can be obtained.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08K 5/00 C08K 5/00 4J100 C08L 33/10 C08L 33/10 51/00 51/00 C09D 133/10 C09D 133 / 10 F term (reference) 4J002 AA064 BG04X BG05X BG06W BG06X BP031 CD003 CD054 CF003 EH096 EH126 EH146 EN037 EN047 EP017 ER007 EW046 FD010 FD023 FD026 FD090 FD144 FD147 GH01 AJAA A26A00 AJ00 BA32 BA34 DA03 DA04 DB03 DB04 EA08 EA09 EA10 FA03 FA07 GA09 HE01 4J034 BA03 DA01 DA05 DB03 DB07 DP03 DP18 HA01 HA07 HC03 HC12 HC61 HC71 HD03 QC10 RA03 RA07 RA08 RA10 4J036 AD01 AK09 AK11 DC02 FA01 FB03 CH01 CH04 JA03 DB062 DG262 GA02 GA03 GA06 GA07 GA09 GA11 JA61 JB04 JB05 JB12 KA10 MA03 MA14 NA11 NA26 NA27 4J100 AB02R AB03R AE18S AG04R AJ01S AJ02S AJ08S AL03P AL03Q AL04Q AL08Q AL08S AL09S AL10S AL15Q14 BC15 BC15 BC15 06 EA11 FA34 JA01 JA03 JA67

Claims (7)

[Claims] (A) A core shell containing a reactive functional group (F1) in a core portion and containing no reactive functional group different from the reactive functional group (F1) capable of reacting at 200 ° C. or lower. Acrylic polymer particles having a structure;
(B) a plasticizer; (C) a reactive functional group (F2) capable of reacting with the reactive functional group (F1) at a temperature of 200 ° C. or lower in the molecule.
An acrylic plastisol composition characterized by comprising, as an essential component, an organic compound which contains at least one and is soluble or dispersible in the plasticizer (B). 2. The acrylic polymer particles (A) having a core-shell structure have an average primary particle diameter of 400 nm.
2. The method according to claim 1, wherein the ratio of the core part to the shell part is 30/70 to 70/30 in terms of the molar ratio of the monomers forming them. Acrylic plastisol composition. 3. The combination of the reactive functional group (F1) and the reactive functional group (F2) is (F1) + (F2) in this order: {epoxy group + amino group, epoxy group + carboxyl group, 3. The method according to claim 1, wherein the group is any one of a β-ketoester group + blocked isocyanate group, a β-ketoester group + epoxy group, a carboxyl group + epoxy group, a hydroxyl group + blocked isocyanate group, and a hydroxyl group + epoxy group. Acrylic plastisol composition. 4. The combination of the reactive functional group (F1) and the reactive functional group (F2) is as follows: (F1) + (F2) in this order: epoxy group + amino group, β-ketoester group + blocked isocyanate group 4. The acrylic plastisol composition according to claim 3, wherein the composition is any one of a hydroxyl group and a blocked isocyanate group. 5. The monomer composition for forming the core portion of the acrylic polymer particles having the core-shell structure (A), wherein the amount of the monomer containing the reactive functional group (F1) is determined by the amount of the monomer forming the core portion. 0.1 to the total amount
The amount is 10.0 mol%.
The acrylic plastisol composition according to any one of the above. 6. The (A) monomers forming the core and shell of the acrylic polymer particles are the following monomer mixtures (Mc) and (Ms), respectively:
The molar ratio of (Mc) to (Ms) is (Mc) / (Ms) = 3
The acrylic according to any one of claims 1 to 5, wherein the main component of the plasticizer (B) is a phthalic acid diester of a C6 to C10 aliphatic alcohol. A plastisol composition. (Mc) The total is 100 mol%, and methyl methacrylate: 20 to 84.9 mol% C2 to C8 (meth) acrylic acid ester of aliphatic and / or aromatic alcohol: 15 to 79.9 mol% Reactive functional group (F1) Monomer containing: 0.1 to 1
0.0 mol% Other copolymerizable monomers: 20 mol% or less (Ms) The total (Ms) is 100 mol%, and methyl methacrylate: 50 to 95 mol% (meth) acrylate of C2 to C8 aliphatic and / or aromatic alcohol: 5 to 50 mol% Other copolymerizable monomer: 20 mol% or less 7. The (A) monomers forming the core part and the shell part of the acrylic polymer particles are the following monomer mixtures (Mc) and (Ms), respectively:
The molar ratio of (Mc) to (Ms) is (Mc) / (Ms) = 3
The acrylic plastisol composition according to claim 4, wherein the plasticizer (B) is a phthalic acid diester of a C8-C9 aliphatic alcohol in a ratio of 0/70 to 70/30. (Mc) The total is 100 mol%, and methyl methacrylate: 20 to 69.9 mol% n-butyl (meth) acrylate and / or i-butyl (meth) acrylate: 30 to 79.9 mol% epoxy group or hydroxyl group or β-keto ester Group-containing monomer: 0.1 to 10.0 mol% Other copolymerizable monomer: 20 mol% or less (Ms) Total is 100 mol%, methyl methacrylate: 60 to 95 mol% n-butyl (meth) acrylate and / or i -Butyl (meth) acrylate: 5 to 40 mol% Other copolymerizable monomer: 20 mol% or less