JP2010024373A - Plastisol composition and article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a (meth)acrylic polymer particle having good storage stability and deformation recovery properties, a plastisol composition, and an article obtained therefrom. <P>SOLUTION: The plastisol composition includes a (meth)acrylic polymer particle (A) containing a t-butyl methacrylate monomeric unit (a), and a basic compound (B) or a moisture absorbent (C). The article obtained by applying the plastisol composition is also provided. The basic compound (B) has a basic functional group showing basicity derived from an unshared electron pair. Actually, amine compounds such as a polyamino amide, an aliphatic polyamine, an alicyclic polyamine and an aromatic polyamine; hydrazide compounds such as an adipic acid dihydrazide (ADH) and a sebacic acid dihydrazide (SDH); a dicyandiamide; and the like are included. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plastisol composition and article comprising (meth) acrylic polymer particles having good storage stability and good deformation recovery of a coating film.

Plastisol in which polymer fine particles are dispersed using a plasticizer as a medium is used in various industrial fields such as automobile undercoat, automobile body sealer, wallpaper, carpet backing material, flooring material, paint, and toy.
Conventionally, most of the plastisols are vinyl chloride sols using vinyl chloride polymer particles, but in recent years, (meth) acrylic plastisols using (meth) acrylic polymer particles (hereinafter referred to as “methacrylic” polymer particles) The transition to “acrylic sol” is under consideration. Since acrylic sol does not contain halogen elements, it does not generate hydrogen halide gas that causes harmful dioxins or acid rain when the product is incinerated.

Various proposals have been made regarding acrylic sols. For example, Patent Documents 1 and 2 disclose plastisol compositions using acrylic polymer particles containing t-butyl methacrylate monomer units. Although these compositions had good storage stability, their deformation recovery properties were insufficient.
Patent Document 3 discloses an acrylic sol containing acrylic polymer fine particles, a block type urethane resin, and a solid hydrazine-based curing agent. The hydrazine-based curing agent is added to improve adhesion, cold resistance of the coating film, and coating film strength by forming a urea bond with the urethane resin. However, the use of t-butyl methacrylate as the monomer unit constituting the acrylic polymer fine particles has not been disclosed, and it has been impossible to achieve both deformation recovery and storage stability.
WO03 / 004568 brochure JP-A-7-102147 JP 2001-329135 A

  An object of the present invention is to provide (meth) acrylic polymer particles, a plastisol composition, and an article to be obtained that have good storage stability and deformation recovery.

The present inventor has found that by suppressing the decomposition of t-butyl (meth) acrylate, a plastisol composition excellent in both storage stability and deformation recovery can be obtained, and the present invention has been achieved.
That is, the first gist of the present invention is that a (meth) acrylic polymer particle (A) containing a t-butyl methacrylate monomer unit (a) and a basic compound (B) or a hygroscopic material (C). It is a plastisol composition containing.
The second gist of the present invention is an article obtained by applying the plastisol composition.

  INDUSTRIAL APPLICABILITY According to the present invention, a plastisol and an article having good storage stability and deformation recovery can be provided, and the industrial significance and the effect on global environment conservation are remarkable.

Hereinafter, the present invention will be described in detail.
The (meth) acrylic polymer particles (A) contained in the plastisol composition of the present invention contain t-butyl methacrylate monomer units (hereinafter referred to as monomer units (a)). The monomer unit (a) in the present invention is a component that improves the storage stability and deformation recovery of the (meth) acrylic polymer particles (A).
In the present application, the (meth) acrylic polymer particles (A) mean those containing 50% by mass or more of (meth) acrylate units among the monomer units constituting the following polymer particles. The (meth) acrylic polymer particles of the present invention preferably contain 80% by mass or more of (meth) acrylate units. In the present application, (meth) acryl is a generic name for methacryl and acrylic, and (meth) acrylate is a generic name for methacrylate and acrylate.

The content of the monomer unit (a) in the (meth) acrylic polymer particles (A) is preferably 5% by mass or more and less than 90% by mass. It is preferable that the monomer unit (a) is 5% by mass or more, since the deformation recovery property of the coating film is improved. Moreover, since it is excellent in storage stability that a monomer unit (a) position is less than 90 mass%, it is preferable.
The content can be quantified by a known analysis means such as NMR.

The (meth) acrylic polymer particles (A) may contain a basic functional group showing basicity derived from an unshared electron pair. The basic functional group is a component that suppresses the elimination of the t-butyl group contained in the monomer unit (a), and has the effect of improving deformation recovery.
Examples of the monomer that polymerizes to give the monomer unit (b) having the basic functional group (hereinafter referred to as the monomer unit (b)) include, for example, dimethylaminoethyl (meth) acrylate, diethylaminoethyl ( Aliphatic amino (meth) acrylates such as meth) acrylate; cycloaliphatic amino (meth) acrylate, N-vinylimidazole, 2-vinylpyridine, 4-vinylpyridine, N-vinylcarbazole, N-vinylimidazoline, N-vinyl Vinyl compounds having a heterocyclic ring such as pyrrolidone; vinylaniline, vinylbenzylamine, allylamine, aminostyrene and the like.

The content of the monomer unit (b) in the (meth) acrylic polymer particles (A) is preferably 0.001% by mass or more and less than 25% by mass. It is preferable that the monomer unit (b) is 0.001% by mass or more because the deformation recovery property of the coating film is improved. Moreover, since it is excellent in stability of superposition | polymerization, it is preferable that a monomer unit (b) is less than 25 mass%.
The content can be quantified by a known analysis means such as NMR.

  Examples of the monomer that is a raw material of the monomer unit constituting the (meth) acrylic polymer particles include monomers having a known (meth) acryloyl group. Specific examples include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl acrylate, hexyl (meth) acrylate, and 2-ethylhexyl (meth). (Meth) acrylates of linear alkyl alcohols such as acrylate and octyl (meth) acrylate; (meth) acrylates of cyclic alkyl alcohols such as cyclohexyl (meth) acrylate; methacrylic acid, acrylic acid, 2-methacryloyloxyethyl phthalate Carboxyl group-containing monomers such as 2-methacryloyloxyethyl hexahydrophthalate; sulfonic acid group-containing (meth) acrylates such as allyl sulfonic acid; 2- (meth) acryloyloxyethyl acid phosphate, etc. Phosphoric acid group-containing (meth) acrylates; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and other hydroxyl group-containing (meth) acrylates; acetoacetoxyethyl (meth) acrylate and other carbonyl groups (Meth) acrylates; (meth) acrylates of aromatic alcohols such as benzyl methacrylate; epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate and (3,4-epoxycyclohexyl) -methyl (meth) acrylate; N-methylol-containing (meth) acrylates such as N-methoxymethyl (meth) acrylamide and N-butoxymethyl (meth) acrylamide; γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropyltri Hydrolyzable silyl group such as toxisilane, vinyltriethoxysilane, vinyltrimethoxysilane, 2-styrylethyltrimethoxysilane, vinyltris (methoxyethoxy) silane; 2-[(3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate And block isocyanate group-containing (meth) acrylates such as 2- [0- (1′-methylpropylideneamino) carboxyamino] ethyl methacrylate.

  In addition to the monomer having a (meth) acryloyl group as required, for example, a vinyl cyanide monomer such as acrylonitrile; styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m- Methyl styrene, p-methyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, Styrene derivatives such as pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene; polyfunctional monomers such as divinyl benzene, divinyl naphthalene, divinyl ether, triaryl isocyanurate; Acid; crotonic acid; maleic acid, maleic ester, maleic anhydride, fumar You may copolymerize monomers, such as unsaturated acids, such as a phosphoric acid and a fumaric acid ester, and its derivative (s).

  The molecular weight of the (meth) acrylic polymer particles is preferably 300,000 to 5,000,000. 500,000 or more is preferable from the viewpoint of storage stability and strength of the plastisol composition, and 4 million or less is preferable from the viewpoint of gelation during heating film formation.

  The particle structure of the (meth) acrylic polymer particles is preferably a multilayer structure or a gradient structure in which the composition of each layer is different. In particular, a multi-layered structure of three or more layers, with the innermost layer being a layer compatible with the plasticizer and the outer layer side having a low compatibility with the plasticizer, storage stability and plasticizer retention This is preferable because both compatibility and flexibility can be achieved.

  As the state of the (meth) acrylic polymer particles, for example, a secondary particle structure in which a large number of primary particles obtained by polymerization are agglomerated or a higher-order particle structure higher than that can be used. . In that case, it is preferable that the primary particles are loosely agglomerated without being firmly bonded to each other so that the aggregated state is destroyed by shearing during plastisol kneading and the primary particles are finely and uniformly dispersed in the plastisol. .

  The primary particle diameter of (meth) acrylic polymer particles is preferably 0.01 to 30 μm. When the polymer particles have a multilayer structure of 0.01 μm or more, it is preferable because a sufficient thickness of the layer for suppressing the absorption of the plasticizer can be obtained and the storage stability of the plastisol is improved. Moreover, it is preferable that it is 30 micrometers or less from a viewpoint of the gelatinization property at the time of plastisol baking. Furthermore, the secondary particle diameter of the (meth) acrylic polymer particles is preferably 5 to 500 μm. When it is 5 μm or more, the handleability at the time of work becomes good. Further, when the thickness is 500 μm or less, in the coating application or the thin film molded product application, there are fewer irregularities due to secondary particles that are not dispersed, and the product appearance tends to be good.

  As a method for producing (meth) acrylic polymer particles, a known method for producing polymer particles can be appropriately selected. For example, a dispersion of (meth) acrylic polymer particles obtained by emulsion polymerization, seed polymerization, soap-free polymerization, dispersion polymerization, and fine suspension polymerization is prepared, and spray drying (spray drying) In addition, acid coagulation and salt coagulation followed by a drying process, a freeze drying method, and a method of pulverization using a centrifugal separation method may be mentioned.

The plastisol composition of the present invention contains a basic compound (B) or a hygroscopic material (C). The basic compound (B) is a component that suppresses the elimination of the t-butyl group contained in the monomer unit (a), and has an effect of improving deformation recovery properties.
The basic compound (B) has a basic functional group showing basicity derived from an unshared electron pair. Specific examples include amine compounds such as polyaminoamides, aliphatic polyamines, alicyclic polyamines and aromatic polyamines; hydrazide compounds such as adipic acid dihydrazide (ADH) and sebacic acid dihydrazide (SDH); dicyandiamide and the like. It is done.
Among them, aliphatic polyamine, alicyclic polyamine, adipic acid dihydrazide or dicyandiamide is used as a main component from the viewpoint of compatibility with (meth) acrylic polymer particles, economy, safety, and availability. Is preferred.

  The content of the basic compound (B) in the plastisol of the present invention is preferably 0.001% by mass or more and less than 20% by mass. When the basic compound (B) is 0.001% by mass or more, the deformation recovery property of the coating film is improved, which is preferable. Moreover, since a sol viscosity is restrained low that a basic compound (B) is less than 20 mass%, it is preferable.

  The plastisol composition of the present invention removes moisture contained in the plastisol (water contained in the (meth) acrylic polymer fine particles (A), plasticizer, compounding agent, etc.) by containing a hygroscopic material. Hydrolysis of the ester moiety contained in the monomer unit (a) can be suppressed. Therefore, a plastisol composition containing a hygroscopic agent can improve deformation recovery.

  The hygroscopic material is a compound that reacts, adsorbs and absorbs moisture dissolved in plastisol, and examples thereof include calcium oxide and silica gel.

  The amount of the hygroscopic material added is preferably 0.1 parts by mass or more and less than 30 parts by mass with respect to 100 parts by mass of the (meth) acrylic polymer particles. When the amount is 0.1 parts by mass or more, flexibility and rubber elasticity are hardly affected by the environment during storage, and when it is less than 30 parts by mass, the tensile strength of the coating film tends to be excellent, which is preferable.

The plastisol composition of the present invention can be obtained by dispersing the aforementioned (meth) acrylic polymer particles in a plasticizer.
Examples of the plasticizer include known plasticizers. Specific examples include phthalate plasticizers such as dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-2-ethylhexyl phthalate, di-n-octyl phthalate, diisononyl phthalate, diisodecyl phthalate, and butyl benzyl phthalate. Adipic acid ester plasticizers such as dimethyl adipate, dibutyl adipate, diisobutyl adipate, dihexyl adipate, di-2-ethylhexyl adipate, diisononyl adipate, dibutyl diglycol adipate; trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate , Tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate Phosphate ester plasticizers such as trixylenyl phosphate and cresylphenyl phosphate; Trimellitic ester plasticizers such as tri-2-ethylhexyl trimellitate; dimethyl sebacate, dibutyl sebacate, di-2-ethylhexyl seba Sebacic acid ester plasticizers such as Kate; Aliphatic polyester plasticizers such as poly-1,3-butanediol adipate; Benzoic acid plasticizers such as diethylene glycol dibenzoate and dibutylene glycol dibenzoate; Epoxidized soybean oil Epoxidized ester plasticizers; alkyl sulfonic acid phenyl ester plasticizers such as alkyl sulfonic acid phenyl esters; alicyclic dibasic acid ester plasticizers; polyether plasticizers such as polypropylene glycol and polybutylene glycol; Citrate-based plasticizers such as acid acetyl tri-butyl.
Among these, it is preferable to use diisononyl phthalate as a main component from the viewpoints of compatibility with (meth) acrylic polymer particles, economy, safety, and availability.

  Other compounding agents for plastisol compositions include pigments such as calcium carbonate, titanium oxide and carbon black, as well as antifoaming agents, antifungal agents, deodorants, antibacterial agents, surfactants, lubricants, UV absorbers, fragrances, and foams. You may mix | blend various additives, such as an agent, a leveling agent, an adhesive agent, a viscosity reducing agent, a diluent, a foaming agent, a foaming adjuvant, suitably.

As a kneading apparatus for producing the plastisol composition of the present invention, a known apparatus may be appropriately used.
Specific examples include a pony mixer, a change-can mixer, a hobart mixer, a planetary mixer, a butterfly mixer, a raider, and a kneader.

The plastisol composition of the present invention can be cured by a known heating method, molding method or gelation method.
The plastisol composition of the present invention is used in the same manner as conventional plastisol compositions, such as coating materials such as automobile undercoats, automobile body sealers, wallpaper, carpet backing materials, flooring materials, paints, and molded articles such as toys. Used for.
When the plastisol composition of the present invention is used as a coating material, a known method may be appropriately used for the coating method.
Specific examples of the method for applying the plastisol composition on the substrate include dip coating, spray coating, knife coating, roll coating, curtain flow coating, brush coating, electrostatic coating, and the like. It is done. By baking the coating film of the plastisol composition, an article having a target coating layer can be obtained.
Examples of articles using the plastisol composition of the present invention include articles similar to those using conventional plastisol compositions. Examples include automobile bodies, wallpaper, carpets, flooring, paints, toys and the like.

  Hereinafter, the present invention will be described using examples. Evaluation methods and evaluation criteria in the examples are as follows.

(1) Deformation recovery property The plastisol composition was cast on a Teflon (registered trademark) -treated iron plate (thickness: about 1 mm) to a thickness of about 2 mm, and this was heated in a gear oven at 130 ° C. for 20 minutes. The obtained sheet-like molded product was cut into a dumbbell shape No. 2 according to the method described in JIS K-7113 to obtain a test piece, and a tensile deformation hysteresis test was performed with a Tensilon measuring machine. Here, the tensile speed was 50 mm / min, the displacement was 40% in terms of elongation, and the measurement temperature was 25 ° C. This hysteresis test was repeated 5 times in succession, but the area (S1) given by the SS curve in the forward path (during tension) and the area given by the SS curve in the return path (during return) (S2). ) And hysteresis storage rate = S2 / S1 × 100 (%) was calculated, and this was used as an index for deformation recovery, and evaluated according to the following criteria.
“◯”: Hysteresis storage rate of 50% or more “×”: Hysteresis storage rate of less than 50% (2) Storage stability After preparing the plastisol composition, the viscosity was measured at 25 ° C. within 2 hours (initial viscosity η1) . Further, this was stored in a constant temperature water bath at 40 ° C. for 10 days, returned to 25 ° C., and the viscosity was measured again (viscosity η2 after storage). These viscosity measurements were carried out using a BH viscometer (manufactured by Toki Sangyo Co., Ltd.) at a measurement temperature of 25 ° C. and a shear rate of 20 s ⁻¹ . From the values of the initial viscosity η1 and the post-storage viscosity η2 measured in this way, “η2 / η1 × 100-100” (thickening rate%) was calculated as storage stability and evaluated according to the following criteria.
“◯”: Thickening rate is less than 300% “×”: Thickening rate is 300% or more (or η2 cannot be measured)

[Example 1]
408 g of pure water is put into a 2 liter four-necked flask equipped with a thermometer, a nitrogen gas inlet tube, a stirring rod, a dropping funnel, and a cooling tube, and nitrogen gas is sufficiently bubbled for 30 minutes to dissolve oxygen in pure water. Was replaced. After stopping the aeration of nitrogen gas, the temperature was raised to 80 ° C. while stirring at 200 rpm. When the internal temperature reached 80 ° C., 20 g of methyl methacrylate (MMA), 15 g of n-butyl methacrylate (nBMA) (initial charge (M1)) and 0.3 g of potassium persulfate were added all at once. Subsequently, a mixture (monomer (M2)) of MMA 259 g, t-butyl methacrylate (tBMA) 245 g, sodium dialkylsulfosuccinate (manufactured by Kao Corporation, trade name: Perex O-TP) and 252 g of pure water was added dropwise. And polymerization was carried out. Thereafter, a mixture of 60 g of MMA, 0.6 g of Plex O-TP and 30 g of pure water (monomer (M3)) was added dropwise to produce polymer particles. Thereafter, stirring was continued at 80 ° C. for 1 hour to complete the polymerization, thereby obtaining a dispersion of (meth) acrylic polymer particles.
A dispersion of (meth) acrylic polymer particles is spray-dried using a CL-8 type spray dryer (manufactured by Okawara Chemical Co., Ltd.) (inlet temperature / outlet temperature = 150/60 ° C., disk rotational speed 20000 rpm). , (Meth) acrylic polymer particles (P1) were obtained.
Subsequently, 50 parts by mass of (meth) acrylic polymer particles (P1) and 50 parts by mass of a plasticizer (diisononyl phthalate: manufactured by J-Plus Co., Ltd.) were weighed, and a vacuum mixer (product name: ARV-200, Co., Ltd.). The mixture was mixed at atmospheric pressure (0.1 MPa) for 10 seconds using a Shinkey Co., Ltd., then reduced in pressure to 2.7 kPa and mixed for 110 seconds to obtain a plastisol composition. The evaluation results of this plastisol composition are shown in Table 2.

[Examples 2 to 4 and Comparative Examples 1 to 2]
The compositions of the monomer mixtures (M2) and (M3) were changed according to Table 1, and the other conditions were the same as in Example 1 to obtain (meth) acrylic polymer particles (P2). Subsequently, the plastisol composition was obtained by the same operation as Example 1 according to the mixing | blending of Table 2 and Table 3. The evaluation results of the obtained plastisol composition are shown in the lower part of Tables 2 and 3.

  Examples 1 to 3 are examples in which acrylic polymer particles (P1) and adipic acid dihydrazide, polyamidoamine and dicyandiamide were blended as basic compounds, and the storage stability of the plastisol composition and the deformation recovery of the molded sheet were It was good.

  Example 4 is an example in which acrylic polymer particles (P1) and a hygroscopic material were blended, and the storage stability of the plastisol composition and the deformation recovery of the molded sheet were good.

  Comparative Example 1 is an example in which a basic compound and a hygroscopic material are not blended, and the storage stability is excellent but the deformation recovery property is inferior.

  Comparative Example 2 is an example (P2) without a t-butyl methacrylate monomer unit and a basic compound, which is excellent in deformation recovery properties but inferior in storage stability.

Claims (2)

A plastisol composition containing (meth) acrylic polymer particles (A) containing a t-butyl methacrylate monomer unit (a) and a basic compound (B) or a moisture absorbent (C). An article obtained by applying the plastisol composition according to claim 1.