JP2003238621A - Polyvinyl chloride resin for paste processing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyvinyl chloride resin for paste processing, low in viscosity when being used as a paste sol, low in variation per hour, excellent in coating property, and capable of obtaining a good foam. <P>SOLUTION: Particle diameter is in the range of at least 0.2-10 μm, wherein component A is below 10-30 wt.% and the weight ratio of component B to component C (B)/(C) is 30/70-60/40 in distribution of particles of <0.5 μm (component A), 0.5 to 4 μm (component B) and 4 μm (component C). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl chloride for paste processing, which can provide a paste sol having a low viscosity, a small change with time, an excellent coating suitability and a good foamed product at the time of foaming. System resin.

[0002]

2. Description of the Related Art Polyvinyl chloride resin for paste processing is generally processed by adding various additives as necessary, mixing and kneading. In particular, polyvinyl chloride resin for wallpaper and floor material processing and paste processing has a plasticizer as an essential component, and is mixed and kneaded with a filler, a foaming agent, a stabilizer, etc. as necessary to form a paste sol. It is a general practice to coat the plastisol on a substrate by utilizing it, to gelate it, and then to perform foaming in a foaming process to obtain a final product. Therefore, plastisol in its application is fluid,
It is necessary to have both coating suitability and foamability.

For example, when the viscosity of plastisol is too high, not only is it difficult to handle, but also the sol wraps around the backside of the coating blade, which is called blade stain during coating, and accumulates to form sol particles, which causes a problem of scoring. , In severe cases, it may cause scraping. Therefore, in order to avoid such a problem, it is generally a common method to mix a diluent and reduce the sol viscosity to perform coating or processing. However, the diluent is mainly composed of aromatic hydrocarbons and aliphatic hydrocarbons, and may evaporate during heat processing to cause environmental pollution such as malodor and photochemical smog. In addition, if it remains in the final product, it may volatilize indoors and become a so-called sick house causative substance.

In order to solve this problem, in recent years, there has been a demand for a polyvinyl chloride resin for paste processing which gives a plastisol having a sufficiently low viscosity even if the diluent is reduced.
For example, in Japanese Patent No. 3203726, the particle size is 5 to 65 μm.
10 to 90% of the particles are 90% and the particles having a particle size of 3 μm or less
A method of obtaining a low viscosity even in a high shear region by granulating a dispersion liquid containing 10% to 10% and other particles of 0% to 10% is shown. However, such a particle size distribution tends to deteriorate the foamability such that the expansion ratio during foaming does not increase and the cells and the surface of the foam become rough. Further, in JP-A-9-309998, the particle size is 0.01 to 0.45.
30 to 50% of particles with a diameter of 0.45 to 4.5 μm
35-55% and 4.5-20 μm particles are 1
A method for realizing a low viscosity in a high shear rate region by granulating a latex composed of 0 to 30% is disclosed. However, with this particle size distribution, the sol viscosity in the low shear rate region and the change with time tend to be high, and there is a problem that the sol viscosity needs to be adjusted again with a diluent during coating.

As another method, the particle size is 20 to 50.
A method using a blending resin of μm is also known. However, in this method, coating suitability at low clearance (thin wall) tends to be poor, and further, the appearance of the foam tends to be impaired, and the expansion ratio tends not to increase particularly in high foaming applications. I could not say.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a polyvinyl chloride-based paste processing material which has a low viscosity when formed into a paste sol, has a small change with time, is excellent in coating suitability, and can obtain a good foam. A resin is provided.

[0007]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of such a background, and as a result, a polyvinyl chloride resin for paste processing having a specific particle size distribution has a low viscosity and its change with time. The present inventors have completed the present invention by finding that it is possible to provide a paste sol which is small in size, excellent in coating suitability, and capable of obtaining a good foam at the time of foaming.

That is, according to the present invention, (1) the particle size is distributed in the range of at least 0.1 to 10 μm, and the particle size is 0.5 μm.
Particles of less than m (A component), particles of 0.5 or more and less than 4 μm (B component), 4 μm or more (C component) are distributed such that the A component is 10 to 30% by weight, the weight ratio of the B component and the C component. Is (B)
/ (C) = 30/70 to 60/40, polyvinyl chloride resin for paste processing (claim 1), (2) A component has a peak at 0.2 to 0.4 μm. The polyvinyl chloride resin for paste processing according to claim 1 (claim 2), (3) 0.7 to 3 µm
3. The method according to claim 1, which has a peak at m.
Polyvinyl chloride resin for paste processing according to claim 3), (4) C component has a peak at 5 to 12 μm, polyvinyl chloride for paste processing according to claim 1, 2 or 3. A resin (claim 4).

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The vinyl chloride resin for paste processing of the present invention is distributed in a particle size range of at least 0.2 to 10 μm, particles (A component) of less than 0.5 μm and a particle size of 0. The distribution of particles (B component) of 5 or more and less than 4 μm (0.5 to 4 μm) and particles (C component) having a particle diameter of 4 μm or more is 10 to 30% by weight of A component, and the weight ratio of B component and C component is It is necessary that (B) / (C) = 30/70 to 60/40.

When the proportion of the component A in the vinyl chloride resin for paste processing of the present invention is lower than 10%, the fouling of the blade when the plastisol is coated tends to be worse, and the foaming property when foaming is also deteriorated. Tend to do. If the proportion of the component A is more than 30%, the sol viscosity in the low shear region and its change with time when plastisol tend to increase. Therefore, the ratio of component A in the resin is 10
It is preferably not less than 15% by weight and less than 25% by weight (1% by weight) in order to further improve stability of sol viscosity and foamability.
5 to 25% by weight) is preferable.

If the peak diameter in the component A is larger than 0.4 μm, the foamability of the foam after coating with plastisol tends to be deteriorated, and the peak diameter is less than 0.
If it is less than 2 μm, the sol viscosity in the low shear region and its change with time when plastisol tend to increase. Therefore, the peak in component A is 0.2-0.4 μm
In order to further improve the stability of the sol viscosity and the foamability, it is preferably 0.25 to 0.35 μm.
It should be in the range of m.

The weight ratio (B / C) of B component and C component is B
When the amount of the component is more than 60/40, the sol viscosity tends to be high and the change with time tends to be large, and the component B is 30/7
When it is less than 0, the foaming property when foaming after coating with plastisol tends to deteriorate. Therefore, the weight ratio (B / C) of B component and C component is 30/70 to 60/40.
In order to further improve the coating characteristics and the foamability, it is preferably 35 / 65-5.
It should be in the range of 0/50.

If the peak diameter in the B component is smaller than 0.7 μm, the sol viscosity in the high shearing region is high, and blade fouling tends to occur, while if it is larger than 3 μm, the foamability during foaming tends to deteriorate. It is in. Therefore, the peak diameter in the component B is preferably 0.7 to 3 μm, and is preferably 0.8 to 3 in order to further improve the coating characteristics and the foamability.
2.5 μm is good. If the peak diameter in the C component is less than 5 μm, the sol viscosity in the high shear region tends to be high, and blade fouling tends to occur. If it exceeds 12 μm, the foamability during heat foaming tends to deteriorate. Therefore, it is appropriate that the peak in the C component is in the range of 5 to 12 μm, and preferably 6 to 10 μm in order to further improve the coating properties and foaming property. Furthermore, A component, B component,
The composition of the present invention containing the C component and the C component preferably has a particle size distributed in a range of at least 0.2 to 10 μm,
A composition having excellent coating properties and foamability can be obtained.

The method for producing the vinyl chloride resin for paste processing of the present invention is not particularly limited, and any method can be used.
The desired particle size distribution can be obtained by preparing the components A, B, and C by the fine suspension polymerization method and then mixing them at a predetermined ratio. The component A is prepared by the usual emulsion polymerization method. The desired particle size distribution can be obtained by preparing the component B and the component C by an ordinary fine suspension polymerization method and then mixing them at a predetermined ratio, or by seeding emulsion polymerization to simultaneously prepare the component A and the component B. Alternatively, the C component prepared by fine suspension polymerization may be mixed. Further, seeded emulsion polymerization may be repeatedly prepared, or may be prepared by a known granulation technique.

The vinyl chloride resin of the present invention is obtained by, for example, adding a vinyl chloride monomer or a mixture of a vinyl chloride monomer and a monomer copolymerizable therewith in an aqueous medium as an emulsifier and, if necessary, as a mixture. It can be obtained by adding a dispersion aid such as higher alcohol or higher fatty acid, and an oil-soluble polymerization initiator to homogenize it and then performing fine suspension polymerization, or adding a water-soluble initiator to carry out emulsion polymerization or seed emulsion polymerization. . Then, the product is obtained by spray-drying an aqueous homogeneous dispersion (latex) of the vinyl chloride resin after polymerization. In the fine suspension polymerization, the size of the monomer droplet size is controlled by the homogenization conditions, and generally, the smaller the pressure difference between the suction side and the discharge side of the homogenizer, the larger the particle size.

Examples of the homogenizers that are usually used include mechanical dispersers such as a single-stage or multistage high-pressure homogenizer, a colloid mill, a single-stage or multistage centrifugal pump and a pipeline mixer, which may be used alone or in combination. Used.

The monomer which can be used in the polymerization method of the present invention is vinyl chloride alone or a mixture of vinyl chloride and a monomer copolymerizable therewith. In the present invention, these are collectively referred to as "vinyl chloride monomer". The copolymerizable monomer is not particularly limited, ethylene, propylene, olefins such as butene, vinyl acetate, vinyl propionate, vinyl stearate and other vinyl esters, methyl vinyl ether, ethyl vinyl ether,
Vinyl ethers such as octyl vinyl ether and lauryl vinyl ether, vinylidene such as vinylidene chloride,
Acrylic acid, methacrylic acid, fumaric acid, maleic acid, itaconic acid, maleic anhydride, unsaturated carboxylic acids such as itaconic anhydride and acid anhydrides thereof, methyl acrylate, ethyl acrylate, monomethyl maleate, dimethyl maleate, Unsaturated carboxylic acid esters such as butylbenzyl maleate, aromatic vinyl compounds such as styrene, α-methylstyrene, divinylbenzene, unsaturated nitriles such as acrylonitrile, and vinyl chloride such as crosslinkable monomers such as diallyl phthalate. All known copolymerizable monomers can be used. The amount of these monomers used is
It is preferably less than 50% by weight in the mixture with vinyl chloride.

The surfactant used for the fine suspension polymerization is not particularly limited, but the anionic surfactant is usually used in an amount of about 0.1 to 3 parts by weight per 100 parts by weight of the monomer. Examples of the anionic surfactant include potassium, sodium, and ammonium salts of fatty acids, alkyl sulfates, alkylbenzenesulfonic acids, alkylsulfosuccinic acids, α-olefinsulfonic acids, alkyl ether phosphates, and the like.

As the dispersion aid, higher alcohols such as lauryl alcohol, myristyl alcohol, cetyl alcohol and stearyl alcohol, and higher fatty acids such as lauric acid, myristic acid, palmitic acid and stearic acid can be used. Other polymerization aids include aromatic hydrocarbons, polyvinyl alcohol, gelatin, particle size regulators (sodium sulfate, sodium bicarbonate, etc.),
Examples thereof include chain transfer agents and antioxidants. These can be used alone or in combination of two or more.

Examples of the oil-soluble initiator used in the fine suspension polymerization include diacyl peroxides such as dilauroyl peroxide, di-3,5,5, trimethylhexanoyl peroxide, diisopropyl peroxydicarbonate and di-2. -Peroxydicarbonates such as ethylhexyl peroxydicarbonate, organic peroxide initiators such as t-butylperoxypivalate, peroxyesters such as t-butylperoxyneodecanoate, and 2,2 order Azo initiators such as | azobisisobutyronitrile, 2,2 order | azobis (2,4-dimethylvaleronitrile), 2,2 order | azobis (4-methoxy-2,4-dimethylvaleronitrile) Can be used. As the water-soluble initiator used for emulsion polymerization, ammonium persulfate,
Potassium persulfate, sodium persulfate, hydrogen peroxide solution, etc. are used, and if necessary, a reducing agent such as sodium sulfite, sodium thiosulfate, formaldehyde sodium sulfoxylate dihydrate, ascorbic acid, sodium ascorbate is used together. I can do things. These are alone or 2
Used in combination of two or more species.

In homogenization during fine suspension polymerization, a one- or two-stage pressure type high pressure pump, colloid mill,
Known methods such as a centrifugal pump, a homomixer, a vibrating stirrer, a high pressure jet from a nozzle or an orifice, and ultrasonic waves can be used.

There is no limitation on the drying method for obtaining the resin of the present invention, and various known methods such as spray drying can be used to obtain a powder.

The polyvinyl chloride resin for paste processing of the present invention comprises a plasticizer as an essential component, a stabilizer if necessary,
Add fillers, reinforcing agents, diluents, viscosity reducers, antioxidants, UV absorbers, foaming agents, flame retardants, antistatic agents, lubricants, pigments, surface treatment agents, thixotropic agents, adhesion promoters, etc. It is kneaded to form a paste sol, and by utilizing its fluidity, it is applied on a substrate such as pulp paper, glass non-woven fabric, flame-retardant paper, etc., and then heat-gelled for foaming.

The plasticizer used in the present invention is not particularly limited, but as the primary plasticizer, phthalic acid esters such as di-2-ethylhexyl phthalate, di-n-octyl phthalate, dibutyl phthalate and diisononyl phthalate, and tricres. Phosphoric acid esters such as dil phosphate and tri-2-ethylhexyl phosphate, adipic acid esters such as di-2-ethylhexyl adipate, di-2-
Sebacic acid esters such as ethylhexyl sebacate, azelaic acid esters such as di-2-ethylhexyl azelate, trimellitic acid esters such as tri-2-ethylhexyl trimellitate, polyester plasticizers and the like can be used. These may be used alone or in combination of two or more kinds, and may also be used in combination with a secondary plasticizer such as citric acid ester, glycolic acid ester, chlorinated paraffin, chlorinated fatty acid ester and epoxy plasticizer. May be. As other compounding agents, known compounds can be used.

[0025]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. In addition,
The particle size distribution, low shear viscosity of the paste sol composition, coating suitability and foamability were measured and evaluated by the following methods.

Particle size distribution: Centrifugal sedimentation type particle size measuring device (CPS Instruments, Model)
2) was used for measurement.

Preparation of paste sol: Resin 100 obtained
Parts by weight, DINP 50 parts by weight, calcium carbonate (manufactured by Bihoku Powder Co., trade name BF-200S) 100 parts by weight, foaming agent (manufactured by Eiwa Kasei, trade name AL-L30) 3 parts, stabilizer (manufactured by Asahi Denka, FL- 103N) 4.5 parts and diluent (Nippon Petroleum, trade name Mineral Spirit-A) 10 parts by weight are weighed in a 500 cc stainless beaker with a resin amount of 100 g, and kneaded with a four-bladed propeller at 1000 rpm for 3 minutes. By doing so, plastisol was obtained.

Low Shear Viscosity: Paste sol composition at 25 ° C.
1 hour, 1 day, 3 days later, the BM type viscometer (manufactured by TOKIMEC), rotor 4, and 6 rpm were used to measure the viscosity.

Coating suitability: One day after the paste sol composition was prepared, the coating tester (manufactured by Furukawa Seisakusho) was used at room temperature and the coater part clearance was 15
The coating suitability was evaluated by setting 0 μm, flowing 50 L of plastisol at a speed of 100 m / s and 200 m / s, and visually observing the presence or absence of stain and scoring (○, good; Δ, blade stain occurred. , Muscle pulling was observed; la and Kasure were observed).

Foamability: The plastisol composition was coated on flame-retardant paper and heated at 140 ° C. for 30 seconds to obtain a gelled film on the flame-retardant paper. At this time, the thickness of the gelled film was 150 μm. Next, this gelled film is cut into an appropriate size together with flame-retardant paper, and a hot air circulation type oven (manufactured by TABAI, HIGHTEMPOO)
VEN PHH-100 type), 220 ° C, air volume; maximum,
Damper: Foamed for 30 seconds or 40 seconds under the condition of full opening, visually observing the surface and cell cross section, and evaluated according to the following criteria (○: good, Δ: slightly rough,
X: considerably rough). (Production Examples 1 to 4) 100 parts by weight of vinyl chloride monomer, 300 parts by weight of deionized water, 1 part by weight of sodium dodecylbenzenesulfonate, and 1 part by weight of cetyl alcohol were placed in a pressure vessel with a stirrer made of stainless steel that had been degassed in advance. And di-2
After charging 0.05 parts by weight of ethylhexyl peroxydicarbonate and homogenizing using a high-pressure homogenizer, the temperature was raised to 60 ° C to carry out polymerization, and unreacted monomers were removed at the time when the polymerization pressure dropped. It was removed and the polymerization was terminated.
The latex shown in Table 1 was obtained by changing the dispersion condition at the time of homogenization, that is, the dispersion pressure level. (Production Example 5) 100 parts by weight of vinyl chloride monomer, 300 parts by weight of ion-exchanged water, 0.05 part by weight of sodium dodecylbenzenesulfonate, and 0.05 parts by weight of sodium nitrite were placed in a pressure vessel with a stirrer made of stainless steel that had been degassed in advance. Charge 05 parts and 0.1 ppm of iron sulfate and raise the temperature to 60 ° C.
Continuously add hydrogen peroxide solution adjusted to the above to start the polymerization, control the addition rate of the hydrogen peroxide solution while monitoring the jacket temperature to proceed the polymerization, and the conversion rate is 5%.
From 1.5 to 75%, 1.5% by weight of sodium dodecylbenzenesulfonate was continuously added as a 5% aqueous solution, and when the polymerization pressure dropped, unreacted monomers were removed to terminate the polymerization. As a result, the peak diameter is 0.3 μm and A
Particles of 100% component were obtained. (Example 1) Latex obtained in Production Example 1, Production Example 4
The latex obtained in 1) and the latex obtained in Production Example 5 were mixed so that the solid content was 54:26:20, and spray-dried to obtain a resin. Using this resin, preparation of a paste sol composition, measurement of low shear viscosity and high shear viscosity, and evaluation of foamability were performed. The results are shown in Table 2. (Examples 2 to 5, Comparative Examples 1 to 4) The polymer latexes obtained in Production Examples 1 to 5 were combined at the mixing ratios shown in Table 1 and spray-dried to obtain a paste sol composition. Was prepared, the low shear viscosity and the high shear viscosity were measured, and the foamability was evaluated. The results are shown in Tables 2 and 3.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

Industrial Applicability According to the present invention, it is possible to provide a paste sol having a low viscosity, a small change with time, an excellent coating suitability, and a good foam when foaming.

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Claims (4)

[Claims] 1. Particles having a particle diameter distributed in a range of at least 0.2 to 10 μm and less than 0.5 μm (component A),
0.5-4 μm particles (B component), 4 μm or more (C component) distribution, A component is 10 to 30% by weight, B component and C
The weight ratio of the components is (B) / (C) = 30/70 to 60/4
Polyvinyl chloride resin for paste processing characterized by being 0. 2. The polyvinyl chloride resin for paste processing according to claim 1, wherein the component A has a peak at 0.2 to 0.4 μm. 3. The polyvinyl chloride resin for paste processing according to claim 1, wherein the component B has a peak at 0.7 to 3 μm. 4. The polyvinyl chloride resin for paste processing according to claim 1, wherein the C component has a peak at 5 to 12 μm.