JP2971014B2 - Sol foamed PVC resin foam - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high expansion ratio sol-foamed vinyl chloride resin foam containing a large amount of a plasticizer suitable as a base material such as a joint material, a sealing material, or an adhesive tape. The present invention relates to the above-mentioned foam, which can maintain excellent sealing properties (such as water leakage prevention property) of the foam at a place where the foam is used for a long period of time, and also has excellent stain resistance and water repellency.

[0002]

2. Description of the Related Art When a vinyl chloride resin foam is used as a base material such as a joint material, a sealing material, or an adhesive tape, generally, a large amount of a plasticizer is contained together with a foaming agent to form a paste sol. A so-called sol-foamed vinyl chloride-based resin foam, which is obtained by coating a vinyl-based resin on a base material such as release paper by various means and heat-foaming it in a sol state, is suitably used.

[0003] The above-mentioned sol-foamed vinyl chloride-based resin foam has excellent flexibility in following a curved surface due to its high flexibility, and has excellent sealing properties because the foam cells (bubbles) have an independent structure. Has the advantage of

[0004]

However, the foam cell may be broken due to a change in the temperature of the environment in which the foam is used or the compression of the foam. If the foam cell is broken, the independent structure of the cells is also broken, and finally the sealing property is impaired.

The present invention provides water-repellency to the foam cell wall itself even when the foam cell of the sol-foamed vinyl chloride resin foam as described above is broken.
Prevents water from entering into the sol-foamed vinyl chloride resin foam, thereby maintaining the excellent sealing properties inherent in the foam for a long period of time and also maintaining excellent stain resistance. It is another object of the present invention to provide a sol-foamed vinyl chloride-based resin foam having a high foaming ratio suitable as a base material such as a joint material, a seal material, or an adhesive tape.

[0006]

In order to achieve the above object, the sol-foamed vinyl chloride-based resin foam of the present invention comprises a linear dimethylpolysiloxane based on 100 parts by weight of an emulsion-polymerized vinyl chloride-based resin. 0.1 to 10 parts by weight.

At this time, (1) the sol foamed vinyl chloride resin foam contains 50 to 150 parts by weight of a phthalate ester plasticizer and / or a trimellitate ester plasticizer per 100 parts by weight of the vinyl chloride resin. (2) The expansion ratio of the sol-foamed vinyl chloride resin foam is preferably 4 to 15 times.

The emulsion-polymerized vinyl chloride resin in the present invention includes a vinyl chloride homopolymer resin obtained by an emulsion polymerization method, vinyl chloride and other monomers,
For example, a copolymer resin with vinyl acetate, acrylonitrile, ethylene, and vinylidene chloride can be used, and these can be used alone or in combination of two or more.

The above-mentioned emulsion-polymerized vinyl chloride resin is mixed with a plasticizer to form a paste sol. The plasticizer may be a usual plasticizer used for a normal vinyl chloride resin, such as phthalate. 2-Ethylhexyl acid (DOP), di-i-nonyl phthalate (DINP), di-i-decyl phthalate (DIDP), di-butyl phthalate (DBP), butyl benzyl phthalate (BBP), phthalate General phthalate plasticizers such as di-undecyl acid (DUP); trimellitate plasticizers such as trioctyl trimellitate (TOTM); dioctyl adipate (DOA), sebacic acid Fatty acid ester-based plasticizers represented by dioctyl (DOS), dioctyl azelate (DOZ) and the like;
Uses phosphate plasticizers such as tricresyl phosphate (TCP); or epoxy plasticizers; high molecular weight plasticizers such as polyester plasticizers such as polypropylene adipate; and chlorinated paraffin. These can be used alone or in combination of two or more. The compounding amount may be such an amount that a normal emulsion polymerized vinyl chloride resin paste can be sol foamed.

[0010] In particular, in the present invention, it is preferable to use a phthalate ester plasticizer and / or a trimellitate ester plasticizer from the viewpoints of foamability, economy and the like. The blending amount of the phthalate ester plasticizer and / or trimellitate ester plasticizer is preferably 50 to 150 parts by weight based on 100 parts by weight of the vinyl chloride resin. If it is less than 50 parts by weight, it is not possible to obtain flexibility suitable for a base material such as a joint material, a sealing material, or an adhesive tape, and if it exceeds 150 parts by weight, the strength of the obtained foam is too low. However, it becomes difficult to use these as a substrate.

Further, a foaming agent is compounded in the above-mentioned paste sol. As the foaming agent, a usual foaming agent used for a usual vinyl chloride resin, for example, azodicarbonamide (ADCA), oxybisbenzene Thermal decomposition type foaming agents such as sulfone hydrazide (OBSH), diazoaminobenzene, azobisisobutyronitrile (AIBN) and the like can be mentioned, and these can be used alone or in combination of two or more.

The mixing ratio of the foaming agent is not particularly limited.
The expansion ratio of the vinyl chloride resin foam of the present invention is 4 to 15
In order to double the amount, the amount is preferably 2 to 16 parts by weight based on 100 parts by weight of the emulsion-polymerized vinyl chloride resin.

If the expansion ratio exceeds 15 times, it becomes difficult to control the foam cells, and cell roughness or cell breakage occurs. If the expansion ratio is less than 4 times, the flexibility decreases, and the joint material and the sealing material are reduced. It becomes unsuitable as a base material. The expansion ratio is controlled by adjusting the mixing ratio of the blowing agent and adjusting the foaming conditions such as the heating temperature as described above.

The linear dimethylpolysiloxane compounded in the paste sol containing the above-mentioned emulsion-polymerized vinyl chloride resin, a plasticizer and a foaming agent has a function of imparting water repellency and stain resistance to the foam. And a compound represented by the general formula (1) of Chemical Formula 1, more specifically, a compound obtained by a hydrolytic polycondensation reaction of dimethyldichlorosilane and triethylmonochlorosilane, or a compound of octamethylcyclotetrasiloxane and hexamethyldisiloxane Those obtained by subjecting a mixture to a ring-opening polymerization reaction through a catalyst such as sulfuric acid or alkali can be preferably used, and these can be used alone or in combination of two or more.

[0015]

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If the molecular weight of the linear dimethylpolysiloxane is too high, it is difficult to uniformly disperse it in the paste sol. If the molecular weight is too low, the above effects of imparting water repellency and stain resistance are not exhibited. Therefore, in order to exhibit a liquid that can maintain a certain degree of fluidity and to exhibit these effects, it is preferable to use one having a viscosity of about 3,000 to 50,000.

For the above reasons, the dimethylpolysiloxane does not need to have a three-dimensional structure with a crosslinking reaction, and therefore, in the present invention, a linear dimethylpolysiloxane is used.

The mixing ratio of the linear dimethylpolysiloxane is less than 0.1 part by weight based on 100 parts by weight of the emulsion-polymerized vinyl chloride resin, although it depends on the expansion ratio of the vinyl chloride resin foam. Does not exhibit the above-mentioned effects of imparting water repellency and stain resistance. Conversely, if the amount is more than 10 parts by weight, the influence of the linear dimethylpolysiloxane becomes large, and at the above-mentioned expansion ratio, the foaming property of the emulsion-polymerized vinyl chloride resin paste is hindered, which is suitable as a base material such as a sealing material. The closed cell structure cannot be obtained. Therefore, in the present invention, 0.1 to 100 parts by weight of the emulsion polymerized vinyl chloride resin.
10 parts by weight.

The above paste sol may further contain, if necessary, additives such as metal composite stabilizers, fillers, pigments and the like used in ordinary emulsion-polymerized vinyl chloride resins. It can be blended in the amount when blended in the system resin.

The emulsion-polymerized vinyl chloride resin paste sol containing the above-mentioned plasticizer, foaming agent, linear dimethylpolysiloxane, and other components is thoroughly kneaded and stirred, and then uniformly dispersed. For example, a foam is prepared by the following method.

For example, a film or paper having releasability on the surface or a releasable film or paper (that is, a releasable film or release paper) is placed on an endless belt made of an appropriate material, and the releasability is checked. The above-mentioned paste sol is coated on the surface of the film or paper having the appropriate thickness. The coating means may be a doctor knife coater, a comma doctor coater, a roll coater, a gravure coater, a spray coater, or any other appropriate means applied at the time of coating an ordinary emulsion polymerized vinyl chloride resin paste sol. . By heating and foaming in the sol state after coating, a vinyl chloride resin foam by sol foaming can be obtained.

A pressure-sensitive adhesive layer may be provided on one side of the thus-prepared foamed polyvinyl chloride resin of the present invention. Examples of the adhesive include rubber adhesives such as low molecular weight polyisoprene (IP), styrene butadiene rubber (SBR) and butyl rubber (BR), and acrylics such as polybutyl acrylate, 2-ethylhexyl polyacrylate, and polyacrylic acid. A system adhesive can be used. In addition, in this pressure-sensitive adhesive, terpene resin, rosin, cumarone-indene resin, terpene phenol, aromatic petroleum resin, aliphatic petroleum resin, and the like are usually blended with these pressure-sensitive adhesives. It can be blended in an amount.

The layer composed of these pressure-sensitive adhesives can be provided by an appropriate means such as a coating method. The coating thickness and the coating method at this time are not particularly limited, and are appropriately selected depending on the purpose of adhesion (for temporary fixing or permanent adhesion, etc.), the type of the adherend, the use environment, and the like. Is done.

The above-mentioned foam of the present invention may be formed into a film or paper having a releasability (e.g., foam preparation) in the same manner as a general joint material, sealing material, adhesive tape, etc. The film or paper used in the process can be used as it is, without peeling it off), and stored and sold in a state of being wound on a core such as a paper tube. Is cut to an appropriate length for use.

[0025]

【Example】

Examples 1 to 16 and Comparative Examples 1 and 2 (Preparation of Paste Sol) Paste sols having the formulations shown in Tables 1 and 2 were prepared.

[0026]

[Table 1]

[0027]

[Table 2]

In Tables 1 and 2, PVC of * 1 indicates an emulsion-polymerized polyvinyl chloride resin. In Examples 1 to 9 and Comparative Examples 1 to 3, those having an average degree of polymerization of 1300 were used. The plasticizer of * 2 uses DOP in Examples 1-2, Examples 5-6 and Comparative Examples 1-3, and uses TOTM in Examples 3-4 and Examples 7-8. Then DOP and T
An equal mixture with OTM was used. * 3 As for the foaming agent, ADCA was used in Examples 1 to 9 and Comparative Examples 1 to 3. The foaming ratio of the foaming agent of 2 parts by weight was 4 times, and the foaming agent of 16 parts by weight was foaming. Magnification was 15 times. As the stabilizer of * 4, a Ba / Zn-based composite stabilizer was used in Examples 1 to 9 and Comparative Examples 1 to 3. * 5 of the filler, was used Examples 1-9 and Comparative Examples 1 to 3 both CaCO _3. * 6 The pigments of Examples 1 to 9 and Comparative Examples 1 to 3
Carbon black was used.

* 7 DMPS refers to linear dimethylpolysiloxane, and is described in Examples 1-2, Examples 5-6, and Example 9.
And in Comparative Examples 1 to 3, the reaction is caused by a hydrolytic polycondensation reaction of dimethyldichlorosilane and triethylmonochlorosilane. In Examples 3 to 4 and Examples 7 to 8, a mixture of octamethylcyclotetrasiloxane and hexamethyldisiloxane Was subjected to a ring-opening polymerization reaction with an alkali catalyst.

(Preparation of foam) A paste sol having the composition shown in Tables 1 and 2 was coated on a release paper by a doctor knife method, and then heated at 195 ° C. for 3 minutes to foam the resin. A 0 mm foam sheet (12 types) was prepared.

An acrylic pressure-sensitive adhesive mainly composed of polybutyl acrylate having a solid content of 40% was wet-coated on the surface (the side not in contact with the release paper) of the foamed sheets (12 types) in a wet state. The layers were laminated by a transfer method so as to have a thickness of 70 g / m ² .

(Evaluation of foam) For each foam sheet obtained as described above, measurement of the closed cell rate by a Beckman air comparison type specific gravity meter, U-shaped water leakage test, water absorption test, Observation of the foam cells was performed, and these results are shown in Tables 3 to 5.

(1) Measurement of closed cell ratio by Beckman air comparison hydrometer: Measured using an air comparison hydrometer 1000 manufactured by Tokyo Science Co., Ltd. [volume of closed cells + volume of cell wall] ] And the [apparent volume of the foam] previously measured with a vernier caliper, the closed cell ratio was calculated by the following equation.

[0034]

[Equation 1]-Apparent volume of foam = volume of closed cell + volume of cell wall + volume of open cell-Closed cell ratio = [volume of closed cell / (volume of closed cell +
Volume of open cells)] x 100

(2) U-shaped water leakage test: A sample obtained by cutting each of the above foam sheets to a width of 10 mm and a length of 300 mm was curved into an arc shape having a diameter of 60 mm as shown in FIG. None, two U-shaped samples
Sandwiched between two transparent acrylic resin plates (so that one transparent acrylic resin plate is in contact with the surface of the foamed sheet, and the other transparent acrylic resin plate is in contact with the adhesive layer provided on the foamed sheet. 2), pressing the two transparent acrylic resin plates to 50% of the original thickness of the U-shaped sample (ie, 2.0 mm and the thickness of the adhesive layer), and bolting the four corners (not shown). Fixed with. The U-shaped sample was filled with water up to a position 10 cm from the bottom of the U-shape, and the water level after 48 hours was observed, which was defined as a U-shaped leak.

(3) Water absorption test: Each foam sheet cut into a square of 100 mm and weighed in advance was measured for 20 cm below the water surface.
mm for 24 hours, water droplets on the surface were gently wiped off, the weight was measured, and the increased weight was determined as a percentage, which was defined as the initial water absorption. After leaving each of the foamed sheets at 80 ° C. for 1 hour,
The temperature change cycle of leaving at 0 ° C for 24 hours is 10
The same water absorption test as described above was performed for the samples that were performed twice, and water absorption was performed after a temperature cycle.

(4) Observation of foam cells:
The cells were observed with an SEM (transmission electron microscope), and the cell shape was evaluated according to the following evaluation criteria.

[Evaluation Criteria] ◎ ・ ・ ・ Round type independent foam cell ○ ・ ・ ・ Slightly vertically independent foam cell △ ・ ・ ・ Vertical foam cell with partially broken cell wall × ・ ・ ・ Vertical continuous Bubble cell

[0039]

[Table 3]

[0040]

[Table 4]

[0041]

[Table 5]

As is clear from Tables 3 to 5, Comparative Example 1
In the foams of Examples 1 to 9, the closed cell ratio and the state of the foam cells are not much different from those of the foams of Examples 1 to 9 of the present invention. It turns out that it is significantly inferior to the body. In Comparative Example 3, the state of the foamed cells was extremely poor, so that the closed cell ratio was small, and it was found that water leakage and water absorption were poor.

[0043]

As described in detail above, according to the present invention,
Water can be effectively prevented from entering into a sol-foamed vinyl chloride-based resin foam having a high expansion ratio containing a large amount of a plasticizer, and thereby the excellent sealing property (prevention of water leakage and water absorption) of the foam can be obtained. Properties, etc.) at the point of use of the foam for a long period of time. Further, according to the present invention, it is possible to provide the foam having excellent water repellency and stain resistance. Therefore, in the present invention, an excellent foam can be provided as a base material such as a joint material, a sealing material, and an adhesive tape.

[Brief description of the drawings]

FIG. 1 is a view showing a test mode adopted when evaluating the sealing performance of a foam in an example of the present invention.

Claims (3)

(57) [Claims] 1. An emulsion-polymerized vinyl chloride resin 10.
0 parts by weight, linear dimethylpolysiloxane 0.1
A sol-foamed vinyl chloride-based resin foam comprising from 10 to 10 parts by weight. 2. A phthalate plasticizer and / or a trimellitate plasticizer 50 to 100 parts by weight of a vinyl chloride resin foam based on 100 parts by weight of the vinyl chloride resin.
2. The composition according to claim 1, wherein the content is 150 parts by weight.
The sol-foamed vinyl chloride resin foam according to the above. 3. A foaming ratio of a vinyl chloride resin foam is as follows:
The sol-foamed vinyl chloride resin foam according to claim 1 or 2, wherein the ratio is 4 to 15 times.