JPH09104778A - Sol foamed vinyl chloride resin foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a sol foamed vinyl chloride resin foam with a high foaming ratio that contains a large amount of a plasticizer and is suitable as a base for sealers, sealants, adhesive tapes, etc., and excellent in soil resistance and water repellency and which when applied to an intended place can keep its excellent sealing properties (e.g. properties of preventing water leakage and water absorption) for a long period of time. SOLUTION: This foam comprises 100 pts.wt. emulsion polymerized vinyl chloride resin and 0.1 to 10 pts.wt. straight-chain dimethylpolysiloxane. Preferably the vinyl chloride resin foam contains 100 pts.wt. vinyl chloride resin and 50 to 150 pts.wt. phthalate plasticizer and/or trimellitate plasticizer and has a foaming ratio of 4 to 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sol-foamed vinyl chloride resin foam having a high expansion ratio and containing a large amount of a plasticizer suitable as a base material for a joint material, a sealing material, an adhesive tape, etc. The present invention relates to the above foam which is capable of maintaining the excellent sealing properties (water leakage prevention property, etc.) of the foam over a long period of time at the location where the foam is used, and also having 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 for a joint material, a sealing material, an adhesive tape, etc., it is generally made into a paste sol by adding a large amount of a plasticizer together with a foaming agent. A vinyl chloride resin foam by so-called sol foaming, in which a vinyl resin is coated on a base material such as release paper by various means and heated and foamed in a sol state, is preferably used.

The sol-foamed vinyl chloride resin foam described above has a good flexibility to follow curved surfaces due to its high flexibility, and has excellent sealing properties because the foam cells (air bubbles) have an independent structure. Have the advantage of.

[0004]

However, the foam cells may be destroyed due to temperature changes in the environment in which the foam is used, compression of the foam, and the like. When the foam cells are broken, the independent structure of the bubbles is also broken, and the sealing property is finally impaired.

According to the present invention, even when the foam cell of the sol foamed vinyl chloride resin foam is broken as described above, the foam cell wall itself is made to have water repellency.
Prevents water from entering 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. Another object is to provide a sol-foamed vinyl chloride resin foam having a high expansion ratio, which is suitable as a base material such as a joint material, a sealing material, or an adhesive tape.

[0006]

In order to achieve the above object, the sol foamed vinyl chloride resin foam of the present invention is a linear dimethylpolysiloxane based on 100 parts by weight of emulsion polymerized vinyl chloride resin. It is characterized in that it comprises 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 trimellitic acid ester plasticizer in 100 parts by weight of the vinyl chloride resin. It is preferable that the expansion ratio of the sol-foamed vinyl chloride resin foam is (2) to 4 to 15 times.

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

The above emulsion-polymerized vinyl chloride resin is blended with a plasticizer to form a paste sol. As this plasticizer, a conventional plasticizer used for ordinary vinyl chloride resins, for example, phthalate is used. Acid di-2-ethylhexyl (DOP), di-i-nonyl phthalate (DINP), di-i-decyl phthalate (DIDP), di-butyl phthalate (DBP), butylbenzyl phthalate (BBP), phthalate General phthalate ester-based plasticizers represented by di-undecyl acid (DUP); trimellitate ester-based plasticizers represented by trioctyl trimellitate (TOTM); dioctyl adipate (DOA), sebacic acid Fatty acid ester plasticizers represented by dioctyl (DOS), dioctyl azelate (DOZ) and the like;
Phosphate ester-based plasticizers such as tricresyl phosphate (TCP); or epoxy-based plasticizers; polymer-based plasticizers such as polyester-based plasticizers such as polypropylene adipate; and chlorinated paraffin These may be used alone or in combination of two or more. The blending amount may be such that a usual emulsion-polymerized vinyl chloride resin paste can sol foam.

In particular, in the present invention, it is preferable to use a phthalic acid ester plasticizer and / or a trimellitic acid ester plasticizer from the viewpoints of foamability and economy. The amount of the phthalate ester-based plasticizer or / and the trimellitic acid ester-based plasticizer blended is preferably 50 to 150 parts by weight with respect to 100 parts by weight of the vinyl chloride resin. If it is less than 50 parts by weight, flexibility suitable for a base material such as a joint material, a sealing material, or an adhesive tape cannot be obtained, and if it exceeds 150 parts by weight, the strength of the resulting foam is too low. However, it becomes difficult to use these as a base material.

Further, the above-mentioned paste sol is blended with a foaming agent, and as the foaming agent, a usual foaming agent used for ordinary vinyl chloride resins, for example, azodicarbonamide (ADCA), oxybisbenzene. Examples thereof include thermal decomposition type foaming agents such as sulfone hydrazide (OBSH), diazoaminobenzene, and azobisisobutyronitrile (AIBN), and these may be used alone or in combination of two or more.

The blending 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, it is preferably 2 to 16 parts by weight with respect to 100 parts by weight of the emulsion-polymerized vinyl chloride resin.

If the expansion ratio exceeds 15 times, it will be difficult to control the foam cells, and cell roughness and cell breakage will occur. If it is less than 4 times, the flexibility will decrease and the joint material and the sealing material will deteriorate. It becomes unsuitable as a base material such as. The control of the foaming ratio is performed by adjusting the blending ratio of the foaming agent and adjusting the foaming conditions such as the heating temperature as described above.

The linear dimethylpolysiloxane compounded in the paste sol containing the emulsion-polymerized vinyl chloride resin, the plasticizer, and the foaming agent functions to impart water repellency and stain resistance to the foam. And a compound represented by the general formula (1) of Chemical formula 1, specifically, by a hydrolysis polycondensation reaction of dimethyldichlorosilane and triethylmonochlorosilane, or of octamethylcyclotetrasiloxane and hexamethyldisiloxane. A mixture obtained by subjecting the mixture to a ring-opening polymerization reaction through a catalyst such as sulfuric acid or an 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 will be difficult to uniformly disperse it in the paste sol. On the contrary, if it is too low, the effect of imparting water repellency and stain resistance will not be exhibited. Therefore, in order to exhibit a liquid state capable of retaining a certain degree of fluidity and to exhibit these actions, it is preferable to use one having a viscosity of about 3000 to 50000.

For the above reason, it is not necessary for the dimethylpolysiloxane to have a three-dimensional structure with a crosslinking reaction. Therefore, in the present invention, a linear dimethylpolysiloxane is used.

The blending 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. Therefore, the effect of imparting the above-mentioned water repellency and stain resistance is not exhibited. On the other hand, when the amount is more than 10 parts by weight, the influence of the linear dimethylpolysiloxane becomes large, and the foaming property of the emulsion-polymerized vinyl chloride resin paste is impaired at the above expansion ratio, which is suitable for a base material such as a sealing material. It becomes impossible to obtain a closed cell structure. Therefore, in the present invention, 0.1 to 100 parts by weight of emulsion-polymerized vinyl chloride resin is used.
10 parts by weight.

Further, the above paste sol may optionally contain additives such as metal composite stabilizers, fillers, pigments and the like used in ordinary emulsion-polymerized vinyl chloride resins, in ordinary emulsion-polymerized vinyl chloride. It can be added in an amount when it is added to the resin.

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

For example, a film or paper having a peeling property on the surface or having a peeling property (that is, a releasing film or a releasing paper) is placed on an endless belt made of an appropriate material, and this releasing property is provided. The surface of the film or paper is coated with the above-mentioned paste sol to an 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 suitable means applied during the coating of an ordinary emulsion-polymerized vinyl chloride resin paste sol. . After coating, if the sol state is heated and foamed, a vinyl chloride resin foam by sol foaming can be obtained.

A pressure-sensitive adhesive layer may be provided on one surface of the vinyl chloride resin foam of the present invention thus prepared. Examples of the adhesive include rubber adhesives such as low molecular weight polyisoprene (IP), styrene-butadiene rubber (SBR) and butyl rubber (BR), acrylics such as butyl polyacrylate, 2-ethylhexyl polyacrylate and polyacrylic acid. A system adhesive can be used. In addition, as the tackifier, a terpene resin, a rosin, a coumarone-indene resin, a terpene phenol, an aromatic petroleum resin, an aliphatic petroleum resin, and the like are usually added to these adhesives. Can be blended in any 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 coating method at this time are not particularly limited, and can be selected as appropriate depending on the purpose of adhesion (whether it is for temporary fixing or permanent adhesion), the type of adherend, the operating environment, etc. To be done.

The foam of the present invention as described above is a long film having an appropriate width, which has a releasability like a general joint material, sealing material, adhesive tape, etc. (foam preparation) The film or paper used at the time of can be used as it is without peeling), and it is stored and sold while being wound around a core such as a paper tube, and the user Will be cut into an appropriate length before use.

[0025]

【Example】

Examples 1 to 16 and Comparative Examples 1 to 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 emulsion-polymerized polyvinyl chloride resin, and in Examples 1 to 9 and Comparative Examples 1 to 3, those having an average degree of polymerization of 1300 were used. As the plasticizer of * 2, DOP is used in Examples 1-2, Examples 5-6 and Comparative Examples 1-3, TOTM is used in Examples 3-4 and Examples 7-8, and Example 9 is used. Then DOP and T
An equal mixture with OTM was used. As the foaming agent of * 3, ADCA was used in all of Examples 1 to 9 and Comparative Examples 1 to 3, and when the compounding ratio of the foaming agent was 2 parts by weight, the expansion ratio was 4 times, and when 16 parts by weight was foamed. The magnification became 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. As the filler of * 5, CaCO ₃ was used in Examples 1 to 9 and Comparative Examples 1 to ₃ . The pigment of * 6 was used in Examples 1-9 and Comparative Examples 1-3.
Carbon black was used.

DMPS of * 7 refers to linear dimethyl polysiloxane, and is used in Examples 1-2, Examples 5-6, and Example 9.
And Comparative Examples 1 to 3 are based on 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 used for the 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, and a thickness of 2. A 0 mm foam sheet (12 types) was prepared.

On the surface (the surface not in contact with the release paper) of the above-mentioned foamed sheets (12 kinds), an acrylic adhesive mainly composed of polybutyl acrylate having a solid content concentration of 40% was wetted. 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, the closed cell ratio was measured by a Beckman type air-comparison hydrometer, a U-shaped water leakage test, and a water absorption test according to the following procedure. The foam cells were observed, and the results are shown in Tables 3-5.

(1) Measurement of closed cell ratio by Beckman type air-comparison hydrometer: Measured using an air-comparison hydrometer type 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 calipers, the closed cell ratio was calculated by the following formula.

[0034]

[Equation 1] -Appearance of foam = Volume of closed cells + Volume of cell wall + Volume of open cells-Ratio of closed cells = [volume of closed cells / (volume of closed cells +
Volume of open cells)] × 100

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

(3) Water absorbency test: For each foamed sheet that was cut into 100 mm square and weighed beforehand, below the water surface 20
It was immersed in mm for 24 hours, the surface water droplets were lightly blown off, the weight was measured, and the increased weight was obtained as a percentage, which was taken as the initial water absorption. Also, after leaving each of the above foam sheets at 80 ° C. for 1 hour,
The temperature change cycle of leaving it at 0 ° C for 24 hours is 10
The water absorption test similar to that described above was also performed for the repeated ones, and water absorption was performed after the temperature cycle.

(4) Observation of foam cells: The cross section of the foam was
The cell shape was evaluated by SEM (transmission electron microscope), and evaluated according to the following evaluation criteria.

[Evaluation Criteria] ◎ ... Round-shaped independent foamed cells ○ ... Slightly vertically elongated independent foamed cells △ ... Longitudinal foamed cells with partially broken cell walls 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 Nos. 1 to 2, the closed cell ratio and the state of the foam cells are not so different from those of the foams of the present invention in Examples 1 to 9, but the water leakage and the water absorption are the foams of the present invention in Examples 1 to 9. You can see that it is significantly inferior to the body. Further, in Comparative Example 3, the state of the foamed cells is extremely poor, so that the closed cell rate is small, and the water leakage and water absorption are inferior.

[0043]

As described in detail above, according to the present invention,
It is possible to effectively prevent the entry of water into the sol foamed vinyl chloride resin foam having a high expansion ratio and containing a large amount of plasticizer, and thus the excellent sealability of the foam (prevention of water leakage and water absorption). Properties, etc.) can be maintained at the place of use of the foam over 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, the present invention can provide a foam excellent 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 diagram showing a test mode adopted when evaluating the sealing performance of a foam in an example of the present invention.

Claims (3)

[Claims] 1. An emulsion-polymerized vinyl chloride resin 10
0.1 part by weight of linear dimethylpolysiloxane
A sol-foamed vinyl chloride resin foam comprising 10 to 10 parts by weight. 2. A vinyl chloride resin foam comprising 50 to 50 parts by weight of a vinyl chloride resin and a phthalate ester plasticizer or / and a trimellitic acid ester plasticizer.
The amount of 150 parts by weight is included.
The sol foamed vinyl chloride resin foam described. 3. The expansion ratio of the vinyl chloride resin foam is
It is 4 to 15 times, The sol foaming vinyl chloride resin foam according to claim 1 or 2.