JP2005306982A - Resin composition and sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems that an acrylate resin is inferior in flexibility, and in flame retardance compared to a soft vinyl chloride resin, and a urethane resin, on the other hand, is excellent in flexibility, but inferior in strength so that it is difficult to be used as a substitute for a soft vinyl chloride resin. <P>SOLUTION: The resin composition comprises 100 pts.mass of a polyvinyl acetal resin, 300-2,000 pts.mass of a modified polypropylene glycol containing 50 mass% or more of a polypropylene glycol and/or a propylene glycol structure, and 4-2,100 pts.mass of a polyisocyanate compound. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is an agricultural vinyl house, marking film, poster, wallpaper, foamed sheet, outdoor leather, resin-coated steel roofing and exterior wall materials, automotive interior and exterior, painting replacement for furniture, elevator interior, rain gutter, floor The present invention relates to a resin composition as a raw material such as a material, a corrugated plate, a decorative pillar, a binder, a lighting skin material, and a heat insulating film, and a sheet formed of the resin composition.

  As the sheet material, various polymers such as a vinyl chloride resin, an acrylic resin, a polyester resin, and a polyolefin resin have been used, but those using a polyvinyl acetal resin are not known. On the other hand, a polyurethane resin is known as a resin using polypropylene glycol as a flexible component, and is widely used.

Vinyl chloride resins softened with a plasticizer are widely used, but have problems such as weather resistance and plasticizer migration. In addition, due to problems such as generation of harmful gases during combustion, alternatives to soft vinyl chloride resin were studied. For example, Patent Document 1 describes the use of an acrylic resin having good weather resistance, and polyester resins and polyolefin resins are also known.
Japanese Examined Patent Publication No. 6-45737

  The resin described in Patent Document 1 is inferior in flexibility and inferior in flame retardancy as compared with a soft vinyl chloride resin. On the other hand, in the case of urethane resin, the flexibility is good, but the strength is inferior, making it difficult to replace soft vinyl chloride resin.

  An object of the present invention is to provide a flexible resin composition exceeding a soft vinyl chloride resin having improved strength while maintaining the flexibility of a urethane resin, and a sheet formed of the resin composition, and Is to provide a resin composition having improved flame retardancy and a sheet formed of the resin composition.

  That is, the present invention is a resin composition comprising 100 parts by mass of a polyvinyl acetal resin, 300 to 2000 parts by mass of a modified polypropylene glycol containing 50% by mass or more of a polypropylene glycol and / or propylene glycol structure, and 4 to 2100 parts by mass of a polyisocyanate compound. It is.

  Another invention is a resin composition containing 100 parts by mass of the resin composition and 50 to 1000 parts by mass of magnesium hydroxide and / or aluminum hydroxide.

  Furthermore, another invention is a sheet formed to have a thickness of 0.1 to 100 mm after reacting the resin composition.

  The resin composition of the present invention can easily produce a sheet excellent in flexibility and strength at low cost. Moreover, the sheet | seat obtained from the resin composition which mix | blended magnesium hydroxide and / or aluminum hydroxide with this resin composition is excellent also in a flame retardance besides being excellent in a softness | flexibility and an intensity | strength.

  The polyvinyl acetal resin in the present invention is a resin having a cyclic acetal structure obtained by a reaction between polyvinyl alcohol (hereinafter referred to as PVA) and aldehydes. Generally, polyvinyl butyral resin produced using butyraldehyde as an aldehyde is often used.

  As a method for producing a polyvinyl acetal resin, for example, PVA is dissolved in warm water, the obtained aqueous solution is kept at a predetermined temperature (for example, 0 to 95 ° C.), an acid catalyst and an aldehyde are added, and the mixture is stirred. The acetalization reaction is allowed to proceed, and then the reaction temperature is raised to ripen to complete the reaction. Thereafter, neutralization, washing with water and drying are performed to obtain a powdered resin, which is powdered in an organic solvent such as methanol or ethanol. The body PVA is suspended, an acid catalyst and an aldehyde are added at 0 to 50 ° C., the acetalization reaction proceeds to a solution while stirring, and then the reaction temperature is raised to complete the reaction, and then neutralized. For example, a solvent method is used in which a precipitation solvent such as water is added to precipitate a resin, which is washed with water and subjected to impressions to obtain a powder resin.

  It is preferable that the average degree of polymerization of PVA used for manufacture of a polyvinyl acetal resin is 300-3000, a more preferable minimum is 500 and a preferable upper limit is 2500. If the average degree of polymerization of PVA is less than 300, the strength of the sheet tends to be insufficient. Conversely, if the average degree of polymerization of PVA exceeds 3000, mixing with polypropylene glycol tends to be difficult.

  The average degree of polymerization of PVA was measured according to JIS K-6726 “Testing method for polyvinyl alcohol”. The hydroxyl value used in the present invention was measured according to JIS K-1557. The average degree of acetalization of the polyvinyl acetal resin was measured according to JIS K-6728 “Testing method for polyvinyl butyral”.

  The polyvinyl acetal resin preferably has a hydroxyl value of 70 to 300, more preferably a lower limit of 80, a particularly preferable lower limit of 100, a more preferable upper limit of 250, and a particularly preferable upper limit of 200. When the hydroxyl value of the polyvinyl acetal resin is small, the strength of the obtained sheet tends to be insufficient, and when it is large, the water resistance tends to be insufficient.

  The resin composition of the present invention contains 300 to 2000 parts by mass of “modified polypropylene glycol containing 50% by mass or more of polypropylene glycol and / or propylene glycol structure”. If these compounding ratios are small, the flexibility of the obtained sheet tends to be insufficient, and if the compounding ratio is large, the strength of the obtained sheet tends to be insufficient.

  Polypropylene glycol is a compound composed of repeating propylene glycol structural units produced by the ring-opening addition reaction of propylene oxide, and is also a raw material for polyurethane resin. The molecular weight is preferably from 100 to 20000, more preferably the lower limit is 200, the particularly preferable lower limit is 300, the more preferable upper limit is 15000, and the particularly preferable upper limit is 10,000. The degree of branching is simply produced using an initiator having three or more hydroxyl groups such as glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, and sorbitan in addition to a bifunctional polypropylene glycol having hydroxyl groups at both ends. Polyfunctional polypropylene glycol can be used. These polypropylene glycols can be used alone or in combination of two or more.

  In “modified polypropylene glycol containing 50% by mass or more of propylene glycol structure”, “containing 50% by mass or more of propylene glycol structure” means that the balance of water resistance, flexibility, transparency, etc. is reduced if the polypropylene structure is small This value is preferably 70% by mass or more, and particularly preferably 90% by mass or more.

  Components other than the polypropylene glycol structure of the modified polypropylene glycol include those produced by a ring-opening addition reaction similar to the propylene glycol structure, for example, a polyethylene glycol structure obtained from ethylene oxide, a polyalkylene ester structure obtained from lactones, There are polyalkylene amide structures derived from lactams.

  The hydroxyl value of the “modified polypropylene glycol containing 50% by mass or more of polypropylene glycol and / or propylene glycol structure” in the present invention tends to decrease the strength of the sheet when it is low and decreases the water resistance when it is high. Since there exists a tendency, 10-700 are preferable, The more preferable minimum is 30, The especially preferable minimum is 50, The more preferable upper limit is 600, The especially preferable upper limit is 500.

  In the present invention, the hydroxyl values of “polyvinyl acetal resin” and “modified polypropylene glycol containing 50% by mass or more of polypropylene glycol and / or propylene glycol structure” are preferably close to ensure affinity. For example, the ratio obtained by dividing the hydroxyl value of polyvinyl acetal resin by the hydroxyl value of “modified polypropylene glycol containing 50% by mass or more of polypropylene glycol and / or propylene glycol structure” is preferably 0.1 to 20, and a more preferable lower limit is 0.2, a particularly preferred lower limit is 0.3, a more preferred upper limit is 15, and a particularly preferred upper limit is 10. Such a value is preferable because the compatibility between the polyvinyl acetal resin and the “modified polypropylene glycol containing 50% by mass or more of the polypropylene glycol and / or propylene glycol structure” decreases and the solubility decreases both in the case of small and large. This is because the composition tends to be difficult to obtain.

  The polyisocyanate compound in the present invention is used as a cross-linking agent for cross-linking both the polyvinyl acetal resin and “modified polypropylene glycol containing 50% by mass or more of polypropylene glycol and / or propylene glycol structure”. If the blending ratio is small, the strength of the obtained sheet tends to be insufficient, and if it is large, the flexibility of the obtained sheet tends to be insufficient, so that it is 4 to 2100 parts by mass. Specifically, the polyisocyanate compound is a compound having two or more isocyanate groups in the molecule. For example, MDI (diphenylmethylene diisocyanate), TDI (toluene diisocyanate), 1,6-HDI (1,6-hexane) Diisocyanate) and CHDI (cyclohexane diisocyanate). Polyisocyanate compounds include those without solvent and those diluted with solvent, and those having no solvent are preferable from the viewpoint of the environment for workers.

  Magnesium hydroxide and / or aluminum hydroxide can be added to the resin composition according to the present invention to impart flame retardancy. When these are heated, they undergo a dehydration reaction and exhibit a flame retardant effect by cooling the surroundings with the volatile heat.

  The lower limit of the compounding ratio of magnesium hydroxide and / or aluminum hydroxide is 50 parts by mass, preferably 80 parts by mass, particularly preferably 100, because the flame retardancy tends to be insufficient if it is too small. The upper limit is 1000 parts by mass, preferably 500 parts by mass, and particularly preferably 300 parts by mass because the flexibility tends to decrease as the upper limit increases.

  The resin composition according to the present invention can obtain a flexible reaction product by reacting at a relatively low temperature. Here, the lower limit of the reaction temperature is preferably 10 ° C., particularly preferably 30 ° C., because if the reaction temperature is too low, the progress of the reaction slows down and the productivity decreases. If the upper limit is too high, an abnormal reaction is caused to cause foaming or coloring, so 200 ° C. is preferable, and 150 ° C. is particularly preferable. In order to control the reaction rate, what is called a urethanization catalyst can be used. In order to prevent foaming, it is also possible to add a material having water absorption properties such as silica gel, calcium oxide, zeolite, bentonite, and sodium polyacrylate.

  In addition to the above-described composition, the resin composition of the present invention may contain known compounding agents such as lubricants, stabilizers, processing aids, impact aids, foaming agents, fillers, colorants, antibacterials as necessary. Agents, UV absorbers, antioxidants and matting agents can also be incorporated.

  The lubricant is used for facilitating peeling between the obtained sheet and the separator or calender roll, and for reducing blocking after winding on the roll. Specifically, fatty acid systems such as metal soap and stearic acid are used. There are lubricants, fatty acid esters, higher alcohols, hydrogen carbonate lubricants such as paraffin wax, natural waxes, and polymer lubricants mainly composed of acrylic polymers. Among these, considering the thermal stability and roll peelability at the time of film formation, a polymer lubricant mainly composed of an acrylic polymer is preferable. As such a lubricant, there is, for example, Metabrene L-1000 (manufactured by Mitsubishi Rayon Co., Ltd.).

  If the blending ratio of the lubricant is too large, it tends to cause a decrease in transparency and a decrease in hygroscopicity, so 0 to 3 parts by mass is preferable with respect to 100 parts by mass of the entire resin composition.

  By forming the resin composition in the present invention into a sheet having a thickness of 0.1 to 100 mm before or after the reaction, a sheet having excellent flexibility and strength and excellent flame retardancy can be obtained. The method of forming into a sheet can be selected according to the purpose of use, and a method in which a low-viscosity reactive resin composition is applied to another sheet or film called a separator with a roll or blade, followed by a heat reaction or relatively high There are a wide range of sheet processing methods such as calendering method, inflation method, heat-reaction method after forming into a sheet by calendering method, inflation method, extrusion method by T-die, casting molding method to heat reaction by flowing into the mold Is possible.

  Hereinafter, the present invention will be described in more detail with reference to Table 1 using Examples and Comparative Examples.

<Creation of resin composition>
In a three-neck separable flask equipped with a stirrer by a motor, a predetermined amount of a modified polypropylene glycol containing 50 mass% or more of polypropylene glycol and / or propylene glycol structure is weighed, and 100 mass of polyvinyl acetal resin is stirred here at room temperature. I put in the parts little by little so as not to be ridiculous. After the addition, the mixture was heated to 70 ° C. in a water bath, kept at 70 ° C., and stirred and mixed for 8 hours. This is cooled to room temperature, weighed 100 parts by weight in a food processor (boiled mode), further added a predetermined amount of magnesium hydroxide or aluminum hydroxide and a predetermined amount of polyisocyanate compound, other additives and mixed for 10 minutes did.

<Evaluation of resin composition>
The viscosity at 25 ° C. was measured with a BM viscosity type immediately after the preparation. For storage stability, 5 ml was placed in a 10 ml screw tube and left in a 50 ° C. water bath, and the flow state was observed. Gelation was defined when the fluidity disappeared after becoming a pudding. The results are shown in Table 1 together with the sheet results.

<Creating a sheet>
The obtained resin composition is poured into a stainless steel frame (1 mm × 100 mm × 100 mm) laid with a polyethylene terephthalate resin film. Further, the polyethylene terephthalate resin film is placed on the resin composition, and a table press is used at 100 ° C./10 Pa. For 30 minutes and sheeted simultaneously with the reaction.

<Evaluation of sheet>
Tensile test according to JIS Z 0237, hardness according to shear A hardness, and flame retardancy according to UL-94 were measured.

  Each Example obtained favorable evaluation.

The present invention includes agricultural vinyl houses, marking films, posters, wallpaper, foam sheets, outdoor leather, resin-coated steel roofing materials and exterior wall materials, automotive interior and exterior, and paint replacement for furniture, elevator interiors, gutters, floors The present invention relates to a resin composition as a raw material such as a material, a corrugated sheet, a decorative pillar, a binder, a lighting skin material, and a heat insulating film, and a sheet formed of the resin composition.

Claims (3)

  A resin composition comprising 100 parts by mass of a polyvinyl acetal resin, 300 to 2000 parts by mass of a modified polypropylene glycol containing 50% by mass or more of a polypropylene glycol and / or propylene glycol structure, and 4 to 2100 parts by mass of a polyisocyanate compound.   The resin composition which mix | blended 100 mass parts of resin compositions of Claim 1, and 50-1000 mass parts of magnesium hydroxide and / or aluminum hydroxide. The sheet | seat formed in thickness of 0.1-100 mm after making the resin composition of Claim 1 or Claim 2 react.