JPH028079B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a process release paper, and particularly to a method for producing a matte type process release paper with no uneven coating. Conventionally, three types of resin compositions have been known as typical resin compositions for making the surface of process paper releasable: polypropylene resins, aminoalkyd resins, and silicone resins. Polypropylene is used.
However, although this polypropylene-based material has excellent durability during repeated use, it has the disadvantage that the heat resistance of the coating film is poor, which limits its use at high temperatures, and the peeling surface is easily damaged. Alkyd resin-based products have excellent heat resistance and gloss control, but lack of mold release properties, making it difficult to develop them into matte types, while silicone-based products have excellent releasability, but Since there are difficulties in controlling the gloss and uniformity of the coating surface, it is not necessarily satisfactory for use on matte type synthetic leather. For this reason, the present inventors have developed (a) a silicone-modified alkyd modified with an organopolysiloxane having a hydroxy-substituted organic group in which 15 to 50% of the organic groups bonded to silicon atoms in one molecule are phenyl groups; A matte whose main ingredient is a silicone-modified resin consisting of a resin or silicone-modified acrylic resin, (b) an alkanol-modified amino resin, (c) a neutral or weakly acidic inorganic filler or matting wax, and (d) an acidic catalyst. We developed a resin composition for release paper in the mold process, but it has good heat resistance and very low gloss, so even though it is an excellent resin for matte release paper in the mold process, it is not subject to treatment. It has been found that depending on the type of substrate, there is a disadvantage in that coating unevenness occurs during coating. The present invention relates to a method for producing a matte type process release paper that solves these disadvantages, and this involves coating the surface of the base material with an alkyd resin or acrylic resin.
An undercoat resin composition consisting of 100 parts by weight, 15 to 150 parts by weight of an alkanol-modified amino resin or isocyanate compound, and 1 to 20 parts by weight of an acidic catalyst is coated and cured, and then on this coated surface, (a) 15 organic groups bonded to silicon atoms in one molecule
~50 mol% is a phenyl group, and at least one of the remaining organic groups has the formula HO-R-(S) _a -R- (where R is a divalent hydrocarbon group and a is 0 or 100 parts by weight of silicone-modified alkyd resin or silicone-modified acrylic resin modified with organopolysiloxane, which is a hydroxy group-substituted organic group shown in 1) (b) Alkanol-modified amino resin 15 to 150 parts by weight (c) Particle size is 0.01 ~20μ neutral or weakly acidic inorganic filler or matte wax
It is characterized by coating and curing a matte type resin composition consisting of 1 to 50 parts by weight (d) and 1 to 20 parts by weight of an acidic catalyst. That is, as a result of various studies by the present inventors regarding solutions to uneven coating in the manufacturing process of process release paper, we found that prior to coating the surface of the base material with a resin composition for process release paper, If an undercoat resin composition consisting of an alkyd resin or acrylic resin and an alkanol-modified amino resin or an isocyanate compound is applied in advance, the coating and penetration properties of the silicone-modified alkyd resin or acrylic resin onto the surface of the base material can be improved. It was discovered that it was possible to obtain a process release paper that was significantly improved and completely free of paint unevenness, and the present invention was completed by conducting research on the constituent elements of the acrylic resin composition that serves as the undercoating agent. The resin composition for undercoating the surface of the substrate used in the method of the present invention is made of an alkyd resin or acrylic resin, an alkanol-modified amino resin or an isocyanate compound, and an acidic catalyst. These alkyd resins and acrylic resins may be commercially available products, including saturated fatty acids such as octyl acid, lauric acid, and palmitic acid, unsaturated oils such as coconut oil, castor oil, and soybean oil,
Alkyd resins obtained by the reaction of unsaturated oil fatty acids such as castor oil fatty acids with polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, and pentaerythritol, polymerization of acrylic acid, methacrylic acid or its esters, methacrylamide, or maleic acid. Examples include acrylic resins obtained by copolymerization with fumaric acid, styrene, vinyl acetate, propionic acid, and the like. In addition, this alkanol-modified amino resin may be one that is generally commercially available, and examples thereof include methoxymethylolmelamine resin, butoxydimethylolmelamine resin, butoxymethylolurea-melamine cocondensation resin, butoxymethylolbenzoguanamine resin, etc. As this acidic catalyst, p-toluenesulfonic acid, hydrochloric acid, etc., which are known as reaction catalysts of this type, may be used. Also,
The resin composition for this undercoat treatment may be one in which 15 to 150 parts by weight of an alkanol-modified amino resin and 1 to 20 parts by weight of an acidic catalyst are added to 100 parts by weight of an alkyd resin or acrylic resin. The resin, acrylic resin, and alkanol-modified amino resin are required to be compatible, so the alkyd resin or acrylic resin must be non-oil modified with a hydroxyl value of 10 to 100 and a molecular weight of 500 to 50,000, or carbon It is preferable to use one modified with 8 to 18 saturated or unsaturated oils. In addition,
The alkanol-modified amino resin mentioned above may be an isocyanate compound, and examples thereof include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate,
An example is hexamethylene diisocyanate, and from the viewpoint of toxicity and storage stability, this may be, for example, a polyhydric alcohol adduct of diisocyanate, a dimer or a polymer of diisocyanate, but when using this isocyanate compound, the above-mentioned It is not necessary to add the acidic catalyst. To treat the surface of the base material with this undercoat treatment agent, first dilute this composition with a solvent as necessary.
After applying this to a thickness of 1μ to 20μ using an appropriate method such as brushing or spray painting,
It may be cured by heating to 100 to 200°C. In the method of the present invention, a resin composition for a matte process release paper is applied to the surface of the base material which has been undercoated with a resin liquid containing an alkyd resin or an acrylic resin obtained in this way. The composition comprises (a) a silicone-modified alkyd resin or a silicone-modified acrylic resin modified with an organopolysiloxane containing a phenyl group and a hydroxyl substituent; and (b) a silicone-modified acrylic resin.
It consists of an alkanol-modified amino resin, (c) an inorganic filler or matting wax, and (d) an acidic catalyst. The silicone-modified alkyd resin or silicone-modified acrylic resin as component (a) can be obtained by modifying the alkyd resin or acrylic resin with an organopolysiloxane containing a phenyl group and a hydroxyl group. This organopolysiloxane has 15 organic groups bonded to silicon atoms in one molecule.
~50 mol% is a phenyl group, and at least one of the remaining organic groups is a hydroxy group represented by the formula HO-R-(S) _a -R-...() (R and a are as described above) It is required that the organopolysiloxane be a substituted organic group, and the remaining organic group may be an alkyl group such as a methyl group, an ethyl group, an octyl group, or an alkyl group substituted with a halogen or cyano group. Either is fine. The molecular structure of this organopolysiloxane may be a linear structure or a branched structure (three-dimensional structure), but it is preferable that the molecular structure has relatively good compatibility with alkyd resins and acrylic resins. A preferred specific example of the structure is the following formula I can give you something. In the above formula, Me is a methyl group, Ph is a phenyl group, m and n are positive numbers, and m+n is 30 to 1000, preferably 50 to
200, R ¹ represents an organic group, at least one of which is a hydroxy group-substituted organic group represented by the above formula (), and the phenyl group is 15 to 50 mol% in all organic groups, The remaining groups in ¹ may be any alkyl group such as a methyl group, ethyl group, or octyl group, or an alkyl group substituted with a halogen group, a cyano group, or the like. In addition, R in the hydroxy group-substituted organic group of the above formula () is the same or different type of divalent hydrocarbon group, a represents 0 or 1, and such organic groups include -CH ₂ CH ₂ -, -
_CH2CH2CH2- , -( _CH2 ) _b -S-( _CH2 ) _c- (b is 1 _or 2, _c is 2 or 3) are exemplified. The method for obtaining the silicone-modified alkyd resin or acrylic resin, which is the component (a), using the above organopolysiloxane mainly involves (1) the normal synthesis reaction for obtaining the alkyd resin, namely, polyhydric alcohol and fatty acid, polyhydric A method in which the organopolysiloxane is simultaneously reacted when reacting with a base acid, etc., or when polymerizing a monomer such as an α,β-unsaturated acid or its ester, in a normal synthesis reaction for obtaining an acrylic resin, ( 2) There are two methods: reacting a pre-synthesized general alkyd resin or acrylic resin with organopolysiloxane. Silicone modification of the alkyd resin or acrylic resin may be carried out by any of the methods described above, but in this case, the amount of organopolysiloxane used is 0.1 to 0.1 to the solid content of the silicone-modified alkyd resin or silicone-modified acrylic resin.
It is desirable that the amount is 50% by weight, preferably 1 to 40% by weight. On the other hand, the alkanol-modified amino resin as component (b) and the acidic catalyst as component (ii) constituting the resin composition of the present invention may be the same as those described above for the resin composition as an undercoat treatment agent. Examples of the inorganic filler as the component (iii) include fine silica powder, and examples of the matting wax include polyethylene wax. The blending ratio of components (a) to (d) is determined from the viewpoint of the purpose of the present invention, that is, to obtain a matte process release paper with excellent heat resistance and peelability.
For 100 parts by weight, the amount of component (b) should be 15 to 150 parts by weight, the amount of component (c) should be 1 to 50 parts by weight, and the amount of component (d) should be 1 to 20 parts by weight. This makes it difficult to obtain materials with desirable physical properties. Note that ordinary alkyd resins and acrylic resins may be blended with this, if necessary. It is usually convenient to use this resin composition in the form of a solvent solution, and the solvent used for this purpose must be one that does not have reactivity with the components (a) and (b). For example, benzene,
Toluene, xylene, methanol, ethanol,
One or a mixture of two or more of isobutanol, n-butanol, methyl ethyl ketone, acetone, tetrahydrofuran, etc. is used.
The amount used is usually such that the resin solid content is in the range of 10 to 60%. In the method of the present invention, the matte type process release paper resin composition obtained by the above method is applied to the surface of a base material that has been previously coated with an undercoat composition as described above. The surface of the material is coated with silicone-modified alkyd resin,
Since it is said to have good wettability with silicone-modified acrylic resin, the coated surface of the resin composition for process release paper can be easily made into a uniform surface with no uneven coating, resulting in improved heat resistance and peelability. This provides the advantage that a process release paper of excellent matte type can be easily obtained. Next, examples of the method of the present invention will be given, where parts in the examples indicate parts by weight. Synthesis example (Manufacture of resin composition for matte process release paper) [Synthesis of organopolysiloxane] Both ends of the molecular chain are blocked with dimethylvinylsiloxy groups, and the main chain contains 68 mol% of dimethylsiloxane units.
A raw material diorganopolysiloxane having a viscosity of 4000 centipoise (25°C) composed of 30% mole of diphenylsiloxane units, 2-mercaptoethanol, benzophenone as a photoreaction accelerator, and toluene as a reaction medium are added in a flask. and then pour it into this flask from the top.
A 100W high-pressure mercury lamp was inserted and irradiated for 2 hours to cause a reaction. When toluene was distilled off from the reaction mixture under reduced pressure, both ends of the molecular chain of the above raw material diorganopolysiloxane were found to have the formula A diorganopolysiloxane containing a hydroxyl group-substituted organic group was obtained, which was converted into a structure shown in the following. [Synthesis of silicone-modified alkyd resin] 109 parts of the hydroxy-substituted organic group-containing diorganopolysiloxane obtained above, 172 parts of coconut oil fatty acid,
Charge 249 parts of phthalic anhydride and 169 parts of glycerin into a reactor, and raise the internal temperature to 150-200 in an atmosphere of nitrogen gas.
After reacting at °C for about 8 hours, the mixture was diluted with toluene so that the solid content was 60% by weight to obtain 1080 parts of a silicone-modified alkyd resin liquid, which had the following physical properties. Viscosity (Note) D Acid value 3.0 Hydroxyl value 65 (Note) The viscosity is the value determined by Gardna viscometer (25℃), the same applies hereafter [Synthesis of silicone-modified acrylic resin] Hydroxy group-substituted organic group-containing diorganopolymer obtained above 42 parts of siloxane and 700 parts of Tesroid 795 (acrylic resin manufactured by Tokushima Essential Oil Co., Ltd., viscosity R, acid value 7.0, hydroxyl value 72, 60% xylene solution) were charged into a reactor and reacted at 130 to 180°C for about 5 hours. 742 parts of silicone-modified acrylic resin was obtained. When this product was diluted with xylene so that the solid content was 60% by weight, its physical properties were as follows. Viscosity: 0 Acid value: 6.3 Hydroxyl value: 66 [Manufacture of resin composition for matte process release paper] 60 parts of the silicone-modified alkyd resin liquid obtained above and Tesmin 350-60 [manufactured by Tokushima Essential Oil Co., Ltd., butylated urea] - Disperse 12 parts of silica fine powder Thyroid 244 [product name manufactured by Fuji Davison Chemical Co., Ltd.] in a composition with 40 parts of melamine cocondensation resin at 2000 rpm using a homomixer, and then use an acidic catalyst dryer to [Product name manufactured by Tokushima Essential Oils Co., Ltd.] 5 parts and diluted with toluene to make a solid content of 40% to prepare a composition, and add butylated urea to the silicone-modified acrylic resin liquid obtained above. Melamine cocondensation resin Tesmin
201-80 [trade name manufactured by Tokushima Seyu Co., Ltd.] 40 parts, polyethylene wax [trade name manufactured by Nippon Polycon Industries Co., Ltd.] 70 parts, and 6 parts of silica fine powder Thyroid 244 (mentioned above) were added to form a homogeneous product. After dispersing with a mixer, 6 parts of acidic catalyst dryer 50 (described above) was added thereto, and the mixture was diluted with toluene to a solid content of 40% to prepare a composition. Example 1 Butylated urea added to 60 parts of coconut oil-modified alkyd resin.
melamine cocondensation resin Tesmin 350-60 (above) 40 parts and acidic catalyst dryer 50 (above) 5 parts are blended,
A resin composition for undercoat [Sample 1] was prepared by diluting the solid content to 40% with toluene, and this was coated on mirror coated paper [manufactured by Kanzaki Paper Co., Ltd., 130 g/m ² ]. Coat it to a thickness of 10μ and dry it in a hot air dryer.
It was cured by heating to 150°C for 1 minute. Next, the resin composition for process release paper made in the synthesis example was coated on the mirror coated paper that had been undercoated in this way so that the coating film had a thickness of 10 μm. After curing by heating for a minute to create a process release paper, a one-component polyurethane solution, Crysbon 5516S (trade name, manufactured by Dainippon Ink and Chemicals Co., Ltd.), was applied on top of the paper and placed in a hot air dryer.
After drying at 150℃ for 2 minutes and lining with synthetic resin tape Lumirror 31B (trade name, manufactured by Nitto Co., Ltd.), this was peeled off and the uniformity of the urethane surface was examined; this gave a uniform urethane surface. However, for comparison, the process release paper manufactured above without the undercoating treatment using sample 1 had uneven urethane surface.
A uniform product could not be obtained. Examples 2 to 10 Three types of alkyd resins made from fatty acids, dibasic acids, and polyhydric alcohols as shown in Table 1, and organic acids, organic acid esters, and olefins as shown in Table 2. A butylated urea-melamine cocondensation resin and an acidic catalyst were added to the two types of acrylic resins produced by polymerization in the same manner as in Example 1 to prepare resin compositions for undercoating [Samples 2 to 6], which were used in Example 1. The resin composition for process release paper obtained in the synthesis example was coated on mirror coated paper in the same manner as in Example 1, and then the process release paper was prepared by applying the resin composition for process release paper obtained in the synthesis example. When the uniformity was examined, as shown in Table 3, a uniform coated surface was obtained in all cases. In addition, in this example, a similar test was conducted using glassine paper or polyester film as the mirror coated paper in the above, and it was found that in this case, a uniform coated surface was obtained even when samples 2 to 6 were not coated. It was done.

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Claims (1)

[Scope of Claims] 1. An undercoat resin composition comprising 100 parts by weight of an alkyd resin or acrylic resin, 15 to 150 parts by weight of an alkanol-modified amino resin or isocyanate compound, and 1 to 20 parts by weight of an acidic catalyst on the surface of a base material. is coated and cured, and then (a) 15 of the organic group bonded to the silicon atom in one molecule is applied to this surface.
~50 mol% is a phenyl group, and at least one of the remaining organic groups has the formula HO-R-(S) _a -R- (where R is a divalent hydrocarbon group and a is 0 or 100 parts by weight of silicone-modified alkyd resin or silicone-modified acrylic resin modified with organoborisiloxane, which is a hydroxy group-substituted organic group shown in 1) (b) Alkanol-modified amino resin 15 to 150 parts by weight (c) Particle size is 0.01 ~20μ neutral or weakly acidic inorganic filler or matte wax
1. A method for producing a matte process release paper, which comprises coating and curing a matte resin composition comprising 1 to 50 parts by weight (d) and 1 to 20 parts by weight of an acidic catalyst.