JPS63202685A - Acrylic release agent - Google Patents

Abstract

PURPOSE:To obtain an acrylic release agent suitable for treating backs of a surface protecting materials, adhesive tapes, etc., and forming release tapes, etc., by crosslinking an acrylic polymer containing two kinds of acrylic acid based esters having respective different aliphatic groups as component. CONSTITUTION:An acrylic release agent obtained by crosslinking an acrylic copolymer, consisting of (A) 100pts.wt. acrylic acid based ester component having a >=12C aliphatic group and (B) 5-60pts.wt. acrylic acid based ester component having a 2-11C aliphatic group and having preferably about 300,000-700,000 weight-average molecular weight using a crosslinking agent, such as polyisocyanate or melamine resin.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention consists of an acrylic copolymer containing two types of acrylic acid esters having 12 or more carbon atoms or an aliphatic group of 2 to 11 carbon atoms. This invention relates to an acrylic release agent suitable for surface protection materials, back surface treatment of adhesive tapes, and formation of release tapes.

Conventional Technologies and Problems Conventionally, release agents used for surface protection materials such as stainless steel plates, back treatments for adhesive tapes, and the formation of release tapes include silicone-based agents, polyvinyl alcohol, and long-chain alkyl isocyanates. The system was known.

However, such release agents have poor adhesion to supporting substrates made of thin sheets of polyvinyl chloride, polyester, etc., and easily fall off from the substrate. The release agent easily transfers to the adhesive side, thereby reducing the adhesive strength of the adhesive layer and contaminating the adherend. Therefore, measures are being taken to reduce the amount of release agent used as much as possible.

Means for Solving the Problems The present inventor has conducted extensive research in order to overcome the above problems and develop a release agent that has excellent adhesion to the substrate, does not cause transfer, and has excellent peeling performance. As a result of repeated research, it was discovered that the object could be achieved by using an acrylic copolymer containing a special acrylic acid ester as a component, and the present invention was completed.

That is, in the present invention, an acrylic copolymer made of an acrylic acid ester and an acrylic compound having a functional group is crosslinked with a crosslinking agent, and the acrylic copolymer has an aliphatic group having 12 or more carbon atoms. and/or an acrylic ester having an aliphatic group having 2 to 11 carbon atoms per 100 parts of the acrylic ester component having an aliphatic group having 12 or more carbon atoms. The present invention provides an acrylic release agent characterized by containing 5 to 60 parts by weight of an acrylic acid ester component having 2 to 11 aliphatic groups.

By using together an acrylic acid ester having an aliphatic group having 12 or more carbon atoms and an acrylic ester having an aliphatic group having 2 to 11 carbon atoms in the above ratio, excellent peeling performance can be achieved. It has excellent adhesion to the substrate and can be used as a release agent to cause transfer.

Examples of Constituent Elements of the Invention The acrylic release agent of the present invention is obtained by crosslinking an acrylic copolymer containing an acrylic acid ester and an acrylic compound having a functional group.

Two types of acrylic esters are used. - has 12 or more carbon atoms, especially 12, as represented by lauryl acrylate, tridecyl acrylate, stearyl acrylate, eicosyl acrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, eicosyl methacrylate, etc. ~36
It is an acrylic acid ester having an aliphatic group. Other examples include ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isononyl acrylate,
It is an acrylic ester having an aliphatic group having 2 to 11 carbon atoms, represented by isodecyl acrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, isononyl methacrylate, isodecyl methacrylate, and the like.

The acrylic compound having a functional group is used to impart crosslinking properties, and any known acrylic compound may be used.

Typical examples include acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, acrylamide, and acrylonitrile.

The appropriate amount of the acrylic compound having a functional group to be used is 0.5 to 10 parts by weight per 100 parts by weight of the acrylic ester. If the amount used is less than 0.5 parts by weight, the resulting acrylic release agent will be insufficiently crosslinked and transfer will occur easily.If the amount exceeds 10 parts by weight, the resulting acrylic release agent will be too crosslinked and the adhesive strength to the substrate will deteriorate. become scarce.

The acrylic copolymer used in the present invention is one or two acrylic esters having an aliphatic group having 12 or more carbon atoms.
A copolymer of one or more acrylic acid esters having an aliphatic group having 2 to 11 carbon atoms, and one or more acrylic compounds having a functional group. may be configured. In this case, the obtained copolymer can be used alone as it is as the acrylic copolymer in the acrylic release agent of the present invention.

On the other hand, the acrylic copolymer contains one or more acrylic esters having an aliphatic group having 12 or more carbon atoms,
A copolymer with one or more acrylic compounds having a functional group, or one or more acrylic esters having an aliphatic group having 2 to 11 carbon atoms, and an acrylic compound having a functional group. It may also be constructed as a copolymer with one or more types of compounds. That is, it may be constructed as an acrylic copolymer using the two types of acrylic acid esters described above separately. In this case, a mixture of the respective acrylic copolymers is used.

In addition, it is also possible to construct a system in which this mixed use method and the above-mentioned batch copolymerization method are used together.

In either case of the above-mentioned batch copolymerization method or mixed use method, the number of carbon atoms in the acrylic release agent is 2 or more.
The content of the acrylic ester component having 11 aliphatic groups needs to be 5 to 60 parts by weight per 100 parts by weight of the acrylic ester component having an aliphatic group having 12 or more carbon atoms.

If the content is less than 5 parts by weight, the resulting acrylic release agent will have poor adhesive strength and will easily fall off from the base material, while if it exceeds 60 parts by weight, the resulting acrylic release agent will have poor release performance. Become.

The weight average molecular weight of the acrylic copolymer is suitably from about 300,000 to about 700,000.

The acrylic release agent of the present invention is obtained by crosslinking the above-mentioned acrylic copolymer with a crosslinking agent.

There are no particular limitations on the crosslinking agent used, and known crosslinking agents such as polyisocyanates, melamine resins, metal salts, etc. can be used. The amount of the crosslinking agent may be customary, and is generally 0.00% per 100M parts of the acrylic copolymer.
5 to 15 parts by weight is suitable.

The acrylic release agent of the present invention can be preferably used for conventional release agent applications, such as back treatment of adhesive tapes and surface protection materials, and the formation of release tapes.

Effects of the Invention The acrylic release agent of the present invention has 12 or more carbon atoms or 2 to 2 carbon atoms.
Since it contains an acrylic copolymer using an acrylic ester having 11 aliphatic groups, it has excellent adhesion to the substrate and excellent peeling performance.

As a result, even when the surface protection material is rolled up and rewound, it is not transferred to the adhesive side (<, it is difficult to effectively prevent a decrease in the adhesive strength of the adhesive layer and contamination of the adherend). can.

Examples Example 1 100 parts of lauryl methacrylate (parts by weight, the same applies hereinafter),
Weight average molecular weight of 450,000 (as determined by gel permeation chromatography) obtained by copolymerizing 10 parts of ethyl acrylate and 2 parts of acrylic acid in a solvent consisting of toluene using 0.2 parts of benzoyl peroxide as an initiator. 5 parts of polyisocyanate was added to 100 parts (solid content) of the acrylic copolymer (based on polystyrene equivalent), and crosslinked.
An acrylic release agent was obtained.

Example 2 100 parts of lauryl methacrylate, 50 parts of ethyl acrylate
An acrylic release agent was obtained in accordance with Example 1, except that 5 parts of acrylonitrile and 2 parts of acrylic acid were used. The weight average molecular weight of the acrylic copolymer was 580,000.

Example 3 An acrylic release agent was obtained according to Example 1, except that 100 parts of stearyl methacrylate, 30 parts of n-butyl acrylate, 2 parts of acrylic acid, and 0.5 part of 2-hydroxyethyl acrylate were used. . The weight average molecular weight of the acrylic copolymer was 500,000.

Example 4 An acrylic release agent was obtained according to Example 1 using 100 parts of stearyl methacrylate, 30 parts of isodecyl methacrylate, 2 parts of acrylic acid, and 0.5 parts of 2-hydroxyethyl acrylate. The weight average molecular weight of the acrylic copolymer was 400,000.

Example 5 A combination of 100 parts of stearyl methacrylate, 1.5 parts of acrylic acid, and 0.5 parts of 2-hydroxyethyl acrylate,
or 30 parts of isodecyl methacrylate and 0.5 parts of acrylic acid
The combination of parts was copolymerized separately according to Example 4, and the two types of acrylic copolymers obtained were mixed,
5 parts of polyisocyanate was added to this and crosslinked to obtain an acrylic release agent. In addition, i of the acrylic copolymer
The n-average molecular weight was 450,000 for the former and 550,000 for the latter.

Comparative Example 1 Example 1 except that the amount of ethyl acrylate used was 3 parts.
An acrylic release agent was obtained according to . The weight average molecular weight of the acrylic copolymer was 400,000.

Comparative Example 2 An acrylic release agent was obtained in accordance with Example 1, except that the amount of ethyl acrylate used was 70 parts. The weight average molecular weight of the acrylic copolymer was 650,000.

Comparative example 3 An addition-type silicone release agent was used.

Comparative Example 4 A release agent obtained by addition-reacting 100 parts of polyvinyl alcohol and 300 parts of octadecyl isocyanate in xylene was used.

The release agents obtained in the evaluation test examples and comparative examples were applied to a polyester film with a thickness of 500,000 m at a solid content of 0.3 g/! It was coated to give a release tape and dried at about 100° C. for 3 minutes.

On the other hand, in toluene, 50 parts of ethyl acrylate, 50 parts of 2-ethylhexyl acrylate, 15 parts of acrylonitrile, and 3 parts of acrylic acid were mixed with 0 parts of azobisisobutyronitrile.
．． Add 5 parts of polyisocyanate to 100 parts of the product obtained by copolymerization using 2 parts as an initiator, and apply this onto a 500,000-layer thick polyester film so that the thickness after drying is 10 μm. Then, it was dried at about 100° C. for 3 minutes to obtain an adhesive tape.

The following tests were conducted using the release tape and adhesive tape described above.

[Peeling force] The adhesive tape was pressed onto the treated surface of the release tape through its pressure-sensitive adhesive layer by making one reciprocation of a 5i roller, and 3 times after the pressure was applied.
After 0 minutes (initial product), or after crimping at 60℃ for 2
After being stored for 2 days and then left at 20℃ for 2 hours and cooled (preserved product), 180℃ beer, peeling speed 300
The force required for peeling was measured under the conditions of rtrtn/min.

[Non-shedding property] After IO reciprocation of felt with a load of 20 g/cd on the treated surface, the force required for peeling was measured in the same manner as above, 30 minutes after pressure bonding. Then, the case where the force required for peeling increased compared to the case of the initial product was evaluated as X (triangle in case of slight increase), and the other case was evaluated as O.

[Adhesive strength] After measuring the peeling force, the adhesive tape was attached to a stainless steel plate (SOCQI
'lQA)I-11)ml IτC7nsuQ 7
I= Mk l φf1*suggestion-h180
degree beer, peeling speed 300 mm/min).

The results are shown in the table.

*; In Example IB, the base material of the release tape was replaced with a polyester film and a polyvinyl chloride film with a thickness of 70mm + mtl was used.From the table, the acrylic release agent of the present invention was satisfactory. It can be seen that in addition to having good peeling performance, it also has excellent adhesive strength to the base material and is difficult to fall off or transfer, so that the adhesive strength of the adhesive layer does not decrease.

Claims (1)

[Claims] 1. An acrylic copolymer made of an acrylic acid ester and an acrylic compound having a functional group is crosslinked with a crosslinking agent, and the acrylic copolymer is a fatty acid having 12 or more carbon atoms. Per 100 parts by weight of an acrylic ester component containing an acrylic ester having a group group or/and an acrylic ester having an aliphatic group having 2 to 11 carbon atoms, and having an aliphatic group having 12 or more carbon atoms. , carbon number 2~
5 acrylic acid ester components having 11 aliphatic groups
An acrylic release agent characterized by containing ~60 parts by weight. 2. A patent in which the acrylic copolymer contains an acrylic ester having an aliphatic group having 12 or more carbon atoms and an acrylic ester having an aliphatic group having 2 to 11 carbon atoms as copolymerization components. The acrylic release agent according to claim 1. 3. An acrylic copolymer containing an acrylic acid ester having an aliphatic group having 12 or more carbon atoms;
The acrylic release agent according to claim 1, which uses a mixture of an acrylic copolymer containing an acrylic acid ester having 11 aliphatic groups as a component.